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Home , 100 Hekate, 1015 Christa, 109 Felicitas, 1101 Clematis, 1107 Lictoria, 116 Sirona

1 THE MINOR

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

VOLUME 31, NUMBER 1, A.D. 2004 JANUARY-MARCH 1.

ASTROMETRIC PROGRAM FOR JR refers to nearby to the 3:1 resonance NEAR- OBJECT SOURCES with , MC are the Mars Crossers, NU are objects in the ν 6 secular resonance. Sergio Foglia UAI Minor Planets Section Recorder References F. Bisleri 11, I-20148 Milano, Italy € [email protected] Morbidelli et. al. (2003). Understanding the distribution on Near Earth Objects. http://www.obs-nice.fr/morby/ESA/ esa.html (Received: 24 September Revised: 6 October) MPC Orbit Database. ftp://ftp-cfa.harvard.edu/pub/MPCORB/ 2003 Sep. 17, Center A new astroometric program is proposed for asteroids located in likely source regions supplying the near-Earth Proper Elements of Minor Planets. http://hamilton.dm object population. .unipi.it/astdys/ 2003 Sep. 17, Dynamic Site

According to Morbidelli et al. (2003), near-Earth objects (NEOs) come mainly from 5 sources with the following contributions to the population: the ν 6 resonance region at the inner border of the asteroid main belt (37 ± 8 %), the 3:1 resonance region in the middle of the asteroid main belt (23 ± 8 %), the Intermediate Mars-Crossing (IMC) population (25 ± 3 %), the Outer Belt (OB) population€ (8 ± 1 %), and the population of dormant Jupiter Family (JFC) (6 ± 4 %).

Astrometric measurements of objects in these source regions would be very useful to increase knowledge about the NEO source population and solar system dynamics. Thus a new astrometric program for NEO source bodies involving amateur astronomers is suggested. For this program, most objects are usually brigther than 18.0 V and thus are within the range of equipment for many observers to obtain good measurements.

Our goal is to suggest an observing program named Near Earth Figure 1. Depiction of asteroids for the NEOSAP program. Light Objects Source Astrometric Program (NEOSAP) involving the grey bordered rectangles are the Mars Crossers, dark grey following objects: Mars Crossers having q < 1.52 and Q > 1.52, bordered rectangles are objects in the ν 6 secular resonance, and where q and Q are perihelion and aphelion distances in AU; filled rectangles are asteroids nearby to the 3:1 mean motion asteroids in the ν 6 secular resonance; asteroids nearby to the 3:1 resonance with Jupiter. mean motion resonance with Jupiter. € Interested observers will find ephemeris and other information at the following€ URL: http://www.uai.it/sez_ast/neosap.htm Table I: Numbers of NEOSAP asteroids. Astrometric measurements must be sent to the in the usual way; no other action is required by observers JR 717 and the listed URL serves only to provide information and MC 726 ephemerides for recommended targets. MC + JR 5 MC + NU 10 NU 116 Figure 1 shows the distribution of these objects in the plane of the Total 1574 semi-major axis (a) and inclination (i). Table I gives numbers of NEOSAP asteroids in the different categories: Minor Planet Bulletin 31 (2004) 2

ROTATION PERIOD AND LIGHTCURVE OF ASTEROID We were lucky enough to observe a well defined peak every night 1635 BOHRMANN we observed. I measured the time differences between peaks on different nights to generate a list of possible alias periods and then Christine M. Simpson to narrow these periods down to a of 11.73 ±0.01 Whitin Observatory . From this period it can be deduced that 2.0 rotations Wellesley College elapsed between the peaks on Sept. 6 and Sept. 7; 22.5 rotations 106 Central Street elapsed between the peaks on Sept. 6 and Sept. 17; and 31.0 Wellesley, MA 02481 rotations elapsed between the peaks on Sept. 6 and Sept. 21. I then translated our differential magnitudes for each night onto the (Received: 14 October Revised: 6 November) time scale for Sept. 6 modulo the period. This result is shown in Figure 1, showing an amplitude near 0.28 magnitudes. I also have observations of 1635 Bohrmann for two more nights during this asteroid 1635 Bohrmann was observed 15 interval and for three nights after this interval. I am over the course of 15 days in September, 2003 at Whitin planning to use these data and other observations during the Observatory in Wellesley, Massachusetts. A period of current apparition to get a solar phase angle curve for the asteroid. 11.73 ± 0.01 hours was determined with an amplitude of about 0.28 mag. Acknowledgements

I would like to thank Steve Slivan for advising me on this project Introduction and observing with me on Sept. 21. Also, many thanks go to Jeff Regester for fixing the CCD coolant chiller when it shorted. Asteroid 1635 Bohrmann is a member of the Koronis family of asteroids, located in the main . Asteroid families like References Koronis are thought to be the fragments of larger bodies broken apart in collisions. This formation method would suggest random Binzel, R. P. (2003). “Spin control for asteroids.” Nature 425, rotation periods and spin vector orientations, but recent 131-132. observations and analysis of some of the larger members of the Koronis family have shown that there are statistically significant Slivan, S. M. (2003). “A Web-Based Tool to Calculate clusters of rotation periods and spin vector orientations (Slivan et Observability of Koronis Program Asteroids.” The Minor Planet al. 2002). Just this Vokrouhlicky´ et al. (2003) have proposed Bulletin 30, 71-72. thermal re-radiation or the “YORP effect” as an explanation for these phenomena (see also Binzel 2003). Bohrmann is a smaller Slivan, S. M., R. P. Binzel, L. D. Crespo da Silva, M. Kaasalainen, member of the Koronis family, and our observations, combined M. M. Lyndaker, and M. Krco. (2002). “Spin Vectors in the with future observations, will be used to determine Bohrmann’s Koronis Family: Comprehensive Results from Two Independent spin vector orientation. Information for observing 1635 Analyses of 213 Rotation Lightcurves.” Icarus 162, 285-307. Bohrmann and other Koronis family asteroids can be found at http://www.koronisfamily.com (Slivan 2003). Vokrouhlicky´, D., D. Nesvorny´, and W. F. Bottke. (2003). “The vector alignments of asteroid spins by thermal torques.” Nature Observations and Analysis 425, 147-151. I observed 1635 Bohrmann for four nights in September of 2003 from Whitin Observatory at Wellesley College in Wellesley, Massachusetts. A 1024 square pixel CCD camera was used to image the asteroid through a V filter at the Cassegrain focus of the 0.61m Sawyer telescope. The field of view was approximately 16 arcminutes square. Observations were made during clear (1635) Bohrmann 2.65 UT Sept 6 conditions, except for those made during the first of UT Sept 7 2.7 UT Sept 17 observations on September 21 when there were some clouds UT Sept 21

2.75

moving in and out. The exposure time for each observation was Magnitude 240s. IRAF software packages were used to analyze the data. All V 2.8 images were corrected for bias, dark and flat field effects. 2.85 Instrumental For each night of data, I selected a non-variable comparison in 2.9 the field that was brighter than the asteroid. The instrumental magnitude of the comparison star was subtracted from the 2.95 Differential instrumental magnitude of the asteroid to get a differential 3 instrumental magnitude for each image. I then selected a non- -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 UT hours on 2003 Sept 6 variable check star in our field similar in brightness to the asteroid. For each image I found a differential instrumental magnitude for Figure 1: Composite lightcurve for (1635) Bohrmann for a this check star with respect to the same comparison star used for rotation period of 11.73 ± 0.01hours. These data are light time the asteroid differential magnitude. The standard deviation of this corrected. The error bars are a one-sigma estimation of the differential instrumental magnitude was then used to estimate the uncertainty with respect to the local comparison star used for each uncertainty in the differential instrumental magnitude of our night. asteroid.

Minor Planet Bulletin 31 (2004) 3

LIGHTCURVE ANALYSIS OF KORONIS FAMILY Table 1: Observing session details. ASTEROID 1635 BOHRMANN Observer Date Obs Phase Robert D. Stephens Stephens Sept 17 85 3.3 Santana Observatory Stephens Sept 18 86 2.9 11355 Mount Johnson Court Stephens Sept 19 21 2.4 Rancho Cucamonga, CA 91737 USA Stephens Sept 20 94 2.0 [email protected] Stephens Sept 21 33 1.5 Stephens Sept 22 62 1.1 Brian D. Warner Warner Sept 29 79 1.9 Palmer Divide Observatory Warner Oct 02 59 3.2 17995 Bakers Farm Road Total 519 Colorado Springs, CO 80908 [email protected] analysis routine developed by Alan Harris (Harris et al., 1989). (Received: 15 October) This program allows combining data from different observers and adjusting the zero points to compensate for different equipment and comparison . All observations were corrected for light The lightcurve for 1635 Bohrmann was obtained by the time. All observations were unfiltered. Dark frames and flat authors in September and October 2003. The rotational fields were used to calibrate the images. period was determined to be 11.730 ± 0.005 hours with an amplitude of 0.28 ± 0.03 mag. Bohrmann was discovered on March 7, 1924 by Karl Reinmuth at Heidelberg. It is named in honor of Alfred Bohrmann who was at the Königstuhl Observatory from 1924 to 1969. He was a well- Our choice of Bohrmann as a target was suggested by Stephen M. known observer of minor planets, publishing 700 observations. Slivan’s Koronis asteroid web site based upon inputted observing Based upon its H value, Bohrmann is estimated to be between 17 parameters. For many , Stephen Slivan has conducted a and 37 km in diameter. study of Koronis asteroids to determine rotational periods and spin vectors. In a letter to Nature he reported that the Koronis family Stephens started this project. However, the telescope used for the seems to be divided into two ‘spin cluster’ groups, each with observations was temporarily mounted in the observatory in such a similar rotational periods and spin vectors. One group averaged manner that its view to the south is somewhat restricted. After the about 3 rotations per day (8 hours) while the other averaged about first night of data he quickly realized that the asteroid was rapidly 2 rotations per day (12 hours). 1635 Bohrmann rotates 11.73 headed south and after a few nights would be below the south wall hours per day and so it apparently belongs to this second group. of the observatory. To make matters worse, with either an 8 or 12 hour rotational period, the asteroid largely showed the same face General descriptions of the equipment and procedures used at to Earth each night. Since Stephens could only observe the first Santana Observatory and the Palmer Divide Observatory have maximum, it was very difficult to remove aliases in the period. been previously published (Stephens 2003, Warner 2003). After five nights, he could not eliminate 7.9 or 15.8 hours as Stephens used a 0.35m F/5.7 SCT with an SBIG ST-9E CCD possible periods. When Stephens could no longer observe the camera generally operating at -10ºC. Exposures were 180s. asteroid, Warner contributed two more sessions, one of which Warner used a 0.5m F/8.1 Ritchey-Chretien using an FLI IMG- caught the second maximum and eliminated the aliases. 1001E camera at -30ºC. Exposures were 60 seconds. The observations from both observatories were taken unfiltered. Aperture was done using the software program However, using the method described in Slivan’s Nature letter, “Canopus” developed by Brian Warner and including the Fourier observations using a Johnsons-Cousins V filter were obtained on September 19, 2003 of a nearby standard star (L092-288, 00h 57m 17s +00d 36m 46s e 2000.0) listed on Slivan’s web site. V filter observations of the asteroid and comparison stars were then obtained and a zero point adjustment was applied to the instrumental magnitudes. The resulting average V brightness for the asteroid was 14.45 ± 0.05.

Table 1 shows that 519 observations over 8 sessions between September 17 and October 2 were used to derive the synodic rotational period of 11.73 ± 0.005 hours with an amplitude of 0.28 ± 0.02 magnitude. During this period, Bohrmann passed through opposition and the phase angle changed from 3 to 1 and back to 3 degrees.

References

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 Figure 1: Lightcurve of 1635 Bohrmann based upon a derived Observations of Asteroids 3, 40, 60, 261, and 863.” Icarus 77, period of 11.730 ± 0.005 hours. 171-186.

Minor Planet Bulletin 31 (2004) 4

Slivan, S. M. (2002). “Spin Vector Alignment of Kornis Gamily estimated to be 41 km in diameter. Four hundred seventy Asteroids”. Nature 419, 49-51. observations over seven nights between August 8 and 22, 2003 were used to derive the synodic rotational period of 8.63 ± 0.005 Slivan, S. M. (2003). “A Web-Based Tool, To Calculate hours with an amplitude of 0.15 ± 0.04 magnitude. During this Observability of Koronis Program Asteriods”. Minor Planet period, the phase angle changed from 11 to 8 degrees. Bulletin 30, 71-72. Lanzia was reported by Carlson (1980) to have a 4.322 hour Stephens, R. D. (2003). “Photometry of 2134 Dennispalm, 2258 rotational period. However, Weidenschilling et al. (1990) reported Viipuri, 3678 Mongmanwai, 4024 Ronan, and 6354 Vangelis”. that the rotational period was 8.6 hours. This unusual four-peaked Minor Planet Bulletin 30, 46-48. lightcurve helps explain the initial half period results obtained in 1980. These data was sent to Mikko Kassalainen at the University Schmadel, L. (1999). “Dictionary of Minor Planet Names”, 4th of Helsinki and combined with other data. However, a unique edition. Springer-Verlag, Heidelberg, Germany. pole solution could not be determined. More observations at future oppositions in November 2004 and January 2006 are Warner, B.D. (2003). “Lightcurve Analysis for Asteroids 436 needed. Patricia, 3155 Lee, 4254 Kamel, 5940 Feliksobolev, (16558) 1991

VQ2 and (45656) 2000 EE45”. Minor Planet Bulletin 30, 21-24.

PHOTOMETRY OF 683 LANZIA, 1101 , 1499 PORI, 1507 VAASA, AND 3893 DELAETER

Robert D. Stephens 11355 Mount Johnson Court Rancho Cucamonga, CA 91737 USA [email protected]

(Received: 22 September)

Results for the following asteroids (lightcurve period and amplitude) observed from Santana Observatory during the period July to September 2003 are reported: 683 Lanzia (8.63 ± 0.005 hours and 0.15 mag.), 1101 Figure 1: Lightcurve of 683 Lanzia based upon a derived period Clematis (12.68 ± 0.01 hours and 0.40 mag.), 1499 Pori of 8.63 ± 0.005 hours. The 0.00 Phase is equal to JD (3.36 ± 0.01 hours and 0.28 mag.), 1507 Vaasa (34.07 ± 2452861.761257 (corrected for light-time). 0.01 hours and 0.24 mag.), 3893 Delaeter (13.83 ± 0.01 hours and 0.33 mag.). 1101 Clematis

This main-belt asteroid was discovered on September 22, 1928 by Santana Observatory (MPC Code 646) is located in Rancho K. Reinmuth at Heidelberg. It is named after a vine or herb of the Cucamonga, California at an elevation of 400 meters and is buttercup family having three leaflets on each leaf and usually operated by Robert D. Stephens. All observations in addition to white or purple flowers. Over 12 sessions between July 8 and the details of the equipment used can be found in Stephens (2003) August 4, 2003, 539 observations were obtained and used to and at the author’s web site (http://home.earthlink.net/ derive the synodic rotational period of 12.68 ± 0.01 hours with an ~rdstephens/default.htm). Most of the asteroids were selected amplitude of 0.40 ± 0.05 magnitude. During this period, the phase from the “CALL” web site “List of Potential Lightcurve Targets” angle changed from 12 to 8 degrees. (Warner 2003). 683 Lanzia was selected from Mikko Laasalainen’s “Future Alert List” of asteroids in need of This was a particularly difficult target due to the dense star field in observations for pole position determination. This list can also be which the asteroid was moving. It was selected due to its high found at the “CALL” web site. declination. During the summer months, few asteroids are visible all night from the temporary location that the telescope is currently Aperture photometry was done using the software program mounted. The dense star field resulted in about a third of the data “Canopus” developed by Brian Warner and including the Fourier not being usable as background stars entered the annulus analysis routine developed by Alan Harris (Harris et al, 1989). measuring the target. After eliminating those observations, there This program allows combining data from different observers and were still many spurious measurements with no known cause. adjusting the zero points to compensate for different equipment One of the causes could possibly be dim background stars not and comparison stars. All observations were unfiltered. Dark easily visible in the annulus. Due to these spurious observations, frames and flat fields were used to calibrate the images. it was difficult to do an analysis find a solution that fit the observations. Petr Parvec of Lenka Sarounova Astronomical 683 Lanzia Institute assisted in the analysis and identified three possible solutions in resonance with each other. Further investigation of Discovered July 23, 1909 by M. Wolf at Heidelberg, Lanzia is a some of the observations narrowed it to one solution of 12.68 member of the Main Belt III family. It is named in honor of Karl hours. Lanz, founder of the Heidelberg Academy of Sciences and is Minor Planet Bulletin 31 (2004) 5

Figure 2: Lightcurve of 1101 Clematis based upon a derived Figure 4: Lightcurve of 1507 Vassa based upon a derived period period of 12.68 ± 0.01 hours. The 0.00 Phase is equal to of 34.07 ± 0.01 hours. The 0.00 Phase is equal to 2452829.857682 JD (corrected for light-time). 2452883.891013 JD (corrected for light-time).

1499 Pori 3893 DeLaeter

Discovered by Y. Väisälä on October 16, 1938 at Turku, Pori Asteroid 3893 was discovered March 20, 1980 by M. P. Candy at belongs to the Marias Family. It is named for an important Bickley. It is named in honor of John DeLaeter, a retired Finnish town and port in the Gulf of Bothnia. One hundred professor at Curtin University, Western Australia, in recognition seventy two observations over three sessions between August 5 of his pioneering application of spectrometry to a range of and 9, 2003 were used to derive the synodic rotational period of astrophysical, chemical, geological and nuclear problems over 3.36 ± 0.01 hours with an amplitude of 0.28 ± 0.03 magnitude. many decades. Based upon its H value, DeLeater is presumed to During this period, the phase angle was 10 degrees. Based upon be 5 to 12 km in size. It is a member of the Hungaria family. On its H value, Pori is estimated to between 17 and 37 km in eleven nights between June 17 and July 7, 2003, 563 observations diameter. were obtained and used to determine the synodic rotational period of 13.83 ± 0.01 hours with an amplitude of 0.33 ± 0.06 magnitude. During this period, the phase angle changed from 22 to 25 degrees.

Figure 3: Lightcurve of 1499 Pori based upon a derived period of 3.36 ± 0.01 hours. The 0.00 Phase is equal to 2452856.946239 JD (corrected for light-time). Figure 5: Lightcurve of 3893 DeLaeter based upon a derived 1507 Vaasa period of 13.83 ± 0.01 hours. The 0.00 Phase is equal to 2452807.787052 JD (corrected for light-time). Vassa is a main-belt asteroid discovered by L. Oterma at Turku on September 12, 1939. It is named for an important Finnish town Acknowledgements and port on the Gulf of Bothnia. Based upon its H value, Vaasa is estimated to be between 7 and 15 km in diameter. On 11 nights Many thanks to Brian Warner for his continuing work and between August 25 and September 7, 2003, 747 observations were enhancements to the software program “Canopus” which makes it obtained and used to derive the synodic rotational period of 34.07 possible for amateur astronomers to analyze and collaborate on ± 0.01 hours with an amplitude of 0.24 ± 0.04 magnitude. During asteroid rotational period projects and for maintaining the CALL this time, the phase angle was 9 degrees.

Minor Planet Bulletin 31 (2004) 6

Web site which helps coordinate collaborative projects between Stephens, R. D. (2003). “Photometry of 2134 Dennispalm, 2258 amateur astronomers. Viipuri, 3678 Mongmanwai, 4024 Ronan, and 6354 Vangelis”. The Minor Planet Bulletin, 30(3), pp. 46-48. References Stephens, R. D. (2003). “Santana Observatory”. http://home. Carlsson, Lagerkvist, C. I., 1980. “Physical studies of asteroids. I - earthlink.net/~rdstephens/default.htm. Photoelectric observations of the asteroids 38, 218, 268, 344, 485, 683, 690 and 792.” and Astrophysics Supplement Warner, B. (2003). “Potential Lightcurve Targets”. http://www Series 44, Apr. 1981, pp. 15-22. .minorplanetobserver.com/astlc.targets.

Harris, A. W., Young, J. W., Bowell, E., Martin, L. J. Millis, R. Warner, B. (2003). “Mikko Kaasalainen's Alert List and FAQ”. L., Poutanen, M., Scaltriti, F., Zappala, V., Schober, H. J., http://www.minorplanetobserver.com/astlc/shape_targets.htm Debehogne, H., and Zeigler, K. W., 1989. “Photoelectric Observations of Asteroids 3, 40, 60, 261, and 863.” Icarus 77, pp. Weidenschilling, S. J., Chapman, C. R., Davis, D. R., Greenberg, 171-186. R., Levy, D. H., 1990. “Photometric geodesy of main-belt asteroids. III - Additional lightcurves.” Icarus 86 pp. 402-447. Schmadel, Lutz D., “Dictionary of Minor Planet Names, 4th Edition.” Springer, 1999.

LIGHTCURVE ANALYSIS OF ASTEROIDS The rotational periods of all objects were unknown at the time that 1225, 1301, 2134, 2741, AND 3974 the observations were made. Since then, two of the objects have had synodic periods published. These are 2134 Dennispalm, Donald P. Pray Stevens (2003), who measured the period as 4.09+0.01h with an Carbuncle Hill Observatory amplitude of 0.30+0.04m, and 1225 Ariane, R. Ditteon, E. P.O. Box 946 Tollefson, and A. Twarek (2003), who measured the period as Coventry, RI 02816 5.505+0.002h. [email protected] Observations and Results (Received: 15 September Revised: 6 October) 1225 Ariane

Lightcurve periods and amplitudes are reported for five Discovered by H. Van Gent at Johannesburg in 1930, 1225 Ariane asteroids observed at Carbuncle Hill Observatory during was determined to have a synodic period of 5.529+0.002h with an February – June 2003. The following synodic periods amplitude of 0.40+0.02m. 99 images taken in three sessions and amplitudes were determined: between February 8 and March 10, 2003 were used to make this 1225 Ariane 5.529 +0.002h, 0.40 +0.02m; measurement. This period is slightly longer (0.02h) than that 1301 Yvonne 7.320 +0.005h, 0.60 +0.03m; found by R. Ditteon, E. Tollefson, and A. Twarek, (2003), who 2134 Dennispalm 4.114 +0.002h, 0.37 +0.05m; measured the period as 5.505+0.002h. The lightcurve is shown in 2741 Valdivia 4.096 +0.001h, 0.40 +0.03m; and Figure 1. 3974 Verveer 8.51 +0.02h, 0.37 +0.03m.

