APASS Update
Tuesday, December 30, 2014 at 7:30AM I received an email this morning from the American Association of Variable Star Observers (AAVSO) telling me that the AAVSO Photometric All Sky Survey (APASS) catalog had been updated yesterday so that it now contained 50 million stars with measured photometric magnitudes. In the past it has been difiicult for amateurs wishing to measure the photometric magnitude of a new or variable object because of the unavailability of comparison and check stars in the same field as the target object. APASS greatly increases the chance of being able to do that so is potentially a major step forward in advancing science. I was working on the open cluster NGC 2477 and imported APASS stars within a 3 degree diameter around the cluster. I set up database using these APASS stars and added this to the SkyX software. The result was over 8000 APASS stars and the resulting image with a 3 degree diameter of these looked like this!
The individual APASS stars are labelled and a path is shown in blue to move the telescope from APASS 1 to 8177 - if I wanted to do that. This illustrates the vast number of comparison stars that are now available to the amateur photometrist.