Sidney C Wolff NOAO/DIR

NATIONAL OPTICAL ASTRONOMY OBSERVATORIES

NATIONAL OPTICAL ASTRONOMY OBSERVATORIES

Cerro Tololo Inter-American Observatory Kitt Peak National Observatory National Solar Observatory

La Serena, Chile Tucson, Arizona 85726 Sunspot, New Mexico 88349

ANNUAL REPORT

October 1996 - September 1997

October 30,1997

TABLE OF CONTENTS

L INTRODUCTION

IL AURA BOARD m. SCffiNTDJIC PROGRAM

A. Cerro Tololo Inter-American Observatory (CTIO) 1. The Search for High Z Supernovae 2. Nearby Stars and Planets 2

B. Kitt Peak National Observatory (KPNO) 3 1. The History of Star Formation in Distant Galaxies 3 2. Oxygen Abundance and the Age of the Universe 4 3. The Age of Elliptical Galaxies - Is There Enough Time? 5

C. National Solar Observatory (NSO) 5 1. Results from GONG 5 2. High-Resolution Images of Solar Magnetic Fields 6 3. Active Optics Control Loop Closed at the Sac Peak Vacuum Tower Telescope 7

IV. DIVISION OPERATIONS 7

A. CTIO 7 Telescope Upgrades and Instrumentation 7 1. 4-m Upgrades 8 2. Major Instrumentation Efforts 9 3. SOAR 4-m Telescope Project 9 4. CCD Implementation and ARCON Controller Development 10 5. Existing Small General-User Telescopes on Cerro Tololo 10 6. New "Tenant" Installations and Upgrades 10 7. Other 11

B. KPNO 12 1. Image Quality Improvements 12 2. WTYN Queue Observing Experiment 12 3. WTYN 13 4. KPNO Instrumentation Improvements 14 5. Burrell-Schmidt 14

C. NSO 15 1. Kitt Peak 15 2. Sacramento Peak 17 3. Digital Library Development 21 D. USGP/ScOpe 21

E. NOAO Instrumentation 25 1. CCD Mosaic Imager 26 2. Phoenix 26 3. Hydra for CTIO 26 4. SQIID Upgrade 27 5. Gemini IR Array Controllers 27 6. Gemini Near-IR Spectrometer 27 7. High-Efficiency Spectrograph 28

V. MAJOR PROJECTS 28

A. GONG 28 B. RISE/PSPT 30 C. SOLIS 32 D. CLEAR 33 E. SOAR 34

VI. CENTRAL COMPUTER SERVICES 34

A. Tucson 34 B. Mountain Programming Group 35 C. CTIO - La Serena 35 D. CTIO -Communications 36 E. NSO-Sunspot 36

Vn. SCIENTIFIC STAFF 36

A. Hired 36 B. Completed Employment 37 C. Changed Status '. 37

Vffl. DIRECTOR'S OFFICE „ 37

EX. NOAO STATISTICS , 38

A. CTIO 38 B. KPNO 39 C. NSO '40 D. NOAO Tucson Headquarters Building 41

APPENDICES

Appendix A NOAO Technical Reports List Appendix B CTIO Publications List Appendix C KPNO Publications List Appendix D NSO Publications List L INTRODUCTION

This report covers the period 1 October 1996 - 30 September 1997.

The National Optical Astronomy Observatories (NOAO) are operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for the National Science Foundation (NSF). The four divisions of the NOAO are: the Cerro Tololo Inter-American Observatory (CTIO) in northern Chile; the Kitt Peak National Observatory (KPNO) near Tucson; the National Solar Observatory (NSO) with facilities on Kitt Peak and at Sacramento Peak, New Mexico; and the US Gemini Program (USGP) based in Tucson. NOAO observing and data reduction facilities are available to the entire astronomical community. The NOAO Home Page contains on-line information about NOAO services, including telescope schedules and instrument availability, and information about how to apply for telescope time. The NOAO Home Page can be accessed through the World Wide Web at http://www.noao.edu/.

IL AURA BOARD

AURA is a private, non-profit corporation that operates world-class astronomical observatories through its "operating centers." NOAO is an operating center managed by AURA, under cooperative agreement with NSF. There are thirty-one AURA member institutions, including four international affiliates. The member institutional representatives elect a governing Board of Directors: thirteen members, including the President, ex-officio. In addition to NOAO, AURA operates and manages the Space Telescope Science Institute under contract with NASA, and the International Gemini Project under cooperative agreement with the NSF on behalf of six partner countries. m. SCIENTIFIC PROGRAM

Several hundred papers are published each year based on data from NOAO. A sample of recent work is described in this section of the report.

A. Cerro Tololo Inter-American Observatory (CTIO)

1. The Search for High Z Supernovae

It has long been known that modeling the observed Hubble Diagram (the magnitude- redshift relation) could lead to the determination of cosmological parameters if "standard candles" of sufficient luminosity could be found and calibrated for use at large redshift (z - 0.3 - 0.6). The recent work of M. Hamuy (U. of Arizona) and collaborators (carried out with CTIO telescopes and reported in the December 1996 Astronomical Journal) establishes the type la supernova as such a calibrated standard candle.

After an initial find of a single object by a Danish group at ESO in 1989 and with standard candle in hand, two groups have made extensive use of CTIO facilities in the past year to carry out searches for high z supernovae in order to determine or constrain the cosmological parameters Q.M (the mean matter density parameter) and Q.A (the vacuum energy density parameter). The high z searches will help to place limits on these parameters for certain cosmologies and may eventually answer the long standing question about the type of universe we inhabit: is it open, closed, or flat? The two groups involved are: S. Perlmutter (Lawrence Berkeley Labs.) and collaborators, collectively known as the Supernova Cosmology Project (SCP), and B. Schmidt (Mt. Stromolo Obs., Australia), N. Suntzeff (CTIO), and collaborators.

The primary problem with using the type la supernovae as cosmological probes (aside from understanding their characteristics as standard candles) is that they are random events which last only a relatively short time. Finding them is a statistical process which requires covering a large area of sky down to faint limiting magnitudes. Both groups have been successful in large part due to the image quality at the CTIO 4-m combined with the large areal coverage and sensitivity provided by the Big Throughput Camera (BTC). The BTC is a visitor instrument currently available for use at CTIO. It was developed by A. Tyson (Bell Labs., Lucent Technologies) and G. Bernstein (U. of Michigan) and employs a mosaic of four 2048 x 2048 CCDs covering 0.25 sq. degrees in a single exposure. Both supernova groups employ a number of other telescopes (including the MMT, CFHT, HST, WIYN, and Keck) in the post-discovery phase to track the light curves (necessary to obtain the intrinsic luminosity of a given supernova) and obtainspectra(necessary to distinguish the type la's from other typesand obtainthe redshift).

The SCP and Schmidt, et al. groups have so far each found roughly 30 type la's in the required redshift range. Preliminary results suggest a near critical value of the density parameter for a universe with no vacuum energy density (see Perlmutter, et al. in the July 1997 issue of the Astrophysical Journal) and that the local and global values of the Hubble constant (H0, the present expansion rate of the universe) do not differ by more than about 10% in a flat or zero vacuum energy density universe (see Kim, et al. in the February 1997 issue of the Astrophysical Journal).

2. Nearby Stars and Planets

Several groups are currently utilizing CTIO telescopes to search for objects at the other end of the astrophysical luminosity scale from type la supernovae. These are the on going programs designed to find new solar neighbors within 10 pc, the Research Consortium on Nearby Stars (RECONS) project, and the Probing Lensing Anomalies NETwork (PLANET) collaboration which is doing follow-on monitoring of microlensing events towardthe Galactic bulge.

a. RECONS, a project of T. Henry (STScI) and collaborators, is searching a volume of space 10 pc in radius for as yet undiscovered solar neighbors. They estimate an additional 130 systems have yet to be found in this volume if the density of stellar systems is the same as that in the volume out to 5 pc radius from the Sun. RECONS is systematically characterizing the coolest (M type) dwarfs in the nearby sample with new JHK photometry, red spectroscopy, and speckle images designed to detect companions. The cool dwarf stars contribute as much as 70% of the Galaxy's stars by number, about 50% by mass. In addition to seeking new members of the solar neighborhood, the RECONS project plans to obtain good infrared photometry for the entire sample of nearby stars (combined with optical photometry from the literature) and spectra for all the faintest (Mv > 8.0) M dwarfs to determine the local mass and luminosity functions to a very high degree of accuracy. These data can be used to study the transition between stellar and sub-stellar objects, Galactic structure, and the star-formation process through a better knowledge of observed stellar multiplicity.

Much of the near infrared photometry and red spectroscopy have been carried out on the CTIO 1.5-m telescope with the facility infrared imager, CIRIM, and on the CTIO 4-m Blanco telescope using the R-C spectrograph. This includes work done on LHS 1565, which RECONS has established as the 20th nearest stellar system to the Sun (see their article in the July 1997 issue of the Astronomical Journal). The most recent CTIO observing session for RECONS promises exciting results for the future: they have identified a number of new solar neighbors as well as new "ultra cool dwarfs," including several likely brown dwarfs.

b. The PLANET collaboration, organized by P. Sackett (Kapteyn Lab.), began extensive monitoring of Galactic bulge microlensing events this year at CTIO using the 0.9-m telescope. The collaboration makes use of telescopes throughout the southern hemisphere to follow the events 24 hours per day. Microlens hunting collaborations monitor millions of stars toward the bulge each night during the southern winter. Occasionally one of the bulge stars will be magnified (brightened) as a foreground object passes through the line of sight to the bulge star. The gravitational field of this foreground "lens" is responsible for "focusing" the bulge star light and enhancingits brightness by an amount given by the general theory of relativity. These lensing events may last from days to months if the lens objects are typical stars. In addition to the primary lens event, secondary lensing events can occur on a much shorter timescale if there is a planet circling the lens. These events appear as "spikes" on the light curve of the primary lensing event and may last as little as a few hours for earth-size planets.

The short timescale of the secondary lensing event is the reason PLANET needs 24 hour coverage of bulge microlensing events. The current microlensing groups are detecting bulge events at a sufficient rate to guarantee PLANET enough objects to monitor during each of their scheduled telescope runs. PLANET observing runs this season at CTIO were monitoring about eight events each night. The probability of detecting an earth-size planet around a typical lens is about 3%. This is large enough that PLANET will detect such objects given the current rates of bulge events if earth-size planets are common. If not, PLANET will find interesting limits to their possible number. Other short timescale events can occur on top of a lensing event, for example, the presence of a multiple stellar lens. PLANET has successfully observed an event of this type, demonstrating their ability to detect short timescale events.

B. Kitt Peak National Observatory (KPNO)

1. The History ofStar Formation in Distant Galaxies

One of the most basic issues in extragalactic astronomy is the origin and evolution of galaxies. As more sophisticated technology becomes available, observers are able to gather much greater detail about this process. Basic questions concerning the first onset of star formation in galaxies, the presence or absence of subsequent epochs of star formation, and the influence of early galactic environment and galaxy-galaxy encounters are now on the verge of being answered. One ofthe richest fields for gathering information about these issues is the Hubble Deep Field (HDF). The area of the sky covered by the Hubble Deep Field has been imaged to fainter levels than any other portion of the celestial sphere. Many new and exciting results are emerging from the multicolor image, and there are even indications that we may be seeing all the galaxies there are to see in this region. However, the Hubble telescope does not "see" in the infrared, and for many very distant objects the cosmological redshift moves many indices of star formation and stellar activity into this wavelength regime. Thus a deep infrared image of the same portion of the sky as covered by the Hubble Deep Field can provide essential complementary information that will allow us to examine the evolution of galaxies and stellar populations with cosmic epoch. Such deep IR observations of the HDF have recently been made by Andy Connolly (JHU), Mark Dickinson (JHU), Matt Bershady (Penn State), Peter Eisenhardt (JPL), Richard Elston (Florida), and Adam Stanford (LLNL). These observers used the KPNO 4-m telescope with the IRIM camera to observe the HDF for 10 nights in the J, H, and K passbands.

Using the infrared data together with already existing data at optical wavelengths, Connolly et al. are able to derive the co-moving luminosity density of galaxies in three redshift ranges: 0.5-1.0, 1.0-1.5, and 1.5-2.0. Assuming the galaxy distribution in luminosity is similar to that found locally, these data can then be used to derive metal enrichment rates and hence inform us about the star formation rates as a function of redshift. It is important to note that the majority of these galaxies are either spiral or "disturbed" objects, as opposed to elliptical galaxies which may have a very different history (see item 3 below). These data show that there is a rise in star formation from a redshift of about 4 until a peak star formation rate is reached at a redshift of 1.5. The rate then declines rapidly from 1.5 to the present. This picture of fast evolution of the stellarpopulation of galaxies is now wellestablished, and it presents a serious challenge to be met by theoretical modeling of galaxy formation and evolution.

2. Oxygen Abundance and the Age of the Universe

A majorproblem with many currently popular cosmological models is that they predict an age of the Universe that may be in direct conflict with the inferred ages of the oldest stars found in globular clusters. However, age determinations of the stars in globular clusters are also subject to assumptions about abundance ratios and uncertainties about the processes occurring in stellar interiors. One such parameter is the ratio of oxygen to iron abundances in the old stars in our galaxy. Stars in the galactic halo and many stars in globular clusters have a higher oxygen to iron ratio than that found in the Sun, but some stars in the clusters show deficiencies of oxygen relative to iron. This deficiency seems to occur in the more luminous stars, and the supposition is that oxygen is burned deep in the interiors, where it is carried by convection. This idea can be tested by observing oxygen abundances in less evolved stars in clusters, and Caty Pilachowski and Taft Armandroff (NOAO) have carried out such a program. Using the KPNO 4-m telescope with the Hydra spectrograph, they have examined 40 stars in the cluster Ml3, and they find for these relatively unevolved stars that the oxygen to iron ratio is on average about one-tenth the solar value. This unexpected result implies that either oxygen is consumed at an earlier stellar age than previously thought or that there exist significant oxygen variations from cluster to cluster. In either case this serves as a warning against the common assumption of uniform abundance ratios when determining the ages of globular clusters.

3. The Age of Elliptical Galaxies - Is There Enough Time?

Over a decade ago, observations of galaxies in nearby clusters revealed what is now known as the Butcher-Oemler effect, namely that there seems to be an increase in blue galaxies as one goes back in cosmic time. This effect has become well documented, especially with data from HST and most recently the Hubble Deep Field. But intermingled with these blue, disk-like and presumably star forming galaxies has been a persistent and disquieting presence of what appear to be old, evolved and stable galaxies similar to the population of nearby elliptical galaxies. If these objects are seen at earlier and earlier cosmic epochs, they will eventually pose a serious threat to current cosmologies in that the models will not provide enough time for these quiescent systems to form and develop old stellar populations. An attempt to define more accurately the formation epoch of elliptical galaxies has been carried out by Adam Stanford (LLNL), Peter Eisenhardt (JPL), and Mark Dickinson (JHU) using the KPNO 4-m and 2.1-m telescopes during the past four years. These observers looked for variations or scatter in the colors of elliptical galaxies as a function of redshift; conventional Cold Dark Matter cosmologies predict an increase in such scatter with increasing redshift. However, the results of this set of observations show less scatter than predicted, and in fact the data are consistent with a single starburst formation at redshifts of order or greater than 4, followed by passive evolution. This is in contrast to the evolutionary history of "disky" systems that is described in IU.B.l., and it provides a major task for galaxy evolution theory to model these two populations of objects. The inconsistency of the observations of elliptical galaxies with CDM models provides an important indicator that our current cosmological thinking may need serious revisions.

C. National Solar Observatory (NSO)

1. Results from GONG

The GONG network became operational in late 1995, and it is living up to our hopes in terms of operational reliability, observing duty cycle, instrument performance, and data processing capabilities. It is fulfilling its scientific promise as well!

GONG was undertaken to test models of stellar internal structure and dynamics, and to explore the interior with these new techniques. Much of the analysis to date has focused on the structure of the base of the convection zone where differential rotation rapidly disappears inward (the so-called tachocline), where sound speed anomalies compared to models are their most striking (presumably arising from shear-driven waves and/or instabilities, and convective overshoot) and where the putative dynamo is believed to reside. It appears that convective overshoot below the unstable zone is quite small, less than a few percent of the scale height, and that the additional mixing required to account for the sound speed anomalies may be described, to some extent, by recent models of stellar evolution. But, this is a very preliminary result, as in fact are most to date. Constraints on a magnetic field at the base of the convection zone are being driven below a megagauss by GONG observations: down to a few hundred thousand, for the moment. Possibly most intriguing are the results on the thickness and shape of the tachocline itself. While at the very limit of the present analysis of the data, the tachocline appears to lie below the base of the convection zone and be barely resolved in radius. There is a suggestion that it may move slightly closer to the surface at higher latitude. Again, this is all very much "work in progress".

Now that we are getting such high signal-to-noise data, in terms of the instruments' performance and of the network's performance in removing the "daily sidelobes", as well as simultaneous acquisition of velocity, intensity, line strength measurements, and the homogeneity of the resulting data, we are discovering all sorts of new challenges associated with the inference of the frequencies of the solar resonant modes of oscillation. As a result, many of the simplifying assumptions that had proven expedient in the past are being challenged. For example, the surface motions of the oscillations are not simply vertical, and the influence that this has on our analysis of what combination of modes gives rise to the observed velocity fields is proving quite challenging to untangle. Possibly most intriguing is the observation that the asymmetry of the line profiles are of opposite sign for velocity and intensity oscillations, and as a result the inferred resonant mode frequencies can differ significantly for the two signals. On the one hand, there is the intriguing physics problem of understanding why this occurs, and on the other we are grappling with the impact of these systematic shifts on our inversions of internal structure. With the improved signal-to-noise data, we are already seeing solar activity induced changes in the frequency, even at the minimum of solar activity. We also now appreciate what a goodjob that GONG can do in the area of local helioseismology as well, but major strides forward in this area await the new, higher- resolution camera.

While the principal scientific issues are helioseismic, the GONG data provide continuous measurements of the surface velocities themselves, and magnetograms with better than one hour sampling. Magnetograms obtained elsewhere around the world, once per day or for a small fraction of a day, miss important aspects of the evolution of the magnetic fields that occurs on a timescale of hours, and which GONG captures. Even with the present low-spatial-resolution camera, quite interesting ancillary science is emerging and this "extra" GONG science will only increase in importance as solar activity starts to increase.

Stay tuned, GONG is just warming up.

2. High-Resolution Images of Solar Magnetic Fields

Magnetic elements are the fundamental structures of the solar magnetic field in plages, in active regions, and in the network along the boundaries of supergranular cells. They have a field strength of 1-2 kG in the lower photosphere and diameters on the order of 100 km, which is comparable to the diffraction limit of the biggest solar telescopes. Occasional magnetograms at a resolution of about 0.5 arcsec have been recorded under excellent seeing conditions, but seeing normally prevents the resolution of magnetic elements. The currently most favored theoretical models of magnetic elements are the so-called flux tubes. These flux tubes appear brighter than the average photosphere, since we see deeper and hotter layers in the partly evacuated flux tube.

Speckle interferometric techniques can greatly improve the spatial resolution of solar observations. The speckle deconvolution technique developed by Christoph Keller and Oskar von der Luehe is able to produce diffraction-limited images of the Sun in very narrow spectral bands by combining short-exposure images from a narrow and a broad band channel. The broad-band images are reconstructed using a modified Knox- Thompson algorithm. By applying this technique to polarimetric observations in the wing of a Zeeman-sensitive spectral line, a few magnetic flux tubes have been resolved in the past.

Hundreds of flux tubes in the quiet network are now being studied based on observations at the 76-cm Sacramento Peak Vacuum Tower Telescope with the Zurich Imaging Stokes Polarimeter (ZIMPOL) I, using the Universal Birefringent Filter with a bandwidth of 25 pm in the Cal line at 610.3 nm. Three hundred simultaneous images in the broad-band and the narrow-band channels with a field of view of 14 x 14 arcsec were collected within less than one minute for each area. Bruce Wilton, an NSO summer student supervised by Christoph Keller, has analyzed more than 60 regions in the quiet network. Many of these magnetograms have a resolution close to 0.2 arcsec. Preliminary results indicate that we barely resolve the larger elements. Most magnetic elements in the network seem to be brighter than the average intensity in white light at disk center, which is in contrast to the dark structures seen in plages at disk center.

3. Active Optics Control Loop Closed at the Sac Peak Vacuum Tower Telescope

In late 1995, the National Solar Observatory and the USAF Phillips Lab group at Sac Peak began the cooperative development of an active optics system for the Vacuum Tower Telescope (VTT). Although the immediate objective of this project is to provide a system for sensing and correcting the slowly varying aberrations in the optical system of the VTT, the system is also intended to provide a platform for further development of a full atmospheric compensation system for use in solar imaging. A correlating 69- subaperture Shack-Hartmann wavefront sensor, capable of using solar granulation as its target, and a 97-actuator deformable mirror, manufactured by Xinetics, Inc., are the key components of the new system. During March 1997, the control loop was closed for the first time at the VTT. The ability of the active optics system to improve the resolution performance of the VTT using both a small sunspot and granulation as the wavefront sensing target was successfully demonstrated. The principal telescope aberrations in this test were introduced by the uncooled entrance window of the VTT. We believe that the corrected telescope was compensated to better than 1/10 wave by the active optics system during this test.

IV. DIVISION OPERATIONS

A. CTIO

Telescope Upgrades and Instrumentation

CTIO's program continues to focus on upgrading and instrumenting the telescopes so that they remain scientifically productive in an era of modern 4-m and 8-m apertures. The Gemini 8-m project is well advanced on Cerro Pachon, and it will have a modern 4-m companion in the SOAR telescope. These projects will be coming on-line within the next five years, and we anticipate that CTIO technical and scientific resources will be used extensively in the SOAR (and possibly Gemini) instrumentation and commissioning. The combination of SOAR and the Blanco 4-m and their instruments will be configured as far as possible—through sharing arrangements between the 4-m telescopes—as a complementary observing system in support of work with Gemini.