Introduction

Carbuncle Hill Observatory, MPC code 912, is located about twenty miles west of Providence, RI, in one of the darkest spots in the state. All observations were made using an SBIG ST-9E CCD camera, binned 1x1, coupled to a 0.3m f6.9 SCT. This combination produced an image dimension of 16x16 arc min. All observations were taken through the “clear” filter.

All targets were selected from the “Call” website “List of Potential Lightcurve Targets” (Warner 2003). Targets were selected based on their location above the local horizon, as well as for their suitability to the equipment. A further requirement was that the targets not have published periods in the list of “Minor Planet Lightcurve Parameters” maintained by Harris (2001). Figure 1. The lightcurve of 1225 Ariane. The synodic period was Image calibration via dark frames and flat field frames was found to be 5.529+0.002h with an amplitude of 0.40+0.02m. performed using “MaxIm DL”. Lightcurve construction and analysis was accomplished using “Canopus” developed by Brian 1301 Yvonne Warner. Differential photometry was used in all cases, stars from the USNO–A 2.0 catalog being used as references. All L. Boyer discovered this asteroid in 1934 at Algiers. The synodic measurements were corrected for light time. period was determined to be 7.320+0.005h with an amplitude of 0.60+0.03m. During four sessions between February 27 and

Minor Planet Bulletin 31 (2004) 7

March 7, 2003, 195 images were taken to derive this period. See Figure 2.

Figure 4. The lightcurve for 2741 Valdivia. The synodic period was found to be 4.096+0.001h with an amplitude of 0.40+0.03m.

Figure 2. The lightcurve of 1301 Yvonne. The synodic period was 3974 Verveer found to be 7.320+0.005h with an amplitude of 0.60+0.03m. This asteroid was discovered by E. Bowell at the Anderson Mesa 2134 Dennispalm station in Flagstaff in 1982. 145 images were taken between April 29 and May 4, 2003, in five sessions. The measured synodic This object was discovered at Palomar by C. Kowal in 1976. The period was 8.51+0.02h with an amplitude of 0.37+0.03m. See its synodic period was determined to be 4.114+0.002h with an lightcurve in Figure 5. amplitude of 0.37+0.05m. There is minor disagreement (0.012h) with the determination by R. Stevens (Stevens, 2003), when both measurements were stretched toward each other using their stated tolerances. 118 images were taken in three sessions over an eighteen-night span between March 7 and March 25, 2003. See Figure 3.

Figure 5. The lightcurve for 3974 Verveer. The measured synodic period was 8.51+0.02h with an amplitude of 0.37+0.03m.

Acknowledgements

Special thanks is given to Brian Warner for his guidance in Figure 3. The lightcurve for 2134 Dennispalm. The synodic period interpreting this data, and his tireless work to improve the was determined to be 4.114+0.002h with an amplitude of astrometry program Canopus and the instrument control program 0.37+0.05m. Connections. His efforts help make this field of research approachable to the amateur astronomer. 2741 Valdivia References This asteroid was discovered in 1975 at Cerro El Roble by C. Torres. From May 4 to June 17, 2003, a total of 124 images were Ditteon, R., Tollefson, E., and Twarek, A. (2003). “Asteroid taken during four sessions. The derived synodic period was Photometry Using a Remote, Commercial Telescope: Results for 4.096+0.001h with an amplitude of 0.40+0.03m. The lightcurve is Asteroids 808, 1225, And 28753.” The Minor Planet Bulletin 30, shown in Figure 4. No. 4, 76-77.

Harris, Alan W. (2001). “Minor Planet Lightcurve Parameters”, found on the Minor Planet Center web site: http://cfa- www.harvard.edu/iau/lists/LightcurveDat.html.

Minor Planet Bulletin 31 (2004) 8

Stevens, R. D. (2003). “Photometry of 2134 Dennispalm, 2258 Warner, B.D. (2003). Collaborative Asteroid Lightcurve Link Viipuri , 3678 Mongmanwai, 4024 Ronan, and 6354 Vangelis.” (CALL) web site. http://www.MinorPlanetObserver.com/astlc/ The Minor Planet Bulletin 30(3), 46-48. default.htm.

CLOSE MUTUAL APPROACHES OF MINOR PLANETS 2. Closest approach: gives the minimum geocentric distance (in IN 2004 seconds of arc) and the position angle (in degrees) of the nearest minor planet with respect to the farthest one. Edwin Goffin Aartselaarstraat 14 3. Minor planet 1: contains information about the nearest minor B-2660 Hoboken (Antwerpen) planet: Belgium • number and name [email protected] • visual magnitude • parallax in seconds of arc (Received: 2 October) • apparent motion in seconds of arc per hour • position angle of the direction of motion in degrees

The table below lists 34 cases where one minor planet 4. Minor planet 2: information about the farthest minor planet. comes to within 120" of another and both are of The same data as for the nearest one are given. In addition the magnitude 16 or brighter. A challenge for minor planet right ascension and declination (2000.0) are printed. observers! 5. and : Here I present a list of close approaches between numbered minor • of the Sun in degrees planets larger than 40 km during 2003 where: • elongation of the Moon (degrees) • illuminated fraction of the Moon in % • the elongation of the Sun is more than 30°. • both minor planets are brighter than visual magnitude 16. The author wants to acknowledge the Computer Center of Agfa- • and the minimum geocentric separation is less than 120". Gevaert N.V. (Mortsel, Belgium), where the computations were executed. The table gives the following data:

1. Date: date and time of closest geocentric approach (in U.T.). All other information is given for this instant.

Close mutual approaches of minor planets

======" 0 (Dist. < 120 ; El. Sun > 30 ; magn. < 16.0)

D a t e (U.T.) Min. Pos. M i n o r p l a n e t 1 M i n o r p l a n e t 2 dist. ang. N a m e Vis. Hor. Motion N a m e Vis. Hor. Motion Right Decli- Elon- Ill. mag. par. per pos. mag. par. per pos. ascens. nation gation frac. hour ang. hour ang. (2000.0) (2000.0) Sun Moon Moon

h m " 0 " "/h 0 " "/h 0 h m 0 ' 0 0 % 2004 jan 18 14 15.8 55.11 171 163 Erigone 15.23 2.71 56.26 95 563 Suleika 14.85 2.22 43.62 99 16 43.08 -18 23.7 46 13 17 jan 18 22 12.2 84.26 24 14.44 2.55 60.78 98 300 Geraldina 15.88 2.18 49.59 94 17 20.35 -23 24.6 37 17 14 jan 21 11 59.5 86.53 162 124 Alkeste 13.27 2.73 69.88 89 598 Octavia 15.46 2.31 54.81 94 17 57.34 -21 20.0 31 29 1 feb 4 2 7.0 94.53 70 14.72 2.82 53.53 63 1001 Gaussia 15.41 2.78 53.30 74 0 37.13 +10 44.6 58 97 94 feb 7 0 5.7 62.41 352 497 Iva 14.64 4.15 56.75 73 152 Atala 13.97 3.04 32.90 67 2 30.07 +19 28.6 83 104 99

? feb 14 20 53.4 6.29 128 679 Pax 13.12 4.90 67.09 45 256 Walpurga 15.66 2.91 24.64 59 3 48.03 + 6 16.5 90 165 37 mar 3 3 4.5 11.68 258 231 Vindobona 15.25 2.77 20.06 95 3578 Carestia 14.19 2.73 23.75 114 4 51.91 +27 50.9 92 46 84 mar 31 18 40.1 66.31 122 514 Armida 15.00 2.46 51.66 69 28 Bellona 13.27 2.34 46.09 74 21 38.43 -11 52.9 48 168 76 apr 1 9 26.6 32.17 4 11.82 4.34 59.63 82 893 Leopoldina 15.27 2.90 34.48 74 19 18.40 - 7 56.4 82 149 81 apr 11 15 24.7 32.28 352 6 Hebe 10.59 3.71 38.10 82 129 Antigone 12.51 3.08 25.60 83 7 28.59 +20 25.9 88 166 55

apr 25 21 22.3 54.08 319 1585 Union 15.92 3.52 26.15 78 75 Eurydike 14.99 2.76 13.11 122 9 10.95 +18 59.4 98 33 33 may 11 15 12.4 63.88 319 12.53 4.18 78.31 66 479 Caprera 14.84 3.21 57.00 73 23 06.51 - 6 48.3 66 23 48 may 28 23 32.5 114.17 288 451 Patientia 11.30 3.84 31.64 264 159 Aemilia 12.85 3.77 29.37 276 16 32.86 -13 48.7 171 72 66 jun 12 12 50.8 3.57 192 1015 Christa 15.30 2.30 45.20 104 537 Pauly 15.54 2.05 36.63 105 9 00.05 +20 33.1 49 110 25 jun 14 18 26.9 45.31 210 284 Amalia 15.73 2.68 51.91 102 444 Gyptis 13.96 2.33 45.58 99 8 52.09 +10 41.0 48 82 10

jun 29 4 46.0 109.29 184 678 Fredegundis 14.72 2.65 53.60 109 1467 Mashona 15.37 2.02 36.22 117 9 53.60 + 8 01.9 50 84 83 jul 1 6 24.3 40.83 197 786 Bredichina 14.17 2.99 49.93 124 977 Philippa 15.59 2.68 43.83 127 11 30.49 +17 41.8 67 92 96 jul 8 1 55.2 76.11 225 161 Athor 14.52 3.03 52.74 119 1269 Rollandia 15.37 2.22 38.78 113 11 11.20 + 7 09.2 59 166 64 jul 9 23 57.9 31.99 185 627 Charis 15.79 2.52 52.56 81 638 Moira 15.98 2.32 45.80 79 4 02.68 +15 17.2 46 37 45 jul 14 8 4.7 105.29 354 14.28 3.22 52.27 121 1567 Alikoski 15.30 2.79 43.75 130 12 22.80 + 6 38.0 70 107 11

aug 29 9 23.0 69.68 164 10.54 4.21 75.87 90 377 Campania 14.14 3.18 54.66 97 6 08.96 +19 29.8 64 125 99 sep 4 21 55.9 24.37 296 442 Eichsfeldia 14.09 5.20 20.15 110 856 Backlunda 15.03 4.76 20.65 131 18 34.24 -21 13.4 115 133 67 sep 9 0 58.6 64.15 350 15.56 2.78 59.92 99 171 14.12 2.54 54.52 101 8 08.36 +20 20.1 46 22 28 sep 10 12 30.5 30.80 346 472 Roma 14.08 2.90 65.79 98 3578 Carestia 14.81 2.00 39.69 114 8 32.64 +14 59.7 41 10 17 sep 11 19 23.7 77.70 349 395 Delia 15.32 3.83 36.24 92 1107 Lictoria 15.40 2.60 19.33 104 17 27.23 -21 37.0 93 125 8

sep 13 17 30.4 80.37 51 387 Aquitania 10.93 6.18 22.79 133 661 Cloelia 14.89 3.60 8.60 341 19 55.41 -25 53.5 124 135 1 oct 2 6 31.1 51.08 333 12.26 5.13 54.21 82 559 Nanon 14.43 3.66 36.28 93 18 45.36 -24 54.3 90 130 86 oct 9 13 18.8 36.91 6 230 Athamantis 11.35 4.99 25.33 113 790 Pretoria 14.34 2.62 9.32 149 5 55.27 +22 31.6 107 53 22 oct 29 11 4.1 67.06 164 270 Anahita 12.50 5.45 65.41 78 60 Echo 13.23 3.52 32.47 83 20 24.66 -16 28.9 88 106 97 nov 1 8 56.4 99.37 100 584 Semiramis 13.73 3.38 44.32 121 1069 Planckia 14.98 2.92 41.49 104 9 46.34 + 9 29.6 73 59 82

nov 8 4 33.5 86.17 4 406 Erna 15.73 2.92 59.04 83 696 Leonora 15.23 2.35 42.79 79 18 43.41 -24 10.6 53 111 23 nov 26 1 9.6 14.50 181 11.34 3.56 66.53 77 661 Cloelia 15.67 2.56 42.73 69 20 41.71 -20 06.2 63 106 98 ? dec 4 11 9.0 15.14 137 1963 Bezovec 14.26 6.49 51.70 56 14.25 3.92 8.55 118 9 48.85 +18 15.3 109 15 56 dec 5 8 28.1 94.51 192 13.75 2.88 65.35 108 834 Burnhamia 15.21 2.50 56.22 109 13 50.01 -10 35.9 44 43 47

Minor Planet Bulletin 31 (2004) 9

CLOSE APPROACHES OF MINOR PLANETS TO NAKED 2. Closest approach: the two columns give the position of the EYE STARS IN 2004 minor planet with respect to the star: • the minimum geocentric distance in seconds of arc Edwin Goffin • the position angle in degrees, measured from north over east Aartselaarstraat 14 B-2660 Hoboken (Antwerpen) 3. Minor planet: gives information about the minor planet: Belgium • number and name [email protected] • visual magnitude • apparent motion in seconds of arc per hour (Received: 2 October) • parallax in seconds of arc

4. Star: the following data of the star are given: A list is presented of approaches of minor planets • Hipparcos star number brighter than magnitude 14 to naked eye stars. This may • visual magnitude be helpful in finding some faint minor planets. • right ascension for the equinox 2000.0 • declination (2000.0) The accompanying table lists close approaches of minor planets to stars during 2004 where: 5. Sun and Moon: • elongation of the Sun in degrees • The event takes place more than 30° from the Sun. • elongation of the Moon (degrees) • The minor planet is brighter than visual magnitude 14. • illuminated fraction of the Moon in % • The star is brighter than magnitude 6. • The minimum angular separation is smaller than 120". The observed minimum distance depends on the location of the observer on the Earth’s surface but is always comprised between This list can be helpful in locating some otherwise faint minor the minimum geocentric distance plus and minus the parallax. An planets. By carefully drawing the star field around the predicted will be visible somewhere on the Earth when the position down to the magnitude of the minor planet and comparing parallax is greater than the geocentric separation. it to the situation some time later, one can detect the intruder by its apparent motion. The close approaches in this article were computed at the Computer Center of Agfa-Gevaert N.V., Mortsel, Belgium. The information contained in the list is divided into 5 groups:

1. Date: gives the date and time in U.T. of the closest geocentric approach. All subsequent data pertain to this instant.

Close approaches of minor planets to stars " 0 ======(Dist. < 120 ; El. Sun > 60 Star < 6.0 ; Min. pl. < 14.0 )

M i n o r p l a n e t S t a r D a t e (U.T.) Minim. Pos. N a m e Vis. App. Hor. Designation Vis. Right Decli- Elon- Ill. dist. ang. mag. mot. par. mag. ascens. nation gation frac (2000.0) (2000.0) Sun Moon Moon

h m " 0 "/h " h m 0 ' 0 0 % 2003 dec 28 5 44.5 49.37 198 121 Hermione 12.3 28.35 3.57 HIP 35941 5.9 7 24.56 +27 38.3 166 129 28 dec 30 9 14.4 80.64 196 44 Nysa 11.6 59.74 3.44 FK6 523 4.2 14 12.90 -10 16.4 63 153 50 dec 31 21 11.6 48.67 196 13.0 34.38 3.72 FK6 1182 5.2 7 2.41 +24 12.9 175 78 64 2004 jan 7 11 16.4 28.86 16 82 Alkmene 13.6 58.72 2.89 FK6 3224 5.5 15 32.61 -19 40.2 50 131 100 jan 11 2 31.5 19.31 134 12.8 10.76 4.64 HIP 15900 3.8 3 24.81 + 9 1.7 120 99 88

jan 13 13 9.3 30.33 16 37 Fides 13.2 45.72 2.53 HIP 76569 6.0 15 38.27 -21 1.0 55 56 68 jan 20 6 36.3 80.65 265 185 Eunike 12.1 30.87 4.59 FK6 2337 5.2 4 34.19 - 8 13.9 120 134 4 jan 21 18 27.5 58.33 182 92 Undina 12.6 55.17 2.23 HIP 89341 3.9 18 13.76 -21 3.5 27 27 0 X jan 31 14 15.5 1.74 160 739 Mandeville 13.0 45.53 4.43 FK6 1375 5.1 14 24.19 + 5 49.2 98 140 71 feb 7 13 44.8 14.01 203 13.8 28.65 3.86 FK6 2824 5.4 10 16.68 +13 43.7 166 2 98

feb 12 8 8.1 40.08 5 476 Hedwig 13.8 56.27 3.16 FK6 3363 5.9 17 8.79 -30 24.2 64 43 64 feb 18 11 9.1 105.97 320 739 Mandeville 12.7 37.62 4.90 FK6 3163 4.9 14 41.65 + 8 9.7 111 91 5 feb 26 21 44.4 10.16 359 270 Anahita 13.4 67.30 3.79 FK6 3430 4.7 17 59.79 -23 49.0 67 144 38 feb 28 3 16.7 86.14 204 772 Tanete 13.8 40.82 3.14 HIP 84893 4.5 17 21.01 -21 6.8 77 167 50 feb 28 9 22.3 67.64 165 250 Bettina 13.1 44.10 2.99 FK6 2214 5.9 3 1.90 +26 27.7 71 22 52

feb 29 0 47.3 52.43 10 154 Bertha 13.6 47.54 2.51 HIP 93174 4.9 18 58.72 -37 6.4 58 155 58 mar 3 4 0.1 97.22 210 799 Gudula 13.8 34.86 5.55 HIP 49637 4.5 10 7.90 + 9 59.8 167 34 85 mar 3 5 50.6 104.63 349 13.8 52.09 2.40 FK6 1529 5.9 20 18.02 -21 48.6 41 175 85 mar 4 1 19.2 74.65 177 270 Anahita 13.3 65.96 3.92 HIP 89153 5.1 18 11.72 -23 42.1 71 144 91 mar 6 22 55.3 61.77 159 13.4 37.09 2.69 HIP 88175 4.7 18 0.48 - 3 41.4 77 101 100

mar 14 6 17.7 28.57 346 250 Bettina 13.2 49.71 2.82 HIP 15696 5.7 3 22.20 +27 36.5 61 146 46 mar 14 17 46.0 14.70 7 55 Pandora 13.4 38.53 3.02 HIP 89931 2.9 18 20.99 -29 49.7 79 3 40 mar 17 12 16.9 49.05 159 9.3 66.24 3.04 FK6 2216 5.8 3 1.94 - 9 57.7 48 84 13 mar 19 7 47.3 116.51 336 949 Hel 14.0 12.75 4.77 HIP 43970 5.3 8 57.25 +15 19.4 133 153 3 mar 19 16 15.3 62.80 160 52 12.1 52.94 2.57 HIP 14764 6.0 3 10.65 +11 52.4 49 64 2

Minor Planet Bulletin 31 (2004) 10

M i n o r p l a n e t S t a r D a t e (U.T.) Minim. Pos. N a m e Vis. App. Hor. Designation Vis. Right Decli- Elon- Ill. dist. ang. mag. mot. par. mag. ascens. nation gation frac (2000.0) (2000.0) Sun Moon Moon

h m " 0 "/h " h m 0 ' 0 0 % mar 20 8 27.8 58.77 345 28 Bellona 13.3 48.49 2.27 HIP 105668 5.6 21 24.19 -12 52.7 40 34 1 mar 22 5 38.3 89.87 167 236 Honoria 13.9 51.22 3.01 HIP 20873 6.0 4 28.39 +14 44.5 66 51 2 mar 25 1 53.0 114.41 208 419 Aurelia 11.6 15.61 6.58 HIP 69269 5.0 14 10.84 -16 18.1 148 164 16 mar 25 17 32.4 72.61 338 674 Rachele 12.7 64.67 2.91 FK6 114 4.4 3 11.63 +19 43.6 45 9 21 mar 28 18 33.1 74.69 227 337 Devosa 12.4 25.03 5.73 FK6 2666 5.7 8 31.51 +24 4.9 115 28 48

mar 29 17 35.5 35.43 329 13.2 10.69 4.16 FK6 2658 5.6 8 26.73 +12 39.3 116 21 57 mar 31 2 3.9 8.59 302 344 Desiderata 11.2 17.35 6.85 HIP 75379 5.0 15 24.20 -10 19.3 138 106 70 mar 31 3 3.3 62.96 7 11.4 21.69 2.84 HIP 32921 5.3 6 51.55 +21 45.7 91 23 70 apr 1 3 50.1 31.05 340 674 Rachele 12.6 65.95 2.86 HIP 15737 5.3 3 22.75 +20 44.5 41 84 79 apr 1 21 2.9 60.31 172 100 Hekate 13.0 42.56 3.34 HIP 95168 4.0 19 21.67 -17 50.8 82 142 85

apr 4 12 32.5 51.71 163 804 Hispania 13.5 60.05 2.48 HIP 12719 4.6 2 43.45 +27 42.4 33 134 99 apr 6 4 32.7 72.27 147 914 Palisana 13.2 87.84 3.65 FK6 3729 5.1 21 39.55 + 2 14.6 50 120 99 apr 12 13 50.2 80.62 9 12.6 34.25 5.52 HIP 64166 5.1 13 9.05 -23 7.1 165 92 45 apr 15 3 42.2 57.16 163 351 Yrsa 12.8 13.78 5.47 FK6 2918 5.5 11 30.48 +18 24.6 138 165 19 apr 15 16 12.6 106.10 161 79 Eurynome 13.1 41.91 3.39 HIP 100345 3.2 20 21.01 -14 46.9 81 37 15

apr 20 7 2.5 100.69 347 751 Fa‘na 13.8 67.80 3.18 FK6 1597 5.2 22 47.55 -19 36.8 55 63 1 apr 21 4 36.6 16.22 30 12.8 38.69 5.26 HIP 69612 5.4 14 14.85 +10 6.0 157 149 3 apr 21 6 5.1 73.32 154 690 Wratislavia 13.5 64.71 2.65 FK6 3871 5.1 23 20.34 + 5 22.9 39 58 3 apr 22 6 39.4 34.43 172 82 Alkmene 12.8 13.65 4.44 HIP 83176 5.9 16 59.96 -25 5.5 135 166 7 apr 23 19 0.3 92.48 26 39 Laetitia 10.5 32.49 4.25 HIP 68092 6.0 13 56.46 + 1 3.0 165 124 16

may 8 7 22.7 10.81 204 94 Aurora 13.5 36.59 2.76 FK6 2666 5.7 8 31.51 +24 4.9 76 152 83 may 11 16 50.0 37.06 359 247 Eukrate 13.3 32.36 3.52 HIP 74380 5.8 15 11.96 -48 44.6 149 83 47 may 11 17 18.7 15.69 359 247 Eukrate 13.3 32.36 3.52 HIP 74376 3.9 15 11.93 -48 44.3 149 83 47 may 15 1 47.3 20.00 158 80 Sappho 12.3 89.05 3.69 FK6 1008 5.4 0 20.60 + 8 11.4 46 8 15 may 20 3 13.9 60.80 159 50 Virginia 13.7 89.48 3.42 HIP 5737 5.3 1 13.73 + 7 34.5 39 50 1

may 21 9 39.7 19.31 191 72 Feronia 13.8 37.03 3.86 FK6 2794 5.9 9 56.43 + 8 56.0 87 64 4 may 25 3 47.4 71.46 12 783 Nora 12.6 29.83 9.31 FK6 1445 4.8 17 1.06 - 4 13.4 158 121 29 may 25 14 59.8 86.07 188 11.6 26.76 7.63 HIP 86313 5.9 17 38.16 -10 55.6 156 127 33 may 26 6 24.8 88.05 191 45 Eugenia 13.1 49.19 2.95 HIP 42911 4.1 8 44.68 +18 9.2 63 15 39 may 30 22 8.9 38.89 159 14.0 58.55 3.71 FK6 1623 5.5 23 47.94 - 2 45.7 73 152 85

may 31 15 7.8 11.23 175 653 Berenike 13.7 23.05 4.38 HIP 73536 5.8 15 1.82 - 0 8.4 148 18 91 jun 1 12 29.3 20.07 223 714 Ulula 12.9 29.88 5.25 HIP 72622 2.8 14 50.88 -16 2.5 153 3 96 jun 1 20 15.4 24.45 223 714 Ulula 12.9 29.63 5.24 HIP 72603 5.2 14 50.69 -15 59.8 153 8 97 jun 2 4 50.9 106.32 359 11.9 25.99 3.79 HIP 88380 5.5 18 2.85 -24 16.9 161 33 99 jun 6 1 14.0 1.50 332 796 Sarita 13.3 90.68 3.84 HIP 8833 4.8 1 53.56 + 3 11.3 48 91 88

jun 7 12 16.1 101.29 352 751 Fa‘na 13.5 57.52 4.00 HIP 910 5.0 0 11.26 -15 28.1 81 39 75 jun 12 23 35.5 94.32 151 690 Wratislavia 13.3 54.30 3.17 FK6 2039 5.9 0 36.79 +15 13.9 68 18 20 jun 12 23 57.3 52.39 29 146 Lucina 13.7 50.92 3.07 FK6 384 3.4 10 16.69 +23 25.0 65 118 20 jun 17 3 50.2 29.82 163 93 Minerva 12.1 23.73 4.59 HIP 113136 3.3 22 54.65 -15 49.3 107 100 1 jun 20 7 19.9 22.33 136 742 Edisona 13.8 24.25 4.66 HIP 98842 5.1 20 4.33 -32 3.4 150 174 6

jul 3 3 20.0 11.55 178 122 Gerda 12.6 27.70 3.83 HIP 89341 3.9 18 13.76 -21 3.5 171 19 99 jul 4 10 6.0 33.21 2 403 Cyane 13.6 30.02 4.24 HIP 97650 5.5 19 50.78 -10 45.8 162 20 94 jul 6 11 34.0 78.14 325 375 Ursula 13.1 45.07 2.78 FK6 74 2.0 2 7.17 +23 27.7 67 59 78 jul 7 5 7.0 110.60 250 199 Byblis 13.0 19.09 4.22 HIP 114119 4.6 23 6.68 -23 44.6 125 17 71 jul 12 15 29.9 106.48 357 13.4 64.00 2.64 FK6 2369 5.3 4 54.80 + 7 46.7 39 22 20

jul 13 11 54.1 55.29 175 12.3 62.79 2.93 HIP 20641 5.3 4 25.42 +22 12.0 43 2 14 jul 14 18 33.6 88.59 221 381 Myrrha 13.8 31.15 3.15 HIP 66936 5.5 13 43.06 + 3 32.3 89 118 7 jul 15 12 53.1 32.78 144 488 Kreusa 13.3 24.44 3.25 HIP 106654 5.8 21 36.18 -26 10.3 153 134 4 jul 17 8 37.9 105.14 178 494 Virtus 13.1 26.28 4.72 FK6 3471 5.3 18 33.96 -33 1.0 159 163 0 jul 18 13 41.5 111.88 170 91 Aegina 14.0 66.63 3.01 FK6 2326 4.3 4 26.31 +22 48.8 47 60 1

jul 19 21 47.9 84.69 176 270 Anahita 10.2 36.42 9.65 FK6 3565 5.7 19 37.06 -18 13.9 174 147 6 jul 25 22 45.2 84.24 1 238 Hypatia 13.7 57.36 2.75 HIP 22667 4.7 4 52.53 +14 15.0 50 149 59 jul 28 12 15.2 16.38 73 426 Hippo 13.2 23.64 4.11 FK6 3366 5.7 17 12.27 -39 30.4 132 13 85 aug 2 2 47.0 76.19 167 106 12.8 52.08 3.07 FK6 1115 5.5 4 9.17 +19 36.6 66 95 97 aug 3 21 52.4 80.78 166 93 Minerva 11.3 23.99 5.76 HIP 113136 3.3 22 54.65 -15 49.3 151 16 87

aug 4 9 20.8 83.38 172 91 Aegina 13.9 63.75 3.20 HIP 23068 6.0 4 57.81 +23 56.9 56 75 83 aug 9 19 18.4 97.99 169 141 Lumen 13.0 67.01 3.58 FK6 181 2.7 4 56.99 +33 10.0 61 11 32 aug 16 20 7.1 12.74 311 4 6.5 24.72 6.14 FK6 2001 5.0 0 4.50 -10 30.6 146 156 1 aug 23 11 48.8 60.35 191 12.2 26.29 3.85 HIP 80343 4.6 16 24.10 -20 2.2 96 7 51 aug 25 2 29.5 40.87 140 12.7 33.18 5.22 HIP 111954 4.2 22 40.66 -27 2.6 162 67 69

aug 30 23 17.6 87.43 165 503 Evelyn 13.8 27.73 4.12 HIP 105576 5.7 21 23.01 -22 40.1 157 33 99 sep 3 12 15.2 13.99 157 87 Sylvia 11.6 27.22 3.94 HIP 114375 4.8 23 9.92 -22 27.5 164 58 79 sep 5 0 53.3 109.60 314 781 Kartvelia 13.6 33.88 4.45 FK6 3868 6.0 23 19.40 -18 4.5 167 73 65 X sep 6 15 28.8 2.48 23 287 Nephthys 12.7 42.65 4.38 HIP 84012 2.4 17 10.38 -15 43.5 93 169 50 sep 8 8 8.0 75.64 201 7 Iris 11.3 55.20 2.37 FK6 1335 4.8 12 54.35 - 9 32.3 30 102 34

sep 8 23 12.4 24.50 199 455 Bruchsalia 13.6 48.49 3.83 HIP 78877 5.9 16 6.11 -23 36.4 77 142 29 sep 13 22 17.0 73.50 186 156 Xanthippe 13.4 58.19 3.82 HIP 80894 4.4 16 31.14 -16 36.8 77 85 1 X sep 20 15 47.0 2.59 189 202 Chryse‘s 13.0 29.09 3.19 HIP 27316 5.8 5 47.22 +14 29.3 91 163 39 sep 22 5 9.0 72.76 16 80 Sappho 11.3 31.71 6.70 HIP 20842 5.8 4 28.01 +21 37.2 110 152 56 X sep 22 15 16.9 0.08 191 344 Desiderata 12.0 83.35 4.87 HIP 80672 6.0 16 28.24 -37 10.8 72 33 61

sep 23 20 10.3 40.47 193 140 Siwa 13.2 65.57 3.50 HIP 78820 2.6 16 5.44 -19 48.3 62 57 74 sep 23 20 11.5 54.16 193 140 Siwa 13.2 65.57 3.50 HIP 78821 4.9 16 5.44 -19 48.1 62 57 74 sep 23 21 50.6 115.92 17 221 Eos 12.9 30.04 3.57 HIP 90806 5.1 18 31.44 -18 24.2 96 25 75 sep 26 8 15.4 61.91 338 539 Pamina 12.2 30.92 7.51 HIP 1067 2.8 0 13.24 +15 11.0 166 38 94 sep 28 19 59.0 109.53 19 39 Laetitia 12.0 53.63 2.42 HIP 73473 4.9 15 0.97 - 8 31.1 40 144 100

Minor Planet Bulletin 31 (2004) 11

M i n o r p l a n e t S t a r D a t e (U.T.) Minim. Pos. N a m e Vis. App. Hor. Designation Vis. Right Decli- Elon- Ill. dist. ang. mag. mot. par. mag. ascens. nation gation frac (2000.0) (2000.0) Sun Moon Moon

h m " 0 "/h " h m 0 ' 0 0 % oct 4 5 4.3 116.14 203 164 Eva 14.0 56.71 3.07 FK6 3275 5.9 16 8.73 -23 41.1 53 168 70 oct 5 16 15.3 25.53 14 213 Lilaea 13.8 64.94 3.15 HIP 80569 4.3 16 27.02 -18 27.4 55 152 57 oct 9 1 19.1 64.62 323 61 DanaΠ12.6 39.37 3.82 FK6 731 5.7 19 26.94 -29 44.6 92 154 26 oct 9 23 24.1 21.01 194 12.5 58.36 2.64 HIP 78400 5.6 16 0.32 -16 32.0 44 95 18 oct 15 23 42.1 13.25 2 344 Desiderata 12.1 90.04 4.41 HIP 86170 4.4 17 36.55 -38 38.1 63 40 4

oct 16 2 14.5 57.68 359 12.4 57.78 4.05 HIP 92931 5.9 18 56.01 -23 10.4 79 54 5 oct 17 5 28.3 109.06 152 12.0 17.16 4.56 FK6 1115 5.5 4 9.17 +19 36.6 140 176 12 oct 21 7 19.4 26.88 187 389 Industria 13.3 65.28 2.68 HIP 78877 5.9 16 6.11 -23 36.4 35 59 54 oct 22 16 41.4 2.22 187 389 Industria 13.3 65.42 2.67 FK6 3275 5.9 16 8.73 -23 41.1 35 78 70 oct 24 17 1.5 17.37 342 192 Nausikaa 10.8 25.05 6.18 FK6 2525 5.7 6 49.69 +32 36.4 110 111 87

oct 27 2 54.8 41.42 216 944 Hidalgo 13.4 87.03 7.45 FK6 1047 5.6 1 42.06 +35 14.7 156 28 99 nov 1 5 27.1 90.94 14 250 Bettina 13.1 44.86 2.99 FK6 384 3.4 10 16.69 +23 25.0 71 62 85 nov 4 14 15.0 87.55 13 402 ChloΠ13.3 19.45 4.75 HIP 35987 5.4 7 24.97 +11 40.2 110 21 56 nov 9 16 45.3 102.01 29 12.8 67.82 2.68 FK6 1335 4.8 12 54.35 - 9 32.3 31 9 11 nov 10 4 10.2 49.96 352 179 Klytaemnestr13.5 46.45 3.18 HIP 99572 5.9 20 12.43 -12 37.1 74 106 8

nov 14 2 16.2 61.77 323 105 Artemis 13.0 36.20 4.57 HIP 23794 5.1 5 6.76 - 4 39.3 144 149 3 nov 18 9 36.0 89.07 160 150 Nuwa 12.0 30.34 5.09 FK6 1079 5.5 2 51.49 +15 4.9 168 89 41 nov 18 23 11.4 75.69 25 944 Hidalgo 13.7 62.11 7.30 HIP 3881 4.5 0 49.81 +41 4.7 138 73 47 nov 20 21 13.0 84.04 210 98 Ianthe 13.8 73.96 2.93 FK6 1348 5.3 13 26.72 -12 42.5 34 144 68 nov 21 22 5.2 105.34 162 12 Victoria 11.2 28.63 4.98 HIP 29616 5.9 6 14.48 +17 54.4 146 90 77

nov 29 0 27.3 70.92 198 432 Pythia 13.8 69.82 3.15 HIP 65198 5.7 13 21.69 + 2 5.2 49 106 96 dec 1 12 56.4 10.41 355 419 Aurelia 12.9 88.70 3.21 HIP 92390 5.4 18 49.67 -20 19.5 32 159 81 dec 2 12 16.0 117.81 152 13.7 49.38 3.36 HIP 107095 5.3 21 41.55 -14 2.9 72 168 73 dec 3 3 34.1 14.76 341 640 Brambilla 13.9 31.34 3.62 FK6 2391 5.2 5 11.69 +16 2.7 170 63 68 dec 7 13 25.1 51.43 4 709 Fringilla 13.6 28.33 4.23 HIP 31832 5.0 6 39.33 +42 29.3 151 97 25

dec 11 11 4.2 112.58 342 11.2 54.93 3.08 HIP 107232 5.9 21 43.07 -14 24.0 63 72 1 dec 14 8 11.1 101.96 132 2892 Filipenko 14.0 28.13 5.45 FK6 2249 5.3 3 32.44 +46 3.4 147 126 8 dec 15 4 10.8 116.97 136 71 Niobe 12.1 31.53 3.77 FK6 120 1.8 3 24.32 +49 51.7 143 114 14 dec 18 3 30.8 3.97 137 416 Vaticana 13.4 35.65 3.11 HIP 117314 5.9 23 47.26 -11 54.7 85 7 44 dec 18 11 8.8 15.02 162 16 Psyche 11.2 57.29 3.00 FK6 1577 5.1 21 53.30 -13 33.1 59 28 48

dec 23 13 37.4 58.16 352 57 Mnemosyne 13.0 50.35 2.50 HIP 106278 3.0 21 31.56 - 5 34.3 51 95 92 dec 23 16 45.2 74.62 161 747 Winchester 12.5 66.77 3.47 FK6 1584 5.1 22 21.59 -21 35.9 57 91 92 dec 27 7 26.9 41.17 185 589 Croatia 13.8 28.66 4.08 FK6 2565 5.9 7 19.79 + 7 8.6 159 21 99 2005 jan 2 4 7.1 20.78 353 11.1 26.66 4.63 FK6 2977 5.6 12 12.15 +20 32.5 106 17 66 jan 2 18 49.7 105.59 177 268 Adorea 13.5 15.86 3.61 FK6 2288 5.9 4 0.81 +18 11.6 139 119 60

ROTATION PERIOD AND LIGHTCURVE in March. The data were analyzed with Canopus. The resulting DETERMINATION OF ASTEROID 1225 ARIANE lightcurve, shown in Figure 1, indicates a synodic period of 5.54 ± 0.01 hours with an amplitude of 0.33 ± 0.03 magnitude. Christopher J. Goeden Kristin A. Klimmek Acknowledgments Matthew P. Viscasillas Dr. Matthew T. Vonk We would like to thank Michael Schwartz and Paulo Holvorcem Department of Physics for their great work at Tenagra Observatory. Saint Mary’s University of Minnesota 700 Terrace Heights #32 References Winona, MN 55987 [email protected] Warner, B. D. (2002). “Potential Lightcurve Targets 2003 January – March.” www.minorplanetobserver.com/astlc/ default.htm (Received: 4 September Revised: 14 November)

Asteroid 1225 Ariane was observed during January and March of 2003. Its lightcurve was measured and its rotation period was determined to be 5.54 ± 0.01 hours with an amplitude of 0.33 ± 0.03 magnitude.

The asteroid 1225 Ariane was discovered by H. Van Gent in 1930. It is the French spelling of the name Ariadne, the heroine who helped Theseus escape from the Cretan Minotaur in . The asteroid was chosen from the suggested targets at the CALL website (Warner 2002).

Observations were made at Tenagra Observatory (observatory code 926) Nogales, Arizona, at an altitude of 1312 meters. The observatory features a 0.81 m F7 Ritchey-Chretien telescope and a 1024 x 1024 x 24µ camera liquid cooled to –50°C yielding ~0.87” per pixel. Observations were conducted on 2003 UT dates January 27, and March 6, 7, and 8. A total of 76 unfiltered images Figure 1. Lightcurve of 1225 Ariane based on a rotational period were collected with exposure times of 300 s in January and 150 s of 5.54 ± 0.01 h. Minor Planet Bulletin 31 (2004) 12

LIGHTCURVE AND PERIOD DETERMINATION Acknowledgements FOR 582 OLYMPIA Thanks go to Brian Warner for his mentoring, continued support, David Higgins guidance on using MPO_Canopus and for spending the time to 7 Mawalan Street, check my data and results Ngunnawal, ACT 2913 Australia [email protected] References

John Menke Harris, A.W (2001). “Minor Planet Lightcurve Parameters”, on [email protected] Minor Planet Centre Web Site.

Valentino Pozzoli Gaffey, M. J., Bell, J. F., and Cruikshank, D. P. (1989). [email protected] “Reflectance Spectroscopy and Asteroid Surface Minerology”, in Asteroids II, eds Binzel, Gehrels, and Matthews, U Arizona Press, Edwin Sheridan Tuscon. [email protected] NASA Planetary Data System (1), Small Body Node, “Taxonomic Roger Dymock Classifications Version 3”, on http://pdssbn.astro [email protected] .umd.edu/sbnhtml/.

(Received: 6 October) NASA Planetary Data System (2), Small Body Node, “IRAS Diameter and from the IRAS Minor Planet Survey Version 4”, on http://pdssbn.astro.umd.edu/sbnhtml/ Minor planet 582 Olympia was observed over a period of 40 days from 9 February to 20 March 2003. More Harris, A.W., Warner, B (2003). “Asteroid Lightcurve Data File, than 3000 data points from 42 sessions were obtained by Updated: October 5, 2003” on the CALL web site 5 observers. The lightcurve obtained shows a rotational (synodic) period of 72.0 ± 0.5 hrs with amplitude of 0.20 Warner, B.W. (2003). CALL website: http://www.minorplanet ± 0.05 mag. observer.com/astlc/default.htm

This lightcurve investigation was initially carried out at Table 1 Ngunnawal Observatory located in Canberra, Australia and was my first attempt at obtaining a lightcurve of any type. After Obs Scope Camera Resolution several days it became very apparent that I wasn’t getting E14 0.25m SCT f/4.3 SX MX516 (A-30°c) 2.15”/px anywhere so I put out a request for collaboration. John Menke 201 0.31m SCT f/10 AP7p (-48°c) 1.65”/px 682 0.35m SCT f/5.5 SBIG ST9E(-30°c) 2.14”/px was the first to offer his assistance and after a week we had XXX 0.28m SCT f/6.3 SBIG ST7E(-30°c) 1.04”/px sufficient data for an initial curve to show itself. It became 940 0.25m Newt f/6.4 SX MX516 (A-30°c) 1.44”/px apparent very quickly that the lightcurve of this asteroid was a multiple of 24 hours and our 2 observing locations were insufficient to provide suitable coverage.

In the following weeks Valentino Pozzoli (201, Johnathan B Postel Observatory, Promiod, Italy), Edwin Sheridan (682, Crescent Butte Observatory, Kanab, Utah, US) and Roger Dymock (940, Waterlooville, Hampshire, UK) joined the effort. By the end of the observing period we were able to cover approximately 4/5th of the curve.

The instrumentation used in this study can be seen in Table 1. The target was selected from the list of lightcurves maintained by Dr Alan Harris (Harris 2001) and from the Collaborative Asteroid Lightcurve Link (CALL) web sites’ “List of Potential Lightcurve Targets” (Warner 2003).

Olympia is a main-belt asteroid discovered on 23 January 1907 by A. Kopff at Heidelberg. It has an absolute brightness of 9.11 and Figure 1. Lightcurve of 582 Olympia based on a period of 72.0 a mean of 0.21 (NASA PDS 1) indicating that it has a hrs. Zero Point of the curve is JD 2452679.61857. Ordinates are diameter of 43 km. It has a taxonomy type of S (NASA PDS 2) relative magnitude. indicating a possible surface mineralogy of metal, olivine and pyroxene (Gaffey et al. 1989). Previous attempts have been made to determine the period and the current lightcurve list (Harris 2003) shows periods of 36.0 hrs (amplitude > 0.6 mag) and 72.0 hrs (amplitude 0.1 mag) both of which were based on incomplete curves.

