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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