1. 4-m Upgrades

A main focus in FY 1997 continued to be the performance and general maintainability of the Blanco 4-m telescope. The addition of active optics, image analyzer, and careful thermal monitoring and controls over the past several years has been very successful, and delivered image performance has improved significantly.

The image analyzer has been in routine use at the Cass focus during the year, which has allowed the active primary support system and careful collimation of the prime focus and secondaries to deliveropticalimages as good as 0.52 arcsec. During FY 1997 a new set of temperature probes and associated control system has been designed, more than doubling the database of thermal environmental information. Analysis of the data produced by the many temperature probes installed on the telescope and dome interior has indicated that heat sources in the dome and building interior are still significant; control and removal of these are being addressed. The primary mirror cooling system is run for up to several hours each day to try to bringthe mirrorto within 0.5 degree of the estimated mean nighttime air temperature. The system is under computer control, and we are experimenting with the algorithm so as to improve the accuracy of the night-time temperature prediction. The capacity of the cooling system has proven to be marginal during winter-time and we are investigating ways to improve this. An air extraction systemwas installed to flush the primary mirror cell and chimney area duringobserving, which has also helped to maintain proper mirror temperature.

During FY 1997 effort has continued on studying and improving the servo system's performance. Initially this involved careful tuning of the existing servo system and the addition of filters, feedback, andramps in theservo loop, all of which was accomplished last year. We have since identified and fixed some sources of flexure and error in the encoder/servo and are still in the evaluation stage of this work. We have also begun a pilot project to replace the actual servo system, in order to provide a modern and maintainable level of performance, using a Gemini-compatible servo controller.

Oneof ourtop-priority projects has been theimplementation of tip-tilt with the new f/14 secondary on the 4-mtelescope. The goal is to make our IR instrumentation compatible with the KPNO 4-m (f/15) and Gemini (f/16). The new secondary has been installed with piezo-electric actuators in place; a fast guiding camera and software control system have been implemented. This gives CTIO the only major IR tip-tilt capability in the southern hemisphere. This is the logical extension of the program to improve the imaging capability of the telescope. The emphasis needs to be on the near IR (JHK) because this is where tip-tilt achieves the greatest proportional reductions in image diameter for a 4-m telescope with good seeing. This will produce an important improvement in the performance of our near IR instrumentation.

This tip-tilt focus feeds the Cryogenic Optical Bench (COB), and the CTIO IR spectrometer, which has been converted to an f/14 system. Initial results are encouraging, although full system performance has been compromised by a variety of minor issues, includingpoor weatherand variablesite seeing. Balzer cyrocooler systems have been installed at the 4-m and in the La Serena laboratory to support these and future IR instruments.

Major Instrumentation Efforts

A major feature of the program during the past year has been preparations for new instruments which are due to arrive in 1998-1999. In collaboration with the Tucson IPG effort, we are equipping the Blanco 4-m with:

• the Cryogenic Optical Bench (COB) with a InSb array; this was installed in November 1996and has been in routine use this fiscal year;

• the NOAO 8K Mosaic CCD imager at prime focus (due January 1999);

• the Phoenix high-resolution IR spectrometer (nominally for July 1998); and

• the Hydra/CTIO multi-fiber spectrograph (October 1998). Thus within 1.5 years we should have a 4-m telescope with excellent image quality over a small field at f/14, mainly for near IR imaging and spectroscopy. In the optical, the wide-field aspects are being emphasized with the Mosaic imager and Hydra spectrograph; the telescope will be able to deliver good image quality over a 45 arcminute field at both prime and Cass focus.

Work has started on the bench spectrograph in preparation for the Hydra system. This involves a change in collimator and camera/detector, to accommodate the slower f/ratio in the change from the prime focus to Cass and the larger number of fibers (from 48 to 2 x 138) as Hydra replaces Argus as the fiber multiple-object spectrograph.

For the Blanco prime focus, we accomplished the commissioning and very successful scientific use of an optical mosaic imager (the BTC, with 4K x 4K, thinned, SITe CCDs), an instrument provided by A. Tyson (Lucent Technologies) and G. Bernstein (U. of Michigan).

3. SOAR 4-m Telescope Project

As reported elsewhere (section V.E.) the initial project definition and scientific requirements phase for the 4-m SOAR telescope have been almost completed, an interim agreement has been signed, and a project manager and project scientist have been hired to begin the SOAR project. CTIO staff have, of course, been heavily involved in the extensive studies, discussions, document preparation, and meetings associated with the preparatory phase of this project.

SOAR is a key component of the current long-range plan at AURA to set up a suite (Gemini South 8-m, SOAR 4-m, and refurbished Blanco 4-m telescopes) of large aperture, general-user, southern-hemisphere, groundbased facilities for open competitive access to the general research community. The plan is fully consistent with the NAS decadal review for the 1990s and the report of the McCray panel on the future of NOAO. Discussions are currently underway with various US university and international groups with a view to constructing a set of 2.4-m telescopes in both hemispheres as a means to cover the smaller-telescope end of the suite of general-user telescopes.

4. CCD Implementation and ARCON Controller Development

Implementation of CCDs at the telescopes and the development of the ARCON CCD controllercontinued to be a central part of the optical instrumentation program this year.

A SITe 2048 x 2048 CCD (with four good amplifiers) was purchased, as a replacement for the prime focus imager and echelle detector, which suffered a mysterious and fatal electrical failure. Efforts are also being made to replace the STIS 2K x 2K CCD at the Schmidt, which also went out of service due to a mechanical failure in the dewar.

During FY 1997, major effort at CTIO has gone into supporting the ARCONs used in the NOAO 8K Mosaic CCD Imager system on Kitt Peak; this integrated hardware and software effort has resulted in a system that was first used for science in June 1997. Several engineers and scientists from CTIO have participated in engineering runs at KPNO.

We also intend to begin retrofitting the existing ARCONs on CTIO with the final versions of three new controller electronics cards (Video, VTT, and ADC), which have been developed over the past years.

5. Existing Small General-User Telescopes on Cerro Tololo

CTIO's second-largest telescope, the 1.5-m, suffers from a poor thermal environment and several optical problems with the secondary mirrors. In order to tackle this problem, more stable secondary mirror mounts have been designed, with encoders to permit reliable collimation runs. Ventilation doors for the 1.5-m dome have been installed, and a revised ventingand heat control systemis being implemented in the building. An array of 32 doors with a total area of over 500 square feet have been installed in the segments around the lower rim of the dome. A telescope control system (TCS) has been installed on the 1.5-m, which now shares the TCS software with the 4-m. The GUI/Guider system being developed on the 4-m will also be installed on the 1.5-m, permitting faster target acquisition and support from extensive stellar databases for target selection.

6. New "Tenant" Installations and Upgrades

Installation of the building and dome for the 1.3-m 2MASS (South) telescope has been completed just below the GONG site on Cerro Tololo. Installation and commissioning of the telescope will begin later this year. More information about the 2MASS project can be found via: http://pegasus.phast.umass.edu/.

The Yale 1-m telescope was withdrawn from service for general users in early 1997 becauseof a lack of adequate NSFfunding. A privateconsortium has been set up, led by Yale University and including the Ohio State University, the University of Lisbon (Portugal), and NOAO. The consortium has so far been characterizing the telescope performance with a view to deciding on the upgrade paths to be followed. It is expected that the telescope will come back on line, for consortium use, sometime in 1998 and be operated for an initial period of three years. Much of the research with this telescope

10 will focus on synoptic studies. Ohio State University will be providing a two-channel IR/optical imager, ANDYCAM, for this telescope. The University of Lisbon is providing the funds for bare-bones operation of the facility. Roughly 9% of the time is likely to be available for NOAO users. NOAO's participation in the project consists mainly of providingaccess to dormitory space and limited technical support. Additional services are provided to the consortium at cost.

An MOU has been signed with the United States Naval Observatory (USNO) to begin a two-yearcampaign to secure astrometric CCD-based measurements and produce a high- density catalog of reference stars in the SouthernHemisphere betweenmagnitudes 7 and 16 with accuracies of ~ 20 mas at epoch. This will be done usinga specially developed 8-inch astrographic lens and a commercial, thermo-electrically cooled CCD camera. This equipment will be attached to a remotely-controlled modified Boiler and Chivens mount originally used for a 24-inch telescope. Details of this project were presented by Steve Gauss, et al. at the Toronto AAS meeting. Further information can be found at: http://aries.usno.navy.mil/ad/ucac-s/.

This astrometric work will provide a dense set of positions ideally suited for initial calibration of the Hydra-CTIO multifiber spectrograph (currently under construction in the NOAO shops in Tucson) and of the near-simultaneous activity at the largest new all- sky survey telescope, 2MASS.

A robotic camera was installed on Cerro Tololo in January 1997 by a group led by John Gaustad (Swarthmore College) and is expected to beginroutine operation in September. Like the GONG station installed during the previous year, this new system is designed to be fully autonomous, only requiring intervention by CTIO staff at weekly intervals in order to change data tapes. This robotic telescope will carry out an H-alpha survey of the entire southern sky with a resolution of 1 arcminute per pixel over a period of approximately two years. The resulting data will primarily be used for studies of the warm ionized component of the galactic interstellar medium. However, the survey also has applications to cosmology since it provides a measure of spatial variations in the microwave emission from galactic hydrogen—a possible complication for studies of fluctuations in the cosmic microwave background.

Other

The Save-the-Bits (STB) software and dedicated exabyte drives have been installed on all CTIO telescopes and are in routine use with the ARCON CCD controllers and with the Wildfire IR data systems.

Although Cerro Tololo and Cerro Pachon are still' very dark sites, CTIO has become increasingly concerned with the growing threat of light pollution from neighboring cities and towns. Thus we are continuing our collaboration with local officials as well as with private industry to ensure that future lighting installations are as "astronomer- friendly" as possible. This program has concentrated on several fronts, including public information, consultations on street lighting installation in local towns, a regional light- pollution ordinance, and work with a newly-created national environmental commission.

11 B. KPNO

The major focus of the programs at KPNO during this year were on improvements to the image quality at the 4-m Mayall telescope; continued operation of the WIYN telescope; and the commissioning of two major new instruments—a mosaic imager for optical work and a high resolution infrared spectrograph. This year also marked the end of NOAO's participation in the operationof the Burrell Schmidttelescope.

1. Image Quality Improvements

This year we continued to make substantial efforts to improve the delivered image quality (DIQ) at the 4-m Mayall telescope. Nightly seeing measurements show that the median DIQ is 1.1", considerably more than the 0.8" achieved by WIYN. What causes this difference? Examination of the seeing data demonstrates that the Mayall image quality is dominated by thermal effects in the 4-m dome, with optical aberrations playing a secondary role at present.

a. If the primary mirror is warmer than the ambient dome air, convection from the primary quickly becomes the dominant effect on the DIQ; the images degrade by 0.3" for every 1°C of temperature difference. (If the mirror is colder than ambient dome air, little effect is seen.) During the past year we implemented a cooling system, which blows refrigerated air on the primary during the day. This year we finished the electronic controls for this system, which is now in daily use. In FY 1998 we plan to fine-tune the system and improve its cooling capacity.

b. If the air at the top of the dome is colder than at the bottom of the dome, large- scale convection occurs and the DIQ is significantly degraded. This year we implemented a dome air mixing fan to move cold air from the floor chillers up to the upper part of the dome in order to maintain a more isothermal environment.

c. Temperature differences between the dome air and outside air significantly degrade the DIQ. The largest Kitt Peak project this year has been to implement dome vents at the 4-m. These vents will provide an additional 1600 ft2 of open area. In a 10 mph wind, there will be between 100 and 300 flushes of the dome each hour, depending upon the direction of the wind relative to the dome. We expect that this air exchange will alleviate many, if not all, of the thermal problems within the dome.

In addition, careful attention is being paid to the telescope optics. Wavefront studies are now used routinely to assure proper collimation. These studies suggest that even when the telescope is fully collimated, the DIQ is degraded by about 0.1" due to astigmatism and other lower-order aberrations, with the effects worse in some parts of the sky. In FY 1998, we are initiating an effort to provide active primary mirror support to remove this contributor to the DIQ.

2. WIYN Queue Observing Experiment

The WIYN Queue observing experiment completed its second year of operation in 1997, which was the first year in which nearly the entire NOAO time allocation on the

12 WIYN 3.5-m telescope was scheduled in a queue format. In this format, NOAO staff execute TAC-approved observing programs and investigators do not come to the mountain to do the work. Using this manner of scheduling, the observatory hopes to maximize the scientific productivity of the 40% share of time that NOAO has on the telescope. Programsare executed primarily on the basis of TAC grade and suitability of observing conditions during a particular night. The queue experiment allows for the implementation of science programs that are difficult, if not impossible, to schedule within classical (investigator present) observing runs. Examples are synoptic programs, programs requiring less than one night to complete, and imaging projects requiring the best possible seeing that the facility can provide. Queue scheduling also easily enables the mixing of spectroscopic and imaging programs during a night because the WIYN telescope is equipped with two permanently mounted facility instruments (Hydra/MOS and CCD Imager) and has the capability of quickly switching between instrument ports. In addition, the queue experiment provides experience for the development of scheduling strategies for the Gemini 8-m telescopes.

During the past two completed observing semesters, queue observing provided data for 35 of 42 TAC-approved "long" programs (observing programs requiring more than 2 hours of telescope time) and fully completed 16. There were 21 "short" programs of which 13 were completed. Unfortunately, no data were obtained for 3 short programs. The fraction of requested observations actually completed for a program largely reflects the standing (TAC grade) of the program within the queue. For these two semesters 97 nights were allocated to the WIYN queue program. Roughly 35% of this time was lost to weather and another 5% to technical problems. Scientific results from WIYN are just beginning to appear in the refereed journals, with slightly more than half of the refereed scientific papers now in print dealing with data obtained through the NOAO queue.

A survey designed to evaluate the effectiveness of the WIYN queue program and the efficiency of its operation was sent to the entire NOAO WIYN user community (370 astronomers) in early October 1997. Responses from this survey will be a major factor in deciding the future of the WIYN queue program.

WIYN

WIYN continues to operate routinely and remarkably effectively, given the small size of the operational support staff (6.5 FTE, including three operators for daytime and nighttime support of visiting astronomers). The overall efficiency of WIYN is 85%, with 9% of observing time lost to overhead and 6% lost to technical problems. Overhead at WIYN includes time for initializing the telescope and subsystems, acquiring objects and setting up the guiders, tuning the optics, focusing the telescope, configuring instruments, and reading out CCDs. Some of the overhead tasks have been streamlined for more efficient operation and other improvements are planned. The time lost to technical problems is dominated by computer and software reliability issues and efforts are in progress to improve both.

A two-year Improvement Project program was launched on 1 January 1997 when special funding was obtained to provide enhanced staffing of approximately 2 FTE for the two year period. The improvement program places emphasis on the safety aspects of the facility. Specific action items include enhancements to the WIYN safety program and policies, upgrades to the hardware limit systems on the telescope, improvements to

13 the access to various subsystems for maintenance, and implementation of a software system to monitor all safety systems and to provide safe shutdown modes and better alarming for the operators. Other improvements projects deal with telescope performance, reliability, and maintainability and include completion of the technical documentation to facilitate maintenance.

4. KPNO Instrumentation Improvements

FY 1997 marked the year of commissioning for the CCD Mosaic Imager. The KPNO/CTIO instrumentation group has produced an imager with 8096 x 8096 format that has an active imaging area of over 12 cm on a side. The imager is being commissioned with 2K x 4K three-side buttable engineering grade CCDs from Loral. Twenty thinned scientific grade CCDs have been ordered from SITE forNOAO through a consortium purchase with Carnegie. We will then have enough CCDS for two Mosaic Imagers, and a clone will be built for CTIO. Two of the CCDs have been delivered and are currently being evaluated and optimized. The Mosaic Imager has been available for shared-risk observingon KPNO telescopes since June 1997 and has been scheduled for a total of 50 nights through January 1998.

Phoenix, which is a high-resolution near-infrared spectrograph that operates over the spectral range 1-5 microns and uses two quadrants of an ALADDIN InSb array detector, has been commissioned and was used for 14 nights of science runs on the KPNO 2.1-m telescope during the first semester of 1997. One of the highlights was a study of the chemical composition of Comet Hale-Bopp. The instrument is heavily scheduled on both the 4-m Mayall and 2.1-m telescopes during the second semester of 1997. Work is in progress to address three outstanding issues: 1) the determination of the cause of the worse than expected image quality, which is thought to be due to the thermal characteristics of the grating and affects the S/N ratio; 2) spectrograph configuration speed; and 3) a graphical user interface to simplify routine operation.

The installation of these instruments has required substantial modifications to the telescopes to support the Mosaic at prime focus and to construct handling equipment for this heavy instrument; to provide new wide-field correctors for the Mosaic at both the 4- m Mayall and 0.9-m telescopes; and to provide closed-cycle cooling at both the 2.1-m and 4-m telescopes for Phoenix.

5. Burrell-Schmidt

For nearly 20 years, KPNO shared operations and observing time at the Burrell-Schmidt with Case Western Reserve University. The unique feature of this telescope is its wide field of view, and after the recent installation of a CCD imaging system, the demand for observing time soared. However, KPNO concluded that because of its declining budget it could no longer support its share of the operation, particularly since the advent of the Mosaic Imager provides thesame wide-field capability with better sampling at the0.9-m telescope. Therefore, we have made arrangements to return operation of the telescope to Case Western, which has formed a consortium of astronomical institutions that will ensure its continued use.

14 NSO

1. Kitt Peak

a. McMath-Pierce Main Spectrograph Control

The purpose of the spectrograph control upgrade is to place the spectrograph functions under computer control, allowing high-resolution and automatic control of grating position. The computer will also allow automatic placement of the spectrograph grating in wavelength and angular coordinates in addition to the current encoder coordinates. Added future benefits of the networked nature of the control system are the possibility of remote observations, remote monitoring of local observations, and World Wide Web access to various instrumental functions.

To date, all the components of the upgrade have been purchased and received with the exception of the new 19-bitgrating positionencoder. A mock-up of the grating system has been constructed to allow for software development in the Tucson lab without disturbing the current spectrograph operations.

A new hand paddle controller is being developed in conjunction with the Kitt Peak Vacuum Telescope (KPVT) upgrade and will be used as the primary interface to the main spectrograph until instruments with automatic control are developed. The basic software components have been completed or are near completion to allow basic manual operation of the spectrograph with the new computer controls installed.

Installation of the control hardware and interim hand paddle and software is scheduled for September 1997 with the completion of the project scheduled for October 1997. This project will yield significant improvements in the flexibility and ease of use ofthe main spectrograph.

b. NIM-2 Near Infrared Magnetograph

The NIM-2 project is constructing an imaging vector magnetograph based on a piezoelectrically-tuned, servo-stabilized Fabry-Perot etalon. The existing Near Infrared Magnetograph maps the true magnetic field strength in the deep solar photosphere, using the McMath-Pierce Telescope, the 13.7-m vertical spectrograph, a liquid crystal polarimeter, and an infrared array camera that records two Zeeman-sensitive iron lines near 1565 nm. Using the same infrared camera with an improved polarimeter and data system, NIM-2 will achieve better time resolution and geometric stability (because the field of view is imaged simultaneously rather than built up by scanning) with little sacrifice in spectral resolution.

NIM-2 was ahead of schedule during FY 1996 but encountered difficulties during FY 1997, mainly related to the optical design. All fabrication is now complete. After several engineering runs, a satisfactory protocol for optical alignment has been established, and test magnetograms have been obtained. The main remaining task is to identify and eliminate software bottlenecks that slow the system down from its nominal modulation speed of 10 Hz to about 3 Hz, introducing excess

15 seeing noise into the magnetograms. The necessary programming resources are expected to be available in the first or second quarter of FY 1998. The NIM-2 project is partially supported by a grant from NASA. c. Large-Format IR Array Camera

The McMath-Pierce facility offers capabilities that are unique in the world for infrared solar observations: an unobstructed, all-reflecting light path (giving full wavelength coverage with low thermal background) and large aperture (for angular resolution and photon flux). These capabilities cannot be fully exploited withouta state-of-the-art infraredarray detector at the focal plane.

The present detector is a commercial 256 x 256 InSb array from Amber Engineering, re-housed in a dewar from Infrared Laboratories. This system was chosen for low initialcost and 1-5 micron wavelength coverage. It has served well but is now becoming obsolete.

NSOplans to replace the Amber array with a state-of-the-art 1-5 micron cameraby taking advantage of NOAO's investment in the ALADDIN array development project. The performance of an ALADDIN-based system will surpass the Amber system in every important respect (dark current, readout noise, quantum efficiency, and immunity from electronic interference); its 15-20 Hz frame rate is well matched to the requirements of NIM and NIM-2.

During FY 1997, NSO committed funds for an ALADDIN controller to be constructed by NOAO/TPG and delivered in late FY 1998. NSO continued to prepare for the ALADDIN era by hosting two runs at the McMath-Pierce with the ALADDIN-based Phoenix cryogenic spectrometer, during which science-quality data were successfully obtained. The NSO infrared program proceeds on the assumption that NOAO will allocate one or more ALADDIN arrays to NSO from the yield of science-grade arrays. d. Kitt Peak Vacuum Telescope Control Upgrade

The aim of this project is to upgrade the 23-year-old control and guiding systems of the KPVT. Maintenance of these systems is becoming difficult since many of the components are no longer available. Performance problems also limit the quality and quantity of data from the focal plane instruments.

The overall goals of the project include better control of image guiding and scanning, reduction of unwanted image motion, replacement of obsolete computerized control systems, and computer control of the Littrow spectrograph. The overall upgrade plan is divided into small, stand-alone segments that provide prioritized, incremental improvements.

