1978 CA and 1978 DA
Abstract
J. Degewij, Lunar and Planetary Laboratory, reports that photometry with the 154-cm reflector yielded for 1978 CA on Mar. 8.374 UT the values V = 14.61, B-V = +0.93, U-B = +0.50, and for 1978 DA on Mar. 8.415 V = 14.00, B-V = +0.83, U-B = +0.42. Uncertainties are +/- 0.02 magnitude in V, 0.03 in B-V, 0.05 in U-B. A full light curve from observations on Mar. 8 and 9 yielded a rotation period of 3h44m.9 +/- 0m.8 for 1978 CA, with amplitude 0.80 +/- 0.03 magnitude in V and a mean V of 14.31 (on Mar. 8.27 UT). The rotation period of 1978 DA appears to be ~ 8h, the amplitude in V ~ 0.5 magnitude. In each case Delta(V-I) < 0.03 magnitude. He also communicates radiometric observations by L. and M. Lebofsky with the 71-cm reflector, giving geometric visual albedo pv = 0.06 +/- 0.01 and diameter 2.0 +/- 0.3 km for 1978 CA and pv = 0.15 +/- 0.03 and diameter 1.0 +/- 0.3 km for 1978 DA. He adds that the combination of reddish color and low albedo for 1978 CA is unique and remarks that narrow-band spectrophotometry of this object is urgently needed.
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- March 1978
- Bibcode:
- 1978IAUC.3193....1D