Monthly Archives: January 2016


It’s a bird, it’s a plane …

A friend recently asked if I’ve ever seen a “UFO” while watching the night sky, and I thought that would be an interesting topic for this blog.  I think that anyone who spends much time looking at the night sky is eventually going to see something strange, and I’ve seen many things that I couldn’t explain.  However, I’ve never seen anything that seemed “alien”.  That is, I’ve never seen anything that was truly bizarre – just things that are hard to know exactly what caused them. First, I have to make a distinction between seeing things (with your eyes) and […]


Back to Nine?

In case you haven’t heard, researchers at the California Institute of Technology have found compelling evidence for the existence of a new planet in our solar system.  Dubbed “Planet Nine”, the large body (about 10 times the mass of Earth) has not been seen or detected by any camera (that we know of), but is strongly believed to exist because of its affect on other bodies. Planet Nine orbits the Sun at an average distance of 2.8 billion miles – far beyond the distance to Neptune, the most distant of the currently known 8 planets, or even the dwarf planet, […]


Another California

I recently posted a picture of the California Nebula (NGC1499) that used special processing to overcome sharpness and noise issues in the oxygen and sulfur channels.  As promised, I have captured some much better frames of these channels.  And I did experiment with other ways of combining them make a color image, but didn’t find any that looked better than the original. So here is the final version, with 4 hours of H-alpha and 3 each of OIII and SII (10 hours total).  It is sharper than the previous attempt, and has better detail throughout.  But perhaps the most important […]


Test Results

I was able to capture some test images last night with the Star71 scope and Canon EOS 6D camera.  These were all unguided captures of 30 seconds duration, manually focused using live view mode.  I got 4 shots of each target and also captured 4 dark frames at each ISO setting (3200 for Orion and 12,800 for M103).  I averaged the dark frames and subtracted them from each light frame, then averaged the light frames (without adjusting their alignment).  Note that the “fog” from light pollution brought the black level up to almost 50%, higher than it should be, and […]


A New Camera

I do most of my astro-imaging with a monochrome CCD camera that lets me use a variety of filters.  This provides the best image quality and flexibility, but there are 2 significant drawbacks:  First, because of the expense of these specialty cameras, I can only afford one with a fairly small sensor (the same size as digital cameras using the “four thirds” format, which is smaller than the typical APS-sized DSLR).  Second, capturing a color image takes much longer because you have to take separate red, green, and blue exposures (and sometimes luminance exposures as well).  Processing these separate exposures […]


First Image of 2016

The sky had been cloudy for what seemed to be an eternity, but we’re now in a brief period of sunny days and clear nights.  Of course, it is also very cold and windy.  The cold I can deal with by operating the observatory from inside the house as much as possible.  Wind, especially a strong jet stream, is more problematic. I’ve been shooting the California Nebula (NGC1499) for the last 2 nights, using the William Optics Star71, which is relatively insensitive to atmospheric turbulence because of its small aperture and low magnification.  The first night I captured a couple […]