The Minor Planet Bulletin and How the Situation Has Gone from One Mt Tarana Observatory of Trying to Fill Pages to One of Fitting Everything In

BULLETIN OF THE MINOR PLANETS SECTION OF THE BULLETIN ASSOCIATION OF LUNAR AND PLANETARY OBSERVERS

VOLUME 33, NUMBER 2, A.D. 2006 APRIL-JUNE 29.

PHOTOMETRY OF ASTEROIDS 133 CYRENE, adjusted up or down to line up with the V-band data). The near- 454 MATHESIS, 477 ITALIA, AND 2264 SABRINA perfect overlay of V- and R-band data show no evidence of color change as the asteroid rotates. This result replicates the lightcurve Robert K. Buchheim period reported by Harris et al. (1984), and matches the period and Altimira Observatory lightcurve shape reported by Behrend (2005) at his website. 18 Altimira, Coto de Caza, CA 92679 USA [email protected]

(Received: 4 November Revised: 21 November)

Photometric studies of asteroids 133 Cyrene, 454 Mathesis, 477 Italia and 2264 Sabrina are reported. The lightcurve period for Cyrene of 12.707±0.015 h (with amplitude 0.22 mag) confirms prior studies. The lightcurve period of 8.37784±0.00003 h (amplitude 0.32 mag) for Mathesis differs from previous studies. For Italia, color indices (B-V)=0.87±0.07, (V-R)=0.48±0.05, and phase curve parameters H=10.4, G=0.15 have been determined. For Sabrina, this study provides the first reported lightcurve period 43.41±0.02 h, with 0.30 mag amplitude.

Altimira Observatory, located in southern California, is equipped with a 0.28-m Schmidt-Cassegrain telescope (Celestron NexStar- 454 Mathesis. DiMartino et al. (1994) reported a rotation period of 11 operating at F/6.3), and CCD imager (ST-8XE NABG, with 7.075 h with amplitude 0.28 mag for this asteroid, based on two Johnson-Cousins filters). Details of the equipment and instrument nights of observation at the 1991 opposition. Their lightcurve was characterization are available at the author’s website incomplete (it showed roughly half of the rotation, with good (http://www.geocities.com/oca_bob). Differential photometry, coverage of only a single maximum). Cieza et al. (1998) reported usually in more than one filter (e.g. BB-VV-RR-...) was done a period of 7.745 h. A total of 8 nights from Sep. 24 to Dec. 4, throughout most nights. On nights that were clear and stable, 2004 UT, were devoted to this object. The R-band lightcurve from standard stars were imaged to calibrate the photometry. this study indicates a rotation period of 8.37784±0.00003 h with amplitude 0.32 mag. This data set provides nearly complete All of these objects were selected for study because the current coverage of the shape of the lightcurve. The lightcurve changes apparition presented the opportunity to observe them at very small noticeably at large waning solar phase angle. Note the data near solar phase angle for determination of their phase curve rotational phase 0.8. The data for Dec. 4, 2004, at solar phase characteristics. Unfortunately, these projects provided angle 14.1 degrees (waning), are significantly different from the circumstantial evidence for a suspected correlation between orbital other nights [which range from 1.3 to 12.2 deg (waxing)]. This parameters and meteorology, in which the presence of an asteroid effect appears to be real, since it is replicated on V-band data (not at near-zero solar phase angle seems to cause cloudy weather in shown). Measured color indices for 454 Mathesis were: southern California. As a result, only medium-quality phase (B-V)=0.63±0.05 and (V-R)=0.35±0.05. The (B-V) measurement curves were determined. is consistent with the value (B-V)=0.662±0.055 reported at the Small Bodies Node. 133 Cyrene. V- and R-band lightcurves were developed from four consecutive nights of data, Feb. 2–5, 2005 UT. The lightcurve The target fields were re-measured in late 2005 to determine the presented is wrapped to the best-fit period of 12.707±0.015 h. The brightness and color indices of comparison stars. Two possible peak-to-peak amplitude is 0.22 mag. For all nights, both the solutions to the phase function were examined. Using the V-band and R-band data are shown (with each night’s R-band data “default” value of G=0.15, the best-fit absolute magnitude is Minor Planet Bulletin 33 (2006) Available on line http://www.minorplanetobserver.com/mpb/default.htm 30

H=9.39 (RMS error: 0.061 mag). The best fit with both parameters free is H=9.48, G=0.32. The latter is a slightly better overall fit (RMS error: 0.044 mag). These are both slightly fainter than the value H=9.2 reported by the Small Bodies Node.

References

Behrend, et al. (2005). Results and lightcurve are reported at website: http://obswww.unige.ch/~behrend/page2cou.html

Bowell, E. et al. (1989), “Application of Photometric Models to 477 Italia. Data were gathered on 6 nights, from March 16 to April Asteroids”, in Binzel, R. P. et al. (ed) Asteroids II, University of 6, 2005 UT. My data alone were insufficient to establish the Arizona Press, Tucson, 1989. lightcurve period. However, Behrend (2005) combined my data with that from Roy and Kitazato (also during the 2005 apparition), Cieza, L.A., Ciliberti, L.N., Iserte, J.A. (1998) “Determination of to establish a provisional value of P≈19.4189 h and an amplitude Rotation Periods of Asteroids Using Differential CCD ≈0.2 mag. That value and the resulting lightcurve shape were used photometry”, IAPPP Communication 74, P 12 ff, December, 1998. for phase curve analysis. Examination of my lightcurve data in different colors each night showed that the color index is constant DiMartino, M., Blanco, C., Riccioli, D., and DeSanctis, G. (1994). during a rotation cycle. Measured color indices were “Lightcurves and Rotational Periods of Nine Main Belt (B-V)=0.87±0.07 and (V-R)=0.48±0.05. The (B-V) result agrees Asteroids”. Icarus 107, 269-274. well with the value reported by the Small Bodies Node [(B-V)=0.884±0.031]. Phase curve analysis found a best fit of Harris, A. W., Carlsson M., Young J. W., and Lagerkvist C. I. H=10.4, G=0.15 when using the parameters of the IAU-accepted (1984). “The lightcurve and phase relation of the asteroid 133 model (Bowell 1989). This value of absolute magnitude is Cyrene”. Icarus 58, 377-382 somewhat different from the value reported by the Small Bodies Node (H=10.25 with G=0.15 assumed). I have no explanation for Small Bodies Node at: http://pdssbn.astro.umd.edu/ this discrepancy; it may simply represent the different viewing orientation of the asteroid between apparitions. Acknowledgements

(2264) Sabrina. This object was observed on eleven nights from Asteroid distance and solar phase angle were determined using Aug. 27–Sep. 30, 2005. No previous lightcurve has been reported Chris Marriott’s SkyMapPro. Lightcurves and standard-magnitude for this asteroid. My data provide a subjectively good fit when reductions were done with Brian Warner’s MPO Canopus- wrapped to P=43.41±0.02 h, with amplitude 0.30 mag. This period PhotoRed program. seems to be well-anchored by the three nights that all found the sharp minimum centered at rotational phase 0.75. A search of other possible periods from 6 h to 60 h, considering both subjective “goodness” and RMS error of the Fourier fit, did not find any other plausible periods. The lightcurve presented is based on R-band data. On all of these nights, V-band data were also CALL FOR OBSERVATIONS gathered, but they have a lower signal-to-noise ratio. There was no detectable change (±0.05 mag) in color index during the asteroid’s Frederick Pilcher rotation. Calibrated colors and standard magnitudes were gathered Illinois College on four nights with solar phase angle ranging from 2.8 to 7.5 deg. Jacksonville, IL 62650 USA The color indices were measured to be (B-V)=0.75±0.05 and (V-R)=0.34±0.05. The data from this study yield an incomplete Observers who have made visual, photographic, or CCD phase curve, which can be reasonably fit using the “default” slope measurements of positions of minor planets in calendar 2005 are parameter of G= 0.15, and absolute V-magnitude H=10.9. encouraged to report them to this author on or before April 1, 2006. This will be the deadline for receipt of reports which can be included in the “General Report of Position Observations for 2005,” to be published in MPB Vol. 33, No. 3.