Minor Planet Bulletin 31 (2004) 13

MINOR PLANETS AT UNUSUALLY FAVORABLE are from EMP 1992, except that for all planets for which new or ELONGATIONS IN 2004 improved elements have been published subsequently in the Minor Planet Ciculars or in electronic form, the newer elements have Frederick Pilcher been used. Planetary positions are from the JPL DE-200 Illinois College ephemeris, courtesy of Dr. E. Myles Standish. Dr. Reed’s Jacksonville, IL 62650 USA ephemeris generating program, a list of minor planet elements, and the JPL planetary ephemeris are freeware which may be obtained (Received: 1 October) from the author by sending a 100 Megabyte zip disk and stamped, addressed return mailer. They cannot be downloaded directly over the Internet. A list is presented of minor planets that are much brighter than usual at their 2004 apparitions. Very close Minor planets whose brightest magnitudes near the time of approaches of 4179 Toutatis, 25143 Itokawa, and 6239 maximum elongation vary by at least 2.0 in this interval and in Minos are the highlights of the year. 2004 will be within 0.3 of the brightest occuring, or vary by at least 3.0 and in 2004 will be within 0.5 of the brightest occuring; The minor planets in the lists that follow will be much brighter at and which are visual magnitude 14.5 or brighter, are included. For their 2004 apparitions than at their average distances at maximum minor planets brighter than visual magnitude 13.5, which are elongation. Many years may pass before these planets will be within the range of a large number of observers, these standards again as bright as in 2004. Observers are encouraged to give have been relaxed somewhat to include a larger number of objects. special attention to those which lie near the limit of their Magnitudes have been computed from the updated magnitude equipment. parameters published in MPC28104-28116, on 1996 Nov. 25, or more recently in the Minor Planet Circulars. Minor planet 4179 Toutatis will make in 2004 its closest approach to Earth of all of its series of close approaches. Observers are Oppositions may be in right ascension or in celestial longitude. cautioned that brightest magnitude of 8.9 on Sept. 28 and Here we use still a third representation, maximum elongation from minimum distance of 0.0104 AU on Sept. 29 occur more than a the Sun, instead of opposition. Though unconventional, it has the month after maximum elongation from the Sun Aug. 21. Toutatis advantage that many close approaches do not involve actual will make additional fairly close approaches in 2008 and 2012, opposition to the Sun near the time of minimum distance and then not again until 2070. greatest brightness and are missed by an opposition-based program. Other data are also provided according to the following Minor planet 25143 Itokawa will approach Earth within 0.013 AU tabular listings: Minor planet number, date of maximum on June 26, more than a month before the maximum elongation elongation from the Sun in format yyyy/mm/dd, maximum date on July 31. Southern hemisphere observers are strongly elongation in degrees, right ascension on date of maximum favored for this brightest apparition of the 21st century as Itokawa elongation, declination on date of maximum elongation, both in will be south of -32 degrees declination for the entire interval it is J2000 coordinates, date of minimum or brightest magnitude in brighter than magnitude 15. format yyyy/mm/dd, minimum magnitude, date of minimum distance in format yyyy/mm/dd, and minimum distance in AU. Minor planet 6239 Minos, maximum elongation on Jan. 11 but brightest magnitude 14.1 on Jan. 27 and minimum distance 0.056 Users should note that when the maximum elongation is about AU on Feb. 2 is strongly favored for northern hemisphere 177° or greater, the minimum magnitude is sharply peaked due to observers, being north of +44 degrees declination for the entire enhanced brightening near zero phase angle. Even as near as 10 interval it is brighter than magnitude 15. days before or after minimum magnitude the magnitude is generally about 0.4 greater. This effect takes place in greater time There will be a moderately close approach of planet (12008) 1996 interval for smaller maximum elongations. There is some interest TY9 at 0.364 AU on June 10 and magnitude 12.3 on June 11. in very small minimum phase angles. For maximum elongations This will be the most favorable opportunity to observe 1996 TY9 E near 180° at Earth distance ∆, an approximate formula for the until the year 2052, when the next apparition under circumstances minimum phase angle α is α=(180°-E)/(∆+1). very similar to those of 2004 will occur. Table 1. Numerical Sequence of Favorable Elongations The year 2004 also marks the perihelion passage of planet 944 Planet Max Elon D Max E RA Dec Min Mag D Mag Min Dist D Min Dist Hidalgo in its highly eccentric 14-year orbit around the Sun. This 1 2004/01/09 171.9° 7h25m +30° 2004/01/09 6.8 2004/01/11 1.626 object will be a magnitude brighter on Oct. 28 at 13.4 than on any 11 2004/07/09 177.4° 19h14m -19° 2004/07/09 8.9 2004/07/12 1.225 17 2004/06/23 174.1° 18h 7m -17° 2004/06/23 9.9 2004/06/22 1.129 occasion for the next 60 years. Hidalgo is noteworthy for being 49 2004/11/05 175.1° 2h38m +20° 2004/11/05 10.6 2004/11/03 1.377 the first and brightest object discovered with a -like orbit of 62 2004/12/10 177.4° 5h 9m +20° 2004/12/10 12.1 2004/12/05 1.666 81 2004/10/22 173.3° 1h42m +17° 2004/10/23 11.1 2004/10/24 1.286 high eccentricity and inclination and a completely asteroidal 88 2004/06/20 178.7° 17h55m -24° 2004/06/20 9.8 2004/06/25 1.391 93 2004/08/27 172.8° 22h34m -16° 2004/08/26 10.8 2004/08/22 1.485 appearance. Discoverer Walter Baade, on 1920 Oct. 31 at 100 2004/07/15 177.4° 19h38m -18° 2004/07/15 10.9 2004/07/17 1.590 Bergedorf, set with Hidalgo the precedent for the current 106 2004/12/05 178.5° 4h49m +23° 2004/12/05 10.9 2004/12/01 1.730 convention of assigning asteroidal designations to all small objects 128 2004/10/23 172.2° 2h 1m + 4° 2004/10/23 10.5 2004/10/21 1.413 156 2004/05/15 177.6° 15h26m -21° 2004/05/15 10.7 2004/05/13 1.127 lacking gaseous comas even if their orbits have long term 166 2004/10/09 159.2° 1h38m -12° 2004/10/10 12.5 2004/10/11 1.164 175 2004/09/06 176.7° 23h 7m - 9° 2004/09/06 11.2 2004/09/05 1.439 instability. 227 2004/06/04 165.5° 16h39m -36° 2004/06/03 12.2 2004/06/01 1.567

265 2004/04/03 139.9° 12h27m -45° 2004/04/08 13.3 2004/04/12 0.917 270 2004/07/16 176.8° 19h40m -18° 2004/07/16 10.2 2004/07/21 0.911 These lists have been prepared by an examination of the maximum 273 2004/09/12 172.5° 23h37m -10° 2004/09/11 12.7 2004/09/04 1.211 319 2004/11/27 165.3° 4h28m + 6° 2004/11/27 13.5 2004/11/25 1.664 elongation circumstances of minor planets computed by the author 325 2004/11/04 168.5° 2h27m +26° 2004/11/04 12.3 2004/11/05 1.691 for all years through 2060 with a full program written by Dr. John Reed, and to whom he expresses his thanks. Elements Minor Planet Bulletin 31 (2004) 14

Planet Max Elon D Max E RA Dec Min Mag D Mag Min Dist D Min Dist Planet Max Elon D Max E RA Dec Min Mag D Mag Min Dist D Min Dist

344 2004/05/05 178.0° 14h53m -14° 2004/05/06 9.8 2004/05/19 0.991 3270 2004/02/10 162.5° 8h38m + 3° 2004/02/08 14.5 2004/02/05 0.492 347 2004/05/17 169.8° 15h43m - 9° 2004/05/16 11.9 2004/05/11 1.370 3519 2004/07/19 178.7° 19h59m -21° 2004/07/19 13.9 2004/07/19 0.771 364 2004/12/15 175.4° 5h33m +18° 2004/12/15 11.4 2004/12/12 0.930 3581 2004/10/26 173.3° 1h45m +17° 2004/10/24 13.9 2004/10/10 0.955 378 2004/11/22 178.3° 3h56m +18° 2004/11/22 12.7 2004/11/19 1.469 3632 2004/12/29 167.4° 6h31m +10° 2004/12/28 14.5 2004/12/24 0.965 387 2004/07/24 175.5° 20h 8m -15° 2004/07/24 9.5 2004/07/21 1.090 3674 2004/01/01 162.8° 6h25m +39° 2003/12/27 13.3 2003/12/15 0.731

394 2004/10/13 171.8° 1h27m + 0° 2004/10/12 12.2 2004/10/06 1.243 3702 2004/07/31 175.7° 20h49m -22° 2004/07/31 14.1 2004/08/08 1.229 458 2004/12/12 162.1° 5h19m + 5° 2004/12/10 12.7 2004/12/06 1.364 3729 2004/09/22 177.5° 0h 0m - 2° 2004/09/22 14.4 2004/09/15 1.202 463 2004/10/22 175.9° 1h50m + 7° 2004/10/21 13.2 2004/10/16 0.896 3861 2004/03/18 176.2° 11h47m - 2° 2004/03/18 14.4 2004/03/20 1.078 468 2004/07/31 179.3° 20h45m -18° 2004/07/31 13.1 2004/08/05 1.636 4150 2004/08/22 176.9° 22h11m -14° 2004/08/22 14.1 2004/08/19 0.853 476 2004/06/23 175.2° 18h 8m -28° 2004/06/23 11.5 2004/06/24 1.447 4157 2004/05/18 176.0° 15h42m -15° 2004/05/18 14.5 2004/05/22 1.297

479 2004/09/24 168.7° 0h25m - 9° 2004/09/25 12.2 2004/09/29 1.235 4179 2004/08/21 179.2° 22h 4m -12° 2004/09/28 8.9 2004/09/29 0.010 499 2004/11/06 178.4° 2h45m +17° 2004/11/06 13.8 2004/11/08 2.236 4264 2004/09/28 179.8° 0h20m + 2° 2004/09/28 13.9 2004/10/01 0.745 517 2004/12/13 178.7° 5h21m +24° 2004/12/13 12.6 2004/12/09 1.615 4265 2004/09/09 174.2° 23h23m -10° 2004/09/09 14.5 2004/09/12 0.958 539 2004/10/01 167.4° 0h 9m +14° 2004/10/01 12.2 2004/09/30 1.168 4272 2004/09/24 178.9° 0h 5m + 1° 2004/09/24 14.3 2004/09/24 0.773 548 2004/11/06 172.7° 2h57m + 9° 2004/11/07 12.8 2004/11/09 0.899 4482 2004/09/17 153.6° 23h33m +24° 2004/09/18 14.3 2004/09/18 0.781

578 2004/05/07 176.8° 14h54m -19° 2004/05/07 12.1 2004/05/15 1.428 4522 2004/08/05 179.5° 21h 4m -17° 2004/08/05 14.4 2004/08/11 1.224 594 2004/03/07 159.1° 12h13m +19° 2004/03/12 14.1 2004/03/20 0.965 4711 2004/07/14 179.4° 19h36m -20° 2004/07/14 13.8 2004/07/25 0.971 599 2004/11/06 179.7° 2h48m +16° 2004/11/06 11.1 2004/10/26 1.261 4797 2004/10/15 176.8° 1h15m +11° 2004/10/15 14.2 2004/10/16 0.983 605 2004/09/03 178.7° 22h50m - 8° 2004/09/03 13.1 2004/09/03 1.581 5064 2004/06/03 165.8° 16h54m - 8° 2004/06/04 14.4 2004/06/08 0.857 634 2004/10/09 161.8° 1h31m -10° 2004/10/08 13.0 2004/10/05 1.532 5525 2004/08/15 174.4° 21h47m -19° 2004/08/15 14.4 2004/08/15 0.875

663 2004/05/12 179.4° 15h20m -18° 2004/05/12 12.6 2004/05/09 1.701 5622 2004/10/02 166.2° 0h11m +16° 2004/10/01 14.4 2004/09/26 1.408 664 2004/06/05 165.8° 17h 0m - 8° 2004/06/05 13.3 2004/06/07 1.525 5642 2004/07/24 167.5° 20h 8m -32° 2004/07/27 14.4 2004/08/05 0.671 689 2004/08/06 172.9° 20h55m -10° 2004/08/06 13.6 2004/08/13 0.858 5682 2004/10/10 174.4° 0h52m +11° 2004/10/09 14.5 2004/10/01 0.639 690 2004/10/20 166.6° 1h17m +22° 2004/10/19 11.5 2004/10/17 1.598 5817 2004/10/07 147.8° 0h38m +37° 2004/10/15 14.1 2004/10/20 0.760 749 2004/06/20 175.9° 17h56m -19° 2004/06/20 13.2 2004/06/16 0.877 5855 2004/09/29 172.6° 0h33m - 4° 2004/09/29 14.2 2004/09/26 1.180

755 2004/04/16 177.5° 13h41m - 7° 2004/04/16 13.3 2004/04/18 1.710 6192 2004/07/10 173.2° 19h 9m -15° 2004/07/10 13.4 2004/07/11 0.674 787 2004/09/30 178.2° 0h32m + 1° 2004/09/30 12.5 2004/09/25 1.333 6239 2004/01/11 156.6° 8h25m +42° 2004/01/27 14.1 2004/02/02 0.056 821 2004/04/12 178.8° 13h23m - 9° 2004/04/12 14.3 2004/04/19 1.285 6669 2004/05/19 177.9° 15h44m -21° 2004/05/19 14.2 2004/05/30 0.907 846 2004/09/14 179.5° 23h28m - 2° 2004/09/14 13.5 2004/09/17 1.627 7393 2004/09/06 170.2° 23h15m -15° 2004/09/06 14.1 2004/09/07 0.796 854 2004/08/01 169.3° 20h36m - 7° 2004/07/31 14.1 2004/07/27 1.002 7505 2004/08/18 167.5° 22h12m -24° 2004/08/21 13.2 2004/09/03 0.776

883 2004/09/11 170.6° 23h 4m + 4° 2004/09/10 13.9 2004/09/06 0.809 7638 2004/09/12 174.6° 23h28m - 9° 2004/09/13 14.5 2004/09/22 0.841 885 2004/09/10 178.1° 23h21m - 6° 2004/09/10 13.7 2004/09/10 1.504 7965 2004/04/18 128.2° 12h17m -60° 2004/04/29 14.3 2004/05/02 0.932 896 2004/05/05 171.7° 14h39m -24° 2004/05/06 13.5 2004/05/11 0.942 9601 2004/06/29 173.7° 18h41m -29° 2004/06/29 13.9 2004/07/01 0.818 913 2004/08/06 171.9° 21h17m -24° 2004/08/05 13.3 2004/07/31 0.849 10261 2004/09/21 170.6° 23h43m + 8° 2004/09/20 14.3 2004/09/15 0.821 915 2004/09/11 176.2° 23h26m - 7° 2004/09/12 13.5 2004/09/16 1.031 10936 2004/12/04 167.3° 4h57m + 9° 2004/12/02 14.3 2004/11/23 0.920

938 2004/07/13 179.4° 19h33m -21° 2004/07/13 14.2 2004/07/19 1.710 12008 2004/06/12 164.2° 16h25m -32° 2004/06/11 12.3 2004/06/10 0.364 939 2004/08/10 179.0° 21h21m -16° 2004/08/10 13.2 2004/08/12 0.845 13538 2004/08/14 165.4° 21h59m -27° 2004/08/13 14.5 2004/08/10 0.723 944 2004/10/22 157.6° 1h52m +33° 2004/10/28 13.4 2004/11/03 1.171 13920 2004/08/08 178.8° 21h15m -14° 2004/08/08 14.5 2004/08/08 0.635 949 2004/02/08 179.2° 9h27m +15° 2004/02/08 13.1 2004/02/15 1.707 13934 2004/06/07 178.2° 17h 5m -21° 2004/06/08 14.4 2004/06/20 0.843 954 2004/06/23 178.2° 18h 8m -21° 2004/06/23 13.4 2004/06/27 1.704 14196 2004/07/25 177.5° 20h22m -22° 2004/07/25 14.2 2004/07/24 0.756

981 2004/08/11 176.5° 21h30m -18° 2004/08/11 13.6 2004/08/14 1.496 14653 2004/08/16 157.2° 22h24m -34° 2004/08/09 14.3 2004/07/31 0.561 995 2004/10/08 168.9° 0h34m +15° 2004/10/07 12.9 2004/10/03 1.228 14982 2004/09/19 179.3° 23h49m - 1° 2004/09/19 14.4 2004/09/07 0.620 1019 2004/08/19 176.6° 22h 5m -15° 2004/08/19 13.8 2004/08/16 0.826 25143 2004/07/31 167.5° 20h44m -30° 2004/06/29 12.6 2004/06/26 0.013 1022 2004/07/16 178.3° 19h48m -22° 2004/07/16 13.5 2004/07/11 1.476 28565 2004/09/21 178.3° 23h52m + 1° 2004/09/21 14.5 2004/09/12 0.574 1057 2004/10/05 174.0° 0h37m +10° 2004/10/05 13.3 2004/10/04 1.171

1067 2004/10/28 162.3° 1h43m +29° 2004/10/28 13.7 2004/10/28 1.353 1082 2004/08/29 179.4° 22h31m - 9° 2004/08/29 13.5 2004/08/28 1.549 Table 2. Temporal Sequence of Favorable Elongations 1089 2004/01/04 176.1° 7h 0m +26° 2004/01/04 13.3 2003/12/31 0.995 1090 2004/02/02 165.7° 8h33m + 4° 2004/02/02 14.1 2004/02/02 0.868 1110 2004/08/24 165.6° 21h52m + 2° 2004/08/23 12.7 2004/08/20 0.688 Planet Max Elon D Max E RA Dec Min Mag D Mag Min Dist D Min Dist

1120 2004/10/28 172.9° 2h20m + 6° 2004/10/27 14.3 2004/10/24 0.891 3674 2004/01/01 162.8° 6h25m +39° 2003/12/27 13.3 2003/12/15 0.731 1122 2004/11/25 179.9° 4h 5m +20° 2004/11/25 12.6 2004/11/18 0.997 1089 2004/01/04 176.1° 7h 0m +26° 2004/01/04 13.3 2003/12/31 0.995 1180 2004/07/21 174.7° 20h10m -25° 2004/07/21 13.8 2004/07/21 2.345 1 2004/01/09 171.9° 7h25m +30° 2004/01/09 6.8 2004/01/11 1.626 1181 2004/12/19 178.7° 5h51m +22° 2004/12/19 13.7 2004/12/15 1.211 1657 2004/01/10 176.2° 7h28m +25° 2004/01/10 14.4 2004/01/17 0.935 1197 2004/04/15 161.8° 12h59m -26° 2004/04/13 12.9 2004/04/10 1.282 6239 2004/01/11 156.6° 8h25m +42° 2004/01/27 14.1 2004/02/02 0.056

1212 2004/03/14 175.5° 11h44m + 6° 2004/03/13 14.1 2004/03/11 2.311 1664 2004/01/23 167.3° 8h33m +31° 2004/01/24 13.7 2004/01/29 0.881 1224 2004/10/06 164.7° 0h23m +19° 2004/10/07 13.0 2004/10/08 0.871 1090 2004/02/02 165.7° 8h33m + 4° 2004/02/02 14.1 2004/02/02 0.868 1247 2004/07/23 178.1° 20h11m -18° 2004/07/23 13.7 2004/07/23 1.594 2331 2004/02/04 173.4° 9h 2m + 9° 2004/02/04 13.7 2004/02/02 0.916 1267 2004/07/08 170.5° 19h17m -31° 2004/07/08 14.1 2004/07/09 1.017 949 2004/02/08 179.2° 9h27m +15° 2004/02/08 13.1 2004/02/15 1.707 1278 2004/07/12 171.2° 19h42m -30° 2004/07/14 12.2 2004/07/21 0.836 1584 2004/02/09 163.1° 9h23m - 2° 2004/02/08 12.6 2004/02/08 0.953

1312 2004/08/23 165.9° 22h39m -23° 2004/08/25 14.4 2004/08/29 1.638 3270 2004/02/10 162.5° 8h38m + 3° 2004/02/08 14.5 2004/02/05 0.492 1318 2004/03/14 175.1° 11h41m + 7° 2004/03/14 13.2 2004/03/18 0.865 1816 2004/02/21 178.7° 10h16m + 9° 2004/02/21 13.4 2004/02/19 0.858 1326 2004/10/01 150.1° 1h21m -23° 2004/10/02 13.6 2004/10/02 1.144 2375 2004/03/03 160.7° 11h35m +23° 2004/03/05 14.4 2004/03/10 1.676 1331 2004/08/02 179.0° 20h54m -18° 2004/08/02 13.1 2004/08/01 1.512 594 2004/03/07 159.1° 12h13m +19° 2004/03/12 14.1 2004/03/20 0.965 1346 2004/12/04 155.2° 4h56m - 2° 2004/12/03 14.1 2004/12/01 1.240 1508 2004/03/08 142.8° 11h21m +41° 2004/02/25 14.0 2004/02/20 0.886

1450 2004/11/25 178.2° 4h 7m +19° 2004/11/25 14.2 2004/11/27 1.213 1212 2004/03/14 175.5° 11h44m + 6° 2004/03/13 14.1 2004/03/11 2.311 1459 2004/10/19 172.0° 1h47m + 2° 2004/10/19 13.6 2004/10/16 1.422 1318 2004/03/14 175.1° 11h41m + 7° 2004/03/14 13.2 2004/03/18 0.865 1473 2004/10/22 176.5° 1h42m +14° 2004/10/22 13.8 2004/10/14 1.070 3861 2004/03/18 176.2° 11h47m - 2° 2004/03/18 14.4 2004/03/20 1.078 1508 2004/03/08 142.8° 11h21m +41° 2004/02/25 14.0 2004/02/20 0.886 2328 2004/03/23 179.6° 12h12m - 1° 2004/03/23 14.1 2004/03/22 1.022 1537 2004/09/13 173.8° 23h16m + 1° 2004/09/13 14.2 2004/09/18 1.172 265 2004/04/03 139.9° 12h27m -45° 2004/04/08 13.3 2004/04/12 0.917

1572 2004/10/05 177.5° 0h41m + 7° 2004/10/05 12.9 2004/10/02 1.459 821 2004/04/12 178.8° 13h23m - 9° 2004/04/12 14.3 2004/04/19 1.285 1584 2004/02/09 163.1° 9h23m - 2° 2004/02/08 12.6 2004/02/08 0.953 1197 2004/04/15 161.8° 12h59m -26° 2004/04/13 12.9 2004/04/10 1.282 1625 2004/08/08 177.1° 21h15m -18° 2004/08/07 14.1 2004/07/31 1.813 755 2004/04/16 177.5° 13h41m - 7° 2004/04/16 13.3 2004/04/18 1.710 1657 2004/01/10 176.2° 7h28m +25° 2004/01/10 14.4 2004/01/17 0.935 7965 2004/04/18 128.2° 12h17m -60° 2004/04/29 14.3 2004/05/02 0.932 1664 2004/01/23 167.3° 8h33m +31° 2004/01/24 13.7 2004/01/29 0.881 344 2004/05/05 178.0° 14h53m -14° 2004/05/06 9.8 2004/05/19 0.991

1683 2004/08/27 176.7° 22h23m - 6° 2004/08/27 14.1 2004/08/24 1.258 896 2004/05/05 171.7° 14h39m -24° 2004/05/06 13.5 2004/05/11 0.942 1719 2004/08/07 176.3° 21h15m -19° 2004/08/08 13.9 2004/08/15 1.298 578 2004/05/07 176.8° 14h54m -19° 2004/05/07 12.1 2004/05/15 1.428 1816 2004/02/21 178.7° 10h16m + 9° 2004/02/21 13.4 2004/02/19 0.858 663 2004/05/12 179.4° 15h20m -18° 2004/05/12 12.6 2004/05/09 1.701 1843 2004/08/07 168.4° 20h58m - 5° 2004/08/06 14.2 2004/08/04 1.207 156 2004/05/15 177.6° 15h26m -21° 2004/05/15 10.7 2004/05/13 1.127 2105 2004/12/27 177.4° 6h26m +20° 2004/12/27 13.2 2004/12/24 1.076 347 2004/05/17 169.8° 15h43m - 9° 2004/05/16 11.9 2004/05/11 1.370

