Hi Guys, many thanks,
Star GSC 5065-218 located in the constellation of Ophiuchus was serendipitously discovered recently while measuring for photometric purposes Minor Planet 3492 Petra-Pepi which was observed originally from Cherryvalley Observatory in May and June of 2011. It was during a testing software routine within MPO Canopus on the June 2011 data when the discovery was made.
Back in 2011 Cherryvalley was only becoming established and submitting astrometric measurements to the MPC. In 2012, Cherryvalley Observatory undertook additional work in photometry on minor planets, I thought I would look at the selection of older minor planet data that I did not worked on for photometric purposes and see for the first time if any photometric data could be extracted and that’s when you come across situations where you say, “Oh, that’s funny”. One of the stars seem to display a ~0.5 magnitude dip, so just to be sure of my own basic analysis I checked the AAVSO VSX database and sure enough no variable star was listed for that precise location and an email was sent to Mr. Brian D. Warner (author of MPO Canopus software) of the Centre for Solar System Studies - Palmer Divide Station, USA and he quickly replied to say “that looks interesting” and he would free a scope for observations on the star in question. A few days later Brian kindly sent me on all his observations and confirmed it was a variable star and probably an eclipsing binary
Next step was to contact the B.A.A. (British Astronomical Association of which Cherryvalley Observatory is affiliated) and informing them of the discovery. Mr. Roger Pickard of the Variable Star Section sent out an alert requesting observations. Although there is only tentative data at the moment the star seems to be an eclipsing binary classed as an “EA” type, The B.A.A.’s describes such a system as…
EA Systems - Algol Type Systems
These are systems in which the light curve shows little variation outside of eclipses. If
there is a significant difference in brightness between the two stars the primary minimum will be marked whereas the secondary minimum may not be observable visually.
The stars in an EA system are spherical and may be well separated or ʻ detachedʼ. They may also be ʻ semi-detachedʼ. In this case there will usually be a mass transfer taking place between the stars of the system. The periods of an EA system can vary from a fraction of a day to years.
So what next? There is an involved process with the AAVSO in submitting a new variable star discovery which needs to be worked through and of course observations from any variable star observers is most welcomed as the exact lightcurve and period needs to be secured.
I would not be at this stage it wasn’t for the help of Mr. Brian D. Warner and Mr. Roger Pickard which to both I am greatly indebted and to Mr. Dave McDonald whom has walked this path before and shown the way for Irish amateur astronomers.
Here is the preliminary lightcurve and finder charts
flic.kr/p/sfAn1w
flic.kr/p/tcmbVh
flic.kr/p/tcDrsP
