Photometric Elements for Five Newly Discovered Variable Stars

A. Liakos, P. Niarchos
Department of Astrophysics, Astronomy and Mechanics, National and Kapodistrian University of Athens, Athens, Greece

Received:   18.02.2010;   accepted:   26.02.2010
(E-mail for contact: alliakos@phys.uoa.gr)

Comments:


1. The new variable star 2MASS J00511854+5022580 (indicated as V in the finding chart) is inside the field of view of the known variable star V364 Cas. GSC 3270-01412 and GSC 3270-00210 were used as comparison (C) and check (K) stars, respectively, