150 Georgia State University Department of Physics and Astronomy Center for High Angular Resolution Astronomy Atlanta, Georgia, 30303-3083 This report covers the period 1 July 1993 through 30 June Laura R. Penny, Lewis Roberts, Jon Sowers, Michelle L. 1995. Thaller and Nils H. Turner. The following students joined the graduate program in this period: Liu Ning, Reed Riddle, and Xiong Ying. Fu received his Ph.D. and is now on the faculty 1. PERSONNEL at National Taiwan Normal University. Frazin joined the Astronomy faculty in the Department of Physics and As- Ph.D. program in Astronomy at the University of Illinois tronomy were Ingemar K. Furenlid, Douglas R. Gies, Donald after receiving his M.S. degree. Upon the award of his Ph.D., H. Gudehus, Harold A. McAlister ~CHARA Director!,H. Mangalam accepted a post-doctoral associateship at the Uni- Richard Miller, Paul J. Wiita, and David W. Wingert. versity of Illinois. Riddle spent three months as a summer Stephen Ridgway has a half-time appointment as a CHARA research assistant at the National Solar Observatory. visiting scientist along with his primary appointment as As- Long–term visitors included N. Carleton ~Harvard- tronomer at NOAO. Staff scientists and post-doctoral fellows Smithsonian CfA!, S.K. Chakrabarti ~Tata Inst. Fundamental within CHARA were William G. Bagnuolo, Jr., Theo ten Research!, F. Fekel ~Tennessee State U.!, Gopal-Krishna Brummelaar; William I. Hartkopf, and Brian D. Mason; John ~NCRA!, V. Krishan ~IIA!, D. Saikia ~NCRA!, and W.-S. W. Wilson was the Coordinator of Laboratories, Alexandra Tsay ~National Central University, Taiwan!. The University Land was the CHARA business manager, and Molly Raby Center in Georgia Visiting Scholars for 1994 and 1995 were was Astronomy Secretary. Margaret Burbidge ~UCSD! and Shri Kulkarni ~Caltech!, re- Ingemar Furenlid passed away on 11 February 1994 while spectively, and a College of Arts and Sciences Distinguished on sabbatical at the Harvard–Smithsonian Center for Astro- Lecturer for 1994 was Owen Gingerich ~Harvard! whose ad- physics ~cf. BAAS vol. 26, p. 1603, 1994!. Gies was pro- dress was presented in memory of Ingemar Furenlid. moted to Associate Professor with tenure in September 1994, and was given the 1993 College of Arts and Sciences Out- standing Junior Faculty Award. Gies acted as Technical Edi- 2. HARD LABOR CREEK OBSERVATORY tor for the paper and electronic versions of the Be Star News- Hard Labor Creek Observatory is operated by Georgia letter for issues 28–30 ~URL http://www.chara.gsu.edu/ State University and houses the 309 Beck telescope of Agnes BeNews/intro.html!. Gudehus, previously of Oklahoma State Scott College, the 169 KPNO telescope which was awarded University, was appointed as Visiting Assistant Professor in to Georgia State University by the National Science Founda- September 1993. Mason remained as a post-doctoral research tion through a grant to CHARA, and the Multi–Telescope associate in speckle interferometry after receiving his Ph.D. Telescope ~discussed below!. The observatory hosted 16 in December 1994 from GSU. McAlister served as Chair of public nights during 1993–95 as part of an agreement with the Kitt Peak Users’ Committee through December 1993, as the Georgia Department of Natural Resources which allowed Chair of the AAS Warner/Pierce Prizes Committee for 1994 GSU to locate the observatory on the grounds of Hard Labor and continues as a member of the JPL New Millenium Sci- Creek State Park. Well over 1000 visitors attended these pub- ence Working Group. Miller returned from a two year leave lic nights. In addition, the observatory has hosted a number of absence as a Senior Program Scientist with the UV/Visible of amateur astronomy gatherings sponsored by CHARA. Branch of the Astrophysics Division at NASA/HQ in Wash- The refurbishment and upgrading of the Beck Telescope ington, D.C. in September 1994; he received NASA Group continues. A number of major improvements remain to be Achievement Awards and DARA and NASA Recognitions completed, so it is not certain when this telescope will be for Individual Merit for the ORFEUS-Astrospas Shuttle Mis- brought into routine operation. A Research Corporation grant sion and for the 1st Hubble Servicing Mission. Ridgway provided for our purchase of a Photometrics, Ltd. CCD cam- joined the CHARA staff as Technical Manager of the era and associated electronics, including a Macintosh micro- CHARA Array project in December 1994. Wiita was pro- computer for its control, which we have installed at the 169 moted to Professor in September 1993 and succeeded McAl- telescope at HLCO. ister as Director of Graduate Studies in Astronomy in Sep- Bagnuolo, Barry, Furenlid, and Gies designed and built an tember 1994; he spent two months as a Visiting Professor at inexpensive ~about $80 K! 1-meter class spectroscopic tele- the Indian Institute of Astrophysics ~IIA! and the National scope and a fiber-fed spectrograph, that achieved ‘first stellar Centre for Radio Astrophysics ~NCRA! in India. Mark A. spectra’ in October, 1994. This project was