June 27, 2009

M13 & M56

M13 is known as "The Great Globular Cluster M13" for a reason. These two images were taken with the same equipment on the same night. M13 is just a bit closer to us than M56---25,000 light years for M13 as opposed to 32,900 light years for M56, but notice how large M13 is. It is quite a showpiece in any telescope. It helps that M13 is in a part of the sky without a lot else to look at, whereas M56 is in Lyra, in the plane of the Milky Way, in an area chock full of stars. Anyway, I've wanted a decent image of M13. It's a popular target. North is up in the image of M56, and to the right in the M13 image.

One thing to notice about the M13 image is that two galaxies also make an appearance. The brighter one in the upper right is NGC 6207. It is perhaps 60 million light years away (one recent study puts the distance at 66.5 million light years, another at 60 million). The dimmer spiral galaxy between NGC 6207 and M13 is IC 4617 or PGC 2085077. IC 4617 is magnitude 15 or 16 and probably further away still.

These are last night's images. I actually imaged these targets twice this week, but the first time my guiding was not good enough to post. Even on this version of M13 it was not quite where it needs to be: notice that many stars are elongated slightly from north to south (it's human error, I assure you, and not the equipment). After I finished the M13 exposures, though, I fiddled around with PHD, the autoguiding program, and figured out what the problem was. With that problem worked around (not quite solved yet), I put M56 in the crosshairs and started the second set of exposures. This was all around 3:00 in the morning. I post them both together to show progress on the guiding front, about which I am quite happy. The guiding on M56 was not perfect, but I kept an hour's worth of frames in which the stars are actually round. For M13 I had few frames that showed truly round stars, so I kept enough of the best ones to make the image bright. Both are somewhere around an hour's worth of two minute exposures. I slept while the camera took the subframes.

By the time I imaged M56, it had been six hours since polar alignment: a quarter of a sidereal day had passed. Any error in polar alignment would have been at its maximum, and that probably accounts for my losing so many of those frames at a time when the guiding setup was actually working much better.

Images were taken with the Atik 16 through the AT66ED at f/6 (400mm), autoguided by a DSI Pro controlled by PHD through the Orion 100mm f/6. The mount is a Tak EM-10. Processing was done in Nebulosity and PSE7.

June 23, 2009

The Joys of Visual Observing - Globulars

The stars are beautiful! First light with the new mount went to Albireo---what a sight! Wow! It reminded me of why I started exploring the night sky in the first place. Tonight's list included Epsilon Lyrae (a stunner at 120x); Struve 2474 and 2470, also in Lyra (stunning at 60x); M7 (an amazing sight at 17x and always one of my favorite clusters); and M4 (dim and boring, even though close for a globular cluster at 7,200 light years).

Two objects stood out above all others tonight, though. One was M80. It is often overlooked because of the much larger M4 to the south, but M80's core is brighter than M4's, and that makes it a more dramatic scene. Even more dramatic than that is NGC 6441. I recommend it to anyone who hasn't looked yet! It sits just next to G Scorpii, a third magnitude star just south of M7. The contrast of the bright star and the ghostly globular is stunning. Wow!

June 22, 2009

New Mount First Light

After selling the LXD75, I felt the immediate lack of an equatorial mount for visual use. I have a 6" achromat, and I don't want to put that on the EM-10 (the 6" was more than the LXD75 could handle without more jiggling than I wanted). Also, I wanted a mount I could put a large newt on later. Enter the Meade DS-10 (shown here with the motor cover removed):
This is the largest mount I have yet used. It will hold the 6" refractor without even blinking. It is built for a 10" newtonian and seems to me could easily handle 35lbs. It came with a short stand, but I need the refractor up high, so I wanted the mount on the walnut tripod, instead. Getting the mount on the tripod required putting various parts together. I have a Vixen tripod hub on the walnut legs. Just above the hub is the bottom part of an Orion pier extension for the Orion middle-weight mount, the SVP. Between the pier extension part and the DS-10 mount is a piece of aluminum machined to attach them together. I had the Conroe Machine company build the part. It is machined to a very close fit and looks great!
In fact, the mount is rock solid. The dec axis, a piece of steel 1" in diameter, is almost heavy enough to act as a counterweight to the 100mm achromat, but not quite.
The clock drive is pretty accurate--perhaps a tad slow. But the mount is also simple enough that it is easily adjustable, and I look forward to fiddling with its inner workings. Each axis has a clutch that allows manual movement of the mount without unhitching anything! The ultimate in convenient! I've had it out the last two nights with the 100mm, and it is pretty sweet, just what I need.

June 19, 2009

Abell 2065

In this image, if you see something that looks to fuzzy or too out of round to be a star, it is probably a galaxy! This cluster of galaxies is over 1 billion light years from us! Light hitting my camera was generated in reactions over a billion years ago!
Really this image needs more time, but I was waiting for Pluto. This image is certainly a distance record for me. It is 31x120".

Pluto Confirmation

Here is another shot of Pluto two days later with the same equipment and comparable exposure time. Just to be more accurate, the two images were taken around 7:30 UT on 6-17-09 and 8:10 UT on 6-19-09. Here are smaller shots that show the difference more plainly:

June 17, 2009


The arrowed 14th magnitude dot in the first image is Pluto. Pluto looks like a rather dim star, but that speck really is the planet. Compare the Digital Sky Survey II image obtained from Wikisky.org. I also have carefully compared my image with the June Sky & Telescope chart that records stars down to 14th magnitude. Pluto is exactly where both that chart and Wikisky.org place it. This observation completes all nine (former) planets!

NGC5490 & 5490C (Arp 79) & Arp 117 (IC 0983 & 0982)

Here is a retake of the earlier. This version is a little deeper and is clearer, though not by much. It is 39x150" with the same setup as the earlier version. I like this one better, as the interaction between IC 0983 and 0982 is more obvious. It is more obvious still in the inverted version.