Archive for December 6th, 2007

The Illusive Horsehead Nebula

Posted by anthony

I got my first ever images of IC434, the Horsehead Nebula in the constellation Orion. The Horse Head is the faintest object that I’ve ever attempted to image at mag 10 or so. I’d taken about 20 images or so that on Monday night (12/3/07). Unfortunately, due to a number of mishaps, only about 12 were actually usable.

These 12 images were stacked using RegiStax to give me a good starting point. FYI, each original/raw image barely showed the horsehead. You could kind of see where the nebula was. This was brought out quite a bit after the stacking. However, it wasn’t until I brought the image into The GIMP that things really came into view. Its amazing how much data was ‘hidden’ originally. Almost like pealing the layers off an onion, the nebula slowly revealed itself with each processing option.

I’m happy with the results of this first attempt to capture the illusive Horse Head Nebula. This is a very tough object. I’ve only seen this on a small handful of occasions. This is a faint object. Its also just large enough that the minimal light arriving in the telescope is spread out enough to make this a highly difficult target. Only seriously dark skies and a fairly substantial aperture will allow you to see this in the eyepiece.

As far as the image goes, it seem that 12 minutes was not quite long enough Additionally, as the constellation Orion is still fairly low in the southeast early on, I was fighting a bit of local light pollution. Had there been a bit less moisture in the sky and had this been a bit higher in the sky, I’d have taken longer exposures. These, were all 60 seconds a piece. Longer exposures had the background sky looking all washed out due to light pollution from a neighboring shopping center. Perhaps, towards the end of the month, I’ll have another shot at the Horsehead before the moon rises. This, plus another round of telescope alignments, should hopefully allow me to hit this pretty hard. My goal is to get perhaps 50-100 minutes of exposures (5 minutes at a time). With the nebula sitting a bit higher in the sky and more and longer exposures, my signal to noise ratio should be dramatically improved. If this works out as planned, I should have quite a bit more data to start with as well as a much darker background. Anyway… I’m happy with this, my first image of IC434, The Horsehead Nebula.