March 20, 2011

Full Moon, March 19, 2011

The full moon this month looked very large because it was at perigee. Lots of folks took pictures of it. Here is mine. The moon was just past full, at about 99%. That's the Sam Houston State Observatory north of Huntsville, TX, in the foreground.

I brought Bigfoot to the observatory, and Rory Glasgow had the great idea of projecting that big moon on a white surface, so he held up the back of a star chart, and we snapped an 8-second image with my Canon 400D at ISO 800. The projection of the moon on Rory (along with Rory's fine lunar images) is posted here. The image was mentioned on the front page at, here.

March 17, 2011

Camping at the Dark Sky Site (3-14-2011)

This week was Spring Break in Texas, so Monday night I took my boys camping at the Houston Astronomical Society dark sky site. I'd never been, and the moon would be about 60% full, so rather than try to set up for imaging, I decided to take Bigfoot, the 15" dob. We had a great time (Bigfoot, the boys, and I), and I learned several things I'd like to share:

1. Seeing matters to the big dob! A few weeks ago, I saw Sirius B clearly through the dob at 380x. I tried on this night early on, and at 190x Sirius would not even focus clearly. Seeing was lousy. In fact, anything over 80x was mush. Saturn just rising over the trees had a moon, Titan. There may have been others. As the night continued, seeing improved. By midnight, Saturn had four moons, but they'd twinkle in and out. By 6 am, Saturn had five moons (that were obvious to me without a chart), and they were clear as a bell. After midnight, when seeing had improved, I learned these other things:
2. The Telrad needs dew protection. It's harder to find things when the Telrad is dewed up. Bigfoot has no finderscope. I will build a dew shield.

3. NGC 2477 in Puppis is the most awesome open cluster! I used to think M37 was the best view. M37 must now yield. Images (and I have one of M37 myself) do neither cluster justice.

4. For starhopping with a big dob, Uranometria is pretty ideal. Sitting on the ladder with a red flashlight and a volume of Uranometria on my lap is slightly awkward, but the scale is easy with a big eyepiece on a 15" f/5 dob.

5. The Meade Series 5000 28mm SWA is a fine eyepiece. It gives a nice view in the f/5 dob. There is some distortion around the outer quarter of the view, but it is not distracting. Eye relief is enough for this eyeglass wearer. I could basically forget the eyepiece and observe. No coma corrector that night.

6. Only about two members of Markarian's Chain fit in my field of view at a time. I was just browsing around the field, not looking at charts, and found four members in a row before I realized what I was looking at.

7. M13 doesn't hold a candle to Omega Centauri! I have never seen so many stars stuffed into one place. There is hardly space between them! I flipped over to M13 quickly just to compare. Nope, no comparison at all. Actually NGC 3201 is also a better view than M13. Though dimmer, it is bigger and more impressive.

8. There is nothing like a dark sky. The moon went down around 3:30. I got up again at 5:45 for the final 45 minutes of darkness. Wow! It's been too long since I've seen the bar of the Milky Way dominate the sky like that. Under that kind of sky and with that size of scope, one gets lost in Sagittarius. Everything is interesting, and there is a hint of light, either stars or nebulosity, almost everywhere. Amazing!

Those are the primary lessons learned. I also starhopped to M85 and M64 for the first time. I'm still working through a Messier list (it's taken me 32 years so far; I have three or four left).

For those of you still reading, I also caught a nice conjunction of Jupiter and Mercury in the evening sky. They had evened up the next night, but on Monday night Jupiter on the left was still higher. Here's the image. Please click for the full size:

March 12, 2011

M51 (3-11-2011)

M51 is such a beauty, and so interesting. It's a favorite target for imagers. This is 105x150" with the 10" f/4.7 newt, Baader MPCC, IDAS-LPS-P2 filter, and SXVF-H9C camera. The subs were short both because they did not need to be any longer (the histogram was moved well off of the left side) and because I have not sorted out all the flex in this system and that's as long as they could be without using the off-axis guider. I still have not figured out how to make the OAG hold the weight of the camera, so I was using a guidescope. I threw out only three subs. This image is probably about what I can do from the burbs, at least in one night. I've taken a couple of images of this galaxy before, when I knew less of what I am doing.

March 8, 2011

IC 443 in Color (2-28-2011 added)

Here is the earlier H-a data combined with 16x7' through the 6" I-newt and an IDAS-LPS-P2 and Baader MPCC, with the SXVF-H9C.

March 7, 2011

NGC 2683 (2-28 & 3-1-2011)

This lovely galaxy, found in the constellation Lynx, lies several million (more than 15 but less than 40 million, based on several studies) light years away. This image is 34x7' through the 6" I-newt and an IDAS-LPS-P2 and Baader MPCC, with the SXVF-H9C. Data was collected from the backyard.

IC 447 and some light pollution (3-1-2011)

IC447 is in the constellation Monoceros. It is a beautiful nebula, even from the burbs. This image is 13x7' through the 6" I-newt and an IDAS-LPS-P2 and Baader MPCC, with the SXVF-H9C. Of course, the image could use more time, and what it could really use is time with a scope and camera away from city lights, but I'm glad to catch the nebula, nonetheless.

March 6, 2011

The Companion of Sirius (3-5-2011)

Tonight I saw the companion of Sirius for the first time. Sirius is the brightest star in the sky (partly because it is only 8.6 light years away). It is a double star, and the dim companion is a white dwarf, the second white dwarf star ever discovered. The white dwarf has about the mass of the sun but is about the size of the earth. The dwarf star does not appear that close to Sirius, but the brighter star overwhelms its companion. In the 15" dob, however, at 380x, all that became academic. There was the dim companion, shining clearly outside the glare of the primary star! I'd never seen it in many years of observing. I've never had a scope that would show it. The eyepiece used was a 5mm Vixen Lanthanum.

March 4, 2011

M66 (2-28-2011)

This galaxy is about 36 million light years away in the constellation Leo. This image is 22x7' with the 6" I-newt, IDAS-LPS-P2, Baader MPCC, and SXVF-H9C. I was going to go back the next night for more time, but, against the prediction of every weather report, clouds set in. Just for kicks, please see the image I took of M66 in March 2007 (linked here). It was my first astrophoto. I was thrilled.

March 3, 2011

M35 (2-28-2011)

This cluster is about 2,800 light years away in the constellation Gemini. It's sort of a showpiece in the 15" dob. This image was taken with the 6" I-newt, the SXVF-H9C, the Baader MPCC, and the IDAS-LPS-P2 filter. It is 26x2'.

March 2, 2011

A Combined Horsehead (3-2-2011)

This is the combined data from the two newts, the Ha taken with the Atik 16 through the 10", and the color data taken with the SXVF-H9C through the 6".

A Brief Horsehead Nebula (3-1-2011)

I'm liking this setup. This image was taken with the Orion 6" f/5 imaging newt, Baader MPCC, IDAS-LPS-P2 vfilter, and SXVF-H9C camera, from the backyard. This is just 7x7', so I'm well short of an hour (my neighbor has this tree, you see). Anyway, it's very impressive what this relatively little scope (at least it looks little on the NJP) will pick up in 49 minutes.