Minor Planet Bulletin 33 (2006) 31

LIGHTCURVES OF ASTEROIDS 141 LUMEN, comparison star variation by manually shifting individual night’s 259 ALATHEIA, 363 PADUA, 455 BRUCHSALIA, magnitude scales to obtain a best fit. 514 ARMIDA, 524 FIDELIO, AND 1139 ATAMI The results are summarized in the table below. Columns 1 and 2 Robert A. Koff show the asteroid number and name. Column 3 shows the dates of Antelope Hills Observatory the first and last observations, while column 4 shows the number 980 Antelope Drive West of actual observing sessions. Column 5 shows the range of phase Bennett, CO 80102 angles from the first and last observations. When three numbers [email protected] are shown, the middle number is a minimum phase angle through which the object passed during the interval. Columns 6 and 7 (Received: 30 December) show the ranges for the phase angle bisector longitude and latitude respectively. The four rightmost columns give the period, period error, amplitude and amplitude error. Lightcurve period and amplitude results are reported from Antelope Hills Observatory: 141 Lumen The results are presented without further detail on each asteroid, 19.87±0.01h, 0.12±0.02m; 259 Aletheia 8.143±0.002h, except for any comments that are considered relevant to the 0.12±0.02m; 363 Padua 8.401±0.001h, 0.14±0.02m; 455 analysis. Bruchsalia 11.838±0.001h, 0.12±0.02m; 514 Armida 21.874±0.001h, 0.16±0.02m; 524 Fidelio 14.19±0.01h, 1139 Atami. According to the list prepared by Harris (2005), 0.22±0.02m; 1139 Atami 27.56±0.01h, 0.45±0.02 mag. Atami has been observed by two observers but the period was still considered uncertain at the time of this study. Antelope Hills Observatory, MPC Code H09, is located near Acknowledgements Bennett, Colorado at an elevation of 1740 meters. The equipment and instrumentation have been detailed in a previous paper (Koff, Many thanks to Brian Warner for his continuing work on the 2004). Targets were selected from the “Potential Lightcurve CALL website and the program “Canopus”, which has made it Targets” on the CALL website (Warner, 2005), and further refined possible for amateurs to analyze and share lightcurve data. based on their magnitude and position in the sky. Targets were Thanks also to Alan Harris for his input into the Arecibo target selected for which no lightcurve data, or uncertain results had been list, defining the accuracy and usability of the currently available previously reported. (Harris, 2005). Additionally, targets were periods. selected from the list of upcoming radar study targets provided by M. Nolan and E. Howell of the NAIC Arecibo Observatory. The References radar target asteroids herein reported were also shown as having an uncertain period in the list prepared by Harris. Harris, A. W., Young, J. W., Bowell, E., Martin, L. J., Millis, R. L., Poutanen, M., Scaltriti, F., Zappala, V., Schober, H. J., Asteroids 141 Lumen, 259 Aletheia, 363 Padua, 455 Bruchsalia, Debehogne, H., and Zeigler, K. W. (1989). “Photoelectric 514 Armida and 524 Fidelio were observed in cooperation with Observations of Asteroids 3, 24, 60, 261, and 863.” Icarus 77, pp. the NAIC Arecibo Observatory asteroid radar program. Lumen, 171-186. Aletheia, Bruchsalia and Armida were reported by Harris (2005) to have been observed in the past but the periods were considered Harris, Alan W. (2005). “Minor Planet Lightcurve Parameters”, uncertain. 524 Fidelio had no previous reported lightcurve results. On the Minor Planet Center website: http://cfa- www.harvard.edu/iau/lists/LightcurveDat.html, or on the CALL The images were obtained through a clear filter with an IR cutoff website: http://www.MinorPlanetObserver.com/astlc/default.htm. of 700 nm. All images were calibrated with dark and flat field frames. Lightcurves were prepared using “Canopus”, based on the Koff, R. A., (2004). “Lightcurve Photometry of Mars-Crossing method developed by Harris et al. (1989). The program uses Asteroids 1474 Beira and 3674 Erbisbuhl”. The Minor Planet aperture photometry. Differential photometry was performed to Bulletin 31, pp. 33-34. obtain instrumental asteroid magnitudes. Night-to-night comparison star variation was compensated for by manually Warner, B. D. (2005), “Potential Lightcurve Targets”, on the shifting individual night’s magnitude scales to obtain a best fit. CALL website, http://www.MinorPlanetObserver.com/astlc/ The Canopus program allows compensation for night-to-night default.htm

# Name Date Range Sess Phase LPAB BPAB Per. PE Amp AE (2005) (hr) (mag) 141 Lumen 12/29/2004–1/08 5 5.8, 8.3 94.1, 94.3 11.0, 10.3 19.87 0.01 0.12 0.02 259 Aletheia 11/03-11/13 4 8.8, 6.0 69.2, 69.1 -4.8, -4.6 8.143 0.002 0.12 0.02 363 Padua 11/26-12/11 5 8.1, 1.8 82.3, 82.4 1.7, 2.1 8.401 0.001 0.14 0.02 455 Bruchsalia 11/06-12/13 6 16.8, 0.2, 1.4 77.4, 78.2 -2.0, 0.6 11.838 0.001 0.12 0.02 514 Armida 11/23-12/28 5 4.1, 0.6, 9.5 70.9, 71.0 1.6, 1.0 21.874 0.001 0.16 0.02 524 Fidelio 10/25-11/02 5 18.6, 16 69.1, 70.1 10.5, 10.7 14.19 0.01 0.22 0.02 1139 Atami 09/17-09/30 6 19.8, 12.3 14.1, 16.8 11.0, 8.9 27.56 0.01 0.45 0.02

Minor Planet Bulletin 33 (2006) 32

Minor Planet Bulletin 33 (2006) 33

press), a fast-moving bright object crossed the field and was soon identified to be 1747 Wright. With a semimajor axis of 1.71 AU and an eccentricity of 0.11 (MPC, 2005) it slightly crosses the orbit of Mars. According to the list of known lightcurve parameters (Harris, 2005), no data were yet published for this object and so it was scheduled and observed on six more nights. During the period of observation, the phase angle increased from 28° to 36°. All of our observations for this object were unfiltered. The images were reduced at Geneva with a data reduction pipeline, which uses PSF fitting and aperture photometry to derive differential magnitudes. The period analysis was done with CourbRot (Behrend, 2001). Mid-exposure times were corrected for light time and we assumed the photometric slope parameter to be G = 0.15 (MPC, 2005).

Based on a total of 334 images during 2005 July 6-27 we find a unique period of 5.28965 ± 0.00017 h and an amplitude of 0.61 ± 0.01 mag. The Epoch of a principal minimum of brightness is 2005 July 14.9068 ± 0.0007 UT (corrected for light time).

Acknowledgements. The authors would like to thank Alan W. Harris of the Space Science Institute, Boulder, Colorado, and Brian D. Warner of the Palmer Divide Observatory for their tireless support during the start of the asteroid lightcurve work at the Observatorio Astronomico de Mallorca. LIGHTCURVE OF MINOR PLANET 1747 WRIGHT References Reiner Stoss, Jaime Nomen, Salvador Sanchez Observatorio Astronomico de Mallorca Behrend, R. (2001). “Réduction d'une courbe de rotation/de Cami de l’Observatori, s/n lumière”, Orion 304, 12-15. 07144 Costitx, Mallorca – Spain [email protected] Behrend et al. "Four new binary Minor Planets: (854) Frostia, (1089) Tama, (1313) Berna, (4492) Debussy", A&A, in press. Raoul Behrend Geneva Observatory Harris, A. W. (2005). “Minor Planet Lightcurve Parameters”, CH-1290 Sauverny, Switzerland hosted on the website of the Minor Planet Center (MPC): http://cfa-www.harvard.edu/iau/lists/LightcurveDat.html . (Received: 17 November) MPC (2005). The MPC Orbit (MPCORB) Database. http://cfa- www.harvard.edu/iau/MPCORB.html . Mars-crossing asteroid 1747 Wright was observed on seven nights in July 2005 at the Observatorio Schmadel, L. D. (1999). Dictionary of Minor Planet Names, Astronomico de Mallorca. The lightcurve was found to 4th Edition. Springer-Verlag, Heidelberg, Germany. have a synodic period of 5.28965 ± 0.00017 h and an amplitude of 0.61 ± 0.01 mag.

