NOAO > Library > NOAO Preprint Series > Preprint 899
|
NOAO > Library > NOAO Preprint Series > Preprint 899 |
|
Author(s): Mueller, B.E.A., and Samarasinha, N.H.
Title: Visible Lightcurve Observations of Comet
19P/Borrelly
Abstract:
The final Deep Space 1 (DS1) mission target, comet 19P/Borrelly, was observed
from July 28--August 1, 2000 at the CTIO-1.5m telescope in the R filter. The
observed lightcurve has a large peak to peak variation between 0.84 mag and 1.0
mag. A period of 26.0 \pm 1 hr (assuming a double-peaked lightcurve) was found
using all five nights. This is in good agreement with the period of 25.02 \pm
0.5 hr quoted by Lamy et al. (1998) using only 6 points of HST data and is also
consistent with HST data taken around the DS1 encounter time by Stern et al.
(2002).
Using the mean magnitude R = 20.8 mag and assuming a 4% albedo, we derive an
effective nuclear radius of 2.6 km. The large lightcurve amplitude translates
to a long to intermediate axial ratio a/b \geq 2.2, in excellent agreement with
the HST result of a/b \geq 2.4 (Lamy et al. 1998) and with DS1 images
(Soderblom et al. 2002)
Date Received:
June 11, 2002
Publication Info:
Earth, Moon and Planets 90(1):463-471
Downloadable version (3396 Kb PDF)
|
NOAO > Library > NOAO Preprint Series > Preprint 899 |
|