Sunday, August 25, 2013

The Queen, the Dragon, and the Flying Horse

Finally, a gorgeous and clear Saturday night, and my first chance to test out the new focal reducer. Long story short, it's awesome.

My life will never be the same.

It is simply fabulous to be able to fit M13 (Hercules Cluster) on the chip. It's like having skinny jeans for a telescope. Maybe that's a bad analogy. Anyhow, I took a few images of the bright globular, but honestly, they were sort of meh. I've gotten better results with the Canon Rebel DSLR attached with a T-mount. But still, happy dance because M13 fits!

Here's M13 w/ the focal reducer (it's not too bad):

M13 w/ Opticstar DS145C on 14-inch, 6 2-second exposures stacked

The scopes were well behaved (no alignment issues) and I therefore had lots of time to spend actually looking at objects. Here's the rundown of what I saw by constellation:

The Queen (Cassiopeia)

  • NGC 457 (a.k.a the Owl Cluster, the ET Cluster, or Caldwell 13) is an open star cluster about 7900 light years distant and approximately 21 million years old. Discovered by William Herschel in 1787.

    NGC 457 w/ Opticstar DS145C on 14-inch, 6 2-second exposures stacked
  • M103 (a.k.a. NGC 581) is an open cluster between 8000 to 9500 light years distant and about 25 million years old. Discovered in 1781 by Pierre M├ęchain.

    M103 w/ Opticstar DS145C on 14-inch, 6 2-second exposures stacked
  • M52 (a.k.a. NGC 7654) is an open cluster with an uncertain distance between 3000 and 7000 light years and an estimated ate of 35 million years. Discovered by Charles Messier in 1774.

    M52 w/ Opticstar DS145C on 14-inch, 6 2-second exposures stacked

The Dragon (Draco)

  • NGC 6543 (a.k.a. The Cat's Eye Nebula) is a planetary nebula. I was super excited to see it, but it didn't photograph well. It's small and faint. Basically it looks like a fuzzy little star and of course nothing at all like the Hubble images.

The Flying Horse (Pegasus)

  • M15 (a.k.a. NGC 7078) is a globular cluster estimated to be about 12 billion years old. (One of the oldest globulars!) It was discovered by Jean-Dominique Maraldi in 1746.

    M15 w/ Opticstar DS145C on 14-inch, 7 4-second exposures stacked

Overall, I think the astrophotography is getting a little easier, and a maybe just a little better with each attempt. The major lesson learned from these images is that I really need to take more, and perhaps longer exposures.

I need more photons.

Thursday, August 15, 2013

Focal Reducer

I've played around with our Opticstar CCD cameras enough now that I feel limited by their relatively small field of view (FOV). For the 14-inch telescopes the FOV w/ CCD is approximately 8 x 6 arcminutes. Saturn and the Ring Nebula (and other planetary nebulae) fit just fine, but I'd also like to image larger objects, like globular clusters.

The easy solution is a focal reducer. We recently purchased what seems to be the only focal reducer in the universe that will work with our CGE Pro EdgeHD telescopes. It's a beast of an accessory at 3.25 pounds, so today we balanced one of the scopes with the focal reducer and camera.

The reducer will reduce (go figure) the the focal length by 0.7. By my calculations, the new field of view (for the CCD camera) should be about 12 x 9 arcminutes. It's not a huge gain, but it will allow me to fit globulars like M10 and M12 (constellation Ophiuchus) in the field. The Hercules Cluster, M13, may be too big, but I'll likely try to image the core anyway.

Focal reducer at base of 14-inch w/ Opticstar CCD camera
BTW, I calculated the FOV in arcminutes using this:

FOV = (S x 3438) / f

where S is the size of the CCD chip in mm, and f is the focal length of the telescope in mm. Exciting, I know.

I don't plan on changing out the focal reducer anytime soon since balancing the scope is a pain in the keister. What will the FOV be with a regular eyepiece? A rough calculation gives me 32 arcminutes for our 26 mm eyepiece and 44 arcminutes for our 40 mm eyepiece. Big, but not quite big enough to fit the 60 arcminute Brocchi's Cluster. We may have an eyepiece (a Panoptic?) with a larger apparent FOV, though. I'll have to check.




Nice night, but no pictures

Last night was absolutely gorgeous. I made it to the observatory a little before 9pm. My mission was to re-align the east 14-inch scope. It was being fussy during the observatory beta test. The scope aligned just fine, and tracked well. I played around a bit, bopping here and there, but didn't do any photography. With a first quarter Moon and a tiny amount of haze, the sky was a bit glowy.

I spent some time looking for the possible nova in Delphinus. I think I found it, but since it looks like a regular magnitude 6 star, I can't be certain. On the bright side, I did find a faint planetary nebula (also in Delphinus), NGC 6905.

Monday, August 5, 2013

Observatory Beta Test

We had a clear night for the observatory open house beta test. We were able to see Saturn, M57 (the Ring Nebula), NGC 6826 (the blinking planetary),M13 (Hercules Cluster), and Albireo (double star system in Cygnus, well actually a triple star system, but we can only see two).

I had hoped we'd somehow get to take more pictures, but alas, we only snapped a few of the Albireo system.

Lots to think about before the next open house.