January 31, 2009

Star Party at the Elementary School

Two nights ago I had the opportunity to go to my son's elementary school science night. There were all kinds of science exhibits, from magnets to hamsters! Lots of second- and first-graders and kindergartners were coming! That's just the place for a large refractor. I had just finished setting up when the first students arrived. Venus and the Moon shone brightly in the west (thanks for the image, Phil). Most kids would want to see the Moon, which was just a crescent, so that's where the scope went. A long line formed and did not end until around 8:00. The moon was big and bright magnified 35x. A moderately bright star shone beside it. The moon was a waxing crescent, but it was not dark on the side that was away from the sun! Sunlight shining on the Earth was reflected back onto the dark side of the Moon, lighting it up in eerie twilight! So the Moon looked like a round ball even though a crescent shape along one edge was lit up by the sun! I would bet around 200 kids and parents looked through the scope that evening. What a wonderful opportunity! Thanks to the school for a fine welcome, and thanks to all the kids who looked through my telescope! Sharing the evening with you was great!

January 29, 2009


I left the 4" scope outside last night so that this morning all of its lenses would be of equal temperature. It focuses much better that way. Saturn was still high in the sky when I looked around 5:45 am. At 120x, Saturn was a big ball with a line through it---well, sort of a line. The rings are not edge-on now but tipped a little. The earth crossed through the plane of the rings about a month ago. On one side of the line which is the rings, right where they crossed the planet's face, a sharp, black line now plainly appears---the shadow of the rings on the planet itself. Titan and at least one other moon were easily visible, following the planet like a posse.

January 22, 2009

Uranus & Venus (01-22-09)

Tonight there was a close conjunction of Uranus & Venus. Seeing them together is interesting because Venus is 67 million miles from the sun, but Uranus is, on average, 1.78 billion miles from the sun. At the time this pictures was taken, Venus was between 80 and 100 million miles from Earth, and Uranus was at least about 1.8 billion miles behind it. When we look at the two planets, we are looking back in time. Sunlight took 6 minutes to get to Venus and then 8 or 9 minutes to get from Venus to my camera. But sunlight took 2.65 hours to get to Uranus and another 2.65 hours to get back to my camera. So the light from Venus is 14 minutes old and the light from Uranus is over 5 hours old. If the sun ceased to shine all at once, folks on earth would learn about the sun's darkness a little over 8 minutes after it happened. But even after the sun ceased shining here on earth, Venus would shine for another six minutes, and Uranus would glow for about another 5 hours!

Three of these are 15 seconds with the Canon 400D through the AT66ED with the 0.8x field flattener II. The darker image is only 8 seconds.

January 21, 2009

Leo Trio

The Leo Trio lies about 35 or 36 million light years away. These galaxies are gravitationally bound together. The one in the upper left, M66, is roughly 100,000 light years across. Assuming these systems are all roughly the same distance, they may well be within 1 million light years of each other. It's no wonder that they show signs of distortion. Look carefully at M66. Which side appears longer, left or right? Whichever you decide, it is clear that M66's two sides differ, and this is thought to be the effect of having neighbors nearby. The galaxy on the right, NGC 3628, is also distorted. Its stars are being pulled out all around it, like too much lettuce spilling out of a ham sandwich. Even more interesting, NGC 3628 has a long tidal tail that is too faint to appear in this image but is clear in this very cool and very deep image by Steve Mandel (processed by Ken Crawford).

This image is the last of my January 18 run. This was also taken with the AT66ED and the Atik 16, unguided on the LXD75. It is about an hour's worth of 10-second exposures. No darks, no flats, no bias frames.

January 19, 2009

Trapezium Stars E & F, AR6, and Atik 16

The Trapezium of Orion! These six stars (you must click on the picture to see the larger image) are gravitationally bound. This is a "multiple star," not just a double or triple star. There are several others in the same tiny group. In fact, you can see in this image a hint of a few others---perhaps G, H, and I---if you compare this image with the one near the bottom of this link. There may even be other stars shown in this image. Look at the blobby shape of the lowest star. It turns out that faint stars exist just to the lower left and right of this star. My little AR6 with this makeshift imaging system can't resolve them, but perhaps light from these stars is deforming this component of cluster. (Thanks to Anjal Sharma of the Huntsville Amateur Astronomy Society for pointing out the deformation and the possibility of other stars there.)

Anyone who reads this blog much knows that I check the Trapezium almost every time it is up and I am out. I take great delight in seeing the four stars hanging together in the sky. I am even more delighted when I see the E and F components. I've described them here and in three earlier posts. But they are so easy to see in the AR6! Moreover, they are bright stars. So I figured: The focal length of the AR6 is 1219mm. If I can attach the Atik 16 to the AR6 and use an Ha filter, I can take many very short exposures and stack them to show the E and F components. This is the result. This is unguided on the LXD75, and it was pretty shaky. In fact, this is only 28 out of the 100 sub-exposures I took, but they were only 1- or 2-second subs, so I didn't lose much time. Shakiness and "seeing" took a toll. Also, the thing took some time to set up. I was afraid Orion would move behind my neighbors' tree before I was finished. In the end, I had 30 minutes to spare. The Ha filter is an Astronomik 13nm bandwidth. One key to the process was Nebulosity's Drizzle function, which yielded a better resolution than mere stacking or combining.

Here are two great images of the Trapezium by Samir Kharusi and Roland Christen. Both make me want to try again soon.

M46 (& NGC 2438), M47, NGC 2362

These are some of the fruits of January 18th's night out. This is the Atik 16 attached to the AT66ED. Baader UV/IR cutoff filter only. Unguided on the LXD75.

January 9, 2009

Luna & the Airplane

This prop plane flew right across the moon as I was manually focusing on the moon itself. Lucky for me the focus was a little short: Not a bad shot of the plane! This will be the largest full moon of the year. The moon is nearer now than it will be at the time of any other full moon this year. Perhaps if the moon was not so large, the plane would not have fit so well within it in this shot! This lucky shot was re-published on Spaceweather.com, here. Canon XTi, Nikkor 300mm 1:4.5, ISO 1600, 1/3200 seconds.

January 7, 2009

Luna in a Nikon Nikkor 300mm f/4

Finally, a clear night! It gave me a chance to try out a new (used) Nikon Nikkor 300mm f/4. Here is Luna through the lens. I'd say for a good, classic, relatively inexpensive (auction-obtained) lens, this image is quite free of annoying chromatism. It's relatively easy to focus, too, though the Canon XTi.