Observatorio Astronomico de Mallorca (OAM) is located in the central part of the island of Mallorca, Spain, close to the village of Costitx. The observatory hosts several telescopes which are operated in far-remote mode over the internet. One of these, a 0.30-m f/9 Schmidt-Cassegrain has been used regularly for asteroid lightcurve work since July 2005. The telescope is equipped with an STL-1001E camera. All hardware components are controlled by customized software developed by OAM staff. Observers typically access the telescope from continental Europe via Web browser. Images are transferred by FTP to Geneva Observatory, where the photometry program is coordinated and the photometric data reduction is performed.

Minor planet 1747 Wright was discovered by Carl A. Wirtanen at Mount Hamilton on July 14, 1947. It was named for William H. Wright, a former director of Lick Observatory (Schmadel, 1999). This object was initially not on our schedule, but on July 6, 2005, while imaging the binary asteroid 1089 Tama (Behrend et al., in

Minor Planet Bulletin 33 (2006) 34

LIGHTCURVES ANALYSIS FOR HUNGARIA ASTEROIDS Binary Asteroids Group headed by Dr. Pravec. The three asteroids 3854 GEORGE, 4440 TCHANTCHES, AND in this study are among that latter group. 4674 PAULING The list below summarizes which observatories contributed data Brian D. Warner for each asteroid. Primary data analysis was carried out by Pravec. Palmer Divide Observatory The plots were generated by Warner after importing the data from 17995 Bakers Farm Rd. all observers into MPO Canopus. Colorado Springs, CO 80908 USA [email protected] 3854 George Palmer Divide, Modra Palmer Divide, Modra, Vermilion Cliffs, 4440 Tchantches Petr Pravec, Peter Kušnirák Kharkiv, Simeiz Astronomical Institute Palmer Divide, Ondrejov, Modra, 4674 Pauling CZ-25165 Ondřejov, Czech Republic Elginfield, Hunters Hill, Venus

Cindy Foote 3854 George. Initial observations were made from the PDO on Vermillion Cliffs Observatory, Venus Bdlg. Oct. 25 and 26, 2005. At that time, the data indicated something Kanab, UT 84741 USA other than a simple bimodal curve and Warner contacted Pravec for his analysis. After a session on Oct. 27, a synodic period of Jerry Foote about 3.3h became apparent but there were indications of Vermillion Cliffs Observatory deviations that may have indicated the asteroid was binary. On Kanab, UT 84741 USA Nov. 1, a call for observations was put out to the Binary Asteroids Adrián Galád, Štefan Gajdoš, Leoš Kornoš, Jozef Világi group. The resulting data obtained through mid-November, Modra Observatory showed the lightcurve to have a principal synodic period of Bratislava SK-84248, Slovakia 3.3398±0.0002h and amplitude of 0.14±0.02m. The plot below shows the data phased to that period. David Higgins Hunters Hill Observatory Ngunnawal, Canberra 2913, Australia

Shannon Nudds Elginfield Observatory, University of Western Ontario London, ON N6A 3K7, Canada

Yurij N. Kugly Institute of Astronomy of Kharkiv National University Kharkiv 61022, Ukraine

Ninel M. Gaftonyuk Simeiz Department of Crimean Astrophysical Observatory Semeiz 98680, Ukraine

(Received: 8 December)

As part of the ongoing program at the Palmer Divide Observatory to study the Hungaria group of asteroids, Whether or not 3854 George is a binary remains unresolved. No and in collaboration with several other observatories, the second period could be found that explained the deviations to our lightcurves for three Hungaria asteroids were found and satisfaction. The asteroid had faded too much by mid-November analyzed. Of the three, 4674 Pauling was a previously for the members of the group to follow. The next reasonable known binary (Merline 2004) but its lightcurve period opportunity to study the asteroid does not occur until March 2009. had not been measured. 3854 George had no previously reported lightcurve and showed possible hints of being 4440 Tchantches. This asteroid was previously observed by binary. However, no conclusive evidence was produced. Warner (2003) who reported a period of 6.83h using a sparse data 4440 Tchantches had been previously studied by Warner set. Behrend (2005) reported a period of 3.12h in 2004 and then a (2003) and Behrend (2005). This study corrected or revised period of 2.7886h in 2005. Given the disparity of the refined those previous results. periods and the desire to provide additional modeling data, the asteroid was put on the PDO observing list in 2005. Once again, after some initial sessions showed some suspicious data, a call was The Hungaria group lightcurve project was started at the Palmer put out to the members of the Binary Asteroids group in order to Divide Observatory in 2003 at the urging of Dr. Alan Harris of the obtained prolonged coverage on a given night and determine if the Space Science Institute and author Pravec. Since that time, more anomalies were real or just observing artifacts. In the end, it was than 30 members have had their lightcurves measured either determined that there was nothing conclusive and that in all independently at PDO or in collaboration with members of the probability, the asteroid is not binary. The combined data are

Minor Planet Bulletin 33 (2006) 35 plotted below against the derived synodic period of It is likely that there is a rotational component present that is due 2.78831±0.00005h. The amplitude of the curve is 0.32±0.02m. to the secondary, but we were not able to establish it with the available data. There is the possibility that the deviations have Calibrated observations at Simeiz on November 9 give an more than a single cause, e.g., the rotation of Merline et al.'s

HR=13.6±0.2, assuming G=0.15±0.2. Assuming V–R=0.4, this secondary plus a third body, since the deviations from the primary gives HV=14.0, which is considerably less than HV=12.3 given in period did not fit with a single periodicity. Since the primary and the MPCORB file from the Minor Planet Center (2005). secondary are well removed from one another, it’s unlikely the satellite is tidally locked and so has an asynchronous rotation rate. An apparent event observed on Oct. 13 at PDO indicated a Ds/Dp of 0.37, which agrees reasonably well with the value based on the Merline observations. The estimated orbital period of 2000h did not lend itself to an easy confirmation of that possibility.

Acknowledgements

The work at Ond_ejov was supported by the Grant Agency of the Czech Republic, Grant 205/05/0604.

The work at Modra was supported by the Slovak Grant Agency for Science VEGA, Grant 1/0204/03 and by The Planetary Society Gene Shoemaker NEO Grant.

References

Behrend, R., http://obswww.unige.ch/~behrend/page1cou.html.

Merline, W. J., Tamblyn, P. M., Dumas, C., Menard, F., Close, L. 4674 Pauling. Using Adaptive Optics, Merline et al (2004) M., Chapman, C., Duvert, G., Ageorges, N. (2004). IAUC 8297. discovered this asteroid to be a wide binary. They estimated the size of the satellite to be approximately 2.5km, based on the MPCORB Data File, (2005). Minor Planet Center, http://cfa- assumption that the primary had a diameter of 8km, or a Ds/Dp of www.harvard.edu/iau/MPCORB.html. 0.31. Warner, B.D. (2003). “Lightcurve Analysis for Asteroids 607 Jenny, 1177 Gonnessia, 4440 Tchantches, 4896 Tomoegozen, and (4995) 1984 QR.” Minor Planet Bulletin 30, 33-35.

ASTEROID LIGHTCURVE ANALYSIS AT THE PALMER DIVIDE OBSERVATORY: JULY-SEPTEMBER 2005

Brian D. Warner Palmer Divide Observatory 17995 Bakers Farm Rd. Colorado Springs, CO 80908 [email protected]

(Received: 8 October)

Lightcurves for the following asteroids and one comet originally designated as an asteroid were obtained and Merline did not report a period and at the request of Alan Harris, then analyzed to determine the synodic period and Warner started observing the asteroid in early October 2005. As amplitude: 643 Schehrezade, 663 Gerlinde, 696 with the other two asteroids, the initial data did not establish Leonora, 2199 Klet, 2214 Carol, 2346 Lilio, 2382 anything conclusively beyond the main period. There are apparent Nonie, 2957 Tatsuo, 4116 Elachi, 4368 Pillmore, 5968 deviations from the main periodicity, but we were not able to Trauger, (6065) 1987 OC, (8180) 1992 PY2, (28610) interpret them as being related to the satellite observed by Merline. 2000 EM158, (49385) 1998 XA12, P/2002 EX12 (NEAT). The final plot of the data set, phased to the primary synodic period Two asteroids were observed for which no definitive of 2.5306±0.0003h, is shown in the plot. The amplitude of the solution could be found: 6271 Farmer and 6911 curve for the primary is 0.06±0.02m. Calibrated data obtained at Nancygreen.

