Go straight to:
OV And has *at least* one very close companion which makes it impossible to study the light variations of each star separately. Previous publications devoted to this star (Rossiger 1987, Prosser 1988) report it as a RRab RR Lyrae star, and measured a difference in amplitude of a factor of two! Sounds like a Blazhko effect ...
As Smith, Matthews et al. (1994) put it, AH Cam could be a Rosetta stone for the study of the Blazhko effect. Its unusually short Blazhko period of 10.9 days, and relatively high metallicity of [Fe/H]>-0.5 extend the boundary of the class of Blazhko stars.
TV Boo is one of the very few RRc field stars which was reported to show the Blazhko effect. The Blazhko nature of this star was reported by Detre (1965) and confirmed by Firmanyuk (1974). The star has a pulsation period of 0.313 days and the reported Blazhko period is 33.5 days.
UX Tri is another interesting Blazhko target, which also seems to display a variable Blazhko period. Moreover, the features in the light curevs such as hump and bump are strongly variable over the Blazhko cycle and hence deserve a further study. For more information on the target we refer to the following publications from 2001 and 2006.
We started observing these targets with the Vienna Little Telescope (vlt, mind the small letters!) in November 2004 in the framework of the "Observatoriumspraktikum", where students are taught to perform CCD photometry.
In the meantime observations are also being gathered from Belgium, Greece, Turkey, Michigan, Kansas, Barcelona. Since early March 2005, our spring target TV Boo is also observed with the Vienna-operated APT (Automatic Photoelectric Telescope) located in Arizona.
Participants - Observatories (in alfabetical order):
PB: Paul Beck (Vienna, Austria)
AE: Asli Elmasli (Ankara, Turkey)
KG: Kosmas Gazeas (Athens, Greece)
EG: Elisabeth Guggenberger (Vienna, Austria)
DH: Dieter Husar (Himmelsmoor, Germany)
KK: Katrien Kolenberg (Vienna, Austria)
PLa: Patricia Lampens (Beersel, Belgium)
PLe: Patrick Lenz (Vienna, Austria)
DNU: Deniz Nermin Ulus (Ankara, Turkey)
CWR: C.W. Robertson (Kansas, USA)
HS: Horace Smith (Michigan, USA)
PVC: Paul Van Cauteren (Beersel, Belgium)
AUO: Ankara University Observatory (Turkey)
BHO: Beersel Hills Observatory (Belgium)
HiPOH:Himmelsmoor Private Observatory (Germany)
vlt: Vienna Little Telescope (Austria)
APT: Automatic Photoelectric Telescope (Arizona)
|Date/ JD (2004)||Photometry Target|
|November 19 / 2453329||OV And (BHO)|
|November 24 / 2453334||OV And (BHO, vlt), AH Cam (vlt)|
|November 25 / 2453335||OV And (vlt)|
|December 3 / 2453343||OV And (BHO)|
|December 20 / 2453360||OV And, AH Cam (vlt)|
|December 21 / 2453361||OV And, AH Cam (vlt)|
|January 11 / 2453382||OV And, AH Cam (vlt)|
|January 17 / 2453388||OV And, AH Cam (vlt)|
|March 1 / 2453431||NGC 4422, TV Boo (vlt)|
|March 21 / 2453451||TV Boo (vlt)|
|March 31 / 2453461||TV Boo (vlt)|
|April 1 / 2453462||TV Boo (BHO)|
|April 3 / 2453464||TV Boo (BHO)|
|April 4 / 2453465||TV Boo (Kansas)|
|April 10 / 2453471||TV Boo (BHO)|
|April 11 / 2453472||TV Boo (BHO)|
|April 14 / 2453475||TV Boo (vlt, Kansas)|
|April 15 / 2453476||TV Boo (vlt)|
|April 22/ 2453483||TV Boo (vlt, BHO, Kansas)|
|April 23 / 2453484||TV Boo (BHO)|
|April 24 / 2453485||TV Boo (Kansas)|
|April 28 / 2453489||TV Boo (AUO)|
|May 3 / 2453494||TV Boo (Kansas)|
|May 10 / 2453501||TV Boo (Kansas)|
|May 20 / 2453511||TV Boo (Kansas)|
|May 21 / 2453512||TV Boo (Kansas)|
|June 1 / 2453523||TV Boo (Athens)|
|June 2 / 2453524||TV Boo (Kansas)|
|June 3 / 2453525||TV Boo (Athens)|
|June 6 / 2453528||TV Boo (Kansas)|
|June 14 / 2453536||TV Boo (Kansas)|
|June 15 / 2453537||TV Boo (Kansas)|
|June 19 / 2453541||TV Boo (Kansas)|
|June 20 / 2453542||TV Boo (Kansas)|
|June 23 / 2453545||TV Boo (Kansas)|
|June 24 / 2453546||TV Boo (Kansas)|
Field of view (inverted) on a CCD frame for comparative photometry of OV And. OV And is the left companion of the pair denoted with number 2.
Light curve of OV And obtained with the program MaxIm DL.
The results of the OV And mini-campaign have been published in the Communications of Asteroseismology (Vol.146, p.11).
TV Boo finding chart (15x15 arcmin).
(above) Kansas data of TV Boo phased with the
main period (arbitrary phase 0.0). Data gathered by C.W. Robertson.
(below) BHO data, gathered by Paul Van Cauteren and Patricia Lampens.
These data of the Blazhko star UX Tri have been obtained with the Vienna 80-cm telescope (vlt: Vienna Little Telescope) during the Observatoriumspraktikum.