To date, new gear boxes and motor drivers for the drive system of the #2 mirror have been installed. These have greatly reduced the amount of backlash and improved the reliability of these drives. Mounting and solenoid drives that will allow the #4 mirror to be rapidly tilted to reduce image motion have been installed, tested, and tuned.

16 The overall computer software and hardware architecture to be used to control the telescope has been specified. A design for new sensors to replace existing limb guiders and supporting electronics is complete and breadboard construction and testing is underway. The design activities are intended to be transferable to similar upgrades planned for the McMath-Pierce Telescope and the proposed SOLIS project.

New control and drive systems for the #1 and #2 mirror DC motor drives have been purchased and a design to interface them to the existing interconnect is in process.

New stepper motor drive amplifiers have been purchased to upgrade the existing guider platformsteppercontrols. The update is designed to eliminate the recurring problems with platform mis-registration and stalling problems.

Sacramento Peak a. Mark II Correlation Tracker

The development of the Mark II correlation tracker was completed in February 1997. The system is now operational at the Vacuum Tower Telescope at Sac Peak. Relative to the Mark I CT, performance of the Mark II CT has been improved, with a higher servo bandwidth (60 Hz) and a capability to track low contrast granulation images during moments of bad seeing. Cloning of the CT system to provide tip/tilt correction at the McMath-Pierce telescope is being considered. The Big Bear Solar Observatory has expressed interest in obtaining a copy of the Mark II CT. b. Fast CCD Cameras

NSO/SP is working towards replacing the custom built MDA detector system with state-of-the-art, large-format CCD detectors. A variety of detectors offering different capabilities have been requested by users. In addition to the MDAs, the following cameras are now available at NSO/SP:

• Two Thomson IK x IK cameras with 10-bit resolution and a frame rate of up to 5 frames/sec. Typically these cameras are used for high-speed imaging and frame selection.

•A 2K x 2K 12-bit camera from Xedar Inc. in Boulder. The 2K x 2K camera achieves a high frame rate of 2 frames/sec at a low noise level (30 e). The Xedar camera is a universal camera which has been used, for example, to image the corona and for spectral imaging of large fields of view with high pixel resolution.

• A512x512 camera from Pixel Vision has been ordered and will be available to users beginning January 1998. The camera features a back illuminated CCD chip from Site and offers high quantum efficiency throughout the visible

17 spectrum, in particular at the blue end of the spectrum (CaK). The user can choose between two readout rates. At the 850 kHz rate used to achieve high frame rates, the readout noise is < 30 e. At the slow 50 kHz readout rate primarily used for low light level applications, the readout noise is < 9 e. At least one additional 512 x 512 camera will be added during FY 1998.

The data storage media is exabyte. However, DLT tape drives are now available to provide high-speed recording capabilities (5 Mb/s) and large storage capacity (15 Gb) for special applications.

Image Quality Improvement at the VTT

Wavefront sensor experiments revealed two major sources of optical aberrations in the optics of the VTT: the entrance window and one of the two turret flats.

The thermal effects on the wavefront due to heating of the window have been greatly reduced by an active cooling system that senses the gradient of temperature, both across the face of the window and through its 4-cm thickness, by combining the measurements from pairs of sensors on the outside and on the vacuum side of the window. Interferograms show that the window figure errors have been reduced from several waves to a fraction of a wave, implying that the window temperature is now uniformly maintained to a few tenths of a degree. The performance of the VTT has been significantly improved by this; frame selection procedures now achieve diffraction-limited resolution.

The turret (elevation) flat was re-figured at Kodak and re-installed into the VTT during September 1997. The overall optical performance of the VTT is currently evaluated using Shack-Hartmann wavefront sensor measurements.

Active Optics

The term active optics describes a low bandwidth system that corrects optical aberrations, produced, for example, by telescope flexure or thermal stresses, and hence vary on relatively long time scales. The optical figure of modern large aperture nighttime telescopes is controlled by active optics. Active control of the telescope optics will also be required for the large solar telescope planned by NSO. The development of an active optics system that works on solar granulation is an important step toward demonstrating the technological feasibility of such a telescope. An active optics system can, of course, also compensate any residual optical aberrations in the VTT. Furthermore, active optics can be considered an intermediate step toward an adaptive optics system, which in addition to instrumental aberrations, will also correct atmospheric seeing. The three key components of adaptive optics (as well as active optics) are the wavefront sensor, the reconstructor, and the adaptive mirror. Active optics operates with a low bandwidth, on the order of 1 Hz or less, while atmospheric correction requires a closed loop bandwidth of a few hundred Hertz. The active optics system will therefore provide a convenient platform for further development of a full atmospheric compensation system for use in solar imaging.

18 The active optics system at NSO/SP consists of a correlating Shack-Hartmann wavefront sensor, capable of using solar granulation as its target, and a 97-actuator deformable mirror, manufactured by Xinetics, Inc.

During March 1997, the control loop was closed for the first time at the VTT. Although active optics simulations and lab experiments were recently performed by the LEST group, to our knowledge this is the first real demonstration of solar active optics using granulation as a target. The ability of the active optics system to improvethe resolution performance of the VTT, using both a small sunspotand granulation as the wavefront sensing target, was successfully demonstrated. The diagnostic output of the active mirror suggests that the corrected telescope was compensated to better than 1/10X. by the active optics system during this test.

Adaptive Optics

Based on the progress we have made in several subareas of adaptive optics, we are confident that we can build a solar adaptive optics system. A viable wavefront sensor concept exists, the adaptive mirror technology is now commercially available, and we have learned to operate such an adaptive mirror within a short time with relatively little effort. From our active optics experiments we have gained experience at the integrated system level.

In principle, what is required to implement adaptive optics is to speed up the servo loop by several orders of magnitude. This involves parallel processing using powerful digital hardware. Due to tremendous advances in digital signal processing (DSP) technology during the last 5-10 years, it is now possible to purchase many, if not all, of the required hardware components off-the-shelf at reasonable cost. In fact, we have just completed development of a second generation correlation tracker, which, unlike the first generation correlation tracker, was built entirely from commercial hardware components. A correlation tracker can be regarded as one channel of a SH-WFS based adaptive optics system. We have been able to successfully stabilize granulation images formed by subapertures as small as 7 cm using the Mark II correlation tracker. During good seeing conditions the residual image motion was 0".04 rms.

As the next step, we will implement a low order adaptive optics system that will correct on the order of 20 Zernike modes, with the idea that the system can be expanded to a full-up adaptive optics system later. We are following the path that was taken by some nighttime adaptive optics projects which have proven to be quite successful (e.g., Roddier, et al., CHFT). The low order adaptive optics system will be capable of delivering diffraction-limited imaging in the visible during good seeing conditions, and in the infrared under most seeing conditions. The hardware design is near completion and we hope to have the development completed within the next two years.

Dual Fabry-Perot Filter

A dual Fabry-Perot (FP) filter system for visible wavelengths is under development at NSO/SP. The existing narrowband (< 20 mA) Fabry-Perot filter is

19 combined with a newly purchased 60 mA passband FPand a set of narrow (3-4 A) blockers to provide a tunable narrow band filter with high transmission, capable of tuning at very fast speeds. In FY 1997 both FPs and the blockers were characterized. Parameters like the FPs passband, finesse and transmission were measured, and a tuning formula for the dual FP system was developed. In September 1997, the first scans of the solar spectrum at 6302 A were performed, and narrow bandfiltergrams wererecorded. The data are currently being analyzed. g. Preparations for Eclipse 1998

NSO/SP, in collaboration with HAO, Rhodes College, and Lindau Institute, is preparing three infrared experiments for the upcoming 26 Febuary 1998 eclipse in the Caribbean. The first two experiments, to be conducted on board a CI30 airplane, search for coronal spectral lines between 1 to 5 microns and circumsolar dust out to 10 solar radii. Another groundbased experiment will measure the coronal magnetic fields using Hanle effect. h. Infrared Program

The NSO/SP maintains two near-IR camera systems which were developed by outside collaborations with Michigan State University (MSU), Wyoming Infrared Observatory, and Haverford College. These cameras account for about 25% of the user time allocated at the VTT and the Evans coronagraph and are used for diffraction-limited imaging and high-precision (10"4) Stokes polarimetry for the study of various solar magnetic features.

A new IR camera for the 1-5 micron range that will be available year-round at NSO/SP is under development in collaboration with MSU and Starfire Optical Range, Albuquerque. The development of the 1-5 micron camera system is progressingon schedule. The electronics has been manufactured and is now being tested. i. Near-IR Imaging Vector Magnetograph

The USAF Phillips Laboratory, solar research group at NSO/Sacramento Peak has designed a narrow-band tunable near-infrared filter which uses two tunable Fabry- Perot (FP) etalons and works between 1200 and 1700 nm with appropriate blockers. The FP etalons and their controllers have been purchased from Queensgate. The order-sorting, broad-band FP has a full-width-at-half maximum (FWHM) pass band of 0.19 nm and a free spectral range (FSR) of 4.09 nm at 1565 nm. The narrow FP has a FWHM pass band of 171 mA and FSR of about 0.548 nm, at 1565 nm. A high transmission prefilter is available for use between 1563 and 1566.5 nm. Initial tests of this filter system at the NSO/SP Vacuum Tower Telescope using a 128 x 128 InGaAs camera from Sensors Unlimited, the Michigan State 128 x 128 HgCdTe camera, and a specially constructed rotateable wave-plate and polarizer system have demonstrated the capabilities of this system in making spectropolarimetric images in the spectral line, Fel 1564.85 nm. Tests on the dual FP system at the VTT are in progress with the goal of evolving the system to a stand-alone vector magnetic field patrol instrument. Several vector

20 magnetograms of sunspots were recorded recently. The instrument and its components are available for use at the VTT on a shared-risk basis.

3. Digital Library Development

During FY 1997, NSO continued to populate its 300-disc CD-ROM jukebox with data from the FTS and KPVT. Currently, the jukebox holds a complete set of 38 discs of non-proprietary FTS transformed spectra, 13 discs of 512-channel magnetograph data, and 20 discs of spectromagnetograph data, for a total of about 50 GB of on-line storage. A high-resolution scanner has been obtained at NSO/SP to transfer the daily Evans Facility Ca K and H-Alpha spectroheliograms from film to CD.

Even in advance of the implementation of a user-friendly search engine, the jukebox is already heavily used, with over 7000 files transferred in the period of 11 April 1996 to 1 August 1997. With funding from the NSF Space Weather Program, there has been substantial progress in the development of a Web-based user interface and search tool. A prototype system for the KPVT data is now undergoing evaluation, and a system for the FTS data is substantially complete. We anticipate releasing the system for general use by scientists and the public in early 1998.

D. USGP/ScOpe

The US Gemini Program (USGP) serves as a liaison between the International Gemini Project Office (IGPO) and the US community. The Gemini Project is an international consortium to build two 8-meter telescopes, one on Mauna Kea, Hawaii, and one on Cerro Pachon, Chile, in which the US maintains a 50% share. The USGP was established in 1993 as a fourth division of NOAO with a status which is on a par with Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and the National Solar Observatory.

During the construction phase of the Gemini telescopes, the major activities of the USGP have involved the procurement of the Gemini instruments assigned to the US and the discussion of scientific issues between the Gemini project and the US astronomical community. In the operations phase, beginning shortly after the first Gemini telescope sees first light at the end of 1998, the USGP will have an additional role as the interface for US users of the telescope. The recognition of this additional role and the resources needed to carry it out have led to a restructuring of NOAO, with the USGP taking on responsibility for these community interface activities in support of all the telescopes to which NOAO supplies access. This increase in responsibility was accompanied by an increase in resources, begun in FY 1997. In FY 1998, the USGP will become an element of an enlarged division, known as Science Operations, or ScOpe. ScOpe will include more scientific staff as well as the NOAO units which provide support for the community interface activities, including Central Computing Services (of which IRAF is a part), the Tucson Photo Lab, and the Tucson Library. This report principally details Gemini-specific accomplishments, but also highlights some of the areas in which the ScOpe staff has begun to turn its efforts.

A major part of the work of the USGP during the past year has been connected with procurement of the Gemini instruments assigned to the United States. The United States is responsible for three instruments, a near-IR (1-5 microns) imager, a near-IR spectrograph, and a mid-IR (8-30 microns) imager. The near-IR imager was assigned by the NSF to the University of Hawaii; the USGP is responsible for the procurements of the other two

21 instruments. The near-IR spectrograph was assigned to the NOAO instrumentation group through a competitive selection in FY 1995. The mid-IR imager is still in the selection process. At the request of the IGPO, the USGP has taken on the management of these instruments as the Gemini IR Instrument Program. This approach allows one group, the USGP, to look out for interface issues, to identify areas of commonality among instruments, and to help to solve problems in areas of budget, schedule, and risk.

During FY 1997, the USGP carried out the procurement of the Gemini mid-IR imager in a two-stage process. Two groups, at the University of Arizona and the University of California at Irvine,.were awarded funding on the basis of a competitive selection to conduct conceptual design studies for this instrument. In addition, two groups, at the University of Florida and Mauna KeaInfrared/JPL, agreed to perform studies at their own expense. The results of these four studies were presented to a panel of technical and scientific experts, andthe comments of these experts were incorporated into the RFP for a second competitive selection of a supplier to producea final design and fabricate the instrument. Proposals in response to this RFP were evaluated by an outside committee, and negotiations are now in progress with one of the proposers to build this instrument. We have been pleased to see that this approach has facilitated involvement in the Gemini instrumentation program by a number of US institutions.

In addition to these IR instruments, the United States has been asked to provide the detectors and controllers for the Gemini optical instruments. The USGP has been monitoring development programs at a number of CCD vendors, and based on a review of proposals by an international committee of experts, a contract was negotiated with EEV to provide the optical detectors. For the CCD controllers, the USGP faced a situation similar to that of the Near-IR Spectrograph, where both NOAO and university or commercial groups wished to propose for this work. Following the recommendations of the workshop held by AURA and NOAO in Albuquerque, we held an informal open meeting at which each potential supplier was invited to present arguments supporting his approach and capabilities. A panel of impartial experts listened and questioned the proposers. As a result of this meeting, a collaboration was forged that involved hardware purchased from San Diego State University and software developed jointly at NOAO and the Royal Observatories in the United Kingdom.

After the selection of a supplier for each instrument is made, the USGP remains responsible to the Gemini Project for seeing through the successful design, fabrication, and delivery of each US-allocated instrument. This activity includes day-to-day monitoring of progress by each of the instrument suppliers, identifying concerns that have implications for cost, schedule, or risk, and helping the groups work out solutions to these concerns. During FY 1997, USGP personnel worked with the University of Hawaii near-IR imager group to help them develop a schedule and management plan for that instrument. The USGP also worked with groups at NOAO involved in the near-IR spectrograph, the near-IR arrays, and the near-IR array controllers.

Following the USGP workshop in August 1996 on US interests in future instruments for the Gemini telescopes, the international Gemini Project organized a similar workshop in Abingdon, England in January 1997. As in the US workshop, the discussion was focused on the science that the communities will want to do with the Gemini telescopes and the instruments that will be needed to carry out this science. The USGP organized and supported the participation by ten astronomers from US institutions in this international forum. The

22 output from this meeting provides the scientific motivation for the suite of instruments that makes up the Gemini ongoing instrumentation program. Major elements of that program are an aggressive adaptive optics program, ultra-high resolution optical spectroscopy, and Near- IR spectroscopy with spatial multiplexing, eitherwith multiple slitlets or with an integral field feed.

The USGP is responsible for keeping the community informed about Gemini's progress and fostering community support for Gemini. Displays are regularly presented at AAS meetings, and USGP staff contribute status information to both NOAO and Gemini newsletters. In addition, the USGP provides routine information about Gemini activities and milestones of interest to US astronomers and the public through electronic and printed media.

Another USGP responsibility is the monitoring of technical developments within the project. The US Gemini Project Scientist serves on the Gemini Science Committee (GSC) and represents there the views of the US scientific community. In addition to the GSC and project scientist team teleconferences, formal input is contributed through participation in reviews and working group meetings organized by the project. The USGP also solicits membership for US participants in these reviews and meetings and organizes the US participation in the GSC.

In a similar way, the national project managers meet regularly to discuss procurements and other management issues. USGP staff take part in these discussions, and the US Project Scientist represents US issues in these matters at semi-annual national project managers meetings and the Gemini Director's review. During 1997, a new group, the Gemini instrument forum, met immediately after each of the Director's reviews. This group, comprising the national project scientists, national project managers, and Gemini personnel involved in the scientific instruments, is responsible for formulating and carrying out the Gemini instrumentation program. Using input from the GSC and the Abingdon instrumentation workshop and costing exercises carried out by the national project offices, this group assembled a plan for ongoing programs. Early elements in this plan, which covers a ten year period, include initial work on laser guide star adaptive optics for Gemini south and the addition ofa polarimetric capability for all the phase 1 instruments.

In a less formal sense, the USGP personnel interact frequently and directly with the Gemini Project to provide scientific and technical feedback, to identify scientific performance issues and to help define technical solutions to meet the science requirements, to evaluate implementation plans, and to participate in source selection for critical systems and components.

The USGP has participated intensively in the development of a plan for the evolution of responsibilities in the operations phase of Gemini. It is clear that the international Gemini Office will continue to depend on the national Gemini offices for a great deal of assistance in interacting with the user communities of the partner countries. The national Gemini offices will solicit proposals, perform technical evaluations, run national time allocation and users' committees, and will provide assistance to astronomers in writing Gemini proposals and reducing Gemini data. As a result of these considerations, the process of turning the USGP into an organization with the capability to carry out these activities has begun, as mentioned at the start of this report. As ScOpe, this division has responsibility for:

23 Providing information to the US astronomical community about all the capabilities available through NOAO and how they can most effectively be used;

Unifying and coordinating the process by which telescope time proposals are submitted, processed, and reviewed;

Organizing a mechanism by which astronomers can obtain assistance in preparing observing proposals, preparingfor observing runs, and reducingtheir data. This may include, in the case of Gemini and the independent observatories that are supplying national access time in exchange for NSF funding for their instruments, identifying personnel who will become "instrument specialists" for these non-NOAO telescopes;

Providing software, where appropriate, for reduction of data for all instruments to which NOAO provides access;

Developing concepts for, and perhaps implementing, an archive so that the community can make the most effective use of the data that comes from all facilities to which NOAO provides access;

Exploring concepts and implementations for alternative modes of operation such as remote observing and queue scheduling that may enable scientific investigations that are impractical or difficult given the constraints of classical modes;

Developing and implementing a program of scientific outreach, through which a dialog with the astronomical community about NOAO's mission can take place, including both the presentation of that mission in order to foster community support and the solicitation of input from the community to make NOAO more responsive to the community needs.

Although the definition of this program as a coherent effort is just beginning, two activities during the past year should be reported as significant milestones.

• As NOAO moves into an era in which it provides community access to more telescopes that it does not operate, it has been recognized that the community must see a simple, efficient interface to the suite of available facilities. A major element of this interface is the process by which astronomers propose for telescope time. This realization, together with the expectation that the number of proposals submitted each semester will rise from 400 to 700 or 800, has led us to develop an efficient new database system for management of proposals and a new input mechanism for submitting proposals using the World-Wide Web.

Starting in September 1997, all applications for time at KPNO or CTIO were submitted using the same LaTeX proposal form to the same electronic mail address. Applications could be submitted either by electronic mail or through the Web-based interface that serves as a front end to the form. The interface allows the inclusion of text files and figures on the proposer's computer, and it provides a convenient mechanism for proposers to work on a proposal over a period of time before submitting it. As proposals are submitted, they are checked for completeness and formatting problems, and then imported into the database. This whole process is remarkably efficient and over 400 proposals were received, processed, and imported. This work was essentially complete

24 by the afternoon of 1 October, the day after the deadline (midnight, 30 September). With the previous system, this activity took 3-5 days. Clearly, this mechanism is easily capable of handling the much larger flux of proposals that NOAO will receive as additional telescopes become available.

• A second event of note was the workshop on Supporting Capabilities for Large Telescopes, held in Tucson on 26-28 September 1997. This workshop was an attempt to identify and quantify, using a science-based approach, the facilities, software, and operations modes that the entire US community will need in order to use very large telescopes effectively. Approximately 50 astronomers, representing all the large telescopes and telescope-building consortia as well as a substantial number from institutions that depend on publicly available facilities, met for three days to devise scientific programs aimed at answering important questions in eight areas of astronomical research. The result was an understanding by all those present of the crucial role that wide-field imaging capabilities will play in achieving our scientific aspirations. A number of surveys covering areas from a few square degrees to significant fractions of the sky and in a number of narrow and wide bands in the optical and infrared were identified as essential. A broad consensus arose among participants that there was a need to find ways to facilitate many aspects of such surveys, including detector development, software pipelines, archives, and even the sociology of providing community support for the effort needed. A report on the workshop will be written and widely circulated as input to funding agencies and policy-making bodies.

E. NOAO Instrumentation

The mission of the Instrument Projects Group (IPG) is to develop and produce major instruments for the NOAO nighttime telescopes, including KPNO, CTIO, and Gemini. The NOAO scientific staff conceives, directs, prioritizes, and evaluates the instrumentation projects; the engineering managers are responsible for meeting schedule, budget, and performance requirements. NOAO astronomers initiate new instrument projects in response to user requests, scientific staff interests, advances in technology, and announcements of opportunity from the International Gemini Project.

Managing the instrumentation resources efficiently and in a manner that is satisfactory to both sites is crucial to the success of our program. The Instrument Projects Advisory Committee (IPAC) provides scientific prioritization to the IPG. Its current members are Taft Armandroff (NOAO-Opt. Instr.), Todd Boroson (USGP), Dave De Young (KPNO), Jay Elias (GNIRS Project), Richard Green (NOAO-Chair), Brooke Gregory (CTIO), and Bob Schommer (CTIO). IPAC meets with the instrumentation engineering managers once a month to review priorities, schedules, and budgets. They develop the scientific content of the long-range plan, on the basis of input from the users through the Users' Committee and personal contact, from the WTYN and SOAR partners, and from the Gemini advisory structure through the USGP. Every instrument under development has an instrument scientist from the NOAO scientific staff. We believe that this arrangement is essential for successful development: each instrument must have an intellectual champion to see that the project meets its scientific performance goals. IPAC provides a venue where the interests of each site are fairly represented.