funded by grants Shure, of the University of Hawaii, accepted an offer of an from NSF and Georgia State, with donations in materials and Associate Professorship, effective September 1995. labor from Georgia Tech and from volunteer Harry Gelblat, a Our continuing graduate students during this period were local contractor. This novel instrument consists of nine Donald J. Barry, Richard A. Frazin, Hsieh-Hai Fu, Kenneth 33.3-cm mirrors on a single mount, each of which feeds an Guyton, Michael E. Hahula, Jagbir S. Hooda, Minhwan f/11 beam to a 100-micron optical fiber at prime focus via a Jang, Arun V. Mangalam, Brian D. Mason, John C. Noble, Barlow lens. A control system maintains the pointing of each GEORGIA STATE UNIVERSITY 151 individual mirror. The spectrograph, implemented by Barry, served. In order to obtain measurements of very high accu- is based on the Ebert-Fastie design of Furenlid and Cardona racy, a double-slit mask has been constructed for the Hooker but includes ‘‘Newtonian’’ folding mirrors and a spherical telescope. Work on the series of speckle measurements of camera/collimator to yield an isotropic point spread function binary stars resulted in two measurement papers ~Bright across the field of view for improved radial velocity results. Stars and Kitt Peak measurements! being published in this The dedicated availability of the one-meter collecting area period, and six others in process ~White Dwarfs, Lowell Ob- and the stability of the fiber-fed bench-mounted spectrograph servatory measurements, Cerro Tololo, O stars, Occultation make the Multi–Telescope Telescope ~MTT! attractive for a stars, and Mt. Wilson measurements!. The primary partici- number of interesting projects. pants in this effort were Hartkopf, Mason and McAlister. The MTT was inaugurated with an international week- Mason, Gies, Hartkopf, McAlister, and colleagues are long observing campaign of the Be star l Eridani coordi- close to the completion of a speckle survey of over 200 Ga- nated by Ryuko Hirata in November, 1994. Since that time it lactic O stars with V,8 to determine the frequency of bina- has been used in an extensive phase-diverse observing cam- ries with angular separations of 0%03–19 ~complete except paign of Plaskett’s star which has produced, via tomographic for 44 southern objects!. Some 13 new O-binaries have been reconstruction, separated spectra of the component stars, and discovered so far. The scientific goals are: ~1! find candidates permitted detection of abundance anomalies and improved for mass determination, ~2! measure the binary frequency to physical elements for this interesting system. A number of better understand the influence of binaries on O star dynam- other Be stars have been monitored for line profile variability ics, and ~3! aid interpretation of composite spectrum objects. ~LPV! as part of a long-term study by Gies. Hartkopf and Combined speckle/spectroscopic orbits offer the potential for Gies have begun a radial-velocity program to complement direct measurement of mass. First results from this survey ongoing CHARA speckle interferometric work, which has have already bridged the period gap between astrometric and already resulted in the detection of a third spectral compo- spectroscopic binaries for 15 Mon producing the first com- nent in the 55 UMa system. Bagnuolo and Barry continue an bined spectroscopic/astrometric O-star orbit. New spectro- intensive program to gather separated spectra of binary sys- scopic and astrometric ~HST/FGS! observations are planned tems via the application of tomographic techniques to re- as this system progresses to periastron in 1998. The derived solve blends through phase-diverse observations. Barry has binary frequency itself is an important result of the survey extended this program with echelle spectroscopy on the 829 since binaries can affect the dynamical evolution of clusters at UT Austin’s McDonald Observatory, and the MTT will be through gravitational encounters. Ejected stars should be de- used to gather information on narrower passbands and to pleted in binaries, and indeed all the new binaries are mem- complete phase coverage on the numerous systems which do bers of clusters and associations. Finally, speckle observa- not present convenient phases during prescheduled block ob- tions will aid significantly in identification and interpretation serving on major telescopes. of composite spectrum objects. Both graduate and undergraduate students have been An additional goal of these observing runs was the survey trained in spectroscopic observation using this facility, and of occultation binaries. This program also nears completion we expect it to become even more heavily utilized during the and has resulted in the first resolution of two dozen binary coming year. Bagnuolo is supervising an upgrade to several systems and new orbits for seventeen systems. Analysis of major systems scheduled during the coming year, which will these occultation systems was the subject of the dissertation improve tracking stability through replacement of the shaft of Mason.