OBS-V: C/2006 M4 (SWAN) & C/2006 L1 (Garradd)

OBS-V: C/2006 M4 (SWAN) & C/2006 L1 (Garradd)

Sunday, Dec 10, 2006

C/2006 M4 (SWAN) :

A strong cold front swept here swiftly, which led to quite a lot of rains. The temperature fell to 14 in nights. However, the minimum temperature was 19 some times ago. It gradually turned clear on morning of Dec 10. The transparency was extremely clear so I decided to make observations of some bright comets in my grandparents’ home.

I started my observation at about 10: 35 UT. The first target was comet C/2006 M4 (SWAN) that I hadn’t seen for long. I easily pointed to the position where the comet was using a rough stars field drew by myself through the finder. To my surprise, I could see the stars of over magnitude of 8th, which was still rare just in the suburb here. I observed through the main telescope then. The field contained a large number of faint stars. However, I couldn’t see anything like a diffuse comet. I kept on observing concentrated, finding something extremely faint in the predicted position of the comet. I doubted myself, regarding it as my phantom, for it appeared at times. I still kept observing and decided to make a sketch of the field to prove my result next day. It took me long to finish all of these. What’s more, measuring its magnitude and diameter was really hard under the slight-light-pollution circumstances. I doubted myself all the time during the observation for I didn’t catch its motion. I told myself it was just my phantom again and again. That’s it. However, after I had checked the electronic skymap, I was quite sure about it because that was just the right position for the comet. I was successfully finding this fading out object again.

Here comes my measurement:


Comet C/2006 M4 (SWAN)

IIIYYYYMnL YYYY MM DD.DD eM mm.m:r AAA.ATF/xxxx &dd.ddnDC &t.ttmANG ICQ XX*OBSxx

   2006M4  2006 12 10.47  S[ 9.2 TJ 10.0R 7  28   5    2            ICQ XX  XUxx

PS: Extremely clear sky. Slight light pollution in this direction. Barely seen. Hard to measure its magnitude.

I stopped my observation of comet C/2006 M4 at about 12: 15 UT.


The constellations of winter was getting higher and higher. Pleiades was easily seen high in the evening sky. Since I had finished the observation of C/2006 M4, I decided to have a good look at the clusters and nebulae. I firstly pointed to NGC 1778 in Auriga. Then NGC 1857, M38, M36, NGC 1893, NGC 1857, M42, M43, etc. Not had brought any other sketch books except the ones of specializing in comets, I didn’t do any sketches of these objects.

C/2006 L1 (Garradd)

I started my observation of C/2006 L1 (Garradd) at about 12: 25 UT. It was almost on the borderline of Auriga and Lynx. The condition of this comet was much better than the one of comet C/2006 M4 that nearly no light pollution towards NE and N. The sky was rarely and terrific dark under this circumstances. More faint stars could be seen through the telescope, whose magnitude could nearly reach to 11.8. I almost immediately detected that the star TYC3391-02440-1 of 11.33m had a very faint and diffuse “nebula”. As I knew, the weakly condensed comet now was just in this area according to myself-drawing sky chart. However, when starting to observe it systemically, I could not see anything except the fix stars. Resting for a while and observing again, I got it and lost it soon as before. I made every effort to observe in my field but nothing has changed much. Although I doubted myself again, I planned to sketch it. About an hour later, I “felt” that the diffuse object had moved a bit, which suggested it was a real object in the sky. I measured its size and magnitude and something necessary. My measurements are offered below:


Comet C/2006 L1 (Garradd)

IIIYYYYMnL YYYY MM DD.DD eM mm.m:r AAA.ATF/xxxx &dd.ddnDC &t.ttmANG ICQ XX*OBSxx

   2006L1  2006 12 10.56  S  9.3 TJ 10.0R 7  28   5    2            ICQ XX  Xuxx

PS: Extremely clear sky. Easier seen.

I hurriedly finished my observation there at about 14: 20 UT because I had to go to school next day. After checking the track of comet C/2006 L1 next day, I was quite self-confident. That was my second harvest on the day.

I took me about 3 hours and 35 minutes totally to observe comets. The total time of specially observing comets is about 43h05m up to date. I’ll clear up my all observations before including observing sun, planets, asteroids and deepsky when I’ve got enough time. That’ll be a huge mission, I think.

OBS-V: C/2006 M4 (SWAN) & C/2006 L1 (Garradd)