SCV Astronomy - PMDO Sky Survey - Asteroids Spotted

[SCV Astronomy] -- [SCV: PMDO Survey]

Here's my gallery of asteroids captured in PMDO Sky Survey images. It's a challenge to see how faint a moving object can be detected in this way. I prefer to show them as Red-green-blue "triplets", like the following:

Here is 51 Nemausa in Jan 2003. It was magnitude 11.1 at the time. Note that a close look shows the 1/11 image (red) was merged into the image of the star marked.

Here's a much fainter one ... 235 Carolina (mag 13.9). I could only spot this one because I knew exactly where to look. Even then, I had to crank up the contrast and stare at pixels up close.

I doubt that an unknown object this faint could be reliably discovered in this survey, though magnitude 13 objects do stand out. Still, this beats the limiting magnitude of about 12 for Stardial images!

As far as "discoveries" go, there are a fair range of "singletons" on PMDO plates, which are tiny starlike blips that appear on only one night's images. These often occur in lines, evenly spaced, suggesting that they're reflections from tumbling satellites. I have found two cases of "pairs", though: an object that appears on two plates, seeming to move from one night to the next. But, unless these can be followed for more nights, they are most likely nothing.

Here's a fun image that shows all kinds of things:

What's going on here? I was trying to track asteroid 129 Antigone (mag 12.9). It started off beyond the right edge of the plate, so there are only green & blue images over there. But in the middle of the image, there was another clear green & blue pair, with a faint point that might be the red counterpart (marked "1/21?", not visible in this GIF version). Still, this only matters if the object can be tracked and found on other plates. So I projected where the "object" would be on the next few nights, but weather didn't permit any new photos.

The next available photo was on 2/2/03. So I overlaid two small pieces of that image, and you can see that the mystery object was nowhere to be seen. But, you can also see that 129 Antigone was barely visible, so maybe the object was there, but undetected? I don't know. I'm waiting for the next plate 26 image to find out! Of course, I can also backtrack, but the object soon moves into plate 25, and images are few & far between.

Note the singleton (labeled "?") at the top center of the image -- this only appeared on one night, and can be ignored.