Ondrejov found HR=13.6±0.2, assuming G=0.15±0.2. Using V–R=0.4, this gives HV=14.0. The Palmer Divide Observatory is equipped with three telescopes, a 0.5m Ritchey-Chretien and two 0.35m SCT. The 0.5m and one

Minor Planet Bulletin 33 (2006) 36

0.35m use Finger Lakes Instruments CCD cameras with Kodak Comments are presented below for cases of particularly unusual or 1001E chips run at –30°C and 2x2 binning. The pixel scale is difficult solutions. approximately 2.4 arcseconds per pixel on both telescopes. The remaining 0.35m SCT uses an SBIG ST-9 and OPTEC focal 2346 Lilio. When reviewing asteroids available for observation, a reducer that also gives a pixel scale of approximately 2.4 crosscheck with the list of known lightcurves showed a previously arcseconds with 1x1 binning. This camera was run between –5° reported period for this asteroid of only 1.5h based on and –10°C as ambient conditions allowed. All observations were observations made in 2003 (Behrend 2004). This would be unfiltered (Clear). Exposure times were 120–180s, all unguided. inordinately fast given the presumed size of the asteroid. At the suggestion of Alan Harris, the asteroid was observed and it was Targets were chosen by comparing the list of known lightcurve determined that a longer period, 3.029h, was more likely correct periods maintained by Harris and Warner (Harris 2005) against a and that the curve was quad-modal instead of bimodal. The list of well placed asteroids. Asteroids are often selected with the Behrend web site has since been updated to give a solution of intent of removing the observational biases against faint objects 3.029h for the original 2003 observations as well as for additional (due to size and/or distance) as well as those with lightcurves of observations made in 2005. small amplitudes, long periods, or a complex nature. High priority is given to the Hungaria group as part of a long-term study of 4368 Pillmore. The first session, July 29, covered more than one these inner main-belt objects. The images were measured using cycle. On one of the passes, the lightcurve failed to reach the same MPO Canopus, which employs differential aperture photometry to minimum as in other passes. However, the phenomenon was never determine the values used for analysis. The period analysis was observed again. The measurements were rechecked and there was also done within Canopus, which incorporates the Fourier analysis no apparent reason for the deviation. The physical cause remains algorithm developed by Harris (1989). unexplained.

The results are summarized in the table below. The individual 5968 Trauger. The tri-modal solution is not common but provided plots are presented afterwards. The data and curves are presented the best fit of the data. Assuming a bimodal curve, the Canopus without additional comment except when the circumstances for a software found a period near 3.78h. However, the RMS scatter given asteroid require more details. Column 3 gives the full range was higher and the fit between 0.8 and 1.0 showed excessive of dates of observations while column 4 gives the number of deviations. actual runs made during that time span. Column 5 is the range of phase angles over the full date range. If there are three values in 2002 EX12. While observing this object, a faint tail of about 90” the column, this means the phase angle reached a minimum with length at PA 145° was observed during two sessions, July 28 and the middle value being the minimum. Columns 6 and 7 give the 29. These observations were reported to CBAT and the Minor range of values for the Phase Angle Bisector (PAB) longitude and Planet Center. Follow-up observations were made and the object latitude respectively. Columns 8 and 10 give the period and was confirmed to be an active comet and redesignated P/2002 amplitude of the curve while columns 9 and 11 give the respective EX12 (NEAT) (see IAUC 8587). errors in hour and magnitudes.

Date Range Data Per # Name 2005 (mm/dd) Pts Phase LPAB BPAB (h) PE Amp AE 643 Schehrezade 09/16-19 279 6.6-6.0 6.5 15.2 14.171 0.007 0.36 0.02 663 Gerlinde 07/17-22 324 10.3-9.4 317.4 21.0 10.240 0.003 0.28 0.02 696 Leonora 09/17-26 458 21.2-20.1 353.5-355.1 10.3-11.0 17.988 0.005 0.10 0.02 2199 Klet 06/30 – 07/14 160 11.0-17.1 268.7-270.8 10.8-9.6 4.0235 0.0003 0.13 0.02 2214 Carol 07/31 – 08/02 245 9.6-9.2 316.8 15.6 4.987 0.002 0.60 0.02 2346 Lilio 07/12-17 314 7.4-5.5 299.7 6.8 3.029 0.0002 0.24 0.02 2382 Nonie 08/23-28 295 28.1-27.3 8.1-9.2 39.0 15.099 0.004 0.49 0.02 2957 Tatsuo 09/20-30 377 5.4-8.1 350.2 10.7 6.8191 0.0004 0.53 0.02 4116 Elachi 08/29 - 09/06 263 13.2-9.0 352.7 11.5-10.1 38.12 0.02 1.02 0.05 4368 Pillmore 07/29 – 08/07 324 10.7-9.6 322.0 25.4 3.6054 0.0003 0.29 0.02 5968 Trauger 09/03-08 151 12.1-9.7 353.0 12.9-12.0 7.560 0.004 0.10 0.02 6065 1987 OC 08/08-18 130 21.4-21.0 328.1-329.4 28.9-30.5 33.15 0.08 0.20 0.02 6271 Farmer 07/28 – 08/09 274 24.8-22.0 338.8-340.4 22.7-25.3 35.8? n/a >0.1 n/a 6911 Nancygreen 07/18-23 95 24.0-23.5 309.7 33.9 5.3? n/a 0.52 0.03 8180 1992 PY2 09/13-21 311 9.1-8.9 356.4 17.7 13.014 0.008 0.24 0.02 28610 2000 EM158 09/11-12 224 7.1 348.7 12.0 3.288 0.001 0.24 0.02 49385 1998 XA12 08/30 – 09/01 145 27.0 350.0 32.0 2.5231 0.0007 0.15 0.02 P/2002 EX12(NEAT) 07/28-30 192 60.2-67.0 294.6 38.3-41.1 8.369 0.005 0.60 0.02

Minor Planet Bulletin 33 (2006) 37 Acknowledgments

Thanks are given to Dr. Alan Harris of the Space Science Institute, Boulder, CO, and Dr. Petr Pravec of the Astronomical Institute, Czech Republic, for their ongoing support of all amateur asteroid photometrists and for their input during the analysis of some of the lightcurves presented here.

References

Behrend, R., 2004. http://obswww.unige.ch/~behrend/ page_cou.html

Harris, A.W., Young, J.W., Bowell, E., Martin, L.J., Millis, R.L., Poutanen, M., Scaltriti, F., Zappala, V., Schober, H.J., Debehogne, H., and Zeigler, K.W., (1989). “Photoelectric Observations of Asteroids 3, 24, 60, 261, and 863.” Icarus 77, 171-186.

Harris, Alan W. (2005). "Minor Planet Lightcurve Parameters", On Minor Planet Center web site: http://cfa- www.harvard.edu/iau/lists/LightcurveDat.html

Minor Planet Bulletin 33 (2006) 38

Minor Planet Bulletin 33 (2006) 39

used: 0.5m Ritchey-Chretien/FLI-100E, 0.35m SCT/FLI-1001E, or 0.35m SCT/ST-9E. The scale for each was about 2.4 arcseconds/pixel. Exposure times were 120–240s, all unguided. The operating temperature for the FLI cameras was –30°C while the ST-9E was run between –15° to –25°C, depending on ambient conditions. The 1999 and 2003 observations were made with a 0.25m SCT and the ST-9E.

When selecting targets, first priority is given to members of the Hungaria group, those being part of an ongoing study at the Palmer Divide Observatory. When no suitable Hungarias were available, other targets were chosen by comparing the list of known lightcurve periods maintained by Harris and Warner (Harris 2005) against a list of well placed asteroids. Asteroids are often selected with the intent of removing the observational biases against faint objects (due to size and/or distance) as well as those with lightcurves of small amplitudes, long periods, or a complex nature. All images were measured using MPO Canopus, which employs differential aperture photometry to determine the values used for analysis. The period analysis was also done within Canopus, which incorporates the Fourier analysis algorithm developed by Harris (1989).