2119 2004/06/09 178.7° 17h11m -24° 2004/06/09 14.2 2004/06/14 0.916 4157 2004/05/18 176.0° 15h42m -15° 2004/05/18 14.5 2004/05/22 1.297 2231 2004/09/15 177.0° 23h30m + 0° 2004/09/15 14.3 2004/09/17 1.050 6669 2004/05/19 177.9° 15h44m -21° 2004/05/19 14.2 2004/05/30 0.907 2328 2004/03/23 179.6° 12h12m - 1° 2004/03/23 14.1 2004/03/22 1.022 5064 2004/06/03 165.8° 16h54m - 8° 2004/06/04 14.4 2004/06/08 0.857 2331 2004/02/04 173.4° 9h 2m + 9° 2004/02/04 13.7 2004/02/02 0.916 227 2004/06/04 165.5° 16h39m -36° 2004/06/03 12.2 2004/06/01 1.567 2375 2004/03/03 160.7° 11h35m +23° 2004/03/05 14.4 2004/03/10 1.676 664 2004/06/05 165.8° 17h 0m - 8° 2004/06/05 13.3 2004/06/07 1.525

2379 2004/10/14 179.4° 1h20m + 7° 2004/10/14 13.8 2004/10/05 1.495 3089 2004/06/06 173.2° 16h56m -15° 2004/06/06 14.0 2004/06/08 1.408 2509 2004/08/13 177.7° 21h36m -16° 2004/08/13 14.2 2004/08/14 0.975 13934 2004/06/07 178.2° 17h 5m -21° 2004/06/08 14.4 2004/06/20 0.843 2571 2004/08/27 173.5° 22h36m -15° 2004/08/28 14.1 2004/08/29 0.798 2119 2004/06/09 178.7° 17h11m -24° 2004/06/09 14.2 2004/06/14 0.916 2599 2004/08/17 165.1° 22h 1m -27° 2004/08/17 13.6 2004/08/18 1.128 12008 2004/06/12 164.2° 16h25m -32° 2004/06/11 12.3 2004/06/10 0.364 2771 2004/08/13 155.1° 20h55m + 8° 2004/08/13 14.5 2004/08/13 1.101 88 2004/06/20 178.7° 17h55m -24° 2004/06/20 9.8 2004/06/25 1.391

2848 2004/09/23 179.3° 0h 3m + 0° 2004/09/23 14.3 2004/09/26 1.612 749 2004/06/20 175.9° 17h56m -19° 2004/06/20 13.2 2004/06/16 0.877 2887 2004/07/12 178.6° 19h28m -20° 2004/07/12 14.4 2004/07/09 0.924 3018 2004/06/22 173.3° 18h 8m -16° 2004/06/23 14.5 2004/06/27 0.952 2892 2004/11/28 152.9° 3h47m +47° 2004/11/27 13.8 2004/11/26 1.574 17 2004/06/23 174.1° 18h 7m -17° 2004/06/23 9.9 2004/06/22 1.129 3018 2004/06/22 173.3° 18h 8m -16° 2004/06/23 14.5 2004/06/27 0.952 476 2004/06/23 175.2° 18h 8m -28° 2004/06/23 11.5 2004/06/24 1.447 3037 2004/12/15 164.7° 5h27m + 8° 2004/12/15 14.2 2004/12/14 1.210 954 2004/06/23 178.2° 18h 8m -21° 2004/06/23 13.4 2004/06/27 1.704

3054 2004/08/21 179.7° 22h 2m -12° 2004/08/21 14.1 2004/08/21 1.435 9601 2004/06/29 173.7° 18h41m -29° 2004/06/29 13.9 2004/07/01 0.818 3089 2004/06/06 173.2° 16h56m -15° 2004/06/06 14.0 2004/06/08 1.408 1267 2004/07/08 170.5° 19h17m -31° 2004/07/08 14.1 2004/07/09 1.017 3165 2004/07/15 176.5° 19h43m -24° 2004/07/15 14.1 2004/07/20 0.875 11 2004/07/09 177.4° 19h14m -19° 2004/07/09 8.9 2004/07/12 1.225 3220 2004/10/19 179.5° 1h36m + 9° 2004/10/19 14.0 2004/10/21 0.871 6192 2004/07/10 173.2° 19h 9m -15° 2004/07/10 13.4 2004/07/11 0.674 3229 2004/08/01 179.0° 20h46m -16° 2004/08/01 14.3 2004/08/03 0.955 1278 2004/07/12 171.2° 19h42m -30° 2004/07/14 12.2 2004/07/21 0.836

Minor Planet Bulletin 31 (2004) 15

Planet Max Elon D Max E RA Dec Min Mag D Mag Min Dist D Min Dist Planet Max Elon D Max E RA Dec Min Mag D Mag Min Dist D Min Dist

2887 2004/07/12 178.6° 19h28m -20° 2004/07/12 14.4 2004/07/09 0.924 846 2004/09/14 179.5° 23h28m - 2° 2004/09/14 13.5 2004/09/17 1.627 938 2004/07/13 179.4° 19h33m -21° 2004/07/13 14.2 2004/07/19 1.710 2231 2004/09/15 177.0° 23h30m + 0° 2004/09/15 14.3 2004/09/17 1.050 4711 2004/07/14 179.4° 19h36m -20° 2004/07/14 13.8 2004/07/25 0.971 4482 2004/09/17 153.6° 23h33m +24° 2004/09/18 14.3 2004/09/18 0.781 100 2004/07/15 177.4° 19h38m -18° 2004/07/15 10.9 2004/07/17 1.590 14982 2004/09/19 179.3° 23h49m - 1° 2004/09/19 14.4 2004/09/07 0.620 3165 2004/07/15 176.5° 19h43m -24° 2004/07/15 14.1 2004/07/20 0.875 10261 2004/09/21 170.6° 23h43m + 8° 2004/09/20 14.3 2004/09/15 0.821

270 2004/07/16 176.8° 19h40m -18° 2004/07/16 10.2 2004/07/21 0.911 28565 2004/09/21 178.3° 23h52m + 1° 2004/09/21 14.5 2004/09/12 0.574 1022 2004/07/16 178.3° 19h48m -22° 2004/07/16 13.5 2004/07/11 1.476 3729 2004/09/22 177.5° 0h 0m - 2° 2004/09/22 14.4 2004/09/15 1.202 3519 2004/07/19 178.7° 19h59m -21° 2004/07/19 13.9 2004/07/19 0.771 2848 2004/09/23 179.3° 0h 3m + 0° 2004/09/23 14.3 2004/09/26 1.612 1180 2004/07/21 174.7° 20h10m -25° 2004/07/21 13.8 2004/07/21 2.345 479 2004/09/24 168.7° 0h25m - 9° 2004/09/25 12.2 2004/09/29 1.235 1247 2004/07/23 178.1° 20h11m -18° 2004/07/23 13.7 2004/07/23 1.594 4272 2004/09/24 178.9° 0h 5m + 1° 2004/09/24 14.3 2004/09/24 0.773

387 2004/07/24 175.5° 20h 8m -15° 2004/07/24 9.5 2004/07/21 1.090 4264 2004/09/28 179.8° 0h20m + 2° 2004/09/28 13.9 2004/10/01 0.745 5642 2004/07/24 167.5° 20h 8m -32° 2004/07/27 14.4 2004/08/05 0.671 5855 2004/09/29 172.6° 0h33m - 4° 2004/09/29 14.2 2004/09/26 1.180 14196 2004/07/25 177.5° 20h22m -22° 2004/07/25 14.2 2004/07/24 0.756 787 2004/09/30 178.2° 0h32m + 1° 2004/09/30 12.5 2004/09/25 1.333 468 2004/07/31 179.3° 20h45m -18° 2004/07/31 13.1 2004/08/05 1.636 539 2004/10/01 167.4° 0h 9m +14° 2004/10/01 12.2 2004/09/30 1.168 3702 2004/07/31 175.7° 20h49m -22° 2004/07/31 14.1 2004/08/08 1.229 1326 2004/10/01 150.1° 1h21m -23° 2004/10/02 13.6 2004/10/02 1.144

25143 2004/07/31 167.5° 20h44m -30° 2004/06/29 12.6 2004/06/26 0.013 5622 2004/10/02 166.2° 0h11m +16° 2004/10/01 14.4 2004/09/26 1.408 854 2004/08/01 169.3° 20h36m - 7° 2004/07/31 14.1 2004/07/27 1.002 1057 2004/10/05 174.0° 0h37m +10° 2004/10/05 13.3 2004/10/04 1.171 3229 2004/08/01 179.0° 20h46m -16° 2004/08/01 14.3 2004/08/03 0.955 1572 2004/10/05 177.5° 0h41m + 7° 2004/10/05 12.9 2004/10/02 1.459 1331 2004/08/02 179.0° 20h54m -18° 2004/08/02 13.1 2004/08/01 1.512 1224 2004/10/06 164.7° 0h23m +19° 2004/10/07 13.0 2004/10/08 0.871 4522 2004/08/05 179.5° 21h 4m -17° 2004/08/05 14.4 2004/08/11 1.224 5817 2004/10/07 147.8° 0h38m +37° 2004/10/15 14.1 2004/10/20 0.760

689 2004/08/06 172.9° 20h55m -10° 2004/08/06 13.6 2004/08/13 0.858 995 2004/10/08 168.9° 0h34m +15° 2004/10/07 12.9 2004/10/03 1.228 913 2004/08/06 171.9° 21h17m -24° 2004/08/05 13.3 2004/07/31 0.849 166 2004/10/09 159.2° 1h38m -12° 2004/10/10 12.5 2004/10/11 1.164 1719 2004/08/07 176.3° 21h15m -19° 2004/08/08 13.9 2004/08/15 1.298 634 2004/10/09 161.8° 1h31m -10° 2004/10/08 13.0 2004/10/05 1.532 1843 2004/08/07 168.4° 20h58m - 5° 2004/08/06 14.2 2004/08/04 1.207 5682 2004/10/10 174.4° 0h52m +11° 2004/10/09 14.5 2004/10/01 0.639 1625 2004/08/08 177.1° 21h15m -18° 2004/08/07 14.1 2004/07/31 1.813 394 2004/10/13 171.8° 1h27m + 0° 2004/10/12 12.2 2004/10/06 1.243

13920 2004/08/08 178.8° 21h15m -14° 2004/08/08 14.5 2004/08/08 0.635 2379 2004/10/14 179.4° 1h20m + 7° 2004/10/14 13.8 2004/10/05 1.495 939 2004/08/10 179.0° 21h21m -16° 2004/08/10 13.2 2004/08/12 0.845 4797 2004/10/15 176.8° 1h15m +11° 2004/10/15 14.2 2004/10/16 0.983 981 2004/08/11 176.5° 21h30m -18° 2004/08/11 13.6 2004/08/14 1.496 1459 2004/10/19 172.0° 1h47m + 2° 2004/10/19 13.6 2004/10/16 1.422 2509 2004/08/13 177.7° 21h36m -16° 2004/08/13 14.2 2004/08/14 0.975 3220 2004/10/19 179.5° 1h36m + 9° 2004/10/19 14.0 2004/10/21 0.871 2771 2004/08/13 155.1° 20h55m + 8° 2004/08/13 14.5 2004/08/13 1.101 690 2004/10/20 166.6° 1h17m +22° 2004/10/19 11.5 2004/10/17 1.598

13538 2004/08/14 165.4° 21h59m -27° 2004/08/13 14.5 2004/08/10 0.723 81 2004/10/22 173.3° 1h42m +17° 2004/10/23 11.1 2004/10/24 1.286 5525 2004/08/15 174.4° 21h47m -19° 2004/08/15 14.4 2004/08/15 0.875 463 2004/10/22 175.9° 1h50m + 7° 2004/10/21 13.2 2004/10/16 0.896 14653 2004/08/16 157.2° 22h24m -34° 2004/08/09 14.3 2004/07/31 0.561 944 2004/10/22 157.6° 1h52m +33° 2004/10/28 13.4 2004/11/03 1.171 2599 2004/08/17 165.1° 22h 1m -27° 2004/08/17 13.6 2004/08/18 1.128 1473 2004/10/22 176.5° 1h42m +14° 2004/10/22 13.8 2004/10/14 1.070 7505 2004/08/18 167.5° 22h12m -24° 2004/08/21 13.2 2004/09/03 0.776 128 2004/10/23 172.2° 2h 1m + 4° 2004/10/23 10.5 2004/10/21 1.413

1019 2004/08/19 176.6° 22h 5m -15° 2004/08/19 13.8 2004/08/16 0.826 3581 2004/10/26 173.3° 1h45m +17° 2004/10/24 13.9 2004/10/10 0.955 3054 2004/08/21 179.7° 22h 2m -12° 2004/08/21 14.1 2004/08/21 1.435 1067 2004/10/28 162.3° 1h43m +29° 2004/10/28 13.7 2004/10/28 1.353 4179 2004/08/21 179.2° 22h 4m -12° 2004/09/28 8.9 2004/09/29 0.010 1120 2004/10/28 172.9° 2h20m + 6° 2004/10/27 14.3 2004/10/24 0.891 4150 2004/08/22 176.9° 22h11m -14° 2004/08/22 14.1 2004/08/19 0.853 325 2004/11/04 168.5° 2h27m +26° 2004/11/04 12.3 2004/11/05 1.691 1312 2004/08/23 165.9° 22h39m -23° 2004/08/25 14.4 2004/08/29 1.638 49 2004/11/05 175.1° 2h38m +20° 2004/11/05 10.6 2004/11/03 1.377

1110 2004/08/24 165.6° 21h52m + 2° 2004/08/23 12.7 2004/08/20 0.688 499 2004/11/06 178.4° 2h45m +17° 2004/11/06 13.8 2004/11/08 2.236 93 2004/08/27 172.8° 22h34m -16° 2004/08/26 10.8 2004/08/22 1.485 548 2004/11/06 172.7° 2h57m + 9° 2004/11/07 12.8 2004/11/09 0.899 1683 2004/08/27 176.7° 22h23m - 6° 2004/08/27 14.1 2004/08/24 1.258 599 2004/11/06 179.7° 2h48m +16° 2004/11/06 11.1 2004/10/26 1.261 2571 2004/08/27 173.5° 22h36m -15° 2004/08/28 14.1 2004/08/29 0.798 378 2004/11/22 178.3° 3h56m +18° 2004/11/22 12.7 2004/11/19 1.469 1082 2004/08/29 179.4° 22h31m - 9° 2004/08/29 13.5 2004/08/28 1.549 1122 2004/11/25 179.9° 4h 5m +20° 2004/11/25 12.6 2004/11/18 0.997

605 2004/09/03 178.7° 22h50m - 8° 2004/09/03 13.1 2004/09/03 1.581 1450 2004/11/25 178.2° 4h 7m +19° 2004/11/25 14.2 2004/11/27 1.213 175 2004/09/06 176.7° 23h 7m - 9° 2004/09/06 11.2 2004/09/05 1.439 319 2004/11/27 165.3° 4h28m + 6° 2004/11/27 13.5 2004/11/25 1.664 7393 2004/09/06 170.2° 23h15m -15° 2004/09/06 14.1 2004/09/07 0.796 2892 2004/11/28 152.9° 3h47m +47° 2004/11/27 13.8 2004/11/26 1.574 4265 2004/09/09 174.2° 23h23m -10° 2004/09/09 14.5 2004/09/12 0.958 1346 2004/12/04 155.2° 4h56m - 2° 2004/12/03 14.1 2004/12/01 1.240 885 2004/09/10 178.1° 23h21m - 6° 2004/09/10 13.7 2004/09/10 1.504 10936 2004/12/04 167.3° 4h57m + 9° 2004/12/02 14.3 2004/11/23 0.920

883 2004/09/11 170.6° 23h 4m + 4° 2004/09/10 13.9 2004/09/06 0.809 106 2004/12/05 178.5° 4h49m +23° 2004/12/05 10.9 2004/12/01 1.730 915 2004/09/11 176.2° 23h26m - 7° 2004/09/12 13.5 2004/09/16 1.031 62 2004/12/10 177.4° 5h 9m +20° 2004/12/10 12.1 2004/12/05 1.666 273 2004/09/12 172.5° 23h37m -10° 2004/09/11 12.7 2004/09/04 1.211 458 2004/12/12 162.1° 5h19m + 5° 2004/12/10 12.7 2004/12/06 1.364 7638 2004/09/12 174.6° 23h28m - 9° 2004/09/13 14.5 2004/09/22 0.841 517 2004/12/13 178.7° 5h21m +24° 2004/12/13 12.6 2004/12/09 1.615 1537 2004/09/13 173.8° 23h16m + 1° 2004/09/13 14.2 2004/09/18 1.172 364 2004/12/15 175.4° 5h33m +18° 2004/12/15 11.4 2004/12/12 0.930

3037 2004/12/15 164.7° 5h27m + 8° 2004/12/15 14.2 2004/12/14 1.210 1181 2004/12/19 178.7° 5h51m +22° 2004/12/19 13.7 2004/12/15 1.211 2105 2004/12/27 177.4° 6h26m +20° 2004/12/27 13.2 2004/12/24 1.076 3632 2004/12/29 167.4° 6h31m +10° 2004/12/28 14.5 2004/12/24 0.965

ROSEMARY HILL OBSERVATORY PHOTOMETRY OF instrument at Rosemary Hill is a 0.76m Tinsley reflector. For ASTEROIDS 2036 SHERAGUL AND (21652) 1999 OQ2 these observations, the instrument was used at its f/5 newtonian focus with a SBIG ST-7E CCD camera. The images were Dr. Maurice Clark calibrated using dark frames and sky flats. All images were Department of Physics obtained without the use of filters. For asteroid 21652, some Bucknell University supplementary observations were obtained using a 0.20m f/6.3 Lewisburg PA 17837 Schmidt-Cassegrain telescope and a SBIG ST-9E CCD camera at [email protected] the Bucknell University observatory in Lewisburg, Pennsylvania.

(Received: 23 September Revised: 15 October) The target asteroids were selected from a list of potential lightcurve targets posted on the Collaborative Asteroid Lightcurve Link (CALL) home page, maintained by Brian Warner. No Photometric lightcurves measured at Rosemary Hill lightcurve data for any of these asteroids had been previously Observatory during mid-2003 are reported. 2036 reported (Harris, 2001). The differential photometry was Sheragul is found to have a synodic period of 5.41 ± measured using the program “Canopus” by Brian Warner, which 0.01 hours with an amplitude 0.58 ± 0.02 mag. The uses aperture photometry. “Canopus” was also used in preparing results for (21652) 1999 OQ2 are synodic period 16.29 the lightcurves. This program uses a routine based on the method ± 0.02 hours and amplitude 0.70 ± 0.02 mag. developed by Dr. Alan Harris (Harris et al. 1989). Differential magnitudes were calculated using reference stars from the USNO- Equipment and Procedures A 2.0 catalog. Comparison stars differed from night-to-night due to movement of the asteroid. “Canopus” allows compensation for Asteroid lightcurve investigations were undertaken at the night-to-night comparison star variation by offsetting individual Rosemary Hill Observatory (Minor Planet Observatory code 831) night’s magnitude scales to obtain a best fit. Asteroid sizes were located near Bronson in Florida at an elevation of 51m. The main estimated using the table “Conversion of to Diameter” table on the MPC website. (http://cfa- Minor Planet Bulletin 31 (2004) 16 www.harvard.edu/iau/lists/Sizes.html) Discovery details were from August 19 to September 21, 2003, using either 60 or 120 obtained from the MPC “Discovery Circumstances” web page. second exposures. A total of 587 observations were used in the (http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html) solution Figure 2 shows the resulting lightcurve. The synodic period was determined to be 16.29 hours ± 0.02 hours, with an Results amplitude of 0.70 magnitude ± 0.02 magnitude.

2036 Sheragul

This main-belt asteroid has an estimated diameter of around 15 km. It was discovered on 22 September 1973 by N. S. Chernykh at Nanchnyj. Observations were made on five nights during the period from July 29 to August 4, 2003, using either 60 or 90 second exposures. A total of 617 observations were used in the solution. Figure 1 shows the resulting lightcurve. The synodic period was determined to be 5.41 hours ± 0.01 hours, with an amplitude of 0.58 magnitude, ± 0.02 magnitude.

Figure 2. Lightcurve of 21652 1999 OQ2, based on a period of 16.29 hours. Zero Point of the curve is J.D. 2452870.71. Ordinate is relative magnitude.

Acknowledgments

Many thanks to Dr John Oliver for making available the 0.76cm telescope at the Rosemary Hill observatory, and to Brian Warner for his continuing work on the program “Canopus”, which has made it possible for amateurs to analyze and share lightcurve data.

Figure 1. Lightcurve of 2036 Sheragul, based on a period of 5.41 References hours. Zero Point of the curve is J.D. 2452831.66. Ordinate is relative magnitude. Harris, A. W., et al, (1989). “Photoelectric Observations of Asteroids 3, 24, 60, 261, and 863.” Icarus 77, 171-186. (21652) 1999 OQ2 Harris, Alan W. (2001). “Minor Planet Lightcurve Parameters – This main-belt asteroid has an estimated diameter of around 20 Updated March”, on the CALL website: km. It was discovered on 22 July, 1999 as part of the LINEAR http://www.MinorPlanetObserver.com/astlc/default.htm survey. Observations were made on five nights during the period

ASTEROID-DEEPSKY APPULSES IN 2004 2. The separation between the two was less than 360 arcseconds. Brian D. Warner 3. The phase of the moon was between mid-waning gibbous to Palmer Divide Observatory mid-waxing gibbous 17995 Bakers Farm Rd. Colorado Springs, CO 80908 4. The event was at least 45° from the Sun. [email protected] The list below is not comprehensive by any means. However, it’s a good first check. For a more complete check, the Minor Planet (Received: 29 September) Center's web site at: http://scully.harvard.edu/~cgi/CheckMP allows you to enter the location of a suspected asteroid or A list of favorable appulses between asteroids and supernova and check if there are any known targets in the area. brighter deepsky objects during 2004 is presented. The complete set from which the table below is taken can be found at the MPO web site: http://www.minorplanetobserver The following list is a subset of the results of a search for asteroid- .com/htms/dso_appulses.htm deepsky appulses meeting the following criteria: The table gives the following data: 1. The asteroid was brighter than 14.0.

