New variable star - GSC 3693:1720

The variability of GSC 3693:1720 was detected by Arto Oksanen (Nyrola observatory, Finland) while observing a close variable star UV Persei. Arto was checking the suspected variability of another comparision star that suggested by Bruce L. Gary (Hereford, AZ, USA) when the obvioius varability of GSC 3693:1720 was found. Arto requested additional observations from the observers of the AAVSO and the CBA who were already having intense observing campaigns of UV Persei. Data started to pour in and the variability was confirmed. The variability is about 0.04 magnitudes and period is about 0.1531 days. The star seem to be either Delta Scuti or Beta Cephei type, both having low amplitude and short period. The final classification will need spectroscopic observations.

Field image

Following CCD image shows the new variable, UV Persei and the preferred comp star (V=10.981). North up, East left.

Star information

From TheSky:

GSC 3693:1720
Spectral: B9IV 
**** Data from Tycho Catalog ****
Proper motion (mas/yr): RA = 18.50, Dec = 43.90
Magnitudes Bt: 10.684, Vt: 10.077
Parallax: 33.800 mas, 29.5858 pc
Distance: 96.50 light-years
RA: 02h 10m 13.43s  Dec: +57°11'25.50"  (Epoch 2000)

Combined light curve

Following light curve shows all datasets received by November 16, 2003. Contributing observers are David Boyd (DB), Keith Graham (KG), David Messier (DM), Arto Oksanen (AO), Jochen Pietz (JP) and Tonny Vanmunster (TV). Total number of datapoints is 7969!

Light curves of individual JD dates

JD 2452948 - November 4/5, 2003

JD 2452949 - November 5/6, 2003

JD 2452950 - November 6/7, 2003

JD 2452951 - November 7/8, 2003

JD 2452952 - November 8/9, 2003

JD 2452953 - November 9/10, 2003

JD 2452954 - November 10/11, 2003

JD 2452955 - November 11/12, 2003

JD 2452957 - November 13/14, 2003

JD 2452958 - November 14/15, 2003

JD 2452959 - November 15/16, 2003

JD 2452960 - November 16/17, 2003

Period analysis

Period analysis was performed by Arto Oksanen with the AVE software (by Rafael Barbera, Grup d'Estudis Astronomics) using PDM and periodogram methods after averaging all datapoints to 0.002 day bins.The best period was found to 0.1531 (+/- 0.0001) days or 3 hrs 40.4 minutes.

More precise analysis by Aaron Price

Aaron Price used DCDFT using CLEAN (G. Foster 1995) and got following results:
P = 0.153080 +/- 0.000027 = 220.4352 mins +/- 0.03888 mins .

Power spectrum

Spectroscopy

Maurice Gavin has taken a low resolution (25A/pixel) spectra of the variable. More spectras and comparisons with other variables can be found on Maurice's web page.

Publications

A brief discovery report was posted to Information Bulletin of Variable Stars (IBVS) and it appeared on the Konkoly Observatory web site on November 18, 2003 and will be included to IBVS 5500. Also a more complete IBVS report is being compiled.

Further observations

As the star is less than an arc minute from UV Persei they are easy to observe simultaneously. Arto Oksanen is collecting all observations at this point and they can be mailed him to arto dot oksanen at jklsirius dot fi. A suitable chart is the f-scale chart of UV Persei from AAVSO.