The results are summarized in the table below. The individual plots are presented afterwards. The data and curves are presented without additional comment except when the circumstances for a given asteroid require more details. Column 3 gives the full range of dates of observations while column 4 gives the number of data points used in the analysis. Column 5 is the range of phase angles over the full date range. If there are three values in the column, this means the phase angle reached a minimum with the middle value being the minimum. Columns 6 and 7 give the range of values (or average if the range was relatively small) for the Phase ANALYSIS OF 13 ASTEROID LIGHTCURVES OBTAINED Angle Bisector (PAB) longitude and latitude respectively. AT THE PALMER DIVIDE OBSERVATORY Columns 8 and 10 give the period and amplitude of the curve while columns 9 and 11 give the respective errors in hour and Brian D. Warner magnitudes. Palmer Divide Observatory 17995 Bakers Farm Rd. 321 Florentina. This asteroid was previously studied by several Colorado Springs, CO 80908 authors, among them Van Houten (1958) and Slivan (1996 and [email protected] 2003). Of particular interest are the results reported by Frey (2000), who found a period of 2.869h and an amplitude of 0.61m (Received: 8 December) based on observations made in December 1999. The observations made at PDO a month earlier and recently reanalyzed give nearly an identical period, 2.8711±0.0003h, but an amplitude of only The lightcurves for the following asteroids were 0.37±0.02m. Using data from October 1999, Behrend (2004) obtained and then analyzed to find the synodic period reported a period and amplitude similar to the PDO results. The and amplitude. 321 Florentina: 2.8711±0.0003h, PAB values changed relatively little from November to December 0.37±0.02m; 787 Moskva: 6.056±0.001h, 0.61±0.02m; and the phase angle was about the same, though on opposing sides 839 Valborg: 10.366±0.005h, 0.14±0.02m; 912 of opposition, thus providing no strong reason for the significant Maritima: 48.43±0.05h, >0.12±0.02m; 1176 Lucidor: difference in amplitude. 4.0791±0.0006h, 0.06±0.02m; 1862 Apollo: 3.0680±0.0002h, 0.30–1.20±0.02m; 2266 Tchaikovsky: 787 Moskva. The period was previously reported by the author 4.883±0.003h, 0.04±0.01m; 2951 Perepadin: (Warner 1999) as 5.381h. A posting on the Behrend web site 4.7808±0.0001h, 0.60±0.02m; 5108 Lubeck: (2004) with a period of 6.0556h prompted a re-examination of the 8.769±0.003, 0.43±0.02m; (17864) 1998 KK : 38 original data, whereupon a revised period of 6.056±0.001h was 6.56±0.01h, 0.17±0.02m; (18582) 1997 XK : 114±10h, 9 found to provide a better fit of the data than the shorter period. 0.94±0.02m; (20231) 1997 YK: 48.2±0.1h, >0.22±0.02m. Asteroid 868 Lova was also observed but 839 Valborg. The three maxima solution is not common but its long period is only constrained as >24h. provided the best fit of the data, especially considering the different heights of the maxima. Observations of thirteen asteroids were made at the Palmer Divide Observatory from 1999 through late 2005. For the 2005 observations, one of three telescopes/camera combinations was

Minor Planet Bulletin 33 (2006) 40

Date Range Data Per Amp # Name (mm/dd) 2005 Pts Phase LPAB BPAB (h) PE (m) AE 321 Florentina 11/02-06 (1999) 112 4.5-2.8 49.5 47.7 2.8711 0.0003 0.37 0.02 787 Moskva 05/18-22 (1999) 77 11.0-12.5 217.8 12.3 6.056 0.001 0.61 0.02 839 Valborg 11/13-18 262 7.8-8.9 43.8 15.2 10.366 0.005 0.14 0.02 868 Lova 11/11-13 (1999) 101 5.5-6.3 41.2 -7.6 >24 >0.1 0.02 912 Maritima 11/13-20 217 2.8-4.0 51.3 7.0 48.43 0.05 >0.12 0.02 1176 Lucidor 11/13-22 238 4.8-8.5 44.5 6.4 4.0791 0.006 0.06 0.02 1862 Apollo 11/06-20 223 101.3-28.6 97.2-71.0 14.5-12.4 3.0680 0.002 0.30-1.20 0.02 2266 Tchaikovsky 11/04-10 205 0.9,0.8,2.2 42.5 1.9 4.883 0.003 0.04 0.01 2951 Perepadin 11/21-22 201 6.0-6.3 43.7 6.6 4.7808 0.001 0.60 0.02 5108 Lubeck 11/23-29 147 6.0-7.7 58.1 9.3 8.769 0.003 0.43 0.02 17864 1998 KK38 11/23 54 0.3 60.1 -0.1 6.56 0.01 0.17 0.02 18582 1997 XK9 11/21-12/01 193 1.1,0.9,6.1 60.2 -1.8 114 10 0.94 0.02 20231 1997 YK 09/27-10/24 159 28.6-18.9 41.0 22.7 48.2 0.1 >0.22 0.02

912 Maritima. Due to the absence of data covering a minimum, Slivan, S. M., Binzel, R. P., Crespo da Silva, L. D., Kaasalainen, the full amplitude could not be determined. The period being M., Lyndaker, M. M., Krco, M. (2003). Icarus 162, 285-307. nearly commensurate with 24h made covering the entire curve from a single station difficult. However, the plots of the raw data Van Houten-Groeneveld, I., van Houten, C.J. (1958). favor the solution over possible aliases of between 24h and 48h Astrophysical Journal 127, 253-273. and almost certainly preclude a period shorter than 24h. Warner, B.D. (1999). Minor Planet Bulletin 26, 31-33. 1862 Apollo. The observations were made in response to a request from Steve Ostro who had recently reported the asteroid to be Warner, B.D. (2005). http://www.minorplanetobserver.com/htms/ binary (Ostro 2005). The lightcurve shape changed significantly pdo_lightcurves.htm. over the range of dates, as might be expected given the severe change in both phase angle and PAB values.

2951 Perepadin. This was a “bonus” target, being in the same field as a selected target for two consecutive nights. The period agrees with the one previously reported by Behrend (2004) of 4.781h.

(17864) 1998 KK38. This was another “bonus” target. It was in the field of the selected target on only one night. Higher priority targets prevented returning to the asteroid before it faded too much for additional observations. The data cover more than one cycle of the derived period, which lead to an unambiguous solution.

References

Behrend, R., (2004). http://obswww.unige.ch/~behrend/ page_cou.html.

Harris, Alan W. (2005). "Minor Planet Lightcurve Parameters", http://cfa-www.harvard.edu/iau/lists/LightcurveDat.html.

Ostro et al. (2005), IAUC 8627.

Pravec, P., Wolf, M., Sarounova, L. (2004). http://sunkl.asu.cas.cz/~ppravec/neo.htm.

Slivan, S. M., Binzel, R.P. (1996). Icarus 124, 452-470.

Minor Planet Bulletin 33 (2006) 41

Minor Planet Bulletin 33 (2006) 42

THE MINOR PLANET OBSERVER: results. It means adapting on several levels. That’s nothing new in A VICTIM OF PROSPERITY science and, in this case, is just another of those “golden problems” to be handled. Clear Skies! Brian Warner Palmer Divide Observatory 17995 Bakers Farm Rd. Colorado Springs, CO 80908 LIGHTCURVES FROM TWO OPPOSITIONS OF [email protected] 227 PHILOSOPHIA AND 2089 CETACEA

