January 12, 2010

Horsehead Nebula

Today I saw the Horsehead Nebula as I've never seen it, courtesy of an image from the ESO/J. Emerson/VISTA. Here's a link to January 12, 2010's APOD: Horsehead (and Flame). The focus of this image is the Flame Nebula and the cluster of stars in its center, but the Horsehead is stunning. It is basically the reverse of what we normally see. In visible light, the Horsehead is dark and the background lit up around it, as here (and also below). In the APOD image, the head is lit up, and the background is dark except for the stars. The glowing hydrogen that usually frames the dust making up the horse head is invisible in infrared. With the infrared dust glowing against the background, one sees the head for what it is, not its silhouette!

The images below illustrate the point. I've been trying to catch a new image of the Horsehead, and I'm not entirely satisfied with what I have as of yet, but I can use the H-alpha image that I have taken and combine it with the ESO's Horsehead (used here with permission). This allows both visible and H-alpha in one image. The infrared colors are all imaginary, of course, because the infrared lies outside the visible spectrum. H-alpha, on the other hand, lies in the red part of the visible spectrum and is colored red in this image:
In black and white, the image would look like this:
Without the infrared, the Ha shows a much less interesting Horsehead:
Thanks and congratulations to the ESO and collaborators for providing a beautiful image of what would otherwise be an invisible cloud of dust!

January 2, 2010

Test

I'm going to submit these to another site and wanted to see how they looked on other computers before sending them in. I'm about finished working on these, now, I think.

December 22, 2009

Full Narrowband NGC281 Image (12-21-09)

In this image, SII has been added in place of the green of the earlier image. The need for SII is proved by this excellent Cloudy Nights thread: http://tinyurl.com/yeqauur

The final 18x8' set of exposures (2.4 hours) in SII was obtained on the night of 12-18-09 using the TMB80CF and an Astronomik 12nm SII filter. Ha was obtained in October (38x5')and OIII in November (41x5'). Total exposure time is one minute short of 9 hours. Software used to capture and process includes PHD and Nebulosity 2, Registar, Photoshop Elements 7, Maxim DL5, and Photoshop CS3. Thanks to Don Taylor for suggesting effective ways to rid it of pink halos. In the end, I selected the color in CS3, changed it a bit, and de-saturated some.

December 20, 2009

And Another

My favorite version of this object is Adam Block's, here.

Smaller NGC 1491 Narrowband

Here are the same iterations only smaller. The problems from shooting over the chimney clean up nicely when the versions are shrunk slightly.

December 19, 2009

NGC 1491 Narrowband

Here are two iterations of NGC 1491 in narrowband. The first is in Hubble Palette. The second is the other palette I prefer---Ha+L, Ha=C, OIII=M, and SII=Y. I like seeing the Ha as blue, and the yellow stars stand out well against it.

I learned something last night as I collected SII: Never shoot over a chimney. Silly, right? I was befuddled that the guide star was jumping this way and that. I checked my mount over with a flashlight three times. I was getting fuzzy images in the main camera. I realized this morning that I had the fire running inside so that I could warm my feet after checking the camera. The camera took a long time to check because so many things were going wrong because the fire was running! I couldn't figure out what was wrong (ok, it was almost 2 am). Now I realize I was ruining my images by keeping a warm fire waiting. Oh, well. The damaged SII information shows up in the image as a slight smearing of some of the stars in the direction the air currents were coming out of the chimney.

December 4, 2009

The Narrowband Bubble, New Iterations

These images have become my favorites from this set. It is the same data as the others, but the colors are more pleasing, I think. I used Maxim DL 5, which I am trying out, for each. The first is an Ha;SII;Ha;OIII as LRGB. Further processing was then done in PSCS3. In the second, I combined Ha as Cyan, SII as Magenta, and OIII as Yellow. The image was then stretched and minimally processed in CS3.