25 Concurrent with the establishment of IPAC, we put into place a revised system of project management. It placed greater emphasis on initial design and planning and on overall accountability and resource tracking. Neil Gaughan is the engineering projects manager. The IPG reports to him, and he reports to Larry Daggert, the manager of ETS. IPAC works with Neil Gaughan and Larry Daggert to produce a detailed plan for the annual allocation of technical resources that is recommended to the Director and the NSF. It also organizes and participates in non-advocate design reviews for major projects. A system of review gates controls the rate at which resources are made available to a project, subject to the successful completion of the previous review stage.

During FY 1997, our ongoing projects advanced, as described below.

1. CCD Mosaic Imager

The major instrument in commissioning during FY 1997 was the CCD Mosaic Imager, being deployed first at KPNO, then cloned for CTIO. IPG has produced an imager with 8096 x 8096 format that has an active imaging area of over 12-cm on a side. It has a large filter transport mechanism holding 14 six-inch filters and a pneumatically controlled shutter mechanism that gives 1% timing accuracy in 1-second exposures. The Mosaic currently contains eight 2K x 4K three-side buttable CCDs from Loral, but they are engineering grade. Thinned, scientific grade CCDs have been ordered for two Mosaic imagers, through a consortium purchase with Carnegie Observatories. By the end of FY 1997, we had received two of these CCDs, which are being evaluated and optimized in our CCD lab. The CCD controller is a multiplexed quadruple version of the ARCON, developed and produced at CTIO. The first Mosaic Imager was made available for shared risk observing on KPNO telescopes in June 1997 (three science projects totaling nine nights in semester I; eight projects for 41 nights during semester IT). The second Mosaic is scheduled for completion in FY 1999, with deployment at CTIO in the first half of the calendar year. The fabrication of mechanical parts for Mosaic II was well advanced by the end of FY 1997.

2. Phoenix

Phoenix is a high-resolution near-infrared spectrograph operating from 1-5 microns, using two quadrants of an ALADDIN InSb array detector. Phoenix has been commissioned and was used for 14 science runs on the KPNO 2.1-m telescope during 1997 semester I. Some upgrade work has occurred in three areas: 1) understanding the cause of worse-than-expected image quality which affects delivered resolution and signal-to-noise ratio; 2) spectrograph configuration speed; and 3) a graphical user interface to simplify routine operation.

3. Hydra for CTIO

A new version of the Hydra multi-fiber positioner is being constructed for the CTIO 4-m telescope. In the area of wide-field multi-fiber spectroscopy, the existing 4-mtelescopes complement the capabilities of the Gemini telescopes. The present multi-fiber instrument at CTIO is Argus, which was designed almost a decade ago. It is capable of observing 24 objects at a time, which puts it at a factor of four disadvantage compared with more modern instruments such as KPNO's Hydra. The new multi-fiber system is being built in Tucson and is based largely on the design of Hydra as it was converted

26 from use at the Mayall to use at the WIYN. New motor controllers, a new gripper, and new fiber cables are being produced for the system for CTIO, along with a new wide- field corrector with atmospheric dispersion compensating prisms. This instrument will be located at the f/8 Ritchey-Chretien focus and will take advantage of the excellent image quality by using fibers of smaller on-sky diameter than those of Argus. Delivery and first commissioning activities are planned for October 1998. Good progress was made during FY 1997 on the fabrication of mechanical parts for Hydra/CTIO, optics fabrication for the new Corrector/ADC, and electronics andsoftware development.

4. SQIID Upgrade

A high priority for the users, as expressed through the Users' Committee, is wide-field near-IR imaging. The first realization of that capability will be in the upgrade of SQUD, the four-color near-IR imager. The 256x 256PtSi arrays will be upgraded to 512 square InSb arrays with a customized NOAO/Gemini Controller. That instrument should be availablefor shared risk user observations on KittPeak in fall semester 1998, contingent on the availability of the InSb arrays. The primary effort on this project during FY 1997 was optical and mechanical design work to allow the incorporation of the new, larger arrays.

5. Gemini IR Array Controllers

The first instrument required for commissioning the first Gemini telescope is the Near- Infrared Imager (NIRI) under development at the University of Hawaii. NOAO is producing for NIRI an upgraded version of the WILDFIRE controller that relies on the digital signal processor produced by Datacube. That system will be delivered to Hawaii for integration into the imager. Early results indicate that the array controller will have very low noise and will meet NIRI's speed requirements. The design will serve as the basis for controlling the arrays in the other near-infrared instruments that will be used on Gemini, some of which will be provided by and shared with NOAO, such as COB and Phoenix. A software simulator and test hardware (a fully functional array mount with cables and connectors) were delivered to Gemini in FY 1997. This delivery will allow Gemini and Hawaii to progress with interfacing the Gemini Near-Infrared Imager to the NOAO controller. Final delivery of the controller and test dewar will occur in FY 1998.

6. Gemini Near-IR Spectrometer

The major instrument under production for Gemini is the Near-IR Spectrograph (GNIRS). This project is the largest IR instrument ever undertaken by NOAO. The dewar will be 2 meters in length, and the instrument weighs some 2000 kg, including electronics. It will provide long-slit capabilities with a range of dispersions through selectable gratings, covering the wavelength region from 0.9 to 5.5 microns at two pixel scales by means of four interchangeable cameras, which feed a single 1024 square ALADDIN-type InSb detector. The Gemini IRS project successfully passed its Preliminary Design Review in October 1996. The instrument team spent the rest of FY 1997 doing detailed design work in preparation for the Critical Design Review, scheduled for November 1997.

27 7. High-Efficiency Spectrograph

Long-term studies are currently underway to define a new-generation moderate- resolution spectrograph for the 4-m telescopes. Scientific performance tradeoffs are being investigated to identify the most effective combination of field of view, spectral dispersion, and wavelength coverage. A key goal is to use the new generation of large- format CCDs with smaller slits and adequate pixel sampling, in order to exploit the expected improvement in delivered image quality. In addition, the use of holographic volume phase gratings, coupled with the highest performance anti-reflection coatings on all optical surfaces, should allow a significant increase in throughput. Conceptual optical designs are under development.

In FY 1998, we will initiate design efforts for a wide-field infrared imager that will be used on both the Mayall 4-m and a future, proposed 2.4-m imaging telescope. Other new activities will include work on a tip/tilt CCD imager for WIYN, a CCD MiniMosaic for WIYN resulting in a 4K x 4K format, and the integration of CCDs and CCD Controllers for Gemini's GMOS instrument.

V. MAJOR PROJECTS

A. GONG

The Global Oscillation Network Group (GONG) is an international, community-based project designed to conduct a detailed study of the internal structure and dynamics of the closest star by measuring resonating waves that penetrate throughout the solar interior. In order to overcome the limitations of observations imposed by the day-night cycle at a single observatory, GONG is operating a six-station network of extremely sensitive and stable solar velocity mappers located around the Earth obtaining nearly continuous observations of the "five-minute" pressure oscillations. GONG is also operating a distributed data reduction and analysis system to support the coordinated analysis of these data. GONG data are available to any qualified investigator whose proposal has been accepted; however, active membership in a GONG Scientific Team allows early access to the data and to the collaborative scientific analysis that the Teams have already initiated.

A Scientific Advisory Committee continues to provide overall scientific guidance to the Project. In addition, a Data Management and Analysis Center Users' Committee provides important community input in the development of thiscritical partof the Project.

The stations are operating in close collaboration with the Big Bear Solar Observatory in California, the High Altitude Observatory's site on Mauna Loa in Hawaii, the Learmonth Solar Observatory in Western Australia, the Udaipur Solar Observatory in India, the Observatorio del Teide on Tenerife in the Canary Islands, and the Cerro Tololo Inter- American Observatory in Chile.

The Project's operations group maintains daily contact with the automatically operating instruments, largely through the internet. Daily site checks are performed by the Tucson- based staff via modem or internet, checking the current state of the instrument and reviewing any informational messages generated by the real-time system. Each instrument generates a database of 200 parameters recorded at one-minute intervals. These data are transmitted to Tucson via the internet once a day for analysis by an automated system designed to detect

28 performance anomalies and long-term trends. The instruments are also continuously monitored by scientists and technicians from the host observatories. When problems occur or rapid attention is required, the network operations duty respondercan be readily accessed via phone, fax, or e-mail. Small technical teams are dispatched to each site every six to nine months to perform routine preventive maintenance.

The technical performance of the network continues to be excellent. The data duty cycle, including both weather and down-time, is currently about 87%. The best month recorded to date had a 94% fill factor and the worst has been 73%. Of all the possible images that could be obtained at the individual sites, fewer than 2% have been lost to equipment difficulties and many of these were backed up by images taken at adjacent sites.

The operations group also continues to operate the Tucson prototype station as a "ground simulator" for hardware and software modifications which will eventually propagate to the field stations. It also serves as the primary source of "hot spares" and as a test bed for the proof of concept for the incorporation of a higher resolution camera into the existing stations.

The Data Management and Analysis Center continues to process the incoming data at a rate parallel to the more than one gigabyte per day of incoming field data. These data are reduced to 36-day time series (a "GONG month") of oscillation-mode coefficients and transformed to obtain the frequency spectrum for each mode. The data from these and other intermediate steps are archived as defined data products in the Data Storage and Distribution System. The time between the data acquisition and the production of the month-long power spectra has increased to about 18 weeks. This has resulted in an increased tape storage efficiency and has accommodated an improvement in the registration of the images into heliographic coordinates.

The distribution of archived data to the science community declined somewhat as compared to the previous year's activity, but data transfers from the project's Web site increased. Requests for scientific data products are received by e-mail, the World Wide Web, and other forms of communication; however, most data distributions are satisfied by internet transfers. Scientific data distributions during the past twelve months have averaged 31 thousand files and 14 gigabytes per month. Data transfers from the Web site, primarily mode frequency tables, have averaged 0.7 gigabytes per month.

The data group also provides support to the in-house team and interested community contributors in an ongoing effort to improve understanding of the data themselves and enhance the quality of the data reduction processes. Several such enhancements have been developed and incorporated into the current data pipeline during the past two years. Recently, the project embarked on a reprocessing campaign to produce a more homogeneous dataset. This effort is operating in parallel with the processing of newly acquired data and, in order to better satisfy the needs of the GONG scientific community, is proceeding in reverse order beginning with GONG month 16.

Recent helioseismic results unambiguously show that the solar p-mode oscillation frequencies—and the internal solar structure—vary significantly during the solar cycle. Continuing GONG observations to cover a full 11-year solar cycle will add significantly to our understanding of stellar activity and its variability. Continuation of GONG operations will also greatly improve our knowledge of the time-averaged properties of the solar interior. Replacing the existing 256 x 256 pixel GONG camera with a 1024 x 1024 camera will enable

29 us to make higher resolution images of the local interior structures such as active regions and convective patterns and to probe closer to the solar surface. Given the substantial investment in establishing the network and its data management facilities, the incremental cost of continued operations is highly leveraged.

The instrument group has been studying the feasibility of retrofitting a higher-resolution, square-pixel camera to the existing observing stations. A 1024 x 1024 camera model has been identified that has excellent characteristics. This camera could be installed with the existing optical and telescope control systems. A seeing-effects study indicates that the current optics and the image sampling rate are satisfactory for the larger format system. This new detector will provide spatial resolution comparable with the optical system resolution, thuseliminating the spatial aliasing in the current system as well as overcoming some inherent problems with the current rectangular pixels. Increasing the detector scale would provide significantly improved helioseismic resolution in the near-surface regions. These areas are the home of the intense magnetic fields that seemto cause much of the moredramatic aspects of solar activity, extend all aspects of "local helioseismology" dramatically, and enable many non- helioseismic, diachronic solar measurements.

B. RISE/PSPT

The origin of the solar cycle has been a key astrophysical problem for many years. It received wider recognition with the recent suggestion that solar-cycle changes in luminosity may have a measurable influence on terrestrial conditions. A growing expectation that rapid progress can be made against this problem is fueled by: 1) sensitive space observations of total solar irradiance changes; 2) new helioseismic inferences of sub-photospheric solar properties; and 3) high-dynamic-range numerical simulations that allow the "multi-scale" complexity of the cycle problem to be explored. While this is good news, the bad news is that spatially resolved (full-disk) solarobservations with the differential (spatial) photometric accuracy of the space- based photometry do not exist. Such data are needed, both as an outer boundary condition for interpreting helioseismic changes, andto interpret the measurable solarluminosity changes in the context of physical models for the variability mechanism.

The Precision Solar Photometric Telescope (PSPT) project will develop and operate a small network of specialized instruments for obtaining high-spatial-resolution and high- photometric-accuracy solar surface photometry. These data will be obtained with a nearly continuous temporal resolution of about one hour and with spatial resolution only limited by the 15-cm telescope aperture. Based on the GONG site survey data, the PSPT network can expect to achieve occasional uninterrupted observing periods of half a solar rotation period (13 days) using a 3-site network.

To realize diffraction-limited resolution in the presence of seeing, the instrument uses a fast tip-tilt mirror in combination with digital frame-selection hardware. The design of the instrument minimizes optical complexity and scattered light in the image plane. The 2K x 2K CCD camera electronics are beingdeveloped by a commercial vendorto provide an 8 Mpix/s readout with approximately 30 electron read noise. The coated, deep-well detector will be used at four wavelengths between Call K at 393 nm out to approximately 700 nm.

The PSPT project is tightly constrained by budget and by community pressure to deploy the instruments as soon as possible. Our development philosophy has been to depend heavily on commercial vendors and to cultivate partnerships with other astronomical institutions. Since

30 these instruments will produce data with a broad range of applications, the PSPT project has several potential scientific and fiscal collaborations. To date, we have initiated partnerships with two other institutions, Osservatorio Astronomico di Roma and the NCAR High Altitude Observatory. Spanish astronomers at the LAC have also expressed an interest in a partnership to operate a PSPT on Tenerife.

Several PSPT milestones have been achieved during the last year:

• The final (production model) PSPT telescope has been deployed at the Osservatorio Astronomico di Roma.

• An agreement with the HAO has been reached to collaboratively provide a RISE data distribution center (primarily from the HAO).

• A new dome has been constructed at M. Loa and awaits the deployment of the next PSPT.

• Improvements to the flat-fielding algorithm were made that make it feasible to use with the large format 2K x 2K camera data.

• The data-acquisition system and first version software control package have been successfully implemented.

The PSPT programis part of the NSF SunRISE projectwhich is devoted to understanding the mechanisms of solar luminosity variations. NSO began development in FY 1994 of a small network of photometric telescopes to measure solar surface brightness variations. The instruments are designed around a 15-cm objective, a 2K x 2K pixel CCD, and fast frame- selection electronics. Full-disk surface photometry with 0.1% per pixel accuracy with a one- hour cadence will be obtained.

Highlights from this year include: 1) deployment of the final PSPT instrument in Rome; 2) completion of telescope dome at Mauna Loa; and 3) improvements in the calibration and flat-fielding algorithms.

The project is actively working to minimize development costs by seeking other scientific partners interested in the PSPT hardware. For example, the Kiepenheuer Institut fiir Sonnenphysik is currently using copies of our 2K x 2K camera for their observatory. NSO will also share in the software development for the 2K x 2K Thomson camera system. The new camera will be useful for a broad range of high-spatial and photometric dynamic range problems, and we expect the instrument/camera costs to decrease as additional partners are identified.

31 SOLIS

Improved long-term measurements of solar activity are key to any scientific strategy for understanding the solar cycle. NSO is already the acknowledged world leader in full-disk synoptic measurements. SOLIS, proposed to NSF in February 1996 as part of the "Renewing NOAO" proposal, represents a new generation of instruments that will form the core of the US synopticcapability for the next twenty years and can serve as a prototype for a worldwide synoptic network.

In order to relate measurements from GONG, RISE/PSPT, and other space- and groundbased instruments to the overall pattern of solar activity, it is necessary to make daily measurements of magnetic and velocity fields, as well as chromospheric and coronal structure, with a stable suite of well-calibrated instruments. The data provided by the SOLIS instruments will be dramatically improved in quality, quantity, and network availability compared with what is currently available. SOLIS will be cheaper to operate because of consolidation, automation, and modernization, and will replace NSO's existing synoptic facilities.

SOLIS was descopedat the request of NSF and currently includes three instrumentpackages:

1. Vector Spectromagnetograph: measures the strength and direction of the magnetic field in the photosphereover the full solar disk every 15 minutes, which is of prime importance for understanding the dynamics of magnetic fields and their relation to chromospheric and coronal structure (the present spectromagnetograph only measures the net magnetic flux along the line of sight, typically once a day);

2. Full Disk Patrol: delivers digital full-disk images of the Sun in various spectral lines at high cadence (the present instruments typically deliver one image per day on film with a very limited selection of spectral lines);

3. Sun-as-a-star Precision Spectrometer: delivers very precise spectra of integrated sunlight over a substantial spectral range (current measurements are performed in a labor- intensive manner with a heterogeneous collection of older instruments using just a few spectral lines).

During FY 1997, NSO established a Science Advisory Group for SOLIS whose members are drawn from a wide range of solar research organizations. The group met three times and was closely consulted during the descopingexercise. A start-up plan was prepared to enable a fast start if funding becomes available. A close working relationship between NSO and HAO in respect to the Vector Spectro-magnetograph component of SOLIS was initiated. Informal working groups were established at both NSO sites. An international workshop with 80 participants was held at NSO in September and focused on scientific issues that are the main motivation for SOLIS.

During FY 1998, NSO will continue to prepare for possible funding of SOLIS by consulting with the external advisory group; by using its existing synoptic telescopes as testbeds for state-of-the-art hardware and software concepts applicable to SOLIS; by continuing its outreach to the solar physics community through the SOLIS web page, the NSO Users' Committee (which has strongly endorsed SOLIS), AAS/SPD meetings, other fora such as NSO workshops and the community-based Solar Magnetism Initiative; and by continuing to

32 pursue possible partnerships. Potential partners include NASA, the US Air Force, the NCAR High Altitude Observatory, and the NOAA Space Environment Center.

D. Coronagraph and Low Emissivity Astronomical Reflector (CLEAR) Feasibility Study

Large solar telescopes areneeded to answer a number of important science issues. Among the desired capabilities are: (1) high angular resolution needed to resolve the scales at which most of the action takes place in solar magneto-hydrodynamics; (2) access to the infrared part of the solar spectrum, which is required to extend the range of physical conditions over which the solar atmosphere is studied; (3) accurate polarization observations needed to measure solar magnetic fields; (4) high sensitivities, essential to study variations in these and other solar conditions; and (5) low scattered light to observe magnetic fields and small-scale structures in sunspots and in the solar corona. CLEAR is a concept which attempts to combine these qualities in one telescope.

This year saw major progress in the development of the CLEAR project. A technical and budgetary feasibility study of the CLEAR project is nearing completion. It has so far shown no "showstoppers." The study is focused on a 400 cm aperture, air-filled telescope with off- axis, low-scattered-light optics covering the entire 0.3 to 30 micron wavelength region. It has a number of foci, some direct or folded f/30 Gregorian foci, others coude foci. The coude area contains a large rotating instrument platform to allow removal of the image rotation. The technical part of the study is expected to be completed in FY 1998. An interim study report has been published which will form the basis for the final report. It contains, in addition to the technical description of CLEAR, a costing as a function of telescope diameter (down to 200 cm) and degree of scattered light control. Scattered light control at the coronagraphic level adds less than 10% to the cost.

Using solar scintillometry as a proxy measurement for site seeing assessment, we are confirming earlier observations by Evershed and Leighton, who demonstrated the superiority of lake sites for high-resolution observations. Observations at mountain locations (Mauna Loa, Kitt Peak, Sac Peak, and La Palma) show strong effects of the daytime build-up of boundary layer seeing, limiting good seeing most of the time to the early morning. Big Bear, and four other lake sites tested, show on the other hand that the boundary layer seeing is absent all day, resulting in all day long good seeing. As a result, their median seeing values are superior to that of mountain sites, approximating the best of the nighttime sites. Future site measurements will focus on improving the database, testing the effects of lake size, depth and wind direction, and testing the effects of water vapor and measurement of the sky brightness.

CLEAR deviates in a major way from existing "conventional" telescopes in that it does not use a vacuum or helium-filled telescope environment. Both of the latter require a window in front of the telescope, blocking the infrared radiation and introducing scattered light. CLEAR avoids that, at the cost, however, of potentially introducing interior seeing in the telescope primarily due to the heating of the primary mirror. We have constructed a 1/7 scale mock-up of CLEAR to test how well this internal seeing can be controlled by thermal control of the thin primary mirror and by airflow across the mirror. The mock-up is mounted on the large spar of the Evans Solar Facility on Sac Peak. In addition to testing the internal seeing behavior of CLEAR, it will also test the effectiveness of dust control measures planned for CLEAR.

33 Adaptive optics are an essential component of any large solar telescope. The NSO adaptive optics program being developed at the NSO/SP Vacuum Tower Telescope is, in that sense, critical to CLEAR as well. It is described in rV.C.2.

E. SOAR

The SOAR project has as its goal the construction of a 4-m class telescope in Chile. Partners in this project, in addition to NOAO, are the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), representing the astronomical communities of four states in Brazil, the University of North Carolinaat Chapel Hill (UNC), and MichiganState University (MSU).