I’ve commented before on the growing number of submissions to Colin Bembrick the Minor Planet Bulletin and how the situation has gone from one Mt Tarana Observatory of trying to fill pages to one of fitting everything in. As space PO Box 1537, Bathurst, NSW 2795, Australia became tighter, changes had to be made. One of those has been the [email protected] abbreviation and even the absence of this article. I’ve always enjoyed the opportunity to go beyond the technical issues and Bill Allen offer some ruminations on the wonders and excitement that come Vintage Lane Observatory with being involved in asteroid research. I hope that you enjoy 83 Vintage Lane, RD3, Blenheim, New Zealand these occasional mental perambulations and that they serve to remind you of the deeper reasons behind why you read these Tom Richards pages. Woodridge Observatory 8 Diosma Rd, Eltham, Vic 3095, Australia The prosperity of data is not the just the MPB editor’s problem – though he considers it a proverbial “golden” one. I’ve built up the (Received: 10 January Revised: 15 January) Palmer Divide Observatory to include three telescope/camera combinations. Every clear night they are set to work gathering Minor planet 227 Philosophia was observed over data. It’s not uncommon to have one telescope work more than 6 nights in 2004 and 4 nights in 2005. The synodic one asteroid, though this must be done with care. Bouncing among period was 18.048±0.031hr with a peak-to-peak asteroids may mean covering more asteroids but not necessarily amplitude of 0.2mag in 2005. Similarly, 2089 Cetacea getting good data. If the interval between observations is too large was observed over 7 nights both in 2001 and in 2005. due to the time lost slewing among targets and image downloads, The synodic rotation was 39.120±0.093hr with an then the data set may be too sparse. This can be particularly true amplitude of ~0.35mag in 2005. for an asteroid with a period of two to four hours. Here it often helps to have too much data, which has the effect of smoothing out random scatter. It’s also possible that evidence of a binary asteroid Minor planet 227 Philosophia is an outer main-belt asteroid with a might be compromised when an eclipse event is not thoroughly diameter of 90 km and an albedo of 0.065 (Binzel, Gehrels & covered. Just because one can do something doesn’t mean he Matthews, 1989). Minor planet 2089 Cetacea (1977 VF) has a should. diameter of 42km and the B-V=0.82 (Guide, 2002). The Tholen class is S (Binzel, Gehrels & Matthews, 1989). No data on these Even if the data cover the lightcurve well, working several asteroids are present in the latest list (Harris & Warner, 2006). asteroids means more analysis. With the software available today, it’s not so much the measuring of all those images that takes time 227 Philosophia was initially observed by all authors over 6 nights but analyzing the resulting curves. It sometimes seems that the in June 2004. The locations of these sites in Australia and New easy targets have been taken – there are few times when we get a Zealand are listed in Bembrick et al (2004). Crowded star fields clean three-hour curve with large amplitude and low noise. More limited reliable data at this opposition and made period often, at least for me, it seems the periods are 12 to 40 hours determination problematic. Philosophia was again observed by and/or the amplitudes are only 2-4x the noise. That means working Bembrick over 4 nights in September 2005 and full phase those asteroids more than just one or two nights and trying to get coverage was achieved. Table I summarizes the average values for the data properly placed on a common zero point. More data the PAB and phase angle in the sets of observations from each means more work and not always in direct proportion. year. None of the three values changed significantly during the observation runs, but note the large changes from 2004 to 2005. When it comes time to write up results for the Minor Planet Bulletin, we need to keep in mind the growing number of papers Date Range PAB Phase being submitted. For one, this means being as brief as possible long lat without sacrificing quality or clarity. For example, discovery and 2004 Jun 6-22 225.2 -7.9 19.3 naming circumstances should be left out – they’ll probably be cut 2005 Sep 2-8 348.4 3.7 2.4 anyway. The same can be said for information that can be readily computed by the reader, though if it can be included as part of a Table I. Averaged aspect data for 227 Philosophia. summary table that you’d have anyway, that may be OK. Graphics should be clear, concise, and, if part of the document, inserted as 2089 Cetacea was observed over 7 nights by Bembrick in simple bitmap files so that they can be easily moved as required September 2001. A unique period could not be derived and thus for good layout. If in color, use colors that translate well to black Cetacea was again observed by Bembrick over 7 nights in 2005. and white for the printed version. Table II provides averaged aspect data for Cetacea.

As the songwriter said, “The times they are a changin’.” The big professional surveys aren’t the only ones churning out data and

Minor Planet Bulletin 33 (2006) 43 Date Range PAB Phase long lat 2001 Sep 13-23 350.3 -20.0 12.0 2005 Sep 14-Oct 2 344.6 -19.4 14.0 Table II. Averaged aspect data for 2089 Cetacea.

All observations were made using unfiltered differential photometry and were light time corrected. Period analysis was carried out using the “AVE” software (Barbera, 2004).

The period derived for Philosophia from the 2005 data was used to compile the composite lightcurves – both in 2004 (Figure 1) and in 2005 (Figure 2). The peak-to-peak amplitude in 2005 was 0.2mag, while in 2001 it was at best 0.05mag, but the data are Figure 1. Composite lightcurve for 277 Philosophia in 2004. incomplete. The arbitrary zero phase minimum in 2005 is JD 2453615.733. The 2005 composite lightcurve for 227 Philosophia (Figure 2) achieves full phase coverage, and this is considered a secure result. Sparse data from 2004 suggests it was observed nearly pole-on at that opposition (Figure 1). The peak-to-peak variation of 0.2mag in 2005 implies an axial ratio a/b of 1.2. Philosophia’s rotation rate is close to typical for asteroids between 50 and 125 km diameter (see Binzel et al., 1989).

Inspection of the raw data for 2089 Cetacea in 2001 indicated a period much longer than 25hr. Analysis suggested a period of 1.35d or a period in the range 1.6 to 1.7d. A unique value could not be determined. The 2005 data analysis showed a period of 1.28d was possible but the only value to fit both data sets was close to 1.6d. Thus the period derived for Cetacea in 2005 was Figure 2. Composite lightcurve for 277 Philosophia in 2005. used to compile the composite lightcurves, both in 2001 (Figure 3) and in 2005 (Figure 4). The arbitrary zero phase minimum for the 2001 composite is JD 2452166.580, while in 2005 it is JD 2453627.970. Note that full phase coverage has not been achieved either in 2001 or 2005 (Figures 3 & 4) and further checking would be advisable. However, the interpreted period appears to be the only one to fit both data sets. Cetacea is a slow rotator with an axial ratio a/b of 1.38 implied by the peak to peak variation.

References

Barbera, R. (2004). “AVE” Analisis de Variabilidad Estelar, version 2.51. Grup d’Estudis Astronomics. http://usuarios.lycos.es/barbera/AVE/AveInternational.htm

Bembrick, C.S., Richards, T., Bolt, G., Pereghy, B., Higgins, D. Figure 3. Composite lightcurve for 2089 Cetacea in 2001. and Allen, W.H. (2004). “172 Baucis – A Slow Rotator”. Minor Planet Bulletin 31, pp. 51-52.

Binzel, Richard P., Gehrels, Tom and Matthews, Mildred Shapley (1989). Asteroids II. Univ. Arizona Press, Tucson, Arizona.

Binzel, R.P., Farinella, P., Zappala, V. and Cellino, A. (1989). “Asteroid Rotation Rates.” In Asteroids II (Binzel, Richard P., Gehrels, Tom and Matthews, Mildred Shapley, eds.) pp. 416-441. Univ. Arizona Press, Tucson.

GUIDE software, ver. 8. Jan., 2002. Project Pluto. http://www.projectpluto.com

Harris, A.W. and Warner, B.D. (2006). “Minor Planet Lightcurve Figure 4. Composite lightcurve for 2089 Cetacea in 2005. Parameters”. Version updated January 6 2005. http://cfa- www.harvard.edu/iau/lists/LightcurveDat.html

Minor Planet Bulletin 33 (2006) 44

LIGHTCURVE PHOTOMETRY OF indicated that she had received results from other sources, and ASTEROID 705 ERMINIA these results were subsequently sent by the respective observers to Pravec for inclusion in the analysis. Goncalves provided four Robert A. Koff nights of observations while Antonini and Behrend contributed Antelope Hills Observatory three nights. In addition, Pray observed the object for one night. 980 Antelope Drive West Bennett, CO 80102 The synodic period of the lightcurve was found to be 53.96±0.01h [email protected] and its amplitude to be 0.13±0.01mag. Over the range of dates of observation, the phase angle dropped from 10.9° to 6.1° and then

Petr Pravec back up to 8.6°. The PABl ranged from 29.9–29.4° and the PABb Astronomical Institute from 12.1–16.0°. Ondrejov, Czech Republic

Rui Goncalves Instituto Politecnico de Tomar, Portugal

Pierre Antonini Bedoin Observatory Avignon, France

Raoul Behrend, Observatoire de Geneve, Switzerland

Donald P. Pray Carbuncle Hill Observatory Coventry, RI

(Received: 12 January)

Lightcurve period and amplitude results from a collaborative study are reported for asteroid Figure 1. Lightcurve of 705 Erminia based on a period of 53.96h. 705 Erminia. The period was determined to be 53.96±0.01h with an amplitude of 0.13±0.01mag. Acknowledgments

