Astro Images by Bert Halstead

(click image to view & discuss)	2005 YU55 motion across the sky This is a quick shot of the near-Earth asteroid 2005 YU55 using four consecutive exposures from the Harvard MicroObservatory robotic telescope in Amado, Arizona, on the night of Nov. 8, 2011. The asteroid was moving across the sky so fast that each 60-second exposure generated one of the streaks on the picture. Then the gap between streaks is the 2-minute interval before the next exposure begins. It only took about 10 minutes for the asteroid to cross the entire 1-degree field! The coordinates are approximately 22h34m and N17deg21' and the time span was from 03:33 to 03:43 UT on Nov. 9. I'm sure this image would benefit from doing more work on reducing noise, but this is what I have for now. Submitted by Robert Halstead on 11/12/2011 23:02:48
(click image to view & discuss)	Comet Lovejoy C/2014 Q2 on Jan. 10, 2015 This is Comet Lovejoy C/2014 Q2 as it appeared at about 10:30 pm Saturday, Jan. 10, 2015, from my back yard in Belmont, MA, about 5 miles west of downtown Boston.  The comet is quite bright and could be seen easily in my 10x50 binoculars. Technical details: The area pictured here is about 2.2 by 1.5 degrees in size.   This image was made in Photoshop by stacking four exposures taken using a Canon 6D camera on a fixed tripod with a 200mm telephoto lens, each exposure being 2 seconds at f/2.8 and ISO 4000.  I applied a flat-field image to correct for vignetting, and then subtracted out a considerable amount of light-pollution sky glow. Submitted by Robert Halstead on 01/12/2015 11:43:34
(click image to view & discuss)	Comet Lovejoy C/2014 Q2 on Jan. 23, 2015 This is Comet Lovejoy C/2014 Q2, with its beautiful tail, as it appeared in the evening on January 23, 2015, photographed from a location near Bishop, CA.  The field of view is about 7.5 x 5 degrees. I was visiting the area as a tourist, so I had no heavy-duty astronomy gear -- just my 70-200 mm lens and a regular photographic tripod.  I couldn't take an exposure longer than about 2 seconds without getting significant star trailing, so I made 130 exposures of 2 seconds (at 200 mm focal length, f/2.8, ISO 6400 on my Canon 6D) and then stacked them using DeepSkyStacker 3.3.2. The result from my first attempt at using the program was very disappointing, so I gave up for a while, but finally I came back to it and got much better results after changing the stacking mode to Auto Adaptive Weighted Average for my light frames, and to Median Kappa-Sigma clipping for several of the calibration frames, yielding this image as a result (after further tweaking in Photoshop). Submitted by Robert Halstead on 06/28/2015 23:22:04
(click image to view & discuss)	Venus and Jupiter near conjunction, June 29, 2015 This image shows Jupiter and Venus last night, June 29, 2015, at about 8:50 pm EDT.  This is a small crop of an image taken with my 200 mm lens plus a 2x teleconverter, for an effective focal length of 400 mm. You can make out the four Galilean moons of Jupiter at the top right.  (Callisto is the most elusive.)  I added insets (with less exposure) to show the shape and appearance of Jupiter and Venus.  The crescent shape of Venus can be seen easily. Technical details: All images taken at f/11 effective aperture, ISO 400, on a Canon 6D camera.  Main image: 0.6 second exposure.  Jupiter inset: 1/20 second.  Venus inset: 1/320 second.  Processed and assembled using Adobe Lightroom and Photoshop. Submitted by Robert Halstead on 06/30/2015 11:09:49
(click image to view & discuss)	Planets Passing in the Night, June 30, 2015 It stayed clear long enough here for a good look at the close conjunction of Jupiter and Venus tonight. Here are two telescopic views: a bright one in which you can see Jupiter's four Galilean moons (notice that two of them are really close together!), and a darker one that lets you see the shapes and colors of the planets, especially Venus's lovely crescent shape. Captured using my Canon 6D at the prime focus of my 8-inch f/10 Celestron Schmidt-Cassegrain telescope.  ISO 1600, 0.6 seconds for the image at the left; and ISO 400, 1/50 second for the image at the right.  Images captured between 8:57 and 9:02 pm EDT on June 30, 2015. Submitted by Robert Halstead on 06/30/2015 23:19:35
(click image to view & discuss)	M31 wide-field view This is M31, the great Andromeda Galaxy, with satellite galaxies M110 and M32, photographed under very dark skies on January 23, 2015, from a location near Bishop, CA.  The field of view is about 5.5 x 3.5 degrees. Traveling as a tourist, I had no heavy-duty astronomy gear -- just my 70-200 mm lens and a regular photographic tripod.  I couldn't take an exposure longer than about 2 seconds without star trailing, so I made 80 exposures of 2 seconds (at 200 mm focal length, f/2.8, ISO 6400 on my Canon 6D) and then stacked them using DeepSkyStacker 3.3.2, with final processing in Photoshop.  I cropped out the corners and edges of the original frame, where the stacking software did not succeed in aligning the stars well. Submitted by Robert Halstead on 07/07/2015 16:19:52