Minor Planet Bulletin 31 (2004) 17

Date/Time Universal Date and Time of closest approach Mag The approximate total magnitude of the DSO #/Asteroid The number and name of the asteroid Type The type of DSO: OC = Open Cluster; GC = RA/Dec The J2000 position of the asteroid Globular Cluster; G = Galaxy Mag The approximate visual magnitude of the asteroid SE/ME The elongation in degrees from the sun and moon respectively Sep/PA The separation in arcseconds and the position angle from the DSO to the asteroid MP The phase of the moon: 0 = New, 1.0 = Full. Positive = waxing; Negative = waning DSO The DSO name or catalog designation

Date UT # Asteroid RA Dec Mag Sep PA DSO Mag Type SE ME MP ------01/15 15:51 59 Elpis 00 41.31 - 1 39.8 12.9 205 337 UGC 439 13.2 G 74 158 -0.447 01/15 15:53 114 Kassandra 00 42.64 + 0 53.1 13.9 141 336 NGC 223 13.2 G 75 159 -0.447 01/18 14:29 185 Eunike 04 34.28 - 8 34.4 12.0 251 82 NGC 1614 12.9 G 122 147 -0.145 01/19 10:16 306 Unitas 15 48.45 -13 42.0 14.0 303 8 NGC 5995 14.0 G 61 29 -0.083 01/20 15:32 729 Watsonia 12 41.23 +11 55.4 13.9 104 322 NGC 4607 12.8 G 114 99 -0.022 01/22 19:29 84 Klio 00 20.06 +10 58.3 13.6 343 338 UGC 191 13.4 G 67 56 0.014 01/25 12:37 472 Roma 01 31.55 - 6 53.0 13.8 72 325 NGC 586 13.2 G 74 28 0.162 01/27 23:44 398 Admete 09 47.82 + 2 31.5 13.5 333 176 UGC 5249 13.2 G 157 124 0.380 01/28 08:30 98 Ianthe 04 46.05 +44 43.7 12.8 287 268 Ru 148 9.5 OC 125 53 0.415 ------02/17 23:55 12 04.89 - 2 24.0 12.4 123 185 NGC 4079 12.4 G 147 115 -0.073 02/18 03:35 146 Lucina 09 43.41 +31 56.6 12.1 159 209 NGC 2970 13.6 G 159 159 -0.065 02/21 13:23 1467 Mashona 09 40.51 +15 00.3 14.0 317 1 NGC 2954 12.4 G 170 155 0.018 02/21 23:56 786 Bredichina 11 17.74 +26 37.0 12.9 79 223 NGC 3609 13.1 G 159 159 0.032 02/22 11:42 146 Lucina 09 39.34 +32 19.2 12.2 80 25 NGC 2944 14.0 G 156 136 0.052 02/23 18:58 1318 Nerina 12 12.76 +10 54.1 13.9 78 331 NGC 4178 11.4 G 154 160 0.127 02/23 22:39 161 Athor 10 53.02 +17 34.8 12.8 53 17 NGC 3443 13.1 G 170 139 0.138 02/26 01:02 506 Marion 11 08.42 -10 19.7 13.0 222 176 NGC 3537 14.0 G 159 127 0.307 02/27 04:00 1318 Nerina 12 08.30 +10 20.0 13.8 199 153 NGC 4124 11.4 G 158 120 0.409 02/27 09:44 109 Felicitas 13 24.30 -10 12.2 13.8 46 3 NGC 5130 14.0 G 135 143 0.431 02/28 14:30 369 Aeria 11 37.88 +21 58.7 12.7 24 216 NGC 3753 13.6 G 161 91 0.544 ------03/14 20:38 258 Tyche 12 29.12 -11 34.0 13.1 356 34 NGC 4484 14.0 G 162 86 -0.387 03/15 05:56 2 Pallas 02 58.20 -10 20.1 9.3 6 157 NGC 1155 14.0 G 50 111 -0.345 03/15 10:59 472 Roma 02 46.23 + 3 41.4 14.0 357 335 NGC 1085 12.3 G 46 113 -0.322 03/16 15:14 11 40.20 + 8 57.8 10.1 160 214 IC 719 13.1 G 172 131 -0.206 03/17 01:04 265 Anna 12 57.39 -39 41.0 13.5 335 296 NGC 4832 12.2 G 136 94 -0.170 03/20 08:32 506 Marion 10 46.98 - 9 58.2 13.0 71 191 NGC 3375 12.6 G 159 159 -0.004 03/20 10:03 2 Pallas 03 06.87 - 9 31.0 9.3 67 339 NGC 1214 14.0 G 47 51 -0.003 03/20 21:49 265 Anna 12 51.92 -41 09.1 13.5 103 120 NGC 4729 12.3 G 138 135 0.001 03/21 04:42 317 Roxane 10 51.27 + 8 13.8 13.5 278 205 NGC 3427 13.2 G 160 157 0.001 03/24 05:20 77 Frigga 13 04.32 - 7 39.2 12.6 52 19 NGC 4942 14.0 G 166 156 0.106 03/24 14:09 215 Oenone 12 18.32 - 0 59.3 13.3 304 21 NGC 4202 13.6 G 179 138 0.129 03/27 01:24 20 24.58 -43 41.4 13.5 85 194 NGC 6902 10.9 G 71 134 0.321 03/27 22:32 24 Themis 18 09.60 -23 55.9 12.9 188 1 Cr 367 6.4 OC 95 173 0.401 03/29 03:26 19 40.03 -31 02.4 12.1 264 173 M55 7.0 GC 77 168 0.514 ------04/15 02:25 13 20.51 - 2 20.8 12.5 240 199 NGC 5095 13.7 G 172 134 -0.196 04/15 16:53 234 Barbara 14 19.73 + 9 20.5 12.8 110 215 UGC 9169 13.0 G 158 130 -0.148 04/18 04:08 740 Cantabia 12 42.15 +12 59.9 13.1 181 13 NGC 4620 12.2 G 151 164 -0.019 04/19 19:54 236 Honoria 05 10.69 +16 33.5 14.0 94 352 NGC 1807 7.0 OC 48 45 0.001 04/21 00:54 06 08.85 +24 17.2 13.5 170 194 M35 5.1 OC 61 44 0.021 04/22 19:15 22 30.68 -14 05.8 11.5 329 342 NGC 7298 13.7 G 59 95 0.096 04/23 01:36 9 Metis 22 31.09 -14 03.9 11.5 245 162 NGC 7300 12.9 G 59 98 0.111 04/23 10:33 44 Nysa 15 11.08 -11 26.3 10.2 231 19 NGC 5872 14.0 G 164 151 0.135 04/24 12:27 740 Cantabia 12 38.41 +13 08.5 13.2 91 5 NGC 4584 12.9 G 145 93 0.211 04/26 00:13 44 Nysa 15 08.75 -11 15.1 10.2 133 198 NGC 5858 14.0 G 167 120 0.337 04/26 02:24 11 53.90 - 3 55.8 13.8 312 36 NGC 3952 13.1 G 144 73 0.345 04/27 11:18 740 Cantabia 12 36.90 +13 09.3 13.3 40 180 M90 9.5 G 143 58 0.474 ------05/11 18:28 957 Camelia 14 42.75 -18 29.9 14.0 213 217 NGC 5726 12.8 G 172 101 -0.464 05/12 16:43 631 Philippina 07 34.20 + 4 28.6 14.0 201 179 UGC 3912 12.8 G 64 132 -0.365 05/14 22:39 107 Camilla 23 13.62 - 1 41.0 13.8 195 340 NGC 7521 13.9 G 66 19 -0.163 05/17 09:09 139 Juewa 00 39.63 + 3 28.1 14.0 139 333 NGC 203 14.0 G 46 26 -0.029 05/19 16:04 740 Cantabia 12 31.29 +12 16.9 13.7 252 92 NGC 4486A 11.2 G 122 117 0.002 05/19 21:17 304 Olga 20 23.25 + 0 41.3 13.4 88 331 IC 1317 13.8 G 110 116 0.005 05/21 13:42 772 Tanete 17 36.08 -33 27.2 12.6 140 314 Tr 27 6.7 OC 154 173 0.051 05/23 10:10 60 Echo 21 04.64 -12 18.3 13.2 115 331 NGC 7010 14.0 G 108 152 0.154 05/23 19:35 126 Velleda 13 04.31 - 7 39.7 13.5 20 14 NGC 4942 14.0 G 135 85 0.182 05/24 04:34 714 Ulula 14 56.64 -17 14.3 12.7 55 40 NGC 5781 14.0 G 163 109 0.210 05/27 03:06 740 Cantabia 12 31.82 +11 39.3 13.8 213 68 NGC 4497 12.5 G 116 30 0.479 05/27 07:38 20 Massalia 15 17.84 -17 38.1 10.1 191 196 NGC 5890 14.0 G 165 76 0.498 ------06/11 22:32 739 Mandeville 14 09.98 +17 37.0 12.7 107 271 NGC 5490C 13.9 G 118 153 -0.288 06/12 10:01 663 Gerlinde 15 01.13 -14 07.6 13.5 250 56 NGC 5809 14.0 G 145 155 -0.246 06/13 22:42 914 Palisana 23 38.31 +25 38.2 13.0 238 131 NGC 7718 14.0 G 79 42 -0.131 06/13 23:38 128 Nemesis 01 07.46 + 0 57.9 12.6 121 341 NGC 391 13.4 G 67 26 -0.128 06/14 09:14 01 21.33 + 7 03.7 12.0 173 339 NGC 485 13.0 G 62 25 -0.104 06/15 04:08 204 Kallisto 11 20.18 + 2 30.3 13.8 102 193 UGC 6345 13.4 G 86 115 -0.062 06/15 15:26 914 Palisana 23 40.74 +26 12.2 12.9 153 130 UGC 12732 13.3 G 79 57 -0.042 Minor Planet Bulletin 31 (2004) 18

Date UT # Asteroid RA Dec Mag Sep PA DSO Mag Type SE ME MP

06/16 12:49 12008 1996 TY9 16 23.93 -26 31.8 12.4 267 88 M4 5.9 GC 162 176 -0.015 06/17 23:24 107 Camilla 23 36.45 + 0 20.5 13.6 155 343 NGC 7716 12.1 G 92 94 0.001 06/17 23:26 727 Nipponia 18 10.73 - 7 13.7 13.5 105 168 IC 1276 10.3 GC 163 160 0.001 06/19 01:14 126 Velleda 13 04.79 - 8 00.0 14.0 205 208 NGC 4948 14.0 G 110 97 0.015 06/19 03:19 914 Palisana 23 45.62 +27 21.7 12.9 24 131 NGC 7747 13.6 G 81 91 0.017 06/20 10:07 126 Velleda 13 05.28 - 8 03.7 14.0 355 27 NGC 4948A 13.4 G 109 81 0.061 06/20 17:52 375 Ursula 01 49.26 +20 42.8 13.2 57 326 IC 163 13.1 G 57 88 0.076 06/24 07:31 727 Nipponia 18 04.82 - 7 35.9 13.5 53 164 NGC 6539 9.6 GC 164 104 0.347 06/25 01:19 23 12.96 + 6 27.2 13.8 229 327 UGC 12423 13.6 G 102 166 0.422 ------07/10 21:17 404 Arsinoe 22 45.11 -23 41.9 13.3 260 101 NGC 7359 12.5 G 133 64 -0.344 07/12 12:59 204 Kallisto 11 54.31 + 0 08.4 13.9 27 17 IC 745 13.2 G 68 122 -0.204 07/13 15:24 19 36.99 -42 20.3 12.9 78 187 NGC 6806 13.2 G 159 138 -0.127 07/14 00:40 49 Pales 02 01.34 +15 43.3 12.8 347 336 NGC 786 13.3 G 78 41 -0.104 07/14 01:38 187 Lamberta 10 56.77 + 9 48.0 13.0 135 30 NGC 3467 13.4 G 50 87 -0.101 07/15 05:09 494 Virtus 18 35.81 -33 01.8 13.1 170 177 NGC 6652 8.9 GC 162 169 -0.046 07/15 21:33 187 Lamberta 10 59.90 + 9 22.0 13.0 1 224 NGC 3490 13.8 G 49 66 -0.023 07/17 10:58 192 Nausikaa 03 44.81 +24 11.2 11.6 263 341 vdB 20 11.6 BN 56 55 0.002 07/19 14:47 490 Veritas 00 45.15 + 6 03.0 13.6 302 171 NGC 240 13.5 G 104 128 0.045 07/21 05:30 14 12.34 -30 34.9 13.5 310 350 NGC 5494 11.9 G 102 63 0.133 07/24 01:54 7 Iris 11 53.72 - 3 59.1 11.3 56 20 NGC 3952 13.1 G 59 19 0.384 ------08/10 18:17 544 Jetta 00 17.02 +12 23.6 13.8 249 52 UGC 156 14.0 G 129 71 -0.240 08/13 20:54 62 Erato 04 36.09 +19 57.8 14.0 47 353 NGC 1615 13.6 G 71 47 -0.046 08/17 05:31 43 Ariadne 13 18.46 -10 11.4 12.4 165 20 NGC 5066 14.0 G 57 44 0.016 08/17 10:05 259 Aletheia 01 00.56 - 9 09.1 12.9 241 298 NGC 341A 13.0 G 133 149 0.021 08/17 12:10 913 Otila 21 07.65 -25 29.3 13.6 84 151 NGC 7018 14.0 G 164 150 0.023 08/17 22:40 96 Aegle 00 24.06 +16 30.6 13.3 111 28 NGC 100 13.3 G 132 150 0.038 08/18 20:58 00 03.56 -10 45.8 6.4 68 133 NGC 7808 13.5 G 148 172 0.082 08/20 02:16 43 Ariadne 13 24.06 -10 40.5 12.4 96 200 NGC 5122 14.0 G 56 9 0.165 08/20 21:40 50 Virginia 04 36.11 +19 55.4 13.4 97 175 NGC 1615 13.6 G 78 136 0.235 08/21 20:03 31 Euphrosyne 20 03.74 -54 48.7 12.7 156 42 NGC 6850 12.5 G 131 75 0.326 ------09/06 20:52 544 Jetta 00 01.42 +13 03.5 13.3 154 173 NGC 7803 13.1 G 156 71 -0.476 09/09 18:09 17 Thetis 18 04.64 -22 26.5 11.8 213 11 M21 5.9 OC 104 159 -0.219 09/12 12:46 514 Armida 22 22.77 - 4 09.6 13.3 169 157 NGC 7260 14.0 G 165 165 -0.045 09/13 21:49 12 Victoria 05 59.04 +21 49.1 12.2 299 190 Basel 11 8.9 OC 82 74 -0.005 09/14 08:10 1132 Hollandia 01 08.72 + 1 37.0 13.5 119 172 UGC 711 14.0 G 155 152 -0.001 09/14 21:49 772 Tanete 16 56.99 -40 41.1 13.9 68 187 Tr 24 8.6 OC 85 83 0.002 09/15 19:48 490 Veritas 00 43.45 + 2 57.0 12.5 76 320 NGC 236 13.5 G 162 177 0.018 09/15 21:41 44 Nysa 15 37.45 -16 34.5 12.2 158 17 NGC 5959 14.0 G 63 47 0.020 09/17 22:16 423 Diotima 06 08.95 +24 16.0 13.2 244 169 M35 5.1 OC 83 125 0.125 ------10/07 02:14 08 48.34 +18 16.2 14.0 236 194 IC 2409 13.5 G 65 19 -0.436 10/07 14:15 818 Kapteynia 00 58.84 -16 34.4 13.3 325 174 NGC 333B 14.0 G 158 111 -0.389 10/12 09:00 577 23 48.62 + 4 02.0 13.7 317 160 NGC 7756 14.0 G 159 172 -0.035 10/12 12:51 8 Flora 07 31.99 +18 19.1 10.2 115 187 NGC 2407 13.4 G 88 68 -0.029 10/15 07:00 245 Vera 09 16.73 +19 58.2 13.6 134 13 NGC 2801 14.0 G 67 82 0.018 10/15 18:37 479 Caprera 00 11.07 -11 56.4 12.6 246 332 NGC 35 14.0 G 152 132 0.036 10/16 03:33 245 Vera 09 17.72 +19 55.1 13.6 70 13 NGC 2813 13.5 G 67 94 0.053 10/16 20:34 218 10 13.46 + 3 21.1 14.0 122 198 NGC 3165 13.9 G 50 85 0.096 10/17 21:15 944 Hidalgo 02 02.05 +31 52.6 13.5 290 47 NGC 785 14.0 G 157 143 0.177 10/18 04:35 723 Hammonia 01 04.84 + 2 05.9 13.6 71 153 IC 1613 9.2 G 170 116 0.206 10/19 00:33 402 Chloe 07 13.25 +12 18.8 13.6 235 12 NGC 2350 12.3 G 98 158 0.289 10/20 14:58 328 Gudrun 22 55.79 - 5 24.3 13.7 352 14 NGC 7416 12.4 G 136 50 0.467 ------11/06 06:50 487 Venetia 09 40.55 +14 59.6 13.4 278 9 NGC 2954 12.4 G 82 5 -0.399 11/08 08:08 944 Hidalgo 01 13.18 +38 51.7 13.5 255 35 NGC 425 12.6 G 149 129 -0.209 11/08 12:21 325 Heidelberga 02 23.54 +26 28.6 12.3 145 166 NGC 900 13.7 G 168 130 -0.195 11/09 03:34 31 Euphrosyne 20 18.14 -44 47.2 13.3 60 311 NGC 6890 12.3 G 71 113 -0.144 11/12 16:59 71 Niobe 04 04.41 +52 34.3 12.2 161 176 NGC 1496 9.6 OC 144 146 0.000 11/14 15:31 31 Euphrosyne 20 23.83 -43 59.1 13.3 71 313 IC 4946 11.8 G 67 41 0.060 11/14 16:57 31 Euphrosyne 20 23.90 -43 58.5 13.3 110 313 New 5 12.4 G 67 40 0.064 11/16 10:01 410 Chloris 11 43.83 +10 44.1 14.0 245 195 NGC 3839 13.6 G 63 115 0.197 11/16 21:48 179 Klytaemnestra 20 21.14 -12 16.1 13.6 300 350 NGC 6898 14.0 G 70 16 0.245 11/18 01:14 49 Pales 02 28.39 +19 30.8 10.9 352 152 NGC 935 12.9 G 164 91 0.367 11/19 00:25 495 Eulalia 02 49.03 +13 17.9 13.3 187 340 NGC 1109 13.8 G 167 80 0.476 ------12/06 22:09 25 Phocaea 10 58.71 -15 01.1 13.4 251 223 NGC 3479 13.0 G 84 27 -0.311 12/07 06:40 394 Arduina 01 04.65 + 2 08.5 13.7 160 305 IC 1613 9.2 G 120 175 -0.277 12/07 10:06 11 02.40 +16 42.4 11.6 130 222 UGC 6112 13.3 G 95 34 -0.263 12/07 15:47 532 Herculina 08 21.69 +19 08.8 9.9 249 79 NGC 2572 13.8 G 133 74 -0.241 12/11 23:48 04 17.17 + 4 45.5 13.9 150 190 NGC 1542 13.9 G 157 154 -0.000 12/13 00:53 433 Eros 11 18.98 +13 06.2 11.5 101 44 M65 9.3 G 96 110 0.016 12/13 03:22 13 Egeria 11 52.69 +20 38.2 11.4 51 187 NGC 3937 12.5 G 92 108 0.019 12/15 14:01 166 01 20.74 - 9 09.0 13.7 295 308 NGC 481 14.0 G 110 61 0.177 12/16 04:17 548 Kressida 02 32.82 + 9 37.0 13.8 342 270 NGC 975 13.1 G 134 76 0.234 12/16 11:31 410 Chloris 12 19.00 + 8 51.1 13.7 5 8 IC 776 13.8 G 84 146 0.264 12/16 14:54 10 22.30 +21 34.3 12.8 17 345 NGC 3221 13.1 G 115 174 0.278 12/16 19:01 674 Rachele 11 42.60 +18 45.1 12.2 351 181 NGC 3827 13.3 G 97 160 0.296 12/18 09:05 584 Semiramis 10 13.84 + 3 23.6 13.3 310 83 NGC 3165 13.9 G 112 159 0.467

Minor Planet Bulletin 31 (2004) 19

ROTATION RATES FOR ASTEROIDS 875, 926, 1679, 25 members, including , 472 Roma, and 575 Renate. 1796, 3915, 4209, AND 34817 The IRAS survey (Tedesco 1989) gives an effective diameter of 13.75km ± 0.06km and mean albedo of 0.2346 ±0.022. The Brian D. Warner IAU’s MPCORB database gives values of 11.50 and 0.15 Palmer Divide Observatory respectively for H and G. The principal orbital elements for 17995 Bakers Farm Rd. Nymphe are: semi-major axis, 2.553AU; inclination, 14.58°; and Colorado Springs, CO 80908 eccentricity, 0.151. [email protected] Nymphe was observed on five nights from 2003 July 6 through (Received: 29 September) 21. During this time, the phase angle changed from 13.5° to 17.8°. The 0.3m SCT described above was used to make the observations. A total of 246 data points used in the analysis, The lightcurves of seven asteroids obtained in mid-2003 which gave a period of the lightcurve of 12.64 ±0.01h and were analyzed. The following synodic periods and amplitude of 0.42m ±0.02m. The amplitude implies a ratio of amplitudes were determined. 875 Nymphe: 12.64 1.47:1 for the projected a/b axes of the assumed triaxial ellipsoid. ±0.01h, 0.42 ±0.02m; 926 Imhilde: 26.1 ±0.5, >0.20m; 1679 Nevanlinna: 17.94 ±0.02h, 0.16 ±0.02m; 1796 Riga: 11.0 ±0.01h, 0.10 ±0.02m; 3915 Fukushima: 8.40 ±0.01h, 0.64 ±0.02m; 4209 Briggs: 12.235 ±0.01h, 0.44

±0.02m; and (34817) 2001 SE116: 6.382 ±0.005h, 0.75 ±0.03m

Equipment and Procedures

The asteroid lightcurve program at the Palmer Divide Observatory has been previously described in detail (Warner 2003) so only a summary is provided here. The main instrument at the Observatory is a 0.5m f/8.1 Ritchey-Chretien telescope using a Finger Lakes Instruments IMG camera with Kodak KAF-1001E chip. A second instrument also in use was a 0.3m f/9.3 Schmidt- Cassegrain using an SBIG ST-9E camera. Other combinations were used to obtain some of the lightcurves. The specifics are given in the discussion for each asteroid. Figure 1. The lightcurve for 875 Nymphe. The synodic period is Initial targets are determined by referring to the list of lightcurves 12.64 ±0.01h and the amplitude 0.42 ±0.02m. maintained by Dr. Alan Harris (Harris 2001), with additions made by the author to include findings posted in subsequent issues of 926 Imhilde the Minor Planet Bulletin. In addition, reference is made to the Collaborative Asteroid Lightcurve Link (CALL) web site Only preliminary results are reported for Imhilde as circumstances maintained by the author (http://www.MinorPlanetObserver and a longer period did not allow significant coverage of the .com/astlc/default.htm) where researchers can post their findings lightcurve. Imhilde was discovered by K. Reinmuth on 1920 pending publication. MPO Canopus, a custom software package February 15. According to Schmadel (1999), Reinmuth written by the author, is used to measure the images. It uses discovered so many asteroids that he had trouble finding names aperture photometry with derived magnitudes determined by for those that were numbered. So, Reinmuth would resort to calibrating images against field or, preferably, standard stars. Raw chosing names from the calendar Der Lahrer hinkende Bote. The instrumental magnitudes are used for period analysis, which is names did not necessarily have any connections to his friends or included in the program. The routine is a conversion of the acquaintances. The H and G values from the MPCORB database original FORTRAN code presented by Harris et al. (1989). are 10.30 and 0.15. Tedesco (Tedesco 1989) gives an effective diameter of 48.48km ±1.1km and a mean albedo of 0.0570 ±0.003. Note: in the following, the orbital elements are taken from the The principal elements are: semi-major axis, 2.991AU; IAU MPCORB data file available at the Minor Planet Center web inclination, 16.26°; and eccentricity, 0.174. site (ftp://cfa-ftp.harvard.edu/pub/MPCORB/). The date of osculation for the elements was 2453000.5. Imhilde was observed on two successive nights, 2003 April 9 and 10. The phase angle at the time was 5.6°. A total of 257 data Results points were used in the analysis. The period appears to be 26.1 ±0.1h with an amplitude >0.2m. As can be seen in Figure 2, the 875 Nymphe coverage is very incomplete. However, it does appear that the asteroid has a period on the order of one day and future programs Originally designated 1917 CF and at other times as 1926 RL, involving this asteroid should take this into consideration. Such a 1970 GC1, and 1971 UK4, Nymphe was discovered by M.F. Wolf target is a good candidate for collaborative efforts among at Heidelberg on 1917 May 19. The name is for the minor observers widely separated in longitude. divinities of nature and ancient mythology, who were represented as beautiful maidens dwelling in mountains, forests, and waters. The asteroid is a member of the (Zappala 1995). Kozai (1979) puts the asteroid in group 17. That group includes Minor Planet Bulletin 31 (2004) 20 1796 Riga

According to Tedesco (1989), Riga has an effective diameter of 73.83km ±1.8km and mean albedo of 0.0376 ±0.002. The asteroid carries several classifications, including XFCU (Tholen 1989) and CP (Tedesco 1989). The IAU H and G values are 9.84 and 0.15 while the principal elements are: semi-major axis, 3.347AU; inclination, 22.666°; and eccentricity 0.063. N.S. Chernykh discovered Riga at Nauchnyi on 1966 May 16; it’s named in honor of the capital of Latvia.

