Astronomy Archives - Page 51 of 71

September 22, 2018September 22, 2018

Elf’s First Collimation, by me at least

Following up on my post about my new 11″ SCT Elf, I knew it was a little out of collimation. I’ve borrowed an artificial star from my friend Steve and had nebulous plans to use it. Saturday morning I realized that my office had a long hallway that would likely be long enough so this afternoon I gathered up everything I would need, including Samantha Dixon, and headed over there.

We placed Elf on a folding work bench at one end of the hallway and the artificial star on another 39 steps away at the other end. Approximately 115 feet of separation. The blurry thing at the bottom of the first picture is the artificial star and it is featured with all but one “star” covered up in the second picture.

It took a while to actually get the scope aimed directly at the artificial star but once it was, Sam and I were able to tweak the screws to center the black central spot in the rings. See the last two pictures. This was noticeably off center when we started. First we looked through an eyepiece then I switched to my planetary camera to make final adjustments. Looking at it now, maybe it still needs some work to be perfect but its pretty close. That said, the method works.

September 21, 2018September 22, 2018

11 Inch Elf

I haven’t made a big deal about it yet, not sure why, but a week ago I upgraded my 9.25″ Schmidt Cassegrain Telescope to 11″. That’s right, this one goes to 11. This is a Celestron 11 with Starbright coatings and a carbon tube. Yes, you are correct it is also Fastar compatible. I bought it from my friend Chris and debuted it at the star party last Saturday to many oohs and a few aahs. An 11 inch SCT has been my goal for a while, like years, it’s large but not outrageously expensive or too heavy to tote around. By happy coincidence it barely fits in the lightly padded tub I kept the 9.25″ in. Also, C eleven rolls off the tongue much easier than C nine and a quarter.

The carbon tube is more thermally stable than aluminum so it should retain focus better as a night progresses. I don’t have a Fastar or Hyperstar adapter for it but should I get one I could start imaging at F2. I’ve expended my astronomy credits for the foreseeable future so unless I when a contest I probably won’t get one anytime soon. However, you can expect to be seeing “Elf” (German for Eleven) at a star party near you.

July 7, 2018December 16, 2020

7/1/2018 – Jupiter and Saturn

Here are two images from Saturday night at the River Ridge Observatory. Both were shot with a monochrome camera using red, green, and blue filters and a 9.25″ SCT. Each color was picked from the best 50% of about 3000 frames (30 seconds of video). Stacked then aligned and combined in Photoshop. Jupiter was shot with 10 millisecond exposures while Saturn required 50 millisecond. Saturn was barely above the trees and I should have waited but frankly it is near the southern limit of its journey around the Sun and doesn’t get too high. Jupiter was just past the meridian. I may work with it some more when I have time, the raw footage looked like it would be better than this.