Asteroid 705 Erminia was included in a list of upcoming targets Many thanks to Brian Warner for his continuing work on the for the late 2005 Arecibo planetary radar program. According to CALL website and MPO Canopus, which has made it possible for Harris (2005), DiMatrino previously reported a period of 7.22hr. amateurs to analyze and share lightcurve data. Thanks also to Alan This was considered a tentative result. Harris for his input into the Arecibo target list, defining the accuracy and usability of the currently available periods. The participating observatories were: Antelope Hills Observatory, see Koff (2004) for a description of equipment and References instrumentation; Linhaceira Observatory, see Goncalves and Harris, A. W. (2005). “Minor Planet Lightcurve Parameters”. On Behrend (2006); Bédoin (Vaucluse), France, where the the Minor Planet Center website: http://cfa- instrumentation includes an 0.30m f/3.5 Schmidt-Cassegrain and www.harvard.edu/iau/lists/LightcurveDat.html, or on the CALL KAF400ME camera; and Carbuncle Hill Observatory. Details of website: http://www.MinorPlanetObserver.com/astlc/default.htm this observatory are available in Pray (2006). Koff, R. A. (2004). “Lightcurve Photometry of Mars-Crossing Observations were initially started at Antelope Hills Observatory. Asteroids 1474 Beira and 3674 Erbisbuhl”. The Minor Planet It became apparent that the published period was incorrect, and Bulletin 31, 33-34. anomalies were observed in the lightcurve indicating a possible binary system. At this point, assistance was sought from Petr Goncalves, R. and Behrend, R. (2006). “Lightcurve of 62 Erato”. Pravec. Further observations over a total of eleven nights The Minor Planet Bulletin 33, 7. indicated that the asteroid was not a binary system, but that it did have a long period with a number of features. The nightly Pray, D. P. (2006). “Lightcurve Analysis of Asteroid 326, 329, observations were linked by comparing the nightly comparison 619, 1829, 1967, 2453, 10518 and 42267”. The Minor Planet star instrumental magnitudes to those from the first night. Thus, Bulletin 33, 4-5. the first night’s comparison stars were used as an artificial standard. All except one of the linked nights fit within 0.01mag, using a G=0.04. The remaining night was taken 16 degrees from the Moon, and required a shift of 0.026mag. Using this procedure, a unique period was determined.

The results from eleven night’s observations at Antelope Hills were sent to E. Howell at the Arecibo Observatory. Howell

Minor Planet Bulletin 33 (2006) 45

LIGHTCURVE FOR HUNGARIA ASTEROID 1600 VYSSOTSKY OVER SEVERAL APPARITIONS

Brian D. Warner Palmer Divide Observatory 17995 Bakers Farm Rd. Colorado Springs, CO 80908 USA [email protected]

Donald P. Pray Carbuncle Hill Observatory Coventry, RI 02816 USA

Ron Dyvig Badlands Observatory Quinn, SD 57775 USA

Vishnu Reddy Dept. of Space Studies, University of North Dakota Grand Forks, ND 58203 USA Figure 1. The lightcurve of 1600 Vyssotsky in 1999.

(Received: 5 December) Figure 2 shows the data from the 2004 apparition. Note how the curve is similar in shape to that in Figure 1. This makes sense since the viewing aspects for the two data sets were nearly Photometric observations of the Hungaria asteroid 1600 identical, i.e., the phase angle and Phase Angle Bisector (PAB) Vyssotsky were previously reported by Warner (1999). values were approximately the same. The period using only 2004 Those data were reanalyzed to confirm and, if possible, data was found to be 3.2010±0.0002h. The total amplitude was refine the original results. In addition, analysis was 0.16±0.02m while the secondary amplitude was 0.10±0.02m. performed on previously unpublished data obtained during the 2004 and 2005 apparitions. The average synodic period for the three apparitions was found to be 3.2011±0.0004h, with the periods for each apparition within 1-sigma of the average. The amplitude of the lightcurve varied from 0.16–0.18m but most notable was the change in the shape of the curve.

Observations of 1600 Vyssotsky made at the Palmer Divide Observatory used a 0.20m SCT and ST-8E (1999) or a 0.35m SCT and ST-9E (2005). Images from Carbuncle Hill were obtained using a 0.35m SCT and ST-10XME (2004) or a 0.25m Schmidt- Newtonian and ST-7ME (2005). The observations at Badlands Observatory (2004) were made with a 0.66m reflector and AP-8.

The table below shows the average phase angle and PAB values for each apparition. These are important for understanding the changing shape of the lightcurve. Figure 2. The lightcurve of 1600 Vyssotsky in 2004. Date Phase LPAB BPAB 1999 19.8 204.3 15.2 Figure 3 shows the data from the 2005 apparition. Here the shape 2004 17.7 196.8 20.8 of the curve differs significantly from the previous two, most 2005 2.6 60.2 0.5 notable is that the two maxima are now about the same amplitude, implying the presentation areas of the whole disc at the two In order to make comparisons among the lightcurves easier, they maxima were similar. The period using only the 2005 data was were forced to have a maximum at 0% phase. Figure 1 shows the determined to be 3.2012±0.0004h and the amplitude 0.18±0.02m. data from 1999 apparition. Warner (1999) originally reported the The secondary amplitude is larger than in previous years, period to be 3.20±0.01h. After re-measuring the images and 0.15±0.01m. additional analysis, the period was refined to 3.2011±0.0004h. The revised total amplitude of 0.18±0.02m differs from the value Assuming the Z-axis (or c) of a triaxial ellipsoid to be 1.0, the two 0.13m previously reported. The secondary amplitude, that from amplitudes in 1999 and 2004 imply an a/c ratio of 1.18:1 and a b/c first minimum to second maximum, is 0.11±0.01m. ratio of 1.11:1. In 2004, the ratios were 1.16:1 and 1.10:1. In 2005 they were 1.18:1 and 1.15:1 respectively. These results and the data sets will be used by Reddy in further analysis to determine the shape and spin axis parameters of the asteroid.

Minor Planet Bulletin 33 (2006) 46

multiple almost exactly equal to the interval between observing runs or the period is long, i.e., 18 hours to several days.

One asteroid to which we call attention is 264 Libussa. The period has been well established by Pilcher and Cooney (MPB 33, 13- 14), but this was done when the asteroid was likely viewed pole- on. The opposition in late April is almost at right angles to when they worked it and so presents an excellent opportunity to eliminate any lingering ambiguity about the period and provide much needed data for shape modeling.

The Low Phase Angle list includes asteroids that reach very low phase angles. Getting accurate, calibrated measurements (usually V band) at or very near the day of opposition can provide important information for those studying the “opposition effect”, which is when objects near opposition brighten more than simple geometry would predict.

Figure 3. The lightcurve of 1600 Vyssotsky in 2005. The final list is those asteroids needing only a small number of lightcurves to allow Kaasalainen and others to work on a shape Acknowledgements model. Some of the asteroids have been on the list for some time, so work on them is strongly encouraged in order to allow models The authors thank Dr. Peter Pravec, Ondrejov Observatory, Czech to be completed. For these objects, we encourage you to do Republic, for his insights during the analysis of the data. absolute photometry, meaning that the observations are not differential but absolute values put onto a standard system, such as References Johnson V. If this is not possible or practical, accurate relative photometry is also permissible. This is where all differential Warner, B.D., 1999. “Asteroid Photometry at the Palmer Divide values are against a calibrated zero point that is not necessarily on Observatory,” Minor Planet Bulletin 26, 31-33. a standard system.

Keep in mind that as new large surveys, e.g., Pan-STARRS, come on line and start producing data, individual lightcurves obtained LIGHTCURVE PHOTOMETRY OPPORTUNITIES by smaller observatories will become even more important. Using APRIL – JUNE 2006 a sparse sampling technique developed by Kaasalainen, the accumulated data from the surveys, and the high-density coverage Brian D. Warner provided by amateurs or small institutions, period analysis can Palmer Divide Observatory progress at a more rapid rate, providing a better data pool for 17995 Bakers Farm Rd. statistical analysis. It may also be possible to discover binary Colorado Springs, CO 80908 USA asteroids using the combined data. Observers should not see the [email protected] surveys as competition but as a means to obtaining the ever needed “more data” and the opportunity to make new discoveries. Mikko Kaasalainen Rolf Nevanlinna Institute Once you have data and analyzed them, it’s important that you FIN-00014 University of Helsinki, Finland publish your results in the Minor Planet Bulletin and, if nothing else, make the data available on a personal website or upon Alan W. Harris request. If you don’t make the data available, then the potential Space Science Institute gains in cooperation with the large surveys nay not be possible. La Canada, CA 91011-3364 USA Previous issues have covered larger upload sites such as OLAF, SAPC, and the ADU. For more information about those sites, Petr Pravec please contact Warner at the email address given above. Astronomical Institute CZ-25165 Ondřejov, Czech Republic Lightcurve Opportunities