Observations of Riga were made using the 0.3m SCT/ST-9 combination on six nights in the period of 2003 June 2 through July 5. The phase angle went from 9.3° to 15.3° during the period. A total of only 131 data points were available, however. This made analysis difficult, as there were considerable gaps in the curve’s cycle. Despite the lack of data, a reasonable solution for Figure 2. The lightcurve for 926 Imhilde phased against a synodic the curve seems to be a period of 11.00 ±0.01h and an amplitude period of 26.1 ±0.5h. Since no minimum was found, the of 0.10 ±0.02m. The amplitude implies a ratio of 1.1:1 for the amplitude is assumed to be >0.20m. projected a/b axes of the assumed tri-axial ellipsoid. Opposition circumstances do not vary significantly from one time to the next, 1679 Nevanlinna so the 2004 August apparition should provide a good opportunity to confirm these results. Named in honor of Finnish mathematician, Rolf Nevanlinna, on his 80th birthday, this asteroid was discovered by L. Oterma at Turku on 1941 March 18. It has carried numerous designations, starting with 1930 FH and ending with 1974 DD2. The principal elements are: semi-major axis, 3.120AU; inclination, 17.95°; and eccentricity, 0.151. The IAU values for H and G are 10.60 and 0.15. Kozai (1979) puts this asteroid in his group 55, which includes 181 Eucharis and 780 Armenia among the total of 11 members. IRAS (Tedesco 1989) gives an effective diameter of 51.16km ±3.5km and mean albedo of 0.388 ±0.006. The SMASS study (Xu et al. 1995) makes this asteroid a member of the X class.

231 observations were obtained in five sessions from 2003 August 14 through 20 using the 0.3m SCT/ST-9E combination. The phase angle went from 6.8° to 7.5° over that time. The best-fit Fourier analysis gives a period of 17.94 ±0.02h and amplitude of 0.16 ±0.02m. The amplitude implies a ratio of 1.16:1 for the projected a/b axes of the assumed triaxial ellipsoid. Figure 3 Figure 4. The lightcurve for 1796 Riga. The synodic period is shows the data phased against this period. 11.0 ±0.01h with an amplitude of 0.10 ±0.02m.

3915 Fukushima

This is a type C asteroid within the SMASS study (Xu et al. 1995) while the IRAS catalog (Tedesco 1989) puts the effective diameter at 20.38km ±1.6km with a mean albedo 0.0561±0.010. The IAU H and G values are 12.20 and 0.15. The principal elements are: semi-major axis, 2.439AU; inclination, 14.445°; and eccentricity, 0.041. M. Yanai and K. Watanabe discovered the asteroid on 1988 August 15. The name is for Hisao Fukushima, a Japanese mathematician and noted amateur astronomer. The asteroid has carried numerous designations, starting with 1926 GQ and ending with 1988 PA1.

Data for analysis were obtained over four sessions in the period of 2003 July 28 to August 10 using a 0.3m SCT and ST-9E. Over the time, the phase angle went from 8.6° to 11.3°. A total of 256 data points were used in the analysis, which yielded a period of 8.40 ±0.01h and amplitude of 0.64 ±0.02m. The amplitude Figure 3. The lightcurve for 1679 Nevanlinna. The data is phased implies a ratio of 1.8:1 for the projected a/b axes of the assumed against a period of 17.94 ±0.02h. The amplitude is 0.16 ±0.02m. tri-axial ellipsoid. The phased plot is shown in Figure 4.

Minor Planet Bulletin 31 (2004) 21

G values are 13.80 and 0.15. Using a conversion chart provided by Alan Harris that is based on previous work (Harris 2001), the approximate diameter implied by the H value is 5.5km, when an albedo of 0.18 is assumed. The principle elements are: semi- major axis, 1.879AU; inclination, 22.23°; and eccentricity 0.118. These would make the asteroid a likely member of the Hungaria family, which circle the Sun just outside the orbit of Mars and have higher inclinations.

Data were obtained using the 0.3m SCT and ST-9E on 2003 July 22 and 24 when the phase angle was 9.8°. A total of 155 data points were used in the analysis, which gave a period and amplitude of 6.382 ±0.005h and 0.75 ±0.03m respectively. The amplitude implies a ratio of 2:1 for the projected a/b axes of the assumed triaxial ellipsoid.

Figure 5. A phased lightcurve for 3915 Fukushima using a synodic period of 8.40 ±0.01h. The amplitude is 0.64 ±0.02m.

4209 Briggs

This asteroid was discovered by E.F. Helin at Palomar on 1986

October 4. It was given the designation 1984 TG4 but has also carried 1969 SB, 1978 EL8, 1986 WD5, and 1989 CO4. The name is in honor of Geoffrey Briggs, former Director of the Solar System Exploration program at NASA. The principal elements are: semi-major axis, 3.154AU; inclination, 21.61°; and eccentricity, 0.089. The absolute magnitude, H, is 10.80 and G is the typically assumed 0.15. The IRAS catalog (Tedesco 1989) lists an effective diameter of 25.63km ±2.3km and mean albedo of 0.1288 ±0.026.

Using data from sessions on 2003 September 27 and 28 obtained Figure 7. The lightcurve for (34817) 2001 SE116. The best-fit with the 0.5m R/C scope and KAF-1001E camera, the lightcurve synodic period is 6.382 ±0.005h with an amplitude of 0.75 period is 12.235 ±0.01h with an amplitude of 0.44 ±0.02m. A ±0.03m. total of 417 data points were used in the analysis. The phase angle was 6.5° for both nights. Acknowledgments

Thanks go to Dr. Alan Harris of the Space Science Institute for making available the source code to his Fourier Analysis program and his continuing support and advice. I also thank Robert D. Stephens of Santana Observatory, Rancho Cucamonga, for his on- going advice and support.

References

References Note: Asteroid names and discovery information are from Schmadel (1999).

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. (2001). “Minor Planet Lightcurve Parameters”. Figure 6. The lightcurve for 4209 Briggs. The data is phased On Minor Planet Center web site: http://cfa- against a synodic period of 12.235 ±0.01h. The amplitude is 0.44 www.harvard.edu/iau/lists/LightcurveDat.html ±0.02m. Kozai, Y., (1979). “The dynamical evolution of the Hirayama (34817) 2001 SE family.” In Asteroids (T. Geherels, Ed.) pp. 334-358. Univ of 116 Arizona Press, Tucson. As might be expected for such a highly numbered asteroid, there is relatively little information available. Discovery was on 2001 Schmadel, L. (1999). Dictionary of Minor Planet Names, 4th September 21 at the Bisei SG Center. The IAU MPCORB H and edition. Springer-Verlag, Heidelberg, Germany.

Minor Planet Bulletin 31 (2004) 22

Tedesco, E. F., D.J. Tholen, and B. Zellner (1989). “UBV colors Zappala, V., Ph. Bendjoya, A. Cellino, P. Farinella, and C. and IRAS alebedos and diameters”. In Asteroids II (R.P. Binzel, Froeschle. “Asteroid Families: Search of a 12,487-Asteroid T. Gehrels, and M.S. Matthews, Eds.) pp. 1090-1138. Univ. of Sample using Two Different Clustering Techniques”. Icarus 116, Arizona Press, Tucson. 291-314, 1995.

Tholen, D. J. (1989). “Asteroid Taxonomic Classifications”. In Xu, Shui, R.P. Binzel, T.H. Burbine, and S.J. Bus. “Small Main- Asteroids II (R.P. Binzel, T. Gehrels, and M.S. Matthews, Eds.) Belt Asteroid Spectroscopic Survey: Initial results”. Icarus 115, 1- pp. 1139-1150. Univ. of Arizona Press, Tucson. 35, 1995.

Warner, B. D. (2003). “Lightcurve Analysis for [Several] Asteroids”. Minor Planet Bulletin 30, 21-24.

CCD PHOTOMETRY OF ASTEROID 932 HOOVERIA exposures. Relative magnitudes from night to night were uncertain as different comparison star sets were used. This was Pedro V. Sada dealt with by using additive constants to bring all the data into the Departamento de Física y Matemáticas best agreement possible. However, these arbitrary magnitude Universidad de Monterrey shifts were minimized (≤0.05 mag.) because of the overlap in Av. I. Morones Prieto 4500 Pte. comparison stars used on each subsequent night of observing. Garza García, N. L., 66238 Additional magnitude shifts were also used to compensate for the MEXICO intrinsic magnitude variation of the asteroid due to its change of [email protected] distance with respect to the Earth, and to phase angle variations (20.4° to 18.8° in October 2001 and 21.9° to 22.2° in January (Received: 5 August Revised: 4 November) 2002). Johnson V magnitudes were used for the comparison stars in the unfiltered images (October 2001) and Johnson R magnitudes for the filtered ones (January 2002). A minus 0.36 CCD photometry of asteroid 932 Hooveria taken during magnitude shift had to be applied to the unfiltered October 2001 October 2001 and January 2002 at the Universidad de data in order to bring it into agreement with the January 2002 R- Monterrey Observatory is reported. A synodic rotation filtered data. period of either 29.947 or 30.370 hours is determined from eight nights of observations. The best-fit rotational period for the asteroid was eventually obtained by trial-and-error. We attempted to compute the power Observations spectrum of the time series of data (Scargle, 1982; Horne and Baliunas, 1986), but there was not enough overlap in the sampled The observations of 932 Hooveria reported here were made at the lightcurve to yield an unambiguous result. Strong aliases Universidad de Monterrey (MPC 720) Observatory. The prevailed in the power spectrum that, upon reconstruction of the instruments used to gather the data were a computerized 7-inch lightcurve, proved to be only false periods. It was suspected that f/15 (working at f/10) Maksutov telescope with an SBIG ST-9E the asteroid had a relatively long rotation period (>15 hours) since CCD electronic imager. The target was selected from a list of asteroid photometry opportunities published in the Minor Planet Bulletin (Pravec and Harris, 2001). Data were collected on 2001 October 18-23 and 2002 January 18-19. All dates are UT. A total of 371 unfiltered images were obtained in October 2001, followed by 53 more in January 2002 using a standard Johnson R photometric filter. Of the 424 total images obtained, 350 (82.5%) were used in the final analysis; the rest were discarded because of various factors such as poor guiding and asteroid proximity to stars. The exposures for the images were of four minutes duration for the unfiltered data and eight minutes for the filtered data. Standard dark current and flat field corrections were applied. Three to four stars were used in each image as magnitude comparisons for the asteroid. A nearby star field was identified from the ‘LONEOS Photometric Calibration Star List’ (Skiff, 2002) and this field was observed each night. Stars with known magnitudes were used to determine the magnitudes of the asteroid comparison stars. Some of the comparison stars used on a given night were also included in the FOV of the subsequent night so that a link could be established between the relative magnitudes of all the comparison stars used on consecutive observing nights.

Reduction Figure 1: Composite lightcurve of asteroid 932 Hooveria derived Times were corrected for light travel time from the asteroid to the from 350 observations and a 29.947-hour rotation period. Earth and were taken to be at the mid-times of the image

Minor Planet Bulletin 31 (2004) 23 six continuous nights of observing in October 2001 had yielded Pravec, P. and Harris, A. W. (2001). “Asteroid Photometry little duplication of any lightcurve features. An additional set of Opportunities: October-December 2001”. The Minor Planet observations, consisting of two additional nights of images, was Bulletin 28(4) p. 28. therefore taken in January 2002 to complement the data. A software program was devised using IDL to sequentially Scargle, J. D. (1982). “Studies in Astronomical Time Series reconstruct lightcurves with rotational periods greater than 10 Analysis. II – Statistical Aspects of Spectral Analysis of Unevenly hours and using time increments of 0.001 hours. These were Spaced Data”. Astrophysical Journal 263 pp. 835-853. visually inspected until the best match was found. Skiff, B. (2002). “LONEOS Photometric Calibration Star List”. Results Posted on the WWW: ftp://ftp.lowell.edu/pub/bas/starcats/ loneos.phot (2002 February 14 update). The resulting synodic rotational period for 932 Hooveria from the data presented here is 29.947 hours (See Figure 1). There are two Sternberg Astronomical Institute. “General Catalog of Variable similar maxima and minima per rotation. The amplitude of the Stars”. http://www.sai.msu.su/groups/cluster/gcvs/gcvs/ intro.htm lightcurve is 0.15 ± 0.03 magnitudes. The time scale is given in rotational phase with the zero corresponding to a minimum ROTATION PERIOD AND LIGHTCURVE OF MINOR brightness on 2002 January 18 at 0.0 hrs UTC (JD 2452292.5), PLANET 1550 TITO with an uncertainty of ±2 hours. The magnitude scale adopted is referenced to the Johnson R filter observations obtained on the Walter R. Cooney, Jr. same date. This is probably the first reported rotational period for 1927 Fairview Dr. Hooveria since it is not listed within the reference of Harris Port Allen, LA 70767 (2001). [email protected]

However, it was found that an additional rotation period of 30.370 Valentino Pozzoli hours (not shown) also fits the data rather well. The long rotation V.le Morandi 21 period of the asteroid, combined with the time gap between the 20010 Bareggio (MI) two sets of observations, resulted in the available data being Italy insufficient to sample the entire lightcurve and also of yielding [email protected] little overlap. Thus, the result presented here cannot be considered as definitive and additional observations of this asteroid are John Gross required. What is concluded is that the asteroid 932 Hooveria is a 2080 W Speedway #1106 slow rotator with a period of close to 30 hours. Tucson, AZ 85745 [email protected] An additional unexpected result was the discovery of a variable (Received: 10 October) star amongst the comparison stars used to derive the magnitude of the asteroid. The star GSC 2387-0961 (RA: 04h 49m 23.1s, DEC: +30o 52’ 49”, J2000.0), near the known but little-studied long- Unfiltered differential photometry for minor planet period pulsating variable MY Aurigae, was found to have 1550 Tito is presented. The proposed synodic period decreased in brightness by 0.08 ± 0.01 magnitudes between 2001 solution is 54.2 ± 0.3 hours with an amplitude of 0.23 ± October 21-22, and 0.07 ± 0.01 magnitudes between 2001 October 0.03 magnitudes. The nightly photometry was put on a 22-23. A search of several web sites (like AAVSO, VSNET and single instrumental scale to allow all portions of the Simbad) yielded no information regarding the star, and it is not lightcurve to be fit using the slope parameter, G. A included in the General Catalog of Variable stars (See References value of 0.35 is the best fit for the slope parameter section for web URLs). The star was discarded as comparison for indicating a possibly high albedo for this asteroid. this analysis.

References We report here the results of lightcurve observations of minor planet 1550 Tito obtained at Blackberry Observatory (MPC 929). American Association of Variable Star Observers. “AAVSO”. Cooney and Robinson (2002) give full details of the equipment http://www.aavso.org/ and methods used. Images were unfiltered and integration times were 4 minutes. Images were reduced with MIRA. Centre de Données astronomiques de Strasbourg. “Simbad Astronomical Database”. http://simbad.u-strasbg.fr/ Valentino Pozzoli imaged Tito at J. B. Postel Observatory (MPC 201) with a Meade 12” SCT and an AP-7 on a Paramount Department of Astronomy, Kyoto University. “VSNET”. GT1100s. J. B. Postel Observatory is located in Promiod, a small http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/index.html village in the Western Italian Alps at an elevation of 1500 meters. Images were 4 minute unfiltered integrations and were reduced Harris, A. W. (2001). “Minor Planet Lightcurve Parameters”. with MaxIm DL. Cooney and Gross (2003) describe the Posted on the WWW: http://cfa-www.harvard.edu/iau/lists/ equipment and methods used at Sonoran Skies Observatory (MPC LightcurveDat.html (2001 March 1 update). code G94), located in St. David Arizona. The Sonoran Skies images were reduced by the first author (Cooney) with MIRA. Horne, J. H. and Baliunas, S. L. (1986). “A Prescription for Period Analysis of Unevenly Sampled Times Series”. The lightcurves from each observatory were phased together to Astrophysical Journal 302 pp. 757-763. reach a solution by the first author (Cooney). Data were corrected for light travel time from the asteroid and are for mid-exposure.

Minor Planet Bulletin 31 (2004) 24

The period solution for this asteroid was significantly longer than Dr. Vincent imaged Tito as well but Tito had an uncanny ability to a single night’s session, so all data taken at Blackberry hide near bright stars during the time Dr. Vincent was able to Observatory were put on a single instrumental magnitude scale by image it. The authors wish to thank Brian Warner for writing and calibrating all of the reference stars against each other. This maintaining his Collaborative Asteroid Lightcurve Link (CALL) allowed for the data to be phased with only two adjustable web page at http://www.minorplanetobserver.com/astlc/ parameters, rotation period and slope parameter, G. The data of default.htm which greatly facilitates collaborations such as this. Pozzoli and Gross were not on the same instrumental scale but Cooney would also like to thank Jeff Medkeff for his GetPhot could be shifted on the magnitude axis to coincide with the curves script which allowed unattended night-long photometry. This has since they were continuous in time with the data of Blackberry allowed the author to take advantage of clear nights and keep his Observatory. Dates referenced are UT. day job. Jeff makes the script freely available at his Robotic Observatory Home Page, http://www.roboticobservatory.com/. There are no previously published light curves for 1550 Tito per Harris (2001). The proposed lightcurve is based on a synodic References period of 54.2 ± 0.3 hours. The amplitude of variation is 0.23 ± 0.03 magnitudes. The best-fit slope parameter is 0.35 (Figure 1). Cooney, W. R. Jr., and Gross, J. (2003). “Rotation Periods and This is somewhat higher than a typical slope parameter of 0.15, Light Curves of Minor Planets (438) Zeuxo and (4577) Chikako”. typically indicating a high albedo. A slope parameter of 0.15 Minor Planet Bulletin 30, 3. results in a poorer fit of the data between 0 and 0.1 phase as seen in Figure 2. The fit is also degraded slightly between phase 0.4 Cooney, W. R. Jr., and Robinson, L. (2002). “Rotation Periods and 0.5. Adjusting the period length with G of 0.15 does not and Light Curves of Minor Planets (412) Elisabetha, (547) result in a better fit. Praxedis, and (7564) 1988 CA”. Minor Planet Bulletin 29, 78-79.

Acknowledgements Harris, Alan W. (2001). “Minor Planet Parameters”, on Minor Planet Center web site: http:cfa- We give special thanks to Dr. Fiona Vincent of the Physics and www.Harvard.edu/iau/lists/LightcurveDat.html. Astronomy Department at St. Andrews University in Scotland.

LIGHTCURVE ANALYSIS OF 1263 VARSAVIA

Robert D. Stephens Santana Observatory 11355 Mount Johnson Court Rancho Cucamonga, CA 91737 [email protected]

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

(Received: 26 August)

Figure 1. Phased light curve 1550 Tito with G = 0.35 The lightcurve for 1263 Varsavia was obtained by the authors in April and May 2003. The curve was difficult to interpret, as each new data set seemed to find a different period. After several weeks of effort, the lightcurve was determined to have a period of 7.231 ±0.002h and amplitude of 0.15 ±0.03m.

