The Cool Observatory

This is a follow up on the last couple of posts here at LPO about the observatory upgrades and motorized focusers.

The new insulated roof has helped a lot at keeping down temps inside the observatory. However, it just wasnt quite enough once we felt the full brunt of Summer here. We have started insulating the walls with the same 1" foam we put on the new roof, and have installed an a/c unit in the wall. I just came in from checking on things in the observatory and it is a dry 86 degrees inside the observatory. Much better than the humid 100+ degree temps we saw before the upgrades. I feel much better about keeping my equipment out there now.

As soon as I finish up the insulation I will put some blandex (waferboard) on the walls and paint it a flat black. Should be really nice in there for all seasons when that is done. I dont want things cold inside, just cooler. If it were very cold, everything would fog up this time of year when I rolled the roof off. As long as it stays below 90 degrees inside all the equipment should be fine.

Now for the fun stuff. When I wrote about motorized focusers, I had yet to motorize my widefield scope, the Star71. The large single speed knob of the Star71 is not removable. This forced Leon Palmer at Rigel Systems to add an extension to the motor shaft and run the gears off of the fine focus knob. It might not be ideal, or as clean an install as the one on my TS107, but it seems to do the job just fine. It is nice to have the focusers on all three of my imaging scopes motorized now.

I enjoyed using the Star71 for a while, taking several widefield images, but it was time to start using the TS Photoline 107mm triplet again. I had been using my RC telescope for most of the Spring shooting galaxies, then the Star71 for several of the large Summer nebulae. So it was time to give the 107 some attention.

I have now completed two hubble palette images with the 107mm and started on a couple more. The first one was NGC 7380, the Wizard nebula. For this image I used 12 subs of 900 seconds each of Hydrogen Alpha, 14 subs of 1200 seconds each of OIII, and 12 subs of 1200 seconds of SII, just shy of 12 hours total.

I spent considerably more time on the next image, Sh2-86, or Sharpless 86. It was much tough than I expected and with the low OIII sensitivity of my 8300 camera I probably should have tried binning, or shot even longer than the 30 minute subs I used. Binning would have been easier I think than shooting 45 minute to 1 hour long subs. Since I used the H-alpha as my luminance layer after using a weakly stretched H-alpha to combine for the color, I think binning would have been fine. I'm hoping to buy a new camera soon with the Sony ICX814 sensor. Until then I think I will stick with targets with good OIII signal when shooting color narrowband images.

Sharpless 86 is a very interesting area in the constellation Vulpecula, near M27, the Dumbbell nebula.  The most striking feature is the trunk-like pillar of dust and gas protruding from the east side of the nebula towards the open cluster, NGC 6823 in the west. Remarkable dark globules of gas and dust are also visible in the nebula, much as is seen in the better known Eagle Nebula in Serpens or the Lagoon Nebula in Sagittarius. The stars in the center of NGC 6823 are about 2 million years old and are predominantly "young" bright blue stars.

I have over 20 hours in Sharpless 86 and threw away a few hours as well because of focus problems. I used 23 Hydrogen Alpha subs of 1200 seconds each, 12 OIII subs of 1800 seconds each, and 13 SII subs of 1800 seconds. I would like to come back to this one and shoot some RGB for star color. If I dont have RGB for star color I prefer to just make my stars white instead of the typical magenta color you get in hubble palette versions.

The two works in progress are the Bubble Nebula, aka NGC 7635, Caldwell 11, and Sharpless 162, in Cassiopeia, and the Eastern Veil Nebula in Cygnus. The SII and OIII signal in the Veil is super strong, probably the strongest signal I have ever seen since I began narrowband imaging. Here's an example of the three channels.

Hydrogen Alpha, 20X900 seconds

SII, 15X600 seconds, binned 2X2 

OIII, 18X600 seconds, binned 2X2

The SII and OIII were shot binned 2X2 and then stacked using 2X Drizzle to match the resolution of the Hydrogen Alpha shot at 1X1. I have put together a couple preliminary images using this data. I would also like to add some RGB to this one for star color.

Bi-Color image using the Hydrogen Alpha and OIII from the above data

Hubble Palette version of above data

So far I have only the hydrogen alpha data shot on the Bubble Nebula. I'm hoping to get started on some SII and OIII for it as soon as the Moon become less of a factor. These images will be posted soon to my Astrobin gallery.

Happy imaging everyone and stay cool this Summer!!