Discovery story:
Preliminary version
Comet 2010 V1 Ikeya-Murakami
Posted on November 7,
2010
by Shigeki Murakami
On November 4, 2010, I got up at 2a.m. and
changed my clothes. I drove to the usual observing site and arrived there at
around 2:30a.m. I set up my 46 cm comet-seeker and enjoyed observing 103P
Hartley prior to a comet hunting session.
I started comet hunting session
at 3:10a.m. from a few degrees west of Regulus, alpha Leonis. After I identified
13 galaxies in Leo, the other galaxy that looked large and bright came into the
field of view. I tried to identify this galaxy using digital setting circles,
NGC MAX, but there were no candidates! At this moment I judged this object was a
new comet!
All I had to do as the next step was positioning. Of course,
NGC MAX showed the Right Ascension and Right Declination but I need to know the
precise coordinates using a map. I noticed that a bright star rose from the
horizon. It was about three degrees east of the comet position: it was Gamma
Virginis, Porrima. How lucky it was! I thought it must be easy to determine the
position of the new comet.
Contrary to my optimistic prospect, I had a
hard time to determine the position on the star atlas, Uranometria 2000, because
I took Saturn for Porrima at first! This misunderstanding happened because
Saturn looked darker at the lower altitude (5 degrees) and this was the first
time I saw Saturn in the sky since August. Anyway, I could manage to determine
the position of the comet, and made a phone call to National Astronomical
Observatory of Japan (NAOJ) at 4:31a.m. to leave a message in the answering
machine. This is a record that I discovered the comet at this moment at latest.
The preliminary data at the site:
2010 Nov. 4, 4:13a.m. (JST), RA 12h
35m, RD -1.9 deg., mag.=9, coma diameter= 4'
At 4:33a.m. I phoned Syuichi
Nakano, an Associate of the Central Bureau for Astronomical Telegrams and the
Minor Planet Center. He got my call in a second but seemed to be surprised. I
told him what was happening and the comet info. He told me he would ask someone
to confirm the possible comet.
I continued observation to check the
motion. I noticed that the comet had a short and wide tail directed to the east
(position angle= 90 deg.). Also I confirmed the motion! The comet moved east
toward. Everything was fine! I called Nakano again to let him know the motion
and the tail at 5:08a.m. He said that he contacted Koichi Itagaki, Yamagata,
Japan, and that Itagaki headed for his observatory to confirm the
comet.
As twilight proceeded the image of the comet faded and it
disappeared in the field of view at 5:15a.m.
I took down my comet-seeker
and drove back to my home. I got back home before 6a.m. and turned on my PC to
check emails. Wow! Itagaki had already confirmed the comet and his data along
with mine had been sent to CBAT by Nakano. The time stamp of his email was
5:29a.m. It was also posted on the NEO Confirmation page.
I felt
relieved to hear the comet was confirmed and surprised at the speed of the
processes. I forget to send precise information of the comet since I felt that
everything had finished. At home I finalized the position using the digital map
(MegaStar ver. 5) and sent it to Nakano with other data:
2010 Nov. 3.801
UT, 12h 35m.1, -02 01', mag.=9, coma diameter= 4' , tail
length= 2', position
angle= 90 degrees (east), motion= east 2'/ hour
At 7:40a.m. I received an
email from Nakano that read Kaoru Ikeya had discovered the comet on November 3
JST, one day before my discovery! There was a trouble concerning a conveyance of
information that was lucky for me. It is a great honor for me that name of Ikeya
was added at the top.
I have had a faith that visual discovery is still
possible, which is based on the data. Having said that, I thought I might not
discover a new comet anymore through my life. But actually I could and I could
prove it by myself. You will never regret if you do your best, but you will if
you do not.
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