Equipment and Procedures

The asteroid lightcurve programs at the Santana and Palmer Divide Observatories have been previously described in detail (Stephens 2003, Warner 2003) so only a summary is provided here. At Santana, a 0.35m f/5.7 SCT is used with an SBIG ST-9E CCD camera operating at –10°C. Exposures were 180s unguided. At Palmer Divide, there are two telescope/camera combinations. The one used for this project was a 0.5m f/8.1 Ritchey-Chretien using an FLI IMG-1001E camera at –30°C. Exposures were 60s unguided. Figure 2. Phased light curve 1550 Tito with G = 0.15

Minor Planet Bulletin 31 (2004) 25

This asteroid was selected by referring to the list of lightcurves References maintained by Dr. Alan Harris (Harris 2001), with additions made by Harris and Warner to include findings posted in subsequent References Note: Asteroid names and discovery information are issues of the Minor Planet Bulletin and postings on various web from Schmadel (1999). sites, including the Collaborative Asteroid Lightcurve Link (CALL) site maintained by the Warner Harris, A.W., Young, J.W., Bowell, E., Martin, L.J., Millis, R.L., (http://www.MinorPlanetObserver.com/astlc/default.htm). Poutanen, M., Scaltriti, F., Zappala, V., Schober, H.J., Debehogne, H., and Zeigler, K.W., (1989). “Photoelectric Observations of The images were measured using MPO Canopus, a custom Asteroids 3, 24, 60, 261, and 863.” Icarus 77, 171-186. software package written by Warner. This program uses aperture photometry and allows up to five comparison stars to be used for Harris, Alan W. (2001). “Minor Planet Lightcurve Parameters”. differential photometry. It also allows merging of data sets, called On Minor Planet Center web site: http://cfa- sessions, from multiple runs and/or observers to form a single set www.harvard.edu/iau/lists/LightcurveDat.html for period analysis. The period analysis included in the program is based on the original FORTRAN version of the Fourier analysis M. Kaasalainen and J. Torppa (2001). “Optimization methods for algorithm developed by Alan Harris (Harris et al., 1989). asteroid lightcurve inversion. I. Shape determination”. Icarus 153, 24. Results Schmadel, L. (1999). Dictionary of Minor Planet Names, 4th Varsavia is listed by Tholen to be a type X asteroid (Tholen 1989). edition. Springer-Verlag, Heidelberg, Germany. The IRAS survey (Tedesco et al 1989) gives an effective diameter of 49.29km ±1.1km, a mean albedo of 0.0459 ±0.002, and Stephens, R. D. (2003). “Photometry of 2134 Dennispalm, 2258 assumed absolute magnitude of 10.50. The latter is the same value Viipuri, 3678 Mongmanwai, 4024 Ronan, and 6354 Vangelis”. listed in recent versions of the MPCORB file from the Minor The Minor Planet Bulletin, 30(3). Planet Center. The asteroid was discovered by S. Arend at Uccle on 1933 March 23 and has carried the designations 1933 FF and Tedesco, E. F., D.J.Tholen, and B. Zellner (1989). “UBV colors 1948 PB1. Varsavia is the Latin name for Warsaw, Poland. and IRAS alebedos and diameters”. In Asteroids II (R.P. Binzel, T. Gehrels, and M.S. Matthews, Eds.) pp. 1090-1138. Univ. of The initial observations of Varsavia were made on April 9 and 10, Arizona Press, Tucson. 2003, by Warner. Not longer afterwards, one of the most severe blizzards in Colorado history hit the Palmer Divide Observatory Tholen, D. J. (1989). “Asteroid Taxonomic Classifications”. In area, leaving drifts in excess of 2 meters and Warner stranded in Asteroids II (R.P. Binzel, T. Gehrels, and M.S. Matthews, Eds.) his house for three days. The design of the observatory, where the pp. 1139-1150. Univ. of Arizona Press, Tucson. entire building moves, in combination with the slowly melting drifts meant Warner could not observe for about a month after the Warner, B. D. (2003), “Lightcurve Analysis for [Several] storm. So that the asteroid would not be lost for the given Asteroids”. Minor Planet Bulletin 30, 21-24. apparition, Stephens agreed to gather observations staring in early May 2003 from Southern California, where snowdrifts have not been a problem since the last ice age. Working the nights of May 10, 11, 12, and 16, he obtained 225 observations. Warner also managed a session on May 11, bringing his total to three sessions and 257 observations.

With the addition of each data set, the period solution varied from between six and nine hours. It wasn’t until the last data set from Stephens (May 16) was included that a reliable fit of all the data was made. On the plot shown in Figure 1, session 100004 is Stephens’ May 11 data while session 100005 is Warner’s May 11 data. The resultant lightcurve has an unusual shape with two prominent maximums and one prominent minimum. With lightcurves obtained at future oppositions in 2004 July (+11°/15.4m) and 2005 October (–21°/14.0m), this asteroid could be a good candidate for a shape model currently being done by Mikko Kaasalainen at the University of Helsinki.

Acknowledgments

Thanks go to Dr. Alan Harris of the Space Science Institute for making available the source code to his Fourier analysis program and his continuing support and advice. Figure 1. The lightcurve for 1263 Varsavia. The synodic period was found to be 7.231 ± 0.002h. The amplitude is 0.15 ±0.03m.

Minor Planet Bulletin 31 (2004) 26

THE MINOR PLANET OBSERVER: rate and the orientation of its axis. A recent article in Nature UPON A NEW YEAR speculates that the so-called “YORP Effect” can be more significant in determining these attributes for smaller asteroids Brian Warner than collisions. If true, that would be a stunning change in the Palmer Divide Observatory thinking about how the asteroid belt evolved. 17995 Bakers Farm Rd. Colorado Springs, CO 80908 Consider that Stephen Slivan and a number of undergraduate [email protected] assistants worked for nearly a decade to establish some of these theories. Consider that nearly 200 lightcurves were gathered just When I opened the mailbox and saw the big white envelope I to detail results for a handful of asteroids. Reconsider your knew it held the latest issue of the Minor Planet Bulletin. When I thought that yet another lightcurve of an asteroid with a known grabbed it, I was surprised at how thin and light the envelope was. period has no meaning and is not worth your time. So many I assumed that maybe Derald Nye, the MPB distributor, had sent asteroids; so few observers. me a few less issues than normal as part of cutting costs. Instead, I found that the last issue (Vol. 30, No. 4) was just thin, only 12 I mentioned frustrations. Not all of them are directly related to pages – one half the number of the previous issue. gathering images. I decided that my observatory, which was a roll-out building, needed replacing with a more traditional roll-off Is this a sign of the times and the future? I doubt it. Observers in roof design. First, when in use, the telescope was out in the open. the Northern Hemisphere are still doing most asteroid lightcurve While I don’t live in a city, I do live in a small development and work. The dearth of lightcurves, only nine, was probably more an there was concern that some passerby would think a look at Mars indication of the reduction in work during Northern summer when in the middle of the night might be a good idea. Also, it exposed the asteroids are low in the sky and lurking in the heart of the the scope to lights and wind. So, I designed and got ready to build Sagittarius and Scorpius star clouds. There is some hope this dip a new building large enough to hold the scope and let it move in activity will level out in future years. The recent Australian about the sky without fear of it hitting the walls of the building. version of the Minor Planet Amateur Professional Workshop held just after the IAU General Session in June was a big success and it A very important rule: do not let me near tools. At all costs, keep appears to have inspired several observers to pick up this line of them and me well separated. For some reason my 10 by 12 foot work. Astrometry and seem to be the main topics in building is 10 feet, one inch on one side. This makes for a roll-off the news group started after the meeting. I’m hoping that a few of roof a little off square with the building and will allow rain and the list members can be convinced to join David Higgins and snow to come in. Maybe the metal measuring tape expanded or Colin Bembrick, among others, to the “dark side”. shrunk at some point. I do know that without the able assistance and generosity of Bob Koff, a steady contributor to the Minor On a very positive note, there were some new names appearing Planet Bulletin, I never would have been able to get the building under the article titles in the last issue. I hope to see more of that into a usable state. as time goes by. Certainly the number of CCD owners using their cameras for some scientific research is growing. However, the I’m going to forego the finder charts this time around. I’d be percentage of the total number of owners is still very small. Most interested in your feedback about that. With all the excellent folks are interested in getting what some deride as “pretty charting and planetarium programs available these days, I thought pictures.” I wish I could do so well. Maybe that’s why I work the charts may not be as useful as when I started the Minor Planet lightcurves. I’m certainly no artist and many of the images one Observer 14 years ago (has it really been that long?). In the case sees from amateurs are true works of art. Without going into any of NEOs, the charts were significantly off for any observer not at details that would give away secrets, I do know that a new effort the center of the Earth and probably didn’t provide the required will be made by at least one equipment manufacturer to help build detail. If nothing else, not having the charts provides some extra the number of those doing even simple science. That’s in addition room for what I hope will be an ever-increasing number of to the well-documented work already done by some companies. lightcurves published on these pages.

Admittedly, lightcurve work is not really that simple. Sure it’s This issues marks the start of the fifth year I’ve been writing the easy enough to take a number of pictures, have the software MPO article for the Bulletin. I hope you’ve enjoyed reading the measure the target and comparisons, and the plot the differential articles as much as I’ve enjoyed writing them. I’d appreciate magnitudes. Those who’ve been doing this very long know that hearing from some of you so that I can pass along some of what even this process is fraught with pitfalls. Where the real challenge other observers are doing around the world. We all learn by doing comes in is interpreting the data. Yes, there are period search and by listening to others. One can do something for many years programs but one would be wise not to accept the results without only to find out in a casual conversation there is a better way. suspicion. A study a long time ago tested how far people would Send me an email and include pictures if you like. I’ll try to post trust the results given by a machine, in this case, a simple some on my web site or include a link to yours. calculator. A disturbingly high number of people accepted results on full faith even though the calculator had been programmed to Besides the aforementioned Derald Nye, I think kudos should be give results that were at least 50% in error! given to MPB editor Rick Binzel, whose generosity and patience towards amateur observers are seemingly endless. The same goes Despite all the pitfalls and frustrations, lightcurve work really can to Bob Werner, who does the layout for the Bulletin. I did be fun (No, I don’t like root canals). Far more important, and this something similar for ten years on the Minor Planet Observer. I is a point I’ve made before and will keep making, the know how much time and effort is required. At least Bob has opportunities to make a lasting contribution to science are not much better tools than I did back in the stone and chisel days of dwindling but expanding. Take, for example, the developing computer word processing. To everyone, a Happy New Year theory that solar heating and re-radiation of that heat by asteroids filled, I hope, with many nights of Clear Skies! can affect not only the size of the asteroid’s orbit but its rotation Minor Planet Bulletin 31 (2004) 27

ASTEROID PHOTOMETRY OPPORTUNITIES We’ll emphasize again that spin and axis studies rely heavily on JANUARY – MARCH 2004 having sufficient observations and that it’s rare to have too many observations for a given asteroid. Science doesn’t always advance Brian D. Warner by sudden leaps but does so more often by slow, methodical work. Palmer Divide Observatory If your efforts can help confirm (or refute) the new theories about 17995 Bakers Farm Rd. the evolution of the asteroid belt and so the solar system, then you Colorado Springs, CO 80908 will have made a true and lasting contribution to science.

Mikko Kaasalainen The table below presents a list of suitable photometric targets for Rolf Nevanlinna Institute the months of 2004 January through March. Most of the objects P.O. Box 4 (Yliopistonkatu 5, room 714) have been selected from a more extensive list prepared by Brian FIN-00014 University of Helsinki Warner. Objects selected are usually V<15 when brightest and Finland have unknown or poorly established lightcurve parameters. Of

note is 2001 BE10, which passes only 0.058AU from Earth in Alan W. Harris January. Any NEO warrants particular attention. Space Science Institute 4603 Orange Knoll Ave. Periods are given for some of the targets but they are not La Canada, CA 91011-3364 necessarily reliable and could be entirely wrong. The values are given as a guide only and new work should be conducted independent of any expectations based on those values. Observers Astronomical Institute interested in a more extensive list are encouraged to check the full CZ-25165 Ondrejov list on the CALL website at www.MinorPlanetObserver Czech Republic .com/astlc/default.htm. Full references to the period and amplitude estimates cited in this article can be found in the list [EDITOR’S NOTE: We welcome Brian Warner as the new prepared by Alan Harris, which is available at http://cfa- Photometry Coordinator for the Minor Planets Section and thank www.harvard.edu/iau/lists/LightcurveDat.html. Those wanting to Petr Pravec for serving as Coordinator for the past 3 years.] learn more about Mikko Kaasalainen’s program to obtain lightcurves for shape and pole modeling should visit On behalf of all those involved in asteroid lightcurve work, I http://www.astro.helsinki.fi/~kaselain/observations.html. (Warner) want to take this opportunity to thank Petr Pravec for his work as the Photometry Coordinator the past few years. I remember years ago when writing the Minor Planet Observer that Brightest # Name Date Mag Dec Period Amp I would often refer to this article. Alan Harris and Vincenzo [V] [°] [h] [m] Zappala were writing at the time. Alan is still involved, though 7829 Jaroff (F) 1 01.5 14.8 +13 1999 XP19 (F) 1 03.9 15.6 +39 his pressing schedule makes it ever more difficult. The same can 750 Oskar (F) 1 04.8 14.4 +27 be said for Mikko as well. Something amateurs like to boast about 4774 Hobetsu (F) 1 07.0 14.7 +22 1825 Klare (F) 1 08.0 14.5 +23 is having the advantage of not worrying about scheduling 6823 1988 ED1 (F) 1 08.3 13.8 +33 telescope time and nearly “anytime availability.” However, we 2843 Yeti (F) 1 08.6 15.0 +17 5392 Parker (F) 1.09.4 14.3 +62 >45 >0.2 have other, “real world” commitments just as well and so we can 1657 Roemera (F) 1 10.5 14.4 +25 4.5 0.09 afford to forgo one or more nights of observing without having to 18067 2000 AB98 (F) 1 16.0 14.9 +20 2001 BE10 (F) 1 19.2 13.8 +13 answer to anyone. This is not the case with professionals. It’s 3573 Holmberg (F) 1 21.8 14.7 +17 2367 Praha (F) 1 23.4 14.9 +16 their job to observe, to research, and to publish. They must 6239 Minos (F) 1 27.5 14.1 +64 answer to someone and so they must produce results in a timely 27259 1999 XS136 (F) 1 30.1 14.9 +13 1292 Luce (F) 2 01.5 14.1 +15 fashion. While important in its own way, this article was one too 1090 Sumida (F) 2 02.5 14.1 + 4 2.750 0.22 many items on Petr’s desk. 4266 Waltari (F) 2 02.9 15.0 +21 2331 Parvulesco (F) 2 04.3 13.7 +10 5036 Tuttle (F) 2 04.8 14.7 +19 Another reason for a change was that Petr’s work concentrates on 5008 Miyazawakenji (F) 2 05.1 14.9 +15 1584 Fuji (F) 2 08.8 12.6 - 2 10. 0.30 NEOs while this article has concentrated on main belt asteroids, 3270 Dudley (F) 2 08.8 14.5 + 2 MBAs for short, and will continue to do so. The NEOs require 1014 Semphyra (F) 2 11.3 14.6 +11 1816 Liberia (F) 2 21.0 13.4 +10 concentrated efforts, often for only a period of a few days. MBAs 3455 Kristensen (F) 2 22.9 14.7 + 9 1508 Kemi (F) 2 25.9 14.0 +45 9.15 0.52 are available for weeks, if not months, at a time. This is where the 2653 Principia (F) 2 26.0 14.6 + 4 amateur’s time proves most advantageous. Even with a missed 29943 1999 JZ78 (F) 2 26.6 14.5 +33 31368 1998 WW23 (F) 3 02.8 15.0 +31 night here or there, he can eventually get enough data on a target 6972 Helvetius (F) 3 04.5 14.8 - 2 to produce useful results. 1528 Conrada (F) 3 06.7 14.6 +12 180 Garumna (F) 3 07.1 12.9 + 4 1212 Francette (F) 3 13.9 14.1 + 7 >16. >0.03 We’ll continue to beat the drum about shape and pole studies, 1027 Aesculapia (F) 3 14.0 14.1 + 4 4232 Aparicio (F) 3 14.0 15.0 - 4 long? 0.2 especially in light of Stephen Slivan’s article in the last issue 1318 Nerina (F) 3 14.9 13.2 + 7 583 Klotilde (F) 3 17.8 12.7 -11 9.210 0.18 (MPB 30, No. 4, pg. 71). There is growing evidence that external 3861 Lorenz (F) 3 18.8 14.4 - 3 forces, e.g., the YORP Effect (see Richard Binzel’s article in 2486 Metsahovi (F) 3 19.1 14.6 + 1 656 Beagle (F) 3 19.1 13.4 + 0 Nature, vol 425, pp. 131-132; available online for a fee at 2841 Puijo (F) 3 20.0 14.8 + 8 www.nature.com/nature; summarized on page 28), help determine 2328 Robeson (F) 3 23.7 14.1 - 1 5168 Jenner (F) 3 29.2 15.0 -32 and alter the spin rate of asteroids. There is growing evidence of 4027 Mitton (F) 3 30.7 15.0 - 4 clustering of spin rates and axis orientations that contradict standing theories about family formation and collisional evolution.

Minor Planet Bulletin 31 (2004) 28

DISCOVERY OF SPIN VECTOR ALIGNMENTS: THE MINOR PLANET BULLETIN (ISSN 1052-8091) is the quarterly A TRIUMPH FOR ASTEROID LIGHTCURVE OBSERVERS journal of the Minor Planets Section of the Association of Lunar and Planetary Observers. The Minor Planets Section is directed by its Richard P. Binzel, Editor Coordinator, Prof. Frederick Pilcher, Department of Physics, Illinois College, Jacksonville, IL 62650 USA ([email protected]), assisted by Lawrence Garrett, 206 River Road, Fairfax, VT 05454 USA The recent discovery of asteroid spin vector alignments, ([email protected]). Richard Kowalski, 7630 Conrad St., Zephyrhills, FL 33544-2729 USA (qho@bitnik. com) is Associate based on a decade of focused lightcurve work, has given Coordinator for Observation of NEO’s, and Steve Larson, Lunar and new insight to the forces acting on asteroids. Planetary Laboratory, 1629 E. University Blvd., University of Arizona, Tucson, AZ 85721 USA ([email protected]) is Scientific Advisor. The Asteroid Photometry Coordinator is Brian D. Warner, Palmer Divide Owing to collisions, asteroids should have random rotation rates Observatory, 17995 Bakers Farm Rd., Colorado Springs, CO 80908 USA and random rotation pole directions (collectively referred to as ([email protected]). their spin vectors), or at least that has been the long standing collective wisdom. Finding out what is really happening requires The Minor Planet Bulletin is edited by Dr. Richard P. Binzel, MIT 54-410, observational studies. Many studies of asteroid collisional Cambridge, MA 02139 USA ([email protected]) and is produced by Dr. Robert outcomes have focused on families, thought to be collections of A. Werner, JPL MS 301-150, 4800 Oak Grove Drive, Pasadena, CA 91109 fragments formed in the disruption of a common . A USA (robert.a.werner@jpl..gov). Derald D. Nye serves as the distributor. lightcurve study of the Koronis family (Binzel 1988) found that these objects have, on average, higher lightcurve amplitudes The staff of the Minor Planet Section invites MPB subscribers who are not relative to other asteroids. Two hypotheses were offered: either members of our parent organization (Association of Lunar and Planetary (1) the formation of the family led to more elongated fragments or Observers – ALPO) to join by communicating with: Matthew L. Will, (2) the spin vectors are aligned, preferentially giving equatorial A.L.P.O. Membership Secretary, P.O. Box 13456, Springfield, IL 62791- views (large lightcurve amplitudes) to Earth-based observers. 3456 ([email protected]).

The second of the two hypotheses is testable, although the task is The contact for all subscriptions, address changes, etc. is: daunting. An asteroid’s lightcurve must be well observed over multiple apparitions over a wide range of longitudes. Mr. Derald D. Nye Minor Planet Bulletin With typically 15 months between appartitions and the need to 10385 East Observatory Drive statistically sample at least 10 Koronis family asteroids, long-term Corona de Tucson, AZ 85641-2309 USA patience and dedication are requirements. Stephen M. Slivan ([email protected]) undertook the task as part of his MIT Ph. D. thesis and continued (Telephone: 520-762-5504) until the statistics became incontrovertible: 10 out of 10 Koronis family asteroids showed aligned spin vectors in either of two Subscription rates (per year, four issues): states depending on prograde or retrograde rotation (Slivan 2002). Payment Payment by With the discovery of non-random spin vectors staring at them, by check credit card theorists set to work at finding out how such outcomes could be North America $14.00 $15.00 All other $19.00 $20.00 reached. The answer appears to rely on what is called the “Yarkovsky effect” which describes the recoil force on an To minimize our administrative time, please consider subscribing for two asteroid’s surface when it radiates away a thermal photon. years. Checks or money orders should be in US dollars, drawn on a US Because the afternoon side of an asteroid is warmer than the bank, and made payable to the “Minor Planet Bulletin.” To pay by credit morning side, a gentle but steady torque is made on an asteroid’s card, (Visa, Mastercard, or Discover) please send by mail your credit card spin vector. For Koronis family asteroids, Vokrouhlicky et al. number, your name exactly as it appears on the card, and the expiration (2003) found that the combination of the Yarkovsky effect and a date. Be sure to specify the desired length of your subscription. Credit resonance with Saturn’s orbit can nudge their spin vectors into the card charges will be made through “Roadrunner Mkt, Corona AZ.” When observed stable alignments. These are called “Slivan states” in sending your subscription order, be sure to include your full mailing address and an email address, if available. The numbers in the upper-right honor of the lightcurve observer who discovered them. corner of your mailing label indicate the volume and issue number with which your current subscription expires. Thus it appears that slow and steady lightweight forces may win out over sporadic heavyweight collisions in determining asteroid Articles for submission to the MPB should be sent to the editor. All spin states. A new challenge to lightcurve observers is to authors should follow the guidelines given in “Instructions for Authors” in determine how well this theory holds. Is it effective for all shapes issue 30–4 and also available at http://www.MinorPlanetObserver.com/ and sizes? At all locations? What are the exceptions and why? astlc/default.htm . Authors with access to Apple Macintosh or IBM-PC The challenge and the promise for lightcurve observers continues! compatible computers are strongly encouraged to submit their manuscripts by electronic mail ([email protected]) or on diskette. Electronic submissions can be formatted either using a Microsoft Word template document Binzel, R. P. (1988). “Collisional Evolution in the Eos and available at the web page just given, or else as text-only. A printed version Koronis Families: Observational and Numerical Results.” Icarus of the file and figures must also be sent. All materials must arrive by the 73, 303-313. deadline for each issue. We regret that diskettes cannot be returned. Visual photometry observations, positional observations, any type of Slivan, S. M. (2002). “Spin vector alignment of Koronis family observation not covered above, and general information requests should be asteroids.” Nature 419, 49-51. sent to the Coordinator.

Vokrouhlicky, D., Nesvorny, D., and Bottke, W. F. (2003). “The * * * * * vector alignments of asteroid spins by thermal torques.” Nature The deadline for the next issue (31-2) is January 15, 2004. The deadline 425, 147-151. for issue 31-3 is April 15, 2004. Minor Planet Bulletin 31 (2004)