In September 1993, we initiated a regular program of photometric observations of Near-Earth objects. Since that time we have been allocated 5-7 nights per month at the 42'' Hall telescope at Anderson Mesa. There are three goals of our observing program for each asteroid: (1) to obtain an accurate rotation period and characterization of the lightcurve, (2) to obtain the surface color, and (3) to measure the photometric parameters, H and G. All of the lightcurve observations are made in Kron-Cousins R and we always obtain a V-R color. Limited ECAS colors are also obtained when the objects are bright enough. We have secured periods for 9 asteroids, 1864 Daedalus, 1866 Sisyphus, 3200 Phaethon, 4954 Eric, 5693 (1993 EA), 5836 (1993 MF), 6489 (1991 JX), 1993 QP, and 1993 WD. Some of these periods are a confimation of an earlier result but most are new. We obtained colors for all these objects as well as four additional asteroids, 5407 (1992 AX), 1993 UC, 1993 VW, and 1994 LW. We have additional (as yet unreduced) observations of 2062 Aten, 2212 Hephaistos, 3752 Camillo, 5143 Heracles, 5863 (1983 RB), 6053 (1993 BW3), 7025 (1993 QA), 7092 (1992 LC), 1989 VA, 1992 TC, 1994 RC, and 1995 YA3. The fastest rotation period we find is 2.402 hours for 1866 Sisyphus and the slowest is 93QP at ~ 24 hours. The colors for these objects range from V-R=0.34 for 3200 Phaethon to V-R=0.49 for 1866 Sisyphus and 4954 Eric. Most colors fall near V-R=0.43. These observations should help to provide a more complete understanding of the surface properties and rotational states of the Near-Earth asteroids. This work was supported by NASA Grant NAGW-1470.
AAS/Division for Planetary Sciences Meeting Abstracts #28
- Pub Date:
- September 1996