Wednesday, October 05, 2005

Changing Skies: 3 Oct 2005

On the evening of October 3rd I noticed the variable AW Persei, in the nova search area SALC 53, was dimmer than usual. Search Area Location Chart (SALC) 53 lies wholely inside Auriga. Two asterisms extend slightly beyond Auriga's border. One of the them, the 'Double Peaked Triangle', extends into Perseus where the variable is located.

On this night I was reviewing some asterisms from my north facing window on the Upper East Side. Shortly after scanning the area I saw a problem with the figure's outline. One of the peaks was dimmer than usual. From my previous research on this area I remembered that AW Persei was in this section of the sky. A quick check confirmed this was AW Persei.

This is a Classical Cepheid variable star with a period of 6.463589 days. Maximum brightness is magnitude 7.04. Minimum is magnitude 7.89. I haven't made a variable star estimate yet so all I could say about the brightness (sometime before midnight) was that it was noticably dimmer than 'usual' -- possibly magnitude 7.5 or fainter. The optics used were a pair of 8.5x42's.

It was a nice boost in confidence to be able to clearly see, within a matter of seconds, that something was 'up' in a familiar area of the sky. When nova hunting, I'm still referring to charts of asterisms and noting the stars I've seen. My hope is to acquire a knowledge of the search areas so I can scan the skies with a pair of tripod mounted binoculars without having to rely on printed charts. This find was made without referring to charts since I was only reviewing some of the more familiar areas in this section of the sky.