Comet Simonsen

I don't observe comets very often. Unless they have reached naked eye brilliance and sport a magnificent tail, they're just not that exciting to look at. Most are faint fuzzy balls with no real tail to speak of; not what most people picture in their minds eye when they think of a comet.

That said, it would still be pretty cool to stumble upon one in the course of an evening observing variable stars. I spend a lot of time out under the stars with my eye to the eyepiece. After years observing variables, most of the star fields have become very familiar. I've seen lots of unexpected things- meteors streaking through the field of view, asteroids masquerading as new stars, satellites and aircraft blazing through the field, but I've never happened upon a comet.

Tuesday night I was working my way from Auriga, Canis Minor and Gemini heading to Cancer. Cancer has a disproportionate number of cataclysmic variables for such a small, faint constellation, so I always look forward to that part of my program. But just before I get there I make a little side trip to Hydra. I can only view faint objects to a certain angle above the horizon, and much of Hydra is just too low for me. So I only have two stars I observe in Hydra.

When I pointed the scope to the first one, CT Hydra and put my eye to the eyepiece everything seemed normal at first. CT Hya was too faint for me to see, so it was not in outburst. I checked my usual comparison stars to see how faint a limit I would record in my report. When I glanced toward the 14.0V comparison star I was shocked to see a fairly bright fuzzy blob just to the SE of it!

I moved the telescope ever so slightly, back and forth, to make sure it wasn't a reflection in the EP, and it stayed right where it was in relation to the field stars. I looked at it for a while and decided it was real enough, so I took the paper chart out of its page protector and drew the position and size of the object, as accurately as I could, in relation to the stars on the chart.

At this point, I was intrigued enough to go inside and try to identify just what comet this was that had intruded into my night of variable star observing. I fired up my planetarium program and asked it to show all comets within a degree of CT Hya. Nothing. I logged into the Minor Planet Checker website, typed in the coordinates of my 'comet' and searched for anything within 30'. Nothing.

How on earth did the surveys miss anything this bright this close to the celestial equator near new moon? Did I just discover a new comet? Now I was getting excited.

I emailed several observer friends and asked them to take CCD images of the field for confirmation. Then I logged into Global Rent A Scope (GRAS) in New Mexico, and fired up scope 4 which has a pretty enormous field of view for a CCD. I scripted it to run and take a 240 second exposure with a clear filter. If it was real, it should show up as a bright fuzzy object near the middle of the image.

No one got my message until much later or the next morning, but I did get two images of the area from the GRAS scope. I examined them online and was disappointed to see nothing where I expected a bright comet to be.

In the time it took to check for known comets, email friends, start the telescope, cool the CCD, autofocus, slew to the target, take images and upload them to the GRAS site, it had begun to cloud over here at home. I didn't get a second chance to see what was going on in the eyepiece of my telescope. I chalked it up to mysteries of the universe and turned in for the night. I also never made it to my variables in Cancer.

Thursday at lunch time, I was working on my data from Sonoita Research Observatory (SRO) in Arizona, so I had my photometry software up and running on the computer. I decided to download the images I took of the CT Hya field to see if I could detect the variable and submit a positive faint observation of it. When I pulled up the images on the screen and zoomed in, there was my comet!

It was a lot fainter than I expected to see, and it had moved considerably from the position I indicated on my chart, but it was there in both images, and it looked like it had moved in a straight line away from my original sighting between exposures.

I got excited all over again. Here was proof. I had pictures of Comet Simonsen! Not being an expert in cometary images, properties or motion, I emailed my images to several people, some of them experts in CCD imaging and photometry, for feedback. Was this a comet? Can they move this far in an hour or so? How come its so faint? Did I do something wrong? Or is this an artifact on the images?

I was hoping it was a comet. My comet...Comet Simonsen...discovered serendipitously while observing variable stars...I could see the headlines. What are the chances I could see something in the eyepiece, take CCD images of it and nothing was really there. I mean, C'mon, man. It's got to be a real comet, right?

I got the bad news later that night and then confirmation that it was "an interesting artifact, but not a comet" again the next morning. Stop the presses. It's not a comet.

I still don't know what I saw in the telescope that night. I'm gonna call it a UFO: Unidentified Frustrating Object. I'd have been a lot happier just working my way through my CVs in Cancer that night. As it turns out I missed an outburst of one of my favorite stars, SY Cnc, while I was messing around trying to discover Comet Simonsen 2009.

Stuff happens...


Michael said...

Maybe next time, Mike!

RevAaron said...

Never give up, never surrender! Hey, if anybody deserves to discover a comet, it's you :) Keep up the good work.

The Urban Astronomer said...

This is a great story. I am impressed with your skill at identifying the sky in such detail. To me, that is the essence of a good astronomer (and a lot more commitment than I have ever been able to muster!).

I was on a solar eclipse trip in Baja California in 1991 when I met David Levy. We were talking after dinner one evening and I asked him how he discovers comets. He told a very similar story to yours - a lot of time at the eyepiece, a lot of time searching, a lot of concentration looking for that little light that is somehow out of place.

David Levy hit a lot of jackpots in his time. Good luck with your search.