Reports from Geisei Observatory <January 12, 2007>
C/2006 P1 (McNaught) , 2P/Encke, P/2007 A1 (Lovas) , C/2006 XA1 (LINEAR)
, and other comets
C/2006 P1 has a small perihelion distance, but I was able
to catch it at 17:20 on the evening of January 11 with the 20cm refractor
at 40x, which was mounted on the 60cm reflector. The nucleus was completely
stellar with a very faint fan-shaped tail above it. The comet was seen
in reddened evening clouds in twilight and it was difficult to make a magnitude
estimate. Judging from my past experience with comets under similar conditions,
I visually estimated its magnitude to be -1. I observed for about 10 minutes,
but was interrupted by clouds on and off, and then it finally was hidden
by the clouds. The nucleus was bright, but it was far from what was expected
of a great comet. The comet will move south at a fast pace and will become
more and more difficult to observe from the Northern Hemisphere.
I have been observing the famous comet Enke located low in
the southwestern sky. It seems to be 2 magnitudes fainter than predictions
in the 2006 Comet Yearbook. In case a magnitude formula is determined from
visual observations when the comet is near perihelion and bright, photographic
magnitudes at perihelion tend to be fainter when the perihelion distance
is large. The predicted magnitude is 15.
PK07A010 is Comet Lovas 2 which was discovered in 1986. It
hadn't been recovered for 20 years because of insufficient observations
and lack of precise measurements. Comet Lovas 2 was discovered in the same
year as Halley's Comet returned. I observed Lovas 2 many times at Geisei.
Its magnitude at the time of recovery was about 18 and very faint, but
Geisei's observation below indicates it brightened to 15. This comet was
thought to be lost. It hadn't been netted because of a large ΔT. I made
an extensive search at Geisei at each of its return and found it completely
outside the field where it had been predicted to be.
CK06X01A, given in the last line below, is a new comet recently
discovered by LINEAR. It was in the northern Milky Way and many of the
photos showed the comet superimposed on the stars. It was at about 16th
magnitude, bright enough for a CCD camera with a telescope larger than
15cm. The coma was approximately 20" in diameter without any tail.
Mr. Kenichi Kadota estimates its magnitude to be 15.9.
I was searching for the lost comet Denning in late November
and realized that it was only about 1 degree from another lost comet Skiff-Kozai.
I had made an extensive search for this comet without success. Predictions
are provided in Comet Yearbook from OAA every year. The orbit calculator,
Mr. Kenji Muraoka, says that the predicted positions could possibly be
quite a long way from its actual positions. Some day in the future it may
be captured by LINEAR's net. Geisei's 60cm reflector operates with serious
trouble, but I continue to observe relying on my skills and experience.
Recently, four minor planets discovered by Geisei have been
named. I was particularly pleased with the naming of Haneda, commemorating
Mr. Toshio Haneda's discovery. Comet Heneda-Campos is another lost comet.
I promised him about 20 years ago that I would recover it at Geisei before
long. That promise now weighs heavily on my mind. Mr. Haneda's soul riding
on Minor Planet 23504 must be wandering in space looking for his comet.
PK07A010 2007 01 11.42569 23 00 44.51 -04 59 13.1 15.5 T 372
0002P 2007 01 09.41649 23 14 47.90 +03 17 37.1 17.5 T 372
CK06X01A 2007 01 11.44097 02 27 18.60 +53 08 30.4 16.5 T 372
CK06X01A 2007 01 11.45556 02 27 18.84 +53 08 20.4 16.3 T 372
Observations were made by Tsutomu Seki with the 60cm f/3.5 reflector.
The number 372 is Geisei's observatory code.