Today I was able to get away at lunch and made the 200 meter walk to the NOAO offices and found the POSS down in the bowels of the library extension in the basement. The 1000 print pairs (red and blue exposures of the same field) fill a large file cabinet. What made them even more useful back in the '80s was a transparent overlay which labelled nearly everything in the exposure. Shown here is the blue light exposure of the Andromeda Galaxy and repeated with the overlay in place. There are lots of lil' objects there, dominated by globular clusters and a myriad of other things.
So I found the chart showing the Hyades, but in reality, my picture of the little dark clouds (admittedly windowed a little severely here), only barely showed up in the print version of POSS-I, likely printed to show stellar objects better.
However, this afternoon, while Googling the POSS, I found that digital versions are online for anyone to use, with any version of the Sky Survey, including a near infrared version that was part of the latest '90s edition. So I typed in LDN1551 and include the image here - a red exposure from POSS-II. Only a 1 degree square maximum is allowed, but a good comparison can be made. Both images are shown with north to the right. I'm still impressed what the little 135mm lens (2 hour exposure @F/4) did compared to a major observatory instrument, but it was also nice to find the on-line versions of all the Palomar Observatory Sky Survey editions at the click of a finger!
2 comments:
Very cool!
I like the user interface better than SIMBAD. This one's a keeper and I have it bookmarked. Thanks, Dean!
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