Overview of the 2004-2005 northern hemisphere campaign

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Observers - Observatories

Observations in November 2004 - June 2005

Figures - Preliminary results


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)



Figures and preliminary results


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).


Preliminary figures:

(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.


UX Tri:

These data of the Blazhko star UX Tri have been obtained with the Vienna 80-cm telescope (vlt: Vienna Little Telescope) during the Observatoriumspraktikum.