We present here three lists of “targets of opportunity” for the Brightest period 2006 April through June. The first list is those asteroids # Name Date Mag Dec U Per. Amp reaching a favorable apparition during this period, are <15m at ------16525 1991 CU2 4 03.9 15.0 - 6 0 brightest, and have either no or poorly constrained lightcurve 1453 Fennia 4 08.0 14.2 -18 2 6. 0.13 parameters. These circumstances make the asteroids particularly 2826 Ahti 4 09.0 15.0 - 2 0 good targets for those with modest “backyard” telescopes, i.e., 1462 Zamenhof 4 12.1 14.3 - 9 0 756 Lilliana 4 13.0 13.1 -12 2 6.152 0.9 0.2-0.5m. 968 Petunia 4 17.2 13.2 -11 ? 3151 Talbot 4 21.1 14.9 -13 0 The goal for these asteroids is to find a well-determined rotation 264 Libussa 4 25.6 12.8 - 9 2 3840 Mimistrobell 4 26.1 14.9 -13 0 rate, if at all possible. Don’t hesitate to solicit help from other 425 Cornelia 4 29.2 13.4 -12 2 17.56 0.16 observers at widely spread longitudes should the initial finding for 4029 Bridges 4 29.1 15.0 -14 2 3.694 0.24 the period indicate that it will be difficult for a single station to 5731 Zeus 4 29.4 14.9 -50 0 1484 Postrema 5 01.0 14.7 + 2 0 find the period. This could be due to the fact that the period has a (table continues on next page) Minor Planet Bulletin 33 (2006) 47 Lightcurve Opportunities (continued) Low Phase Angle Opportunities (continued)

Brightest # Name Date PhA V Dec # Name Date Mag Dec U Per. Amp ------322 Phaeo 06 06.4 0.27 12.7 -22 4569 Baerbel 5 02.0 14.7 - 9 0 462 Eriphyla 06 10.0 0.77 13.0 -21 3376 Armandhammer 5 02.8 14.7 -21 0 447 Valentine 06 14.1 0.45 13.1 -25 293 Brasilia 5 07.7 13.6 -11 0 261 Prymno 06 16.5 0.57 12.0 -22 5764 1985 CS1 5 14.5 14.4 - 9 0 149 Medusa 06 23.3 0.70 13.2 -22 3305 Ceadams 5 14.8 14.8 -27 0 334 Chicago 06 27.0 0.98 12.9 -20 4644 Oumu 5 15.3 14.4 -22 0 396 Aeolia 06 27.5 0.87 12.4 -21 68950 2002 QF15 5 19.4 14.3 + 7 2 29. >0.3 823 Sisigambis 06 28.2 0.96 14.0 -21 710 Gertrud 5 19.8 14.5 -17 0 570 Kythera 06 29.1 0.60 13.5 -21 1581 Abanderada 5 20.8 14.5 -17 0 8479 1987 HD2 5 21.4 14.7 -18 0 Shape/Spin Modeling Opportunities 1939 Loretta 5 21.1 14.1 -21 0 5135 Nibutani 5 22.1 14.4 -23 0 Brightest Per 17731 1998 AD10 5 24.7 15.0 -20 0 # Name Date Mag Dec (h) Amp. U 37152 2000 VV56 5 24.2 14.0 -32 0 ------2573 Hannu Olavi 5 24.9 14.9 -24 0 377 Campania 4 13.2 12.6 -10 8.507 0.16 3 3002 Delasalle 5 27.7 14.5 -12 0 59 Elpis 4 19.5 12.1 -04 13.69 0.1 3 1436 Salonta 5 28.6 14.3 -26 0 30 Urania 4 27.9 10.9 -17 13.686 0.11-0.45 3 1305 Pongola 5 30.0 14.2 -22 2 8.03 0.18 110 Lydia 5 05.7 11.4 -14 10.927 0.10-0.20 3 5247 Krylov 5 31.9 14.7 + 3 0 487 Venetia 5 14.6 12.2 -05 13.28 0.05-0.30 2 12453 1996 YY 6 03.4 14.7 -35 0 196 Philomela 5 15.3 10.6 -15 8.343 0.07-0.37 4 2050 Francis 6 03.0 13.4 -22 0 776 Berbericia 5 24.1 12.2 -12 7.668 0.13-0.21 2 3527 McCord 6 04.5 15.0 -16 0 114 Kassandra 6 05.0 11.8 -15 10.758 0.25 3 2610 Tuva 6 05.8 14.7 -22 0 334 Chicago 6 27.0 12.9 -20 7.35 0.15-0.67 2 5183 Robyn 6 07.7 14.4 -26 0 1582 Martir 6 08.3 14.6 -17 2 15.757 0.36 21967 1999 WS9 6 09.8 14.9 -22 0 Note that the amplitude in the table just above could be more, or 20423 1998 VN7 6 09.7 15.0 -33 0 less, than what’s given. Use the listing as a guide and double- 4078 Polakis 6 11.1 14.8 -22 0 7262 Sofue 6 11.7 14.0 - 6 0 check your work. Also, if the date is ‘1 01.’ Or ’12 31. ‘, i.e., there 607 Jenny 6 12.7 13.0 -30 2 7.344 0.22 is no value after the decimal, it means that the asteroid reaches its 5722 1986 JS 6 12.8 14.8 -13 0 brightest just as the year begins (it gets dimmer all year) or it 21558 1998 QW77 6 12.4 14.8 -42 0 1264 Letaba 6 12.0 12.3 - 3 1 32.164 0.13 reaches its brightest at the end of the year (it gets brighter all 231 Vindobona 6 14.3 12.3 -32 2 14.244 0.18 year). 6310 Jankonke 6 15.7 15.0 -27 2 3.041 0.30 10479 1982 HJ 6 16.7 14.7 -31 0 2873 Binzel 6 17.7 14.3 -20 0 828 Lindemannia 6 19.6 14.4 -25 0 17512 1992 RN 6 19.5 14.6 -41 0 3652 Soros 6 20.8 14.5 -22 0 1279 Uganda 6 20.0 14.0 -35 1 23.2 0.16 3825 Nurnberg 6 20.7 14.9 -26 0 2149 Schwambraniya 6 22.2 14.3 -30 0 5350 Epetersen 6 23.4 14.5 -27 0 35783 1999 JU20 6 24.9 15.0 -28 0 1517 Beograd 6 25.4 14.4 -28 2 6.943 0.18 40729 1999 SJ12 6 25.7 14.9 -62 0 396 Aeolia 6 27.4 12.4 -21 1 >12. >0.3 12521 1998 HT95 6 27.0 15.0 -21 0 1495 Helsinki 6 28.7 14.5 -46 0 1216 Askania 6 29.5 14.7 -16 0

Low Phase Angle Opportunities

# Name Date PhA V Dec ------2501 Lohja 04 02.6 0.22 13.8 -05 225 Henrietta 04 04.5 0.44 13.4 -07 359 Georgia 04 04.7 0.48 13.0 -07 377 Campania 04 13.2 0.46 12.6 -10 1059 Mussorgskia 04 14.2 0.41 13.7 -08 968 Petunia 04 17.3 0.27 13.2 -11 305 Gordonia 04 24.8 0.24 13.0 -12 1281 Jeanne 04 25.8 0.54 14.0 -12 152 Atala 04 27.0 0.36 12.7 -13 91 Aegina 04 29.1 0.56 12.4 -16 425 Cornelia 04 29.2 0.91 13.4 -12 1590 Tsiolkovskaja 05 02.1 0.40 13.3 -16 27 Euterpe 05 03.4 0.81 10.2 -14 73 Klytia 05 04.1 0.80 12.6 -18 110 Lydia 05 05.6 0.71 11.4 -14 102 Miriam 05 09.9 0.83 13.2 -15 277 Elvira 05 19.6 0.15 13.8 -20 171 Ophelia 05 22.0 0.82 12.4 -18 104 Klymene 05 24.6 0.40 13.2 -22 86 Semele 05 27.5 0.66 13.5 -19 431 Nephele 05 27.8 0.73 12.7 -19 673 Edda 05 29.1 0.57 13.9 -20 674 Rachele 05 29.4 1.00 12.1 -25 145 Adeona 06 02.7 0.69 11.9 -20 2050 Francis 06 03.0 0.30 13.4 -22

Minor Planet Bulletin 33 (2006) 48

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Minor Planet Bulletin 33 (2006)