Following an initial meeting in August 1996, the partners provided $200,000 to fund a preliminary design phase, which explored alternative configurations for the telescope and established the science requirements. This planning phase was evaluated by an External Review Board in July 1997. The product of this design phase, together with the recommendations of the ERB, are now being used as the basis for the concept design phase, which will define the specific performance requirements for the SOAR Telescope, develop the concept for a telescope and associated support facilities that will meet these requirements, and definitively bound the cost of the fabrication and installation phases of the SOAR project. The concept design phase, which will be completed in the spring of 1998, will bring the SOAR Project to the point where the members of the SOAR consortium can review the overall system design and the rationale for design selections and become confident that the cost estimate is accurate and valid. At that point, the partners will be asked to commit full funding for the construction phase.

The project team for SOAR is based in Tucson. The project manager is Tom Sebring, who was project manager for the recently dedicated Hobby-Eberly Telescope, and the project scientist is Gerald Cecil from the University of North Carolina.

The primaryscience requirement for the telescope is superb image quality—the goal is for the telescope to degrade the image quality delivered by the atmosphere by no more than 0.18 arcsec FWHM. The primary mirror will be a thin meniscus, which will have active support and thermal control systems. The mount will be an alt-azimuth configuration with two Nasmyth ports for mounting instruments. Scattered light will be minimized through careful attention to baffling, polishing, etc. The telescope will be located on Cerro Pachon, close to the site selected for the Gemini telescope.

An English-language Web page for SOAR is being maintained at MSU and can be accessed through the NOAO home page.

VI. CENTRAL COMPUTER SERVICES

A. Tucson

The downtown Tucson computing facilities continue to evolve as older systems are replaced by newer, more cost-effective and easier-to-maintain systems. In particular, the machines Gemini (used as a Server on the Scientist Workstation Network) and Ursa (used for data reduction and analysis by staff and visitors) were significantly upgraded during FY 1997 (as they were in FY 1996). Ursa is now a Sun Ultra-2 Model 2200 with two 200 MHz Ultra

34 SPARC processors, 512 MB of RAM memory and more than 70 GB of disk storage. Such a powerful machine is necessary to handle data analysis of frames from the NOAO Mosaic imager.

Also, several older disk drives on various CCS systems failed during the year and were replaced by more reliable, and also larger, disks. Similarly, older laser printers were replaced by newer, more capable, printers.

The proliferation of desktop workstations, PCs and X-terminals to scientists' and engineers' offices has slowed as saturation is approached; however, many desktop systems were upgraded to faster systems over the course of the year. The network infrastructure in the downtown Tucson office building was upgraded with the addition of several special purpose networks (including a Fast Ethernet subnet) and the continued implementation of switched Etherneton the building backbone network. Upgrades to the dial-in networking facilities were also undertaken.

In November, we switched the data connection from Tucson to Kitt Peak from a shared to a dedicated T-l line. Thedata rate increased by a factor of 2.6 from 0.58 to 1.54 Mbps.

B. Mountain Programming Group

During FY 1997, we upgraded four programmers' workstations: two to Sparc 5s, one to an Ultra-1/170, and one to a dual processor PC running Linux. We also moved all the programmers' workstations to their own subnet using Fast Ethernet. Finally, we acquired two additional copies of CapFast, a schematic capture program needed for support of Gemini software development.

C. CTIO - La Serena

The computer facilities in the La Serena offices serve the needs of diverse groups: visiting astronomers; the resident scientific staff; the engineers of the CTIO ETS; and the secretarial and administrative staff.

The desktop workstations used by several members of the scientific staff and those of the ETS programmers and EEs were replaced with modern mid-level machines at the beginning of FY 1997. Additional machines for two new members of the scientific staff were also purchased during the fiscal year. End of FY 1997 funds have been allocated for the replacement of the PCs used by the mechanical engineers and draftsmen. During FY 1997 the network of PCs used by the secretarial and administrative staff also underwent a substantial reorganization which has involved the replacement of most of the hardware. At the same time (and continuing into FY 1998) the operating system is being changed to WindowsNT, and commercially available applications software, wherever possible identical to that in use in Tucson, is being adopted.

End of FY 1997 funds have been allocated for the purchase of switched ethernet hardware, which will be used to replace the existing conventional ethernet backbone, leading to improved speed and reliability. The new network hardware can also be easily upgraded to ATM in the future.

35 D. CTIO - Communications

The implementation of a 64 Kbps terrestrial link between La Serena and Cerro Calan Observatory in Santiago (and thence to the Chilean Internet) was completed during FY 1997 in partnership with Universidad de Chile. This allows for more efficient communication between CTIO and the Chilean astronomical community and the other observatories in Chile. It also serves as a backup Internet connection for CTIO.

E. NSO-Sunspot

1. Upgraded 2 quad CPU servers from 50 MHz to 90 MHz CPUs.

2. Installed a WindowsNT server with software that will allow users to run Window applications from their UNIX stations. The plan is to move from Windowsl6 software, running on our Sun workstations through Wabi, to Windows32 software running on the WindowsNT server. Also several software packages that were supported under Solaris are being discontinued and only supported on the Windows platform.

3. Installed a DLT 7000 tape drive on our SUN Ultra Server. This drive provides the ability to read DLT data tapes from our telescope sites and store the data on our SUN Ultra Server.

4. Upgraded several old SUN IPC workstations to newer SUN workstations.

5. Installed an ethernet switch at the VTT telescope. The switch was installed to segregate ethernet traffic between the bridge and table.

6. Upgraded/migrated software packages (AUTOCad and PADS) to the WindowsNT server. This was in support of the ISOON project.

7. Purchased and installed a high-resolution scanner in support of the NSO data archiving project. The scanner is being used to scan the NSO/SP archive of Ha and CaK photographic images going back to 1960.This is a multi-year project.

VII. SCIENTIFIC STAFF

Hired Date Name Position Division 10/01/96 C. Jason Pun Research Associate STIS 10/01/96 Ivan Hubeny Associate Scientist STIS 10/14/96 James Rhoads Research Associate KPNO 11/11/96 Frederic Baudin Research Associate NSO/GONG 01/02/97 Charles Liu Research Associate STIS 01/06/97 Louis Strous Research Associate NSO/Sunspot 03/03/97 Stuart Jefferies Associate Scientist NSO/SOI 04/24/97 John Worden Research Associate NSO/Tucson 05/05/97 Thomas Brown Research Associate STIS 05/14/97 Robert Blum Assistant Astronomer CTIO 06/02/97 Patrice Bouchet Support Scientist CTIO 08/11/97 JeffValenti Research Associate KPNO

36 Hired (continued) 08/25/97 Harry Teplitz Research Associate STIS 09/01/97 Rene Mendez CTIO-Chile Fellow CTIO

B. Completed Employment Date Name Position Division 10/18/96 Stephane Courteau Research Associate KPNO 12/31/96 Thomas Kinman Astronomer/Tenure KPNO 12/31/96 Richard Elston Associate Astronomer CTIO 01/14/97 Sydney D'Silva Research Associate NSO/Tucson 02/12/97 Yeming Gu Jr. Scientist NSO/SOI 02/21/97 Dave Silva Assistant Astronomer KPNO 04/24/97 Frederic Baudin Research Associate NSO/GONG 08/14/97 Charles Liu Research Associate STIS 08/29/97 Ata Sarajedini Research Associate KPNO 09/12/97 Alejandro Clocchiatti Gemini Fellow CTIO

C. Changed Status Date Name Position Division 10/01/96 Olin Eggen Change from full-time to part-time status CTIO 12/31/96 Jack Baldwin Returned from Sabbatical Leave CTIO 01/06/97 Hoasheng Lin Promotion from Research Associate to Assistant Astronomer NSO/Sunspot 03/27/97 Nick Suntzeff Promotion from Associate Astronomer/Tenure to Astronomer/Tenure CTIO 04/03/97 Thomas Rimmele Promotion from Assistant Astronomer to Associate Astronomer NSO/Sunspot 04/21/97 Richard Green On sabbatical until 10/17/97 NOAO/KPNO 05/01/97 Mark Phillips On sabbatical until 10/31/97 CTIO 06/08/97 Edward Ajhar Change from part-time to full-time status KPNO 08/22/97 Ian Gatley On leave for one year KPNO 09/01/97 Alistair Walker Sabbatical Leave CTIO

VIII. DIRECTOR'S OFFICE

The current management structure for NOAO consists of the following employees: Sidney Wolff, NOAO Director; Richard Green, KPNO Director/NOAO Deputy Director; Malcolm Smith, CTIO Director/NOAO Associate Director; Jacques Beckers, NSO Director/NOAO Associate Director; Todd Boroson, USGP Director/NOAO Associate Director; Mark Phillips, CTIO Assistant Director; Bruce Bohannan, KPNO Assistant Director; Robert Barnes, Assistant to the KPNO Director; Glen Blevins, Controller/Manager, Central Administrative Services; Larry Daggert, Manager, Engineering and Technical Services; John Dunlop, Manager, Central Facilities Operations; Yvette Estok, Manager, Public Information Office; Steve Grandi, Manager, Central Computer Services.

The NOAO Director is responsible for the overall operation of NOAO, which includes providing scientific leadership for NOAO, determining priorities, planning budgets, and allocating resources. The Director represents NOAO, and in particular, the four scientific divisions (CTIO, KPNO, NSO, and USGP) to AURA, NSF and the scientific community.

37 IX. STATISTICS

DuringFY 1997 the KPNOand CTIOdivisions of NOAOadopted a new database program to track observing proposals and programs scheduled on NOAO's nighttime telescopes. To simplify the transition to the new system and to reduce the effort required long-term to provide statistical information on the effectiveness of NOAO's nighttime telescopes, we are changing the reporting period for telescope statistics to coincide with the observing semesters at KPNO and CTIO. For the Annual Report coveringthe period 1 October 1996through 31 September 1997, observingstatistics will be included for the period 1 October 1996 through 31 July 1997. In subsequent years, observing statistics will be reported from 1 August through 31 July. Other information included in the Annual Report will continue to cover the period from 1 October through 30 September.

A. CTIO

During the period of 1 October 1996 through 31 July 1997, a total 176 separate observing programs involving 425 scientists (215 visitors, 210 collaborators) were carried out at CTIO. In the same period, 135 papers were published based on the use of Cerro Tololo facilities. The number of nights CTIO scientific staff spent on CTIO during this period was 198. The number of public visitors to CTIO during this same period is estimated to be 5,486.

Breakdown of CTIO Observational Statistics

(1) The figures in the following table reflect the number of observers/users physically present at the Observatory and do not include multiple visits by a single observer/user. This table does not include NOAO staff. The total number of visits including multiple ones is 293. Visiting astronomers were assigned 90.2% of the observing time and the remaining 9.8% was assigned to the staff.

(2) Observers/Users US Latin A. Foreisn Total PhDs 95 18 39 152 Graduate Students 34 4 12 50 Technicians & Research Students 1 10 2 13 Total visitors 130 32 53 215 (3) Collaborators who were not 123 9 78 210 physically present (4) Institutions represented by the above visits:

USA Institutions (50) Arizona State U. Las Campanas Obs. AT&T Bell Labs. Lawrence Livermore Nat. Lab. Brigham Young U. Los Alamos Nat. Lab. California Inst, of Technology Louisiana State U. Carnegie Inst, of Washington Massachusetts Inst, of Tech. Case Western Reserve U. Middlebury College Columbia U. Middle Tenn. State U. Cornell U. Millikin U. Gemini Project Office NASA Ames Harvard-Smithsonian Ctr. for Astrophys. NASA Goddard Johns Hopkins U. New Mexico State U.

38 Northern Arizona U. U. of Florida Ohio State U. U. of Illinois Pennsylvania State U. U. of Kansas Pomona College U. of Maryland Princeton U. U. of Michigan Purdue U. U. of Missouri Rutgers U. U. of Nevada Space Telescope Science Institute U. of North Carolina State U. of New York U. of Oklahoma U. of Alabama U. of Texas at Austin U. of Arizona U. of Washington U. of California, Berkeley US Naval Observatory U. of California, Sta. Cruz Vanderbilt U. U. of Colorado Yale U.

Latin American Institutions (12) Centro Estudios Cientificos, Chile U. de Sao Paulo, Brazil Facultad de Ciencias, Uruguay U. de Chile Pontificia U. Catolica de Chile U. de Concepcion, Chile Obs. Astron., Argentina U. de La Serena, Chile Obs. Felix Aguilar, Argentina U. Federal Rio Grande do Sul, Brazil Obs. Nacional, Brazil U. Nacional de Cordoba, Argentina

Foreign Institutions (31) Anglo-Australian Obs., Australia Royal Greenwich Obs., UK Dominion Astrophys. Obs., Canada South African Astron. Obs., South Africa European Southern Obs., Chile Sternberg Astron. Institute, Russia European Southern Obs., Germany U. of Cambridge, UK European Space Agency, The Netherlands U. of Central Lancashire, UK Kapteyn Astron. Inst., The Netherlands U. of Durham, UK Leicester U., UK U. of Edinburgh, UK Leiden Obs., The Netherlands U. of Lisbon, Portugal Max-Planck Inst., Germany U. of Montreal, Canada Mt. Stromlo & Siding Spring Obs., Australia U. of Tokyo, Japan Mullard Radio Astron. Obs., UK U. of Toronto, Canada Nat. Central U., Taiwan U. of Victoria, Canada Oss. Astron. di Capodimonti, Italy U. Laval, Canada Oss. Astron. di Roma, Italy Warsaw U., Poland Obs. de Paris-Meudon, France Yonsei U. Obs., Korea York U., Canada

B. KPNO

During the period 1 October 1996 through 31 July 1997, a total of 259 observing programs were carried out on NOAO telescopes on Kitt Peak. During the same period, 265 papers were published by staff and users of KPNO facilities. Associated with these programs were 532 individual scientists, and 40 programs were identified as graduate theses. These programs brought 409 scientific visitors to Kitt Peak, including 267 Ph.D. astronomers, 100 graduate students, and 42 others, with an additional 88 visits by KPNO scientific staff.

39 Astronomers using Kitt Peak telescopes in this period represented 79 US institutions and 28 foreign institutions. The top five represented are:

1) Harvard Smithsonian Center for Astrophysics (16); 2) University of Arizona (15) and Space Telescope Science Institute (15); 3) NASA Goddard Space Flight Center (12); 4) Pennsylvania State University (11); 5) Ohio State University (10) and University of Colorado (10).

The number of public visitors to Kitt Peak in this period is estimated to be 50,000. This number is based on the recorded number of visitors participating in four daily public tours, the recorded number of visitors involved in filming, media, or special tour requests, and an estimated number of visitors who took self-guided tours at Kitt Peak.

Observers/Users US . Foreien Total PhDs 229 38 267 Graduate Students 93 7 100 Technicians & Research Students 41 1 42 Total Visitors 363 46 409

Institutions represented by the above visits 79 28 107

C. NSO

Duringthe periodof 1October 1996 through 31 July 1997, a total of 172 observing programs, involving 109 individual scientific visitors and 30 staff were carried out at NSO facilities. During the same period, 58 papers were published by 23 staff and 9 visitors-in-residence. Astronomers using NSO facilities during this period represented 28 US institutions and 17 foreign institutions. Visiting astronomers were assigned 22% of the scheduled telescope time and the remaining 78% was assigned to the staff.

During the reporting period a total of 633 outside users from 1619 institutions accessed the main NSO/Tucson data archive and distribution area a total of 15,208 times. A total of 20,625 data files were transferred during these accesses. In addition, 23 distributions per observing day are made automatically to outside users, adding approximately 5500distributions per year for a total of over 26,000 data distributions annually to about 650 users. During this same time period, NSO web pages were accessed by outside users a total of 47,798 times. Note that these statistics are for NSO/Tucson only.

During the reporting period a total of 11,424 scientific data files were transferred via anonymous ftp from NSO/Sac Peak.

Observers/Users US Foreien Total PhDs 99 27 126 Graduate Students 5 1 6 Undergraduate Students 2 0 2 Technicians 13 0 13 Total Visitors 119 28 147

Institutions represented by the above visits 28 17 45

40 D. NOAO Tucson Headquarters BuildingStatistics During the period 1October 1996 through 31 July 1997, a total of 1,533 visitors signed in at the NOAO Tucsonheadquarters building.

41

APPENDIX A

National Optical Astronomy Observatories October 1996 through September 1997 Technical Reports The following papers were published by CCS personnel: Bell, D.J. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.371, "Filtering KPNO LaTeX Observing Proposals with Perl"

Davis, L.E. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.85, "CENTERFJT: A Centering Algorithm Library for IRAF"

Fitzpatrick, M., Tody, D. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.310, "Automatic Mirroring of the IRAF FTP and WWW Archives"

Seaman, R., von Hippel, T. 1997, ASPConf. 125, ed. G. Hunt (ASP), p. 306, "WIYN Data Distribution and Archiving"

Seaman, R., Pilachowski, C, Barden, S. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.190, "Asteroseismology-Observing for a SONG"

Tody, D. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.451, "The Data Handling System for the NOAO Mosaic"

Valdes, F. 1997, Conf. 125, ed. G. Hunt (ASP), p.459, "Data Format for the NOAO Mosaic"

Valdes, F. 1997, ASP Conf. 125, ed. G. Hunt (ASP), p.455, "IRAF Data Reduction Software for the NOAO Mosaic"

The following papers were published by ETS personnel:

Fowler, A., et al. 1997, SPIE, 2816, p.150, "ALADDIN, The 1024x1024 InSb Array: Design, Description, and Results"

Vaughnn, D. 1997, SPIE, 2864, p.429, "Identification and Analyses of Phosphorescent Materials for Use in Optical Systems and Instrumentation"

Vaughnn, D. 1997, SPIE, 2864, p.416, "The Electrostatic Application of Black FLocking for Reducing Grazing Incidence Reflections"

Vukobratovich, D. 1997, Handbook of Optomechanical Engineering, ed. A. Ahmad (CRC Press), p.45, "Chapter 2: Optomechanical Design Principles"

Vukobratovich, D. 1997, Handbook of Optomechanical Engineering, ed. A. Ahmad (CRC Press), p.lll, "Chapter 5: Lightweight Mirror Design"

West, S.C., et al. 1997, SPIE, 2871, p.74, "Progress at the Vatican Advanced Technology Telescope"

A-l

APPENDIX B

Cerro Tololo Inter-American Observatory October 1996 through September 1997 Publications List

Baird, S.R. 1996, AJ, 112, p. 2132, "RRLyrae Star Metallicites from Caby Photometry"

Baldwin, J.A. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 80, "Broad Emission Lines in Active Galactic Nuclei"

Barrado, D., et al. 1997, ApJ, 475, p. 313, "The Age of Gliese 879 and Fomalhaut"

Bechtold, J., et al. 1997, ApJ, 477,L29, "Ha Imaging of theCandidate Protogalaxy MS 1512-cB58"

Bechtold, J.,et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 122, "IR Spectroscopy of High-Redshift Quasars"

Bergeron, P., Ruiz, M.T., Leggett, S.K. 1997, ApJS, 108, p. 339, "The Chemical Evolution of Cool White Dwarfs and the Age of the Local Galactic Disk"

Berlind, A.A., et al. 1997, AJ, 114, p. 107, "The Extinction Lawin an Occulting Galaxy"

Blum, R. D., Sellgren, K., DePoy, D.L. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 277, "Really Cool Stars at the Galactic Center"

Blum, R.D., Sellgren, K., DePoy, D.L. 1996, AJ, 112, p. 1988, "ReallyCool Stars at the Galactic Center"

Blum, R.D., Sellgren, K., DePoy, D.L. 1996, ApJ, 470, p. 864, "JHKL Photometry and the K-Band Luminosity Function at the Galactic Center"

Brandner, W., et al. 1997, ApJ, 475, L45, "Ring Nebula and Bipolar Outflows Associated with the B1.5 Supergiant Sher 25 in NGC 3603"

Briley, M.M., et al. 1996, Nature, 383, p. 604, "Sodium Abundance Variations in Main-Sequence Stars of the Globular Cluster 47 Tucanae"

Brown,J.A., et al. 1996,AJ, 112, p. 1551, "Chemical Abundances in the Outer Disk Clusters Tombaugh 2, Melotte 71, and NGC 2112"

Brown, J.A., Wallerstein, G., Zucker, D. 1997, AJ, 114, p. 180, "High-Resolution CCD Spectra of Stars in Globular Clusters. IX. The 'Young' Clusters Ruprecht 106 and PAL 12"

Buta, R., Combes, F. 1996, Fund. Cosmic Physics, 17, p. 95, "Galactic Rings"

Caldwell, N., Rose J.A. 1997, AJ, 113, p. 492, "The Butcher-Oemler Effect at Low Redshift: Spectroscopy of Five Nearby Clusters of Galaxies"

Cellone, S.A., Forte, J.C. 1997, AJ, 113, p. 1239, "The Peculiar Morphology of the Irregular Galaxy NGC 1427A"

B-l Chu, You-Hua 1997, AJ, 113, p. 1815, "Supernova Remnants in OB Associations"

Chu, You-Hua, et al. 1997, PASP, 109, p. 554, "Uncovering a Supernova Remnant Hidden Near LMC X-l"

Clocchiatti, A., et al. 1997, ApJ, 483, p. 675, "SN 1983V in NGC 1365 and the Nature of Stripped Envelope Core-Collapse Supernovae"

Costa, E., Frogel, J.A. 1996, AJ, 112, p. 2607, "Carbon Stars in the Large Magellanic Cloud: Luminosities, Colors, and Implications for the History of Star Formation"

Cowley, A.P., et al. 1997, PASP, 109, p. 21, "Magellanic Cloud X-ray Sources Observed with ROSAT"

Craig, N., et al. 1997, AJ, 114, p. 244, "Extreme Ultraviolet Explorer Optical Identification Campaign. III. A Southern Hemisphere Sample of Active Late-Type Stars and White Dwarfs"

Crowther, P.A., Bohannan, B. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D. Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 437, "On the Nature of Olafpe Stars"

Dahlem, M., et al. 1997, A&A, 320, p. 731, "Evidencefor a New "Superwind" Galaxy - NGC 4666"

Dale, D.A., et al. 1997, AJ, 114, p. 455, "Seeking the Local Convergence Depth. I. Tully-Fisher Observations of the Clusters A168, A397, A1228, and A1983"

De Carvalho, R.R., et al. 1997, ApJS, 110, p. 1, "Redshift Survey of Galaxies Around a Selected Sample of Compact Groups"

De La Reza, R., et al. 1997, ApJ, 482, L77, "On A Rapid Lithium Enrichment and Depletion of K Giant Stars"

De Mello, D. F., Infante, L., Menanteau, F. 1997, ApJS, 108, p. 99 "A Catalog of Faint Interacting Galaxies in Pairs and Groups"

De Mello, D.F., et al. 1997, ApJS, 110, p. 227, "A Catalog of Faint Interacting Galaxies in Pairs and Groups. II."

