Wednesday, May 4, 2016

An Evening With Friends!

With a few days of good weather, there was an opportunity to make plans to try to get out of town for a few hours of observing. By my accounting, I've not had my 11" Newtonian out for an imaging session in 5 months - the last time I've been doing astronomy other than chasing LBT ARGOS lasers! Buddy and co-worker Roger joined me, headed towards Benson to another friend's house a couple hours before sunset. Roger questioned the early departure, but by the time I unloaded and set up the photographic setup, I actually started imaging a little after full darkness, so I could have used even more time!

Once "on the air" and the autoguiding system doing the heavy lifting of accurate guiding, there was ample opportunity to do visual observing with my binoculars, Roger's 8" refractor that he had brought along, and check out Pat's progress with his 12" Newtonian and his new mount. There was also a chance for some selfies shown here. At left with the 11" dutifully taking a programmed set of exposures, I'm checking the guiders performance on the notebook computer. In the background, a sharp-eyed observer might notice Corona Borealis near the top of the frame, and the Keystone of Hercules at the left edge. My selfie at right taken a little later with the first signs of the Summer Milky Way rising shows my favorite kind of observing - head back, eyes open, mouth agape with the wonders revealed by a dark sky!

In my starlight-deprived state, I didn't have much of an observing list - just a half dozen objects of interest. Springtime is galaxy season with the heart of the huge Virgo cluster on the meridian about 10pm. Some interested me more than others, and my list also prompted Roger and Pat to try chasing them down too. Roger is a refractor guy, and brought along an 8" that he had built. Most refractors need multiple glass elements, and he thinks little of polishing 6 glass surfaces to make a triplet lens system! Being much lazier, I'd rather do a single aspheric on a mirror, so that is why I'm fond of Newtonian mirrors, while he prefers the high-resolution view afforded by a fine refractor. At left, he is shown with Scorpio rising behind him, modified into unrecognizability with brighter Mars and Saturn both in the constellation.

Pat has built a very nice little roll-off roof observatory on his acreage, and he is having issues with his new mount.  At right he is shown trying to figure it out with his 12.5" Newtonian mounted atop it.  It will be a nice go-to system when he figures it all out.  The amount of ambient light is misleading in the 13 second exposure.

Finally here are some of my results of the night. These are the quick-and-dirty processing of the jpeg images. Working with the raw images are better, but more time-consuming, so quickly turned these out for the post. My first object at left is likely the easiest galaxy to find photographically! Located just north (above here) of the bright star Regulus in Leo, this is the dwarf galaxy Leo I, thought to be a distant satellite of the Milky Way(at about 820,000 light years distant). While very faint (it wasn't discovered until 1950!), it looks very similar to a reflection or ghostly glow, perhaps even caused by a reflection of Regulus in the optics. But it is real, and clicking to load the full-size image, you can see the glow is partially resolved into stars. Roger did a search for it visually in his 8", and while some of the field stars were seen, the glow was not spotted. This exposure is 32 minutes total, the lines coming out of the bright star Regulus are diffraction from the spider holding the secondary mirror. There are also a couple satellite trails visible on the right side of the image.

Next up was the Leo Triplet, a trio of galaxies located along the rear leg of Leo, the lion. While I've shot it before, none of the shots were great, and even this one needs more time than the 25 minutes of exposure shown here, but still, a nice field. Here north is to the right. The rightmost edge-on galaxy is NGC 3628, and the pair at left are Messier 66 above and Messier 65 below, all about 35 million light years distant.

The last galaxy of the night has never made an appearance here, though is about the most famous in the sky - the edge-on NGC 4565. BTW, NGC stands for New General Catalog, a listing of non-stellar objects dating back to the 1880s. It sits about 45 million light years distant and is aligned nearly exactly edge-on to our line of view. Also called the needle galaxy, it is thought that the smaller galaxy to the lower right, NGC 4562 is a companion. I've observed it visually many times in the past, but was amazed I've never shot it before. Again, it deserves more than the 18 minutes devoted to it here...

Since it was a "school night", I didn't want to be out till dawn, but really wanted to shoot a comet that passed very close to the earth a few weeks earlier - Comet 252P/Linear. Located in Ophiuchus, I was able to spot it in binoculars before getting it in the telescope - perhaps 7th magnitude or just below. Even a short 20 second exposure shows it as a greenish glow, caused by the dissociation of carbon molecules in sunlight. It moved quite rapidly across the sky when it passed just over 3 million miles from us in late March, but is moving quite slowly now. Even though, when the images were aligned on the comet's nucleus, the stars are trailed slightly in the 10 minutes of exposure...

We hated to leave Pat's with the Summer Milky Way just clearing the horizon, but with a work date in the morning we packed up, hit the road about 1215. After dropping off Roger and his equipment I hit the hay at home right about 2am. A rewarding night, spent with friends both human and celestial. I absolutely can't wait 5 months for the next one!


Anonymous said...

great images! enjoyed reading this

Alan Strauss said...

Nice work Dean- I really like the Sombrero image. Keep the observing reports coming!!