Monday, February 16, 2009

Imaging Virgo, February 16, 2009

I tried to do some astrophotography tonight around 12:30 AM in an effort to capture Comet Lulin in Virgo. Unfortunately, my early attempts were a hit-or-miss mess: I kept moving the camera to image different parts of the sky, and the results were an indecipherable smattering of white dots on a black background. I needed a plan.

I studied the Whole Sky Chart on Heavens-Above carefully, working out which part of the sky I wanted to image. When I was pretty sure I had figured it out, I went outside again, set up my tripod, aimed my camera, and took shot after shot of the same portion of the sky - as quickly as I could, because clouds were rolling in from the East, and a last-quarter Moon was rising to flood the sky with light. I got just five images, but it felt like more, each with a ten second countdown and at least a full second of open-shutter time.

I downloaded the images, increased the contrast of each one to 93%, stacked the images so each one lightened the previous image (to reinforce bright areas), and...

...well, I did it. I photographed Virgo, and even captured the apparent movement of the stars across the sky from one photo to the next. Compare to this image, with a star chart for Virgo overlaid on the constellation.

The question now was: did I image Comet Lulin? I zoomed in and enhanced the relevant part of the image. Here is where the comet should have been tonight:

And here is the same image without the star chart.

I don't see Comet Lulin there anywhere. If you'd like to look more closely for yourself, here is the Heavens-Above finder chart by itself.

I believe that everything shown in my photograph is accounted for on this chart. And I am not seeing Comet Lulin in my photograph.

Here is an extreme close-up of the lower portion of Virgo, with the finder chart superimposed.

And here is the same image without the finder chart. Either Comet Lulin is well off its projected track, or it is too dim to be imaged with my camera.

Comet Lulin should be at maximum brightness February 24. Maybe I'll have better luck then!


Skywalker said...

Hm... I don;t know.. there might be a dot on the pic.. oh well.. better luck next time.

whimsical brainpan said...

I hope you are able to catch it later.