De Mello, D. F., Infante, L., Menanteau, F. 1997, ASP Conf. 114, ed. S.M. Viegas, R. Gruenwald, R.R. de Carvalho (ASP), p. Ill, "FaintInteracting Galaxies in Pairsand Groups"

Due, P.-A., Mirabel,I.F., Maza, J. 1997, A&AS, 124, p. 533, "Southern Ultraluminous Infrared Galaxies: An Optical and Infrared Database"

Eenens, P.R.J., Piceno, A., Morris, P., Tapia, M. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D. Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 219, "On the Infrared Spectral Morphology of Wolf-Rayet WN Subtypes"

Eggen, O.J. 1996, AJ, 112, p. 1595, "Star Streams and Galactic Structure"

Eggen, O.J. 1996, AJ, 112, p. 2661, "The Ross 451 Group of Halo Stars"

B-2 Eggen, O.J. 1997, AJ, 114, p. 825, "The Abundance of CN, Calcium and Heavy Elements in High Velocity Stars"

Ferguson, A.M.N., Wyse, R.F.G., Gallagher, J.S. 1996, AJ, 112, p. 2567, "The Spectacular Ionized Interstellar Medium of NGC 55"

Fischer, P., Tyson, J.A. 1997, AJ, 114, p. 14, "The Mass Distribution of the Most Luminous X-ray Cluster RXJ 1347.5-1145 from Gravitational Lensing"

Fry, A.M., Carney, B.W. 1997, AJ, 113, p. 1073, "Chemical Abundances of Galactic Cepheid Variables that Calibrate the P-L Relation"

Geisler, D., Claria, J.J., Minniti, D. 1997, PASP, 109, p. 799, "Washington Photometry of Globular- Cluster Giants: Ten Intermediate-MetallicityClusters"

Ghez, A.M., et al. 1997, ApJ, 481, p. 378, "The Multiplicity of Pre-Main-Sequence Stars in Southern Star-Forming Regions"

Giovanelli, R., et al. 1997, AJ, 113, p. 22, "The I Band Tully-Fisher Relation for Cluster Galaxies: Data Presentation"

Gnidica, M.A., Freeman, K.C. 1997, ASP Conf. 116, ed. M. Arnaboldi, G.S. DaCosta, P. Saha (ASP), p. 54, "Dynamics of the Outer Halos of Ellipticals"

Goswami, A., et al. 1997, PASP, 109, p. 270, "The Spectrum of the Cool R Coronae Borealis Variable S Apodis in a Deep Decline"

Gutierrez-Moreno, A., Moreno, H. 1996, PASP, 108, p. 972, "Spectroscopic Observations of Some D- Type Symbiotic Stars"

Gutierrez-Moreno, A., Moreno, H., Feibelman, W.A. 1997, ApJ, 485, p. 359, "Ultraviolet and Optical Observations of Hen 1213, Hen 1341, and Hen 1761"

Hamuy, M., et al. 1996, AJ, 112, p. 2391, "The Absolute Luminosities of the Calan/Tololo Type la Supernovae"

Hamuy, M., et al. 1996, AJ, 112, p. 2398, "The Hubble Diagram of The Calan/Tololo Type la Supernovae and the Value of H0"

Hamuy, M., et al. 1996, AJ, 112, p. 2438, "The Morphology of Type la Supernovae Light Curves"

Hamuy, M., et al. 1996, AJ, 112, p. 2408, "BVRI Light Curves for 29 Type la Supernovae"

Hawley, S.L., Gizis, J.E., Reid, I.N. 1996, AJ, 112, p. 2799, "The Palomar/MSU Nearby Star Spectroscopic Survey. II. The Southern M Dwarfs and Investigation of Magnetic Activity"

Henry, TJ., et al. 1997, AJ, 114, p. 388, "The Solar Neighborhood. IV. Discovery of the Twentieth Nearest Star System"

B-3 Higdon, J.L., Wallin, J.F. 1997, ApJ, 474, p. 686, "Wheels of Fire. m. Massive Star Formation in the 'Double-Ringed' Ring Galaxy AM 0644-741"

Hoflich, P., et al. 1996, ApJ, 472, L81, "Maximum Brightness and Postmaximum Decline of Light Curves of Type Supernovae la: A Comparison of Theory and Observations"

Hoopes, C.G., Walterbos, R.A.M., Greenawalt, B.E. 1996, AJ, 112, p. 1429, "Diffuse Ionized Gas in Three Sculptor Group Galaxies"

Horner, D.J., Lada, E.A., Lada, C.J. 1997, AJ, 113, p. 1788, "A Near-Infrared Imaging Survey of NGC 2282"

Hughes, J., Wallerstein, G. 1997, PASP, 109, p. 274, "Stars Above the Red Horizontal Branch in M15"

Hunter, D.A., Gallagher m, J.S. 1997, ApJ, 475, p. 65, "An Emission-Line Study of Supergiant Ionized Filaments in Irregular Galaxies"

Ibata, R.A., et al. 1997, AJ, 113, p. 634, "The Kinematics, Orbit, and Survival of the Sagittarius Dwarf Spheroidal Galaxy"

Infante, L., De Mello, D.F., Menanteau, F. 1996, ApJ, 469, L85, "Strong Clustering of Faint Galaxies at Small Angular Scales"

Jewitt, D., Luu, J., Chen, J. 1996, AJ, 112, p. 1225, "The Mauna Kea-Cerro Tololo (MKCT) KuiperBelt and Centaur Survey"

Kaluzny, J. 1996, A&AS, 120, p. 83, "CCD Photometry of Variable Stars in the Globular Cluster NGC 288"

Kaluzny, J. 1997, A&AS, 122, p. 1, "CCD Photometry of Variable Stars in the Field of the Globular Cluster NGC 6397"

Kassis, M., et al. 1997, AJ, 113,p. 1723, "Deep CCD Photometry of Old Open Clusters"

Kastner, J.H., et al. 1996, ApJ, 462, p. 777, "H2 Emission from Planetary Nebulae: Signpost of Bipolar Structure"

King, J.R., Deliyannis, C.P., Boesgaard, A.M. 1997, ApJ, 478, p. 778, "The 9Be Abundances of a Centauri A and B and the Sun: Implications for Stellar Evolutionand Mixing"

Kirkpatrick, J.D., Henry, T., Irwin, M.J. 1997, AJ, 113, p. 1421, "Ultra-Cool M Dwarfs Discovered by QSO Surveys. I. The APM Objects"

Korista, K., et al. 1997, ApJS, 108, p. 401 "An Atlas of Computed Equivalent Widths of Quasar Broad Emission Lines"

Kozhurina-Platais, V., et al. 1997, AJ, 113, p. 1045, "The Age of NGC 3680 and a Test of Convective Overshoot"

B-4 Kuhn, J.R., et al. 1996, ApJ, 469, L93, "Tidal Disruption and Tails From the Carina Dwarf Spheroidal Galaxy"

Lamontagne, R., et al. 1996, AJ, 112, p. 2227, "Photometric Determination of Orbital Inclinations and Mass Loss Rates for Wolf-Rayet Stars in WR+O Binaries"

Layden, A.C. 1997, PASP, 109, p. 524, "Light Curves for 40 Field RRLyrae Variables"

Lehnert, M.D., Heckman, T.M. 1996, ApJ, 472, p. 546, "The Nature of Starburst Galaxies"

Leitherer, C, et al. 1996, PASP, 108, p. 996, "A Database for Galaxy Evolution Modeling"

Lennon, D.J., et al. 1997, ASP Conf. 120, ed. A. Nota, H.J.F.L.M. Lamers (ASP), p. 90, "Luminous Blue Supergiants in the LMC"

Marston, A.P. 1997, ApJ, 475, p. 188, "A Survey of Nebulae Around Galactic Wolf-Rayet Stars in the Southern Sky. III. Survey Completion and Conclusions"

Matthews, L.D., Gallagher m, J.S., van Driel, W. 1997, ASPConf. 117, ed. M. Persic, P. Salucci (ASP), p.98, "Exploration of the Tully-Fisher Relation in Low Surface Brightness Galaxies at the End of the Spiral Sequence"

McCarthy, P.J., Baum, S.A., Spinrad, H. 1996, ApJS, 106, p. 281, "Emission-Line Properties of 3CR Radio Galaxies. II. Velocity Fields in the Extended Emission Lines"

McMillan R.J., Ciardullo, R. 1996, ApJ, 473, p. 707, "Constraining theAges of Supernova Progenitors. I. Supernovae and Spiral Arms"

Mendez, R.A., et al. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 345, "A Large Proper-Motion Survey in Plaut's Low-Extinction Window"

Mermilliod, J.-C, et al. 1997,A&A, 319, p. 481, "Red Giants in Open Clusters"

Minniti, D., et al. 1996, ApJ, 470, p. 953, "High-Dispersion Spectroscopy of Giants in Metal-Poor Globular Clusters. II. Oxygen and Sodium Abundances"

Moitinho, A, et al. 1997, AJ, 113, p. 1359, "CCD UBV Photometry of the Young Open Cluster NGC 3766"

Morel, T., St-Louis, N., Marchenko, S.V. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D. Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 271, "The 'Photosphere-Wind Connection' in Wolf-Rayet Stars: Simultaneous Photometry and Spectroscopy of EZ Cma"

Morris, P.W., Eenens, P.R.J., Blum, R.D. 1996, ApJ, 470, p. 597, "Infrared Spectra of Massive Stars in Transition: WNL, Of, Of/WN, Be, B[e], and Luminous Blue Variable Stars"

Morris, P., et al. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D. Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 405, "Evolutionary Implications for 'Transition' Stars from Ground-Based and ISO-SWS Spectra"

B-5 Niemela, V.S., et al. 1996, Rev. Mex. AA, 5, p. 100, "The Elliptic Orbit of the WR Binary System CV Serpentis"

Orosz, J.A., Bailyn, CD. 1997, ApJ, 477, p. 876, "Optical Observations of GRO J1655-40 in Quiescence. I. A Precise Mass for the Black Hole Primary"

Pahre, M.A., et al. 1997, ASP Conf. 114, ed. S.M. Viegas, R. Gruenwald, R.R. de Carvalho (ASP), p. 137, "Discovery of a Galaxy Responsible for a DLA System at z = 3.15 and a Near-Infrared Search for Primeval Galaxies"

Pak, S., Jaffe, D.T., Keller, L.D. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 28, "H2 Emission from the Inner 400 Parsecs of the Galaxy II. The UV-Excited H2"

Patten, B.M., Simon, T. 1996, ApJS, 106, p. 489, "The Evolution of Rotation and Activity in Young Open Clusters: IC 2391"

Patterson, J., et al. 1997, PASP, 109, p. 468, "Superhumps in Cataclysmic Binaries. XI. V603 Aquilae Revisited"

Perrett, K.M., et al. 1997, AJ, 113, p. 895, "The Globular Cluster Systems of NGC 1400and NGC 1407"

Porto de Mello, G.F., Da Silva, L. 1997, ApJ, 482, L89, "HR 6060: The Closest Ever Solar Twin?"

Porto de Mello, G. F., Da Silva, L. 1996, Stellar Abundances Workshop, ed B. Barbury, W.J. Maciel, J.C, Gregorio-Hetem (IAG/USP), p. 59, "The Abundance Distribution of Solar-Type Solar Neighbourhood Stars"

Prinja, R.K., Fullerton, A.W., Crowther, P.A. 1996, A&A, 311, p. 264 "Variability in the Optical Wind Lines of HD 151804 (08 Iaf)"

Provencal, J.L., et al. 1997, ApJ, 480, p. 383, "Whole Earth Telescope Observations of the Helium Interacting Binary PG 1346 + 082 (CR Bootis)"

Quillen, A.C, et al. 1997, ApJ, 481, p. 179, "Discovery of a Boxy Peanut-Shaped Bulge in the Near- Infrared"

Quillen, A.C, Ramirez, S.V., Frogel, J.A. 1996, ApJ, 470, p. 790, "Detection of Dynamical Structures Using Color Gradients in Galaxies"

Ramirez, A., Quintana, H., Way, M.J. 1997, ASP Conf. 114, ed. S.M.Viegas, R. Gruenwald, R.R. de Carvalho (ASP), p. 145, "Dark Halos around Elliptical Galaxies: NGC4782/3Group"

Ramirez; S.V., et al. 1997, AJ, 113, p. 1411, "Luminosity and Temperature from Near-Infrared Spectraof Late-Type Giant Stars"

Rauw, G., et al. 1996, Liege Int'l Astrophysical Coll., 33, ed. J.M. Vreux, A. Detal, D. Fraipont-Caro, E. Gosset, G. Rauw, (Universite de Liege), p. 303, "A New Orbital Solution for the WNL Binary System WR12"

Reipurth, B., 1997, AJ, 114, p. 757, "Hubble Space Telescope Images of the HH 111 Jet"

B-6 Reipurth, B., Heathcote, S. 1997, IAU Symp. 182, ed. B. Reipurth, C Bertout (Kluwer), p.3, "50 Years of Herbig-Haro Research"

Riess, A.G., et al. 1997, AJ, 114, p. 722, "Time Dilation From Spectral Feature Age Measurements of Type la Supernovae"

Rodrigues, C.V., et al. 1997, ApJ, 485, p. 618, "Dust in the Small Magellanic Cloud: Interstellar Polarization and Extinction"

Rubin, R.H., et al. 1997, ApJ, 474, L131, "[Fe IV] In the Orion Nebula"

Rush, B., et al. 1997, ApJ,484, p. 163, "The High-Redshift Radio Galaxy MRC0406-244"

Sandquist, E.L., et al. 1996, ApJ, 470, p. 910, "CCD Photometry of the Globular Cluster M5. I. The Color-Magnitude Diagram and Luminosity Functions"

Saraiva, M.F. 1997, AJ, 113, p. 1607, "BVRI and Ha Surface Photometry of the Triple-Ringed Galaxy IC4214"

Sarajedini, A., Geisler, D. 1996, AJ, 112, p. 2013, "Deep Photometry of the Outer Halo Globular Cluster in Pyxis"

Sarajedini, A., Layden, A. 1997, AJ, 113, p. 264, "Reddenings, Metallicities, and Possible Abundance Anomalies in Young Globular Clusters"

Seitzer, P., Schweizer, F. 1997, ASP Conf. 116, ed. M. Arnaboldi, G.S. Da Costa, P. Saha(ASP), p. 504, "Young Globular Clusters in NGC 7252"

Sellgren, K., Blum, R.D., DePoy, D.L. 1996, ASP Conf. 102, ed. R. Gredel (ASP), p. 285, "Interstellar Extinction and the Luminosity Function of Galactic Center Stars"

Stauffer, J.R., et al. 1997, ApJ, 475, p. 604, "Rotational Velocities and Chromospheric Activity of M Dwarfs in the Hyades"

Stauffer, J.R., et al. 1997, ApJ, 479, p. 776, "Rotational Velocities and Chromospheric/Coronal Activity of Low-Mass Stars in the Young Open Clusters IC 2391 and IC 2602"

Storchi-Bergmann, T., et al. 1996, ApJ, 472, p. 83, "Circumnuclear Star Formation in Active Galaxies"

Storchi-Bergmann, T., et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 302, "Infrared Emission-Line Signatures of Tori in the Nuclei of Seyferts"

Tiede, G. P., Terndrup, D.M. 1997, AJ, 113, p. 321, "A New Survey of Stellar Kinematics in the Central Milky Way"

Tonry, J.L., et al. 1997, ApJ, 475, p. 399, "The SBF Survey of Galaxy Distances. I. Sample Selection, Photometric Calibration, and the Hubble Constant"

B-7 Wachter, S., Margon, B. 1996, AJ, 112, p. 2684, "Photometry of GX 349+2: Evidence for a 22-Hour Period"

Wachter, S. 1997, ApJ, 485, p. 839, "Recovery of the X-Ray Transient QX Normae (=X1608-52) in Outburst and Quiescence"

Walker, A.R., Nemec, J.M. 1996, AJ, 112, p. 2026, "CCD Photometry of Galactic Globular Clusters, m. IC 4499"

Wallerstein, G., Gonzalez, G. 1996, MNRAS, 282, p. 1236, "The Carbon Cepheid V553 Cen: Evidence of Triple-a and CNO Cycling"

Wampler, E.J., et al. 1996, A&A, 316, p. 33, "High Resolution Observations of the QSO BR 1202-0725: Deuterium and Ionic Abundances at Redshifts Above z = 4"

Wehrie, A.E., Keel, W.C, Jones, D.L. 1997, AJ, 114, p. 115, "The Nature of the Optical 'Jets' in the Spiral Galaxy NGC 1097"

Wilking, B.A., et al. 1997, PASP, 109, p. 549, "Herbig-Haro Objects in the p Ophiuchi Cloud"

Williams, R.M., et al. 1997, ApJ, 480, p. 618, "Supernova Remnants in the Magellanic Clouds. I. The Colliding Remnants DEM L316"

Wills, B.J., et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 104, "The HST Sample of Radio-Loud Quasars: Emission Lines from Lya to HP"

Wills, D., et al. 1997, ASP Conf. 113, ed. B.M. Peterson, F.-Z. Cheng, A.S. Wilson (ASP), p. 106, "The HST Sample of Radio-Loud Quasars: Fe II and Other Correlations"

Wilson, A.S., Binette, L., Storchi-Bergman, T. 1997, ApJ, 482, L131, "The Temperature of Extended Gas in Active Galaxies: Evidence for Matter-Bounded Clouds"

Winge, C, et al. 1996, ApJ, 469, p.648, "Spectroscopic Monitoring of Active Galactic Nuclei from CTIO. II. IC 4329A, ESO 141-G55, Arakelian 120 and Fairall 9"

Zacharias, N. 1996, PASP, 108, p. 1135, "Measuring the Atmospheric Influence on Differential Astrometry: A Simple Method Applied to wide-Field CCD Frames"

Zhao, P., McClintock, J.E. 1997, ApJ, 483, p. 899, "A Dynamical Study of the Eclipsing Nova OY Arae"

Zucker, D., Wallerstein, G., Brown, J.A. 1996, PASP, 108, p. 911, "Abundances of Selected Elements in Five Oxygen-Poor Stars in Omega Centauri"

B-8 Publications by Telescope FY 1997

Blanco 4-m = 64

1.5-m = 39

0.9-m = 25

1-m = 11

Curtis-Schmidt = 7

0.6-m = 2

Staff = 23

Total = 170

These figures include usage of more than one telescopeper publication. Total Publications FY 1997: 135

B-9

APPENDIX C

Kitt Peak National Observatory October 1996 through September 1997 Publications List Abt, H.A. 1996, PASP, 108, p.844, "HD 105262, a Newly Discovered HR 4049 Star with a Large Proper Motion"

Abt, H.A. 1996, PASP, 108, p.1059, "HowLong AreAstronomical Papers Remembered?"

Abt, H.A., Tan, H., Zhou, H. 1997, ApJ, 487, p.365., "Hot Inner Disks That Appear and Disappear Around Rapidly Rotating A-Type Dwarfs"

Adelman, S.J., Philip, A.G.D., Adelman, C.J. 1996, MNRAS, 282, p.953, "Elemental Abundances of the Mercury-Manganese Stars HR89 and 33 Geminorum"

Adelman, S.J., Philip, A.G.D. 1996, MNRAS, 282, p.1181, "ElementalAbundances of the B and A Stars - HI. Gamma Geminorum, HR 1397, HR 2154, HD 60825 and 7 Sextantis"

Ajhar, E.A., et al. 1997, AJ, 114, p.626, "Calibration of the Surface Brightness Fluctuation Method for Use with the Hubble Space Telescope"

Alves, J., et al. 1997, AJ, 113, p.1395, "Optical Outburst of a Pre-Main-Sequence Object"

Ambruster, C.W., et al. 1997, ApJ, 479, p.960, "The Extremely Active Single Giant IE 1751+7046 = ET Draconis: RevisedProperties and a Reevaluation of Its Evolutionary Status"

Andreon, S. 1996, A&A, 314, p.763, "The Morphological Segregation of Galaxies in Clusters. U. The Properties of Galaxies in the Coma Cluster"

Appleton, P.N., Marston, AP. 1997, AJ, 113, p.201, "Multiwavelength Observations of Collisional Ring Galaxies. I. Broad-Band Images, Global Properties, and Radial Colors of the SampleGalaxies"

Arnaboldi, M., et al. 1996, ApJ, 472, p.145, "The Kinematics of the Planetary Nebulae in the Outer Regions of NGC 4406"

Baliunas, S.L., et al. 1997, ApJ, 474, p.L119, "Properties of Sun-Like Stars with Planets: p1 Cancri, x Bootis, and v Andromedae"

Bally, J., Devine, D., Alten, V. 1996, ApJ, 473, p.921, "A Parsec-Scale Herbig-Haro Jet in Barnard 5"

Bally, J., Devine, D., Reipurth, B. 1996, ApJ, 473, p.L49, "A Burst of Herbig-Haro Flows in NGC 1333"

Bally, J., et al. 1997, ApJ, 478, p.603, "New Herbig-Haro Flows in L1488 and L1455"

Bally, J. 1997, ASP Conf. 121, ed. D.T. Wickramasinghe (ASP), p.3, "Observations of Disks and Outflows from Young Stars"

Barnes, III, T.G., et al. 1997, PASP, 109, p.645, "BVRIJHK Photometry of Cepheid Variables"

C-l Barsony, M., et al. 1997, APJS, 112, p.109, "A Near-Infared Imaging Survey of the p Ophiuchi Cloud Core"

Baum, W.A., et al. 1997, AJ, 113, p.1483, "Distance to the Coma Cluster and a Value for H0 Inferred from Globular Clusters in IC 4051"

Bechtold, J., et al. 1997, ASP Conf. 113, ed. B.M. Peterson (ASP), p.122, "IR Spectroscopy of High- Redshift Quasars"

Becker, R.H., et al. 1997, ApJ, 479, p.L93, "The First Radio-Loud Broad Absorption Line QSO and Evidence for a Hidden Population of Quasars"

Belton, M.J.S., et al. 1996, Science, 274, p.377, "Galileo's First Images of Jupiter and the Galilean Satellites"

Bergeron,P., Ruiz, M.T., Leggett, S.K. 1997, ApJS, 108, p.339, "The Chemical Evolution of Cool White Dwarfs and the Age of the Local Galactic Disk"

Bianchi, L., et al. 1996, ApJ, 471, p.203, "Ultraviolet Extinction by Interstellar Dust in External Galaxies: M31"

Bohannan, B. 1997, ASP Conf. 120, ed. A. Nota (ASP), p.3, "The Definition of Luminous Blue Variables"

Bohm, T., et al. 1996, A&AS, 120, p.431, "Azimuthal Structures in the Wind and Chromosphere of the Herbig Ae Star AB Aurigae. Results from the MUSICOS 1992Campaign"

Bond, H.E., et al. 1996, AJ, 112, p.2699, "Asteroseismological Observations of the Central Star of the Planetary Nebula NGC 1501"

Bowen, D.V., et al. 1997, MNRAS, 284, p.599, "Redshifts of Galaxies Close to Bright QSO Lines of Sight"

Bower, G.A., et al. 1997, ApJ, 483, p.L33, "The Nuclear Ionized Gas in the Radio Galaxy M84 (NGC 4374)"

Broeils, A.H., Courteau, S. 1997, ASP Conf. 117, ed. M. Persic (ASP), p.74, "Modeling the Mass Distribution in Spiral Galaxies"

Brown, J.A., et al. 1996, AJ, 112, p.1551, "Chemical Abundances in the Outer Disk Clusters Tombaugh 2, Melotte 71, and NGC 2112"

Brunner, R.J., et al. 1997, ApJ, 482, p.L21, "Toward More Precise Photometric Redshifts: Calibration Via CCD Photometry"

Burstein, D., et al. 1996, Gravitional Dynamics, ed. O. Lahav (Cambridge U. Press), p.141, "A Reconsideration of the Peculiar Velocity Field within the Local Supercluster"

C-2 Caldwell, N., Rose, J.A. 1997, AJ, 113, p.492, "The Butcher-Oemler Effect at Low Redshift: Spectroscopy of Five Nearby Clusters of Galaxies"

Calzetti, D. 1997, AJ, 113, p.162, "Reddening and Star Formation in Starburst Galaxies"

Carpenter, J.M., et al. 1997, AJ, 114, p.198, "Properties of the Monoceros R2 StellarCluster"

Cavallo, R.M., Pilachowski, C.A., Rebelo, R. 1997, PASP, 109, p.226, "Oxygen Abundances in Metal- Poor Subgiant Stars from the O I Triplet"

Chaboyer, B., et al. 1996, MNRAS, 283, p.683, "An Accurate Relative Age Estimator for Globular Clusters"

Chambers, K.C., et al. 1996, ApJS, 106, p.247, "Ultra-Steep-Spectrum Radio Sources. II. Radio, Infrared, Optical,and HST Imagingof High-Redshift 4C Objects"

Chambers, K.C., et al. 1996, ApJS, 106, p.215, "Ultra-Steep-Spectrum Radio Sources. I. 4CObjects"

Chariot, S. 1996, The Universe at High-z, Large-Scale Structure and the Cosmic Microwave Background, ed. E. Martinez-Gonzalez (Springer), p.52, "Spectral Evolution of Galaxies"

Chen, H., et al. 1997, ApJ, 475, p.163, "IRAS 20050+2720: An Embedded Young Cluster Associated with a Multipolar Outflow"

Chromey, F.R., Hasselbacher, D.A. 1996, PASP, 108, p.944, "The Flat Sky: Calibration and Background Uniformity in Wide-Field Astronomical Images"

Chu, Y-H., Chang, T.H., Conway, G.M. 1997, ApJ, 482, p.891, "High-Resolution X-Ray Image of the Hydrogen-Deficient Planetary Nebula Abell 30"

Cimatti, A., et al. 1997, The Early Universe with the VLT, ed. J. Bergeron (Springer), p.300, "Keck Spectropolarimetry of High z Radio Galaxies: Discerning the Components of the AlignmentEffect"

Clayton, G.C., et al. 1997, ApJ, 476, p.870, "Evidence for a BipolarGeometry in R Coronae Borealis?"

Connolly, A.J., et al. 1996, ApJ, 473, p.L67, "Superclustering at Redshift z = 0.54"

Connolly, A.J., et al. 1997, ApJ, 486, p.Lll, "The Evolution of the Global Star Formation History as Measured from the Hubble Deep Field"

Corbin, M.R., Boroson, T.A. 1996, ApJS, 107, p.69, "Combined Ultraviolet and Optical Spectra of 48 Low-Redshift QSOs and the Relation of the Continuum and Emission-Line Properties"

Corbin, M.R., Boroson, T.A. 1997, ASP Conf. 113, ed. B.M. Peterson (ASP), p.260, "A New Luminosity Effect in QSO Spectra"

Cote, P., et al. 1997, ApJ, 476, p.L15, "Discovery of a Probable CH Star in the Globular Cluster M14 and Implications for the Evolution of Binaries in Clusters"

C-3 Coude du Foresto, V., Ridgway, S., Mariotti, J.-M. 1997, A&AS, 121, p.379, "Deriving Object Visibilities from Interferomgrams Obtained with a Fiber Stellar Interferometer"

Crotts, A.P.S., Tomaney, A.B. 1996, ApJ, 473, p.L87, "Results from a Survey of Gravitational Microlensing Toward M31"

Crotts, A.P.S. 1997, ASP Conf. 117, ed. M. Persic (ASP), p.289, "VATT/Columbia Microlensing Survey ofM31 and the Galaxy"

Crowther, P.A., Bohannan, B. 1997, A&A, 317, p.532, "The Distinction Between O Iafpe and WNLha Stars. A Spectral Analysis of HD 151804, HD 152408 and HDE 313846"

Crowther, P.A., Bohannan, B. 1997, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M. Vreux (Universite de Liege), p.437, "On the Nature of Olafpe Stars"

Da Costa, G.S., et al. 1996, AJ, 112, p.2576, "The Dwarf Spheroidal Companions to M31: WFPC2 Observations of Andromeda I"

Dalcanton, J.J., et al. 1997, AJ, 114, p.635, "The Number Density of Low-Surface Brightness Galaxies with 23< |io <25 V Mag/Arcsec"

Davis, D.S., et al. 1997, AJ, 114, p.613, "Gravitational Interactions in Poor Galaxy Groups"

De Young,D.S. 1996, AJ, 112,p.2896, "Numerical Simulations of Airflow in Telescope Enclosures"

De Young, D.S. 1996 IAU Symp.175, ed. R. Ekers (Kluwer), p.461, "Boundary Layers in Extragalactic Jets"

De Young, D.S. 1997, Phys. Fluids, 9, p.2168, "Growth of Large Scale Structures in Two-Dimensional Mixing Layers"

De Young, D.S. 1997, 2nd Workshop on Gigahertz Peaked Spectrum and Compact Steep Spectrum Radio Sources, ed. I.A.G. Snellen (Sterrewacht Leiden), p.275, "How Do CSOs Grow Old?"

Devereux, N., Ford, H., Jacoby, G. 1997, ApJ, 481, p.L71, "Hubble Space Telescope Imaging of the Central 1 Kiloparsec of M81"

Devereux, N.A., Duric, N., Scowen, P.A. 1997, AJ, 113, p.236, "Ha Far-Infrared and Thermal Radio Continuum Emission within the Late-Type Spiral Galaxy M33"

Devine, D., Reipurth, B., Bally, J. 1997, IAU Symp. 182 (Poster Papers), ed. F. Malbet (Observatoire de Grenoble), p.91, "New Herbig-Haro Objects"

Dey, A. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (World Scientific), p.373, "The Host Galaxies of Distant Radio Sources"

Eikenberry, S.S., Fazio, G.G. 1997, ApJ, 475, p.L53, "Time Evolution and the Nature of the Near- Infrared Jets in GRS 1915+105"

C-4 Eikenberry, S.S., et al. 1997, ApJ, 477, p.465, "High Time Resolution Infrared Observations of the Crab Nebula Pulsar and Pulsar Emission Mechanism"

Fekel, F.C, et al. 1997, AJ, 113, p.1095, "New and Improved Parameters of HD 202908 = ADS 14839: A Spectroscopic-Visual Triple System"

Fekel, F.C. 1997, PASP, 109, p.514, "Rotational Velocities of Late-Type Stars"

Feldmeier, J.J., Ciardullo, R., Jacoby, G.H. 1997, ApJ, 479, p.231, "Planetary Nebulae as Standard Candles. XI. Application to Spiral Galaxies"

Ferguson, A.M.N., et al. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.557, "Probing Star Formation in Low Gas Density Environments: A Study of the Outer Disks of Galaxies"

Fesen, R.A., Gunderson, K.S. 1996, ApJ, 470, p.967, "Optical Spectroscopy and Imaging of the Northeast Jet in the Cassiopeia A Supernova Remnant"

Fesen, R.A., et al. 1997, AJ, 113, p.767, "Optical Imaging and Spectroscopy of the Galactic Supernova Remnants CTB 1 (Gl 16.9+0.2), Gl 16.5+1.1, and Gl 14.3+0.3"

Fry, A.M., Carney, B.W. 1997, AJ, 113, p.1073, "Chemical Abundances of Galactic Cepheid Variables That Calibrate the P-L Relation"

Gallagher, J.S., Han, M., Wyse, R.F.G. 1997, ASP Conf. 117, ed. M. Persic (ASP), p.66, "Structures of Dwarf Elliptical Galaxies in Rich Clusters"

Gang, T., et al. 1997, ASP Conf. 120,ed. A. Nota (ASP), p.l 10, "Atmospheric Conditions in LBVs: First Results from a High-Resolution Optical Survey"

Geisler, D., Claria, J.J., Minniti, D. 1997, PASP, 109, p.799, "Washington Photometry of Globular- Cluster Giants: Ten Intermediate-Metallicity Clusters"

Giacani, E.B., et al. 1997, AJ, 113, p.1379, "New Radio and Optical Study of the Supernova Remnant W44"

Gillett, F.C, et al. 1996,RevMexAA (Serie de Conferencias) 4, p.75, "The Gemini Telescopes Project"

Giovanelli, R., et al. 1997, AJ, 113, p.53, "The / Band Tully-Fisher Relation for Cluster Galaxies: A Template Relation, Its Scatter and Bias Corrections"

Giovanelli, R., et al. 1997, AJ, 113, p.22, "The / Band Tully-Fisher Relation for Cluster Galaxies: Data Presentation"

Gomez, M., Whitney, B.A., Kenyon, S.J. 1997, AJ, 114, p.l 138, "A Survey of Optical and Near-Infrared Jets in Taurus Embedded Sources"

Gonzalez Delgado, R.M., et al. 1997, ApJ, 483, p.705, "Are the Super-Star Clusters of NGC 1569 in a Poststarburst Phase?"

C-5 Graham, J.R., Dey, A. 1996, ApJ, 471, p.720, "The Redshift of an Extremely Red Object and the Nature of the Very Red Galaxy Population"

Greenawalt, B., Walterbos, R.A.M., Braun, R. 1997, ApJ, 483, p.666, "Optical Spectroscopy of Diffuse Ionized Gas in M31"

Grillmair, C.J., et al. 1996, AJ, 112, p.1975, "Hubble Space Telescope Observations of M32: The Color- Magnitude Diagram"

Grillmair, C.J., et al. 1997, AJ, 113, p.225, "The Nuclear Region of M51 Imaged with the HSTPlanetary Camera"

Grillmair, C.J., et al. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.308, "Hubble Space Telescope Observations of M32"

Guetter, H.H., Turner, D.G. 1997, AJ, 113, p.2116, "IC 1590, A Young Cluster Embedded in the Nebulosity of NGC 281"

Guseva, N., Izotov, Y., Thuan, T.X. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.577, "The Internal Gas Motions in Blue Compact Galaxies"

Hall, P.B., Ellingson, E., Green, R.F. 1997, AJ, 113, p.l 179, "X-Ray Emission from the Host Clusters of Powerful AGN"

Hall, P.B., et al. 1997, ApJ, 484, p.L17, "The Optical/Near-Infrared Colors of Broad Absorption Line Quasars, Including the Candidate Radio-Loud Broad Absorption Line Quasar 1556+3517"

Hamuy, M., et al. 1996, AJ, 112, p.2408, "BVRI Light Curves for 29 Type la Supernovae"

Hanson, M.M., Conti, P.S., Rieke, M.J. 1996, ApJS, 107, p.281, "A Spectral Atlas of Hot, Luminous Stars at 2 Microns"

Hanson, M.M. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.489, "AT-Band Spectroscopy in the Nearby Obscured HII Region M17: Newly Born Massive Stars"

Harris, W.M., et al. 1997, Science, 277, p.676, "Evidence for Interacting Gas Flows and an Extended Volatile Source Distribution in the Coma of Comet C/1996 B2 (Hyakutake)"

Heckman, T.M., et al. 1997, ApJ, 482, p.114, "A Powerful Nuclear Starburst in the Seyfert Galaxy Markarian 477: Implications for the Starburst-Active Galactic Nucleus Connection"

Heiser, A.M. 1996, AJ, 112, p.2142, "Photometry of the RR Lyrae Variable U Comae"

Henden, A.A. 1996, AJ, 112, p.2757, "Faint Cepheid Studies. II. Stars with Published Periods"

Henry, R.B.C, et al. 1996, MNRAS, 283, p.635, "The Effects of Cluster Environment on the Chemical Evolution of Galaxies - III. NGC 753"

C-6 Hillenbrand, L.A. 1997, AJ, 113, p. 1733, "On the Stellar Population and Star-Forming History of the Orion Nebula Cluster"

Hintz, E.G., et al. 1997, PASP, 109, p.15, "Time-Series Ensemble Photometry of SX Phoenicis Stars. I. BL Camelopardalis"

Hintz, E.G., et al. 1997, AJ, 113, p.1375, "Reddening Study of a Bright High Galactic Latitude Nebula: LBN434"

Hintz, E.G., Joner, M.D. 1997, PASP, 109, p.639, "Fourier Decomposition of the Light Curves of Three Dwarf Cepheids: CY Aquarii, XX Cygni, and V798Cygni"

Horner, D.J., Lada, E.A., Lada, C.J. 1997, AJ, 113, p. 1788, "A Near-Infrared Imaging Survey of NGC 2282"

Hu, X. 1996, AJ, 112, p.2712, "Kinematic Studies of Herbig-Haro Objects in the OrionNebula"

Hubeney, I., Hubeney, V. 1997, ApJ, 484, p.L37, "Non-LTE Models and Theoretical Spectra of Accretion Disks in Active Galactic Nuclei"

Hunter, D.A., Gallagher III, J.S. 1997, ApJ, 475, p.65, "An Emission-Line Study of Supergiant Ionized Filaments in Irregular Galaxies"

Hunter, D.A., et al. 1997, AJ, 113, p.1691, "Ultraviolet Photometry of Stars in the Compact Cluster R136 in the Large Magellanic Cloud"

Hunter, D.A., et al. 1997, ApJ, 478, p.124, "The Intermediate-Mass Stellar Population of the Large Magellanic Cloud Cluster NGC 1818 and the Universality of the Stellar Initial Mass Function"

Itoh, Y., Tamura, M., Kobayashi, Y. 1996, Proc. of the Third East-Asian Meeting on Astronomy: Ground-Based Astronomy in Asia, ed. N. Kaifu (National Astronomical Observatory, Japan), p.138, "Near Infrared Surveys of Taurus Molecular Cloud"

Izotov, Y.I., Thuan, T.X., Lipovetsky, V.A. 1997, ApJS, 108, p.l, "The Primordial Helium Abundance: Systemic Effects and a New Determination"

Izotov, Y.I., Thuan, T.X., Lipovetsky, V.A. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.587, "The Primordial Helium Abundance"

Izotov, Y.I., et al. 1997, ApJ, 487, P.L37, "I Zw 18: A New Wolf-Rayet Galaxy"

Jannuzi, B.T., et al. 1996, ApJ, 470, p.Lll, "The Hubble Space Telescope Quasar Absorption Line Key Project: The Unusual Absorption-Line System in the Spectrum of PG2302+029-Ejected or Intervening?"

Jannuzi, B.T. 1997, ASP Conf. 114, ed. S.M. Viegas (ASP), p.91, "The HST Quasar Absorption Line Survey: A Census of Absorption Lines at Low Redshift"

C-7 Jannuzi, B.T. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (World Scientific), p.309, "The HST QuasarAbsorption Line Survey and the Relationship of Absorbers to Large Scale Structures"

Kaler, J.B., et al. 1996, PASP, 108, p.980, "Spectrophotometry of Planetary Nebulae. DX EDS Observations of Compact Nebulae"

Kaluzny, J. 1997, A&AS, 121, p.455, "CCDPhotometry of Distant OpenClusters. III. Berkeley 18"

Kaspi, S., et al. 1996, ApJ, 471, p.L75, "Measurement of the Broad-Line Region Size in Two Bright Quasars"

Kawara, K., et al. 1996, ApJ, 470, p.L85, "Infrared Spectroscopy of the Graviationally Lensed Quasar B1422+231: Mg II a2798 and Fe II Emission from the Broad-Line Gas at z = 3.62"

Keel, W.C. 1996, PASP, 108, p.917, "A Supergiant-Dominated Starburst in the Nucleus of NGC 4569"

Khare, P., et al. 1997, MNRAS, 285, p.167,"The Lyman Alpha Forest Towards B2 1225 + 317"

Kim, C, Joner, M.D. 1997, PASP, 109,p.951, "A Photometric Study of V798 Cygni"

Kormendy, J., et al. 1996, ApJ, 473, p.L91, "Hubble Space Telescope Spectroscopic Evidence for a 1x 109 M0 Black Hole in NGC 4594"

Kormendy, J., et al. 1997, ApJ, 482, p.L139, "Spectroscopic Evidence for a Supermassive Black Hole in NGC 4486B"

Kraft, R.P., et al. 1997, AJ, 113, p.279, "Proton Capture Chains in Globular Cluster Stars. II. Oxygen, Sodium, Magnesium, and Aluminum Abundances in M13 Giants Brighter Than the Horizontal Branch"

Lacy, C.H.S., et al. 1997,AJ, 113, p.1088, "The SpectroscopicOrbit of II Ceti"

Lacy, C.H.S. 1997, AJ, 113, p.1406, "Absolute Dimensions and Masses of AD Bootis"

Lacy, C.H.S. 1997, AJ, 113, p.2226, "Absolute Dimensions and Masses of SW CanisMajoris"

Lacy, C.H.S., et al. 1997, AJ, 114, p.1206, "Absolute Dimensions andMasses of IT Cassiopeiae"

Laor, A., et al. 1997, ASP Conf. 113, ed. B.M. Peterson (ASP), p.l 16, "The HST Spectrum of I Zw 1: Implications of the C III ^1176 Emission Line"

Lauer, T.R., et al. 1996, ApJ, 471, p.L79, "Hubble Space Telescope Observations of the Double Nucleus ofNGC4486B"

Lauer,T.R., et al. 1997, ASP Conf. 116,ed. M. Arnaboldi (ASP), p.l 13, "The Central Structure of Early Type Galaxies"

Layden, A.C, Sarajedini, A. 1997, ApJ, 486, p.L107, "The Globular Cluster M54 and the Star Formation History of the Sagittarius Dwarf Galaxy" Lehnert, M.D., Heckman, T.M. 1996,ApJ, 472, p.546, "The Nature of Starburst Galaxies"

Lopez-Cruz, O., et al. 1997, ApJ, 475, p.L97, "Are Luminous cD Halos Formed by the Disruption of Dwarf Galaxies?"

Malhotra, S., Rhoads, J.E., Turner, E.L. 1997, MNRAS, 288, p.138, "Through a Lens Darkly: Evidence for Dusty Gravitational Lenses"

Martin, C.L. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.579, "The Dynamic Interstellar Medium in Dwarf Galaxies: A Case Study oflZW 18"

Mason, B.D. 1996, AJ, 112, p.2260, "ICCD Speckle Observations of Binary Stars. XV. An Investigtation of Lunar Occultation Systems"

Mason, B.D. 1997, AJ, 114, p.808, "Binary Star Orbits from Speckle Interferometry. XI. Orbits of Twelve Lunar Occultation Systems"

Mason, C.G., et al. 1996, ApJ, 470, p.577, "Infrared Observations of Dust Formation and Coronal Emission in Nova Aquilae 1995"

Massey, P., et al. 1996, ApJ, 469, p.629, "The UV-Brightest Stars of M33 and Its Nucleus: Discovery, Photometry, and Optical Spectroscopy"

Massey, P. 1997, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M. Vreux (Universite de Liege), p.361, "Numbers and Distribution of Wolf-Rayet Stars in Local Group Galaxies; Clues to Massive Star Evolution"

Mathys,G., et al. 1997, A&AS, 123, p.353, "The Mean MagneticField Modulus of Ap Stars"

McCall, M.L., Buta, R.J. 1997, AJ, 113,p.981, "Discovery of a Second Companion of Dwingeloo 1"

McCarthy, P.J., Baum, S.A., Spinrad, H. 1996, ApJS, 106, p.281, "Emission-Line Properties of 3CR Radio Galaxies. II. Velocity Fields in the Extended Emission Lines"

McMillan, R.J., Ciardullo, R. 1996, ApJ, 473, p.707, "Constraining the Ages of SupernovaProgenitors. I. Supernovae and Spiral Arms"

McNamara, D.H., Powell, J.M., Joner, M.D. 1996, PASP, 108, p.1098, "The Physical Properties of the SX Phoenicis Star CY Aquarii"

Meech, K.J., et al. 1997, AJ, 113, p.844, "Observations of Structures in the Inner Coma of Chiron with the HST Planetary Camera"

Meyer, M.R., et al. 1996, Disks and Outflows Around Young Stars, ed. S. Beckwith (Springer), p.175, "The Stellar Populations of Deeply Embedded Young Clusters: Near-Infrared Spectral Classification"

Mikolajewska, J., Kenyon, S.J. 1996, AJ, 112, p.1659, "The Inscrutable Hot Component in the Symbiotic Binary Z Andromedae"

C-9 Moody, J.W., et al. 1997, AJ, 113, p.1022, "Discovery of a Faint Carbon Star at High Galactic Latitude"

Moran, E.C, Halpern, J.P., Helfand, D.J. 1996, ApJS, 106, p.341, "Classification of /#AS-Selected X- Ray Galaxies in the ROSATAll-Sky Survey"

Morris, P.W., et al. 1996, ApJ, 470, p.597, "Infrared Spectra of Massive Stars in Transition: WNL, Of, Of/WN, Be B[e], and Luminous Blue Variable Stars"

Morris, P. 1997, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M. Vreux (Universite de Liege), p.405, "Evolutionary Implications for "Transition" Stars from Ground-Based and ISO-SWS Spectra"

Morrison, H.L., et al. 1997, AJ, 113, p.2061, "Stellar Populations in Edge-On Galaxies from Deep CCD Surface Photometry. II. One-Dimensional Fits of NGC 891"

Mueller, B.E.A., Ferrin, I. 1996, Icarus, 123, p.463, "Change in the Rotational Period of Comet P/Tempel 2 between the 1988 and 1994 Apparitions"

Mukherjee, J., Peters, G.J., Wilson, R.E. 1996,MNRAS, 283, p.613, "Rotation of Algol Binaries - a Line Profile Model Applied to Observations"

Mulchaey, J.S., Regan, M.W., Kundu, A. 1997, ApJS, 110, p.299, "The Fueling of Nuclear Activity. I. A Near-Infrared Imaging Survey of Seyfert and Normal Galaxies"

Mulchaey, J.S., Regan, M.W. 1997, ApJ, 481, p.L135, "The Fueling of Nuclear Activity: The Bar Properties of Seyfert and Normal Galaxies"

Munn, J.A., et al. 1997, ApJS, 109, p.45, "The Kitt Peak Galaxy Redshift Survey with Multicolor Photometry: Basic Data"

Noble, J.C, et al. 1997, AJ, 113, p.1995, "The Time Scales of the Optical Variability of Blazars. IV. 01 090.4"

Noriega-Crespo, A., et al. 1997, ApJ, 486, p.L55, "The Proper Motions of the Warm Molecular Hydrogen Gas in Herbig-Haro 1"

O'Neal, D., Neff, J.E. 1997, AJ, 113, p.l 129, "OH 1.563 urn Absorption from Starspots on Active Stars"

Orosz, J.A., Wade, R.A., Harlow, J.J.B. 1997, AJ, 114, p.317, "Variable Radial Velocities Among Composite-Spectrum Binaries in the PG Catalog"

Osmer, P.S., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (World Scientific), p.405, "Spectroscopic Observations of Quasar Candidates from a Deep Multicolor Survey"

Papaderos, P., et al. 1996, A&AS, 120, p.207, "Optical Structure and Star Formation in Blue Compact Dwarf Galaxies. I. Observations and Profile Decomposition"

C-10 Parker, J.W., et al. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p. 537, "Starburst Anatomy: Resolved and Composite Properties of Giant HII Regions in the Pinwheel Galaxy (Messier 33)"

Patterson, R.J., Thuan, T.X. 1996, ApJS, 107, p.103, "Surface Photometry of Low Surface Brightness Dwarf Irregular Galaxies"

Perrett, K.M., et al. 1997, AJ, 113, p.895, "The Globular ClusterSystems of NGC 1400 and NGC 1407"

Pesce, J.E., et al. 1997,ApJ, 486, p.770, "Multiwavelength Monitoring of the BL Lacertae Object PKS 2155-304 in 1994 May. I. The Ground-Based Campaign"

Phelps, R.L., Lada, E.A. 1997, ApJ, 477, p.176, "Spatial Distribution of Embedded Clusters in the Rosette Molecular Cloud: Implications for Cluster Formation"

Phelps, R.L. 1997, AJ, 114, p.826, "Berkeley 17: The OldestOpenCluster?"

Pilachowski, C, et al. 1997, AJ, 114, p.819, "Carbon Isotope Ratios from the First Overtone CO Bands in Metal-Poor Giants"

Pilachowski, C.A. 1996,CCD Astronomy, 3, no.3, p.50, "Save Those Bits"

Polyansky, O.L., et al. 1997, Science, 277, p.346, "Water on the Sun: Line Assignments Based on Variational Calculations"

Prestwich, A.H., et al. 1997, ApJ, 477, p.144, "A Search for the Cooling Flow Accretion Population: Optical and Near-Infrared Imaging of NGC 1275"

Provencal, J.L., et al. 1997, ApJ, 480, p.383, "Whole Earth Telescope Observations of the Helium Interacting Binary PG 1346+082 (CR Bootis)"

Pustilnik, S., et al. 1996, The Interplay Between MassiveStar Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.585, "The Chemical Evolutionof Blue Compact Galaxies: Oxygen Abundance vs Gas Content"

Puxley, P., Boroson, T. 1997, SPIE, 2871, p.744, "Observing with a 21st Centry Ground-Based Telescope - or How to Do Unique Science with the Gemini Telescopes"

Rachford, B.L. 1997, ApJ, 486, p.994, "Chromospheric Activity in Dwarf and Evolved Late A- and Early F-Type Stars"

Ram, R.S., Bernath, P.F., Wallace, L. 1996, ApJS, 107, p.443, "Near-Infrared Spectroscopy of TiO: Laboratory Measurements and Identification in Sunspots"

Rand, R.J. 1997, ApJ, 474, p.129, "A Very Deep Spectrum of the Diffuse Ionized Gas in NGC 891"

Regan, M.W., Elmegreen, D.M 1997, AJ, 114, p.965, "AT-Band Observations of Barred Spiral Galaxies"

Reynoso, E.M., et al. 1997, A&A, 317, p.203, "Neutral Hydrogen Compact Absorption Features in Cassiopeia A"

C-ll Rhoads, J.E. 1997, ApJ, 487, p.Ll, "How To Tell a Jet from a Balloon: A Proposed Test for Beaming in Gamma-Ray Bursts"

Rubin, V.C, Kenney, J.D.P., Young, J.S. 1997, AJ, 113, p.1250, "Rapidly Rotating Circumnuclear Gas Disks in Virgo Disk Galaxies"

Ryden, B.S., et al. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.283, "Dwarf Elliptical and Dwarf SO Galaxies in the Virgo Cluster"

Sakai, S., et al. 1997, ApJ, 478, p.49, "Detection of the Tip of the Red Giant Branch in NGC 3379 (Ml05) in the Leo I Group Using the Hubble Space Telescope"

Samec, R.G., et al. 1997, AJ, 113, p.800, "UBVRI CCD Observations and Analyses for the Near-Contact Binary, LP Cephei"

Sarajedini, A., Geisler, D. 1996, AJ, 112, p.2013, "Deep Photometry of the Outer Halo Globular Cluster in Pyxis"

Sarajedini, A. 1997, AJ, 113, p.682, "Palomar 14: A Young Globular Cluster in the Outer Galactic Halo"

Sarajedini, A., Layden, A. 1997, AJ, 113, p.264, "Reddenings, Metallicities, and Possible Abundance Anomalies in Young Globular Clusters"

Sarajedini, V., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (World Scientific), p.411, "Faint AGN/Starburst Nuclei in MDS Galaxies"

Sarajedini, V.L., et al. 1996, ApJ, 471, p.L15, "Compact Nuclei in Moderately Redshifted Galaxies"

Schade, D., Barrientos, L.F., Lopez-Cruz, O. 1997, ApJ, 477, p.L17, "Evolution of Cluster Ellipticals at 0.2 < z < 1.2 from Hubble Space Telescope Imaging"

Schechter, P.L., et al. 1997, ApJ, 475, p.L85, "The Quadruple Gravitational Lens PG 1115+080: Time Delays and Models"

Scodeggio, M., Giovanelli, R., Haynes, M.P. 1997, AJ, 113, p.101, "The Relative Distance Between the Clusters of Galaxies A2634 and Coma"

Seeker, J., Harris, W.E. 1996, ApJ, 469, p.623, "The Early-Type Dwarf-to-Giant Ratio and Substructure in the Coma Cluster"

Seeker, J. 1996, ApJ, 469, p.L81, "A Constraint on the Formation of Dwarf Elliptical Galaxies in the Dense Coma Cluster Core"

Silva, D.R., Bothun, G.D. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.208, "Elliptical Galaxies: Young or Old?"

Smalley, B., et al. 1997, MNRAS, 284, p.457, "The Chemical Composition and Binarity of P Crateris"

C-12 Sogawa, H., et al. 1997, AJ, 113, p. 1057, "Infrared Polarimetry of Star-Forming Regions: The Serpens Cloud Core"

Solanki, S.K.,et al. 1996, A&A, 315,p.303, "The Beatof the SolarChromsophere's Cold Heart"

Spinrad, H., et al. 1997, ApJ, 484, p.581, "LBDS 53W091: An Old, Red Galaxy at z = 1.552"

Stauffer, J.R., et al. 1997, ApJ, 475, p.604, "Rotational Velocities and Chromospheric Activity of M Dwarfs in the Hyades"

Steidel, C.C., et al. 1997, ApJ, 480, p.568, "Quasar Absorbing Galaxies at z< 1: Deep Imaging and Spectroscopy in the Field of 3C 336"

Stern, D., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (World Scientific), p.413, "Radio Galaxies from the 5 GHZ MG Catalog"

Stetson, P.B. 1997, Baltic Astronomy, 6, p.3, "Some InterestingColor-MagnitudeDiagrams"

Strassmeier, K.G. 1996, A&A, 314, p.558, "Doppler Imaging of Stellar Surface Structure. I. The Rapidly -Rotating RS CVn Binary UZ Librae"

Strassmeier, K.G. 1997, A&A, 319, p.535, "Doppler Imaging of Stellar Surface Structure, m. The X-Ray Source HD 116544 = IN Virginis"

Strassmeier, K.G., Hubl, B., Rice, J.B. 1997, A&A, 322, p.511, "Doppler Imaging of Stellar Surface Structure. IV. The Rapidly-Rotating G5III-IV Star HD 112313 = IN Comae"

Sugitani, K., Tamura, M, Ogura, K. 1996, Proc. of the Third East-Asian Meeting in Astronomy: Ground- Based Astronomy in Asia, ed. N. Kaifu (National Astronomical Observatory, Japan), p.183, "Small-Scale Sequential Star Formation in Bright-Rimmed Clouds"

Tamura, M., et al. 1996, AJ, 112, p.2076, "Interferometric Observations of Outflows from Low-Mass Protostars in Taurus"

Taniguchi, Y., et al. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (World Scientific), p.415, "MGII & Fell Emission of a High-z Quasar B1422+231"

Thaller, M., Gies, D. 1997, RevMexAA, Serie de Conferencias 5, p.l 17, "Ha Detection of Colliding Winds in O-Type Binaries"

Titus, T.N., Spillar, E.J., Johnson, P. 1997, AJ, 114, p.958, "Population Analysis of Faint Galaxies with Mixture Modeling"

Tolstoy, E. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.67, "The Colour-Magnitude Diagrams of Three Nearby Dwarf Irregular Galaxies"

Tomaney, A.B., Crotts, A.P.S. 1996 AJ, 112, p.2872, "Expanding the Realm of Microlensing Surveys with Difference Image Photometry"

C-13 Tonry, J.L., et al. 1997, ApJ, 475, p.399, "The SBF Survey of Galaxy Distances. I. Sample Selection, Photometric Calibration, and the Hubble Constant"

Tran, H.D., et al. 1997, PASP, 109, p.489, "Probing the Geometry and Circumstellar Environment of SN 1993JinM81"

Tripp, T.m., Lu, L., Savage, B.D. 1997, APJS, 112, p.l, "High Signal-to-Noise Echelle Spectroscopy of Quasar Absorption Line Systems with Metals in the Direction of HS 1700+6416"

Tsay, W.S., Chen, A., Chen, R. 1997, Baltic Astronomy, 6, p.141, "Snapshots of CCD Fields in a Study of the Verticle Distribution of Stars"

Turner, D.G., Mandushev, G.I., Welch, G.A. 1997, AJ, 113, p.2104, "Galactic Clusters with Associated Cepheid Variables. V. The Case of SU Cygni"

Tweedy, R.W., Kwitter, K.B. 1996, ApJS, 107, p.255, "An Atlas of Ancient Planetary Nebulae and Their Interaction with the Interstellar Medium"

Ulmer, MP., et al. 1996, AJ, 112, p.2517, "Low Surface Brightness Galaxies in the Core of the Coma Cluster"

Van Zee, L., et al. 1996, The Interplay Between Massive Star Formation, the ISM and Galaxy Evolution, ed. D. Kunth (Editions Frontieres), p.563, "HI and Optical Studies of UGCA 20"

Vreux, J.-M., et al. 1996, Wolf-Rayet Stars in the Framework of Stellar Evolution, ed. J.M. Vreux (Universite de Liege), p.337, "Line-Profile Variability and Mass-Transfer in the Early Type Binary BD+40°4220"

Wakker, B., et al. 1996, ApJ, 473, p.834, "The Distance to Two Neutral Hydrogen Clouds: The High- Velocity Complex A and the Low-Latitude Intermediate-Velocity Cloud"

Wallace, L., Hinkle, K. 1996, ApJS, 107, p.312, "High-Resolution Spectra of Ordinary Cool Stars in the K-Band"

Wallace, L., Hinkle, K. 1997, APJS, 111, p.445, "Medium-Resolution Spectra of Normal Stars in the £-Band"

Walter, F., et al. 1997, AJ, 113, p.2031, "A Dynamical Analysis of the H B Galaxy B Zwicky 33 and Its Low Surface Brightness Companion"

Walterbos, R.A.M., Braun, R. 1996, ASP Conf. 106, ed. E.D. Skillman (ASP), p.l, "The Cool and Warm Phases of the Interstellar Medium in Spiral Galaxies"

Wang, J., et al. 1997, ApJ, 474, p.659, "An X-Ray and Optical Investigation of the Infrared-Luminous Galaxy Merger Markarian 266"

Wang, Q.D., Connolly, A.J., Brunner, R.J. 1997, ApJ, 487, p.L13, "A2125 and Its Environs: Evidence for an X-Ray-Emitting Hierarchical Superstructure"

C-14 Watson, J.K., Meyer, D.M. 1996, ApJ, 473, p.L127, "Observations of Ubiquitous Small-Scale Structure in the Diffuse Interstellar Medium"

Weis, E.W. 1996, AJ, 112, p.2300, "Photometry ofStars with Large Proper Motion" Welty, D.E., Morton, D.C, Hobbs, L.M. 1996, ApJS, 106, p.533, "A High-Resolution Survey of Interstellar Ca II Absorption"

Whitney, B.A., Kenyon, S.J., Gomez, M. 1997, ApJ, 485, p.703, "Near-Infrared Imaging Polarimetry of EmbeddedYoung Stars in the Taurus-Auriga MolecularCloud"

Willick, J.A., et al. 1997, ApJS, 109, p.333, "Homogeneous Velocity-Distance Data for Peculiar Velocity Analysis, ffl. The Mark III Catalog of GalaxyPeculiarVelocities"

Wise, M.W., Silva, D.R. 1997, ASP Conf. 116, ed. M. Arnaboldi (ASP), p.364, "Dust Populations in Elliptical Galaxy Cores"

Wolff, S.C, Simon, T. 1997, PASP, 109, p.759, "The Angular Momentum of Main-Sequence Stars and its Relation to Stellar Activity"

Worek, T.F. 1996, PASP, 108, p.962, "The Rossiter-McLaughlin Rotation Effect Observed for Al Draconis and V505 Sagittarii"

Wu, K.L., Faber, S.M., Lauer, T.R. 1997, The Hubble Space Telescope and the High Redshift Universe, ed. N.R. Tanvir (World Scientific), p.179, "Tests of Morphological Peculiarity Indices for Distant and Local Galaxies"

Yanny, B., Jannuzi, B.T., Impey, C 1997, ApJ, 484, p.L113, "Hubble Space Telescope Imaging of the BL Lacertae Object OJ 287"

Young, J.S., et al. 1996, AJ, 112, p.1903, "The Global Rate and Efficiency of Star Formation in Spiral Galaxies as a Function of Morphology and Environment"

Yu, K.C., Bally, J., Devine, D. 1997,ApJ, 485, p.L45, "Shock-Excited H2 Flows in OMC-2 and OMC-3"

Zacharias, N. 1996, PASP, 108, p.1135, "Measuring the Atmospheric Influence on Differential Astrometry: A Simple Method Applied to Wide-Field CCD Frames"

C-15

APPENDIX D

National Solar Observatory October 1996 through September 1997 Publications List

Abrams, D., Kumar, P. 1996, ApJ,472, p. 882, "Asymmetries of Solarp-Mode Line Profiles"

Alexander, D., et al., 1996, SolarWind Eight Workshop, eds. D. Winterhalter, J.T. Gosling, S.R. Habbal, et al. (AIP), p. 80, "The Large Scale EruptiveEvent of April 14 1994"

Altrock, R.C. 1997, Sol. Phys., 170, p. 411, "An 'Extended Solar Cycle' as Observedin Fe XIV"

Altrock, R.C, Henry, T.W. 1997, Solar-Geophysical Data, Part 1 (Prompt Reports), no. 619-630, ed. H.E. Coffey, "Sacramento Peak Coronal Line Synoptic Maps, 1996"

Altrock, R.C, Henry, T.W. 1997, Solar-Geophysical Data, Part 1 (Prompt Reports), no. 619-630, ed. H.E. Coffey, "Coronal Line Emission (Sacramento Peak), 1996"

Altrock, R.C, et al. 1997, Contributions of the Astronomical Observatory Skalnate Pleso, 27, p. 25, "Coronal Index of Solar Activity for 1996"

Aschwanden, M.J., Benz, A.O. 1997, ApJ, 480, p. 825, "Electron Densities in Solar Flare Loops, Chromospheric Evaporation Upflows, and Acceleration Sites"

Balasubramaniam, K.S., Keil, S.L., Tomczyk, S. 1997, ApJ, 482, p. 1065, "Stokes Profile Asymmetries in Solar Active Regions"

Bastian, T.S., Dulk, G.A., Leblanc, Y. 1996, ApJ, 473, p. 539, "High-Resolution Microwave Observations of the Quiet Solar Chromosphere"

Beck, J.G., Hathaway, D.H., Simon, G.W. 1996, 16th NSO/Sac Peak Workshop, eds. K.S. Balasubramaniam, S.L. Keil, R.N. Smartt (ASP), p. 196, "Observing Large-Scale Solar Surface Flows with GONG: Investigation of a Key Element in Solar Activity Buildup"

Beckers, J.M. 1996, Sol. Phys., 169, p. 431, "Comments on the Next Generation of Ground-Based Solar Telescopes"

Beckers, J.M. et al. 1997, ASP Conference 118, eds. B. Schmieder, J.C. del Toro Iniesta and M. Vazquez (ASP), p. 340, "Progress Report on a Feasibility Study for a Large Optical/Infrared Solar Telescope (CLEAR)"

Christou, J.C, Hege, E.K., Jefferies, S.M. 1997, Adaptive Optics Workshop, eds. R. Tyson and R. Fugate, (OSA Technical Digest Series 13) p. 130 "Post-Processing of Adaptive Optics Images: Blind Deconvolution Analysis"

D'Silva, S. 1996, ApJ, 469, p. 964, "Theoretical Foundations of Time-Distance Helioseismology"

D'Silva, S., et al. 1996, ApJ, 471, p. 1030, "Helioseismic Tomography"

D-l Dara, H.C, et al. 1997, A&A, 322, p. 653, "Magnetic and Velocity Field in Association with Ellerman Bombs"

Dere, K.P. 1996, ApJ, 472, p. 864, "The Rate of Magnetic Reconnection Observed in the Solar Atmosphere"

Devi, V.M., et al. 1996, 50th Symposium on Molecular Spectroscopy, ed. T. Miller, p. 105, "C02 Bands inthe 3350-3700 cm"1 Region: Ro-Vibrational Constants and Absolute Intensities"

Erdwurm, W., Pintar, J.A. 1996, Astronomical Data Analysis Software and Systems V, eds. G.H. Jacoby and J. Barnes (ASP), p. 513, "Storing and Distributing GONG Data"

Falconer, D.A., Davila, J.M., Thomas, R.J. 1997, ApJ, 482, p. 1050, "Relative Elemental Abundances of the Quiet Solar Corona as Determined by SERTS"

Falconer, D.A., et al. 1997, ApJ, 482, p. 519, "Neutral-Line Magnetic Shear and Enhanced Coronal Heating in Solar Active Regions"

Gaizauskas, V. 1996, Sol. Phys., 169, p. 357, "Magnetic Reconnection as a Driver of Chromospheric Surges"

Gaizauskas, V., et al. 1997, ApJ, 479, p. 448, "Formation of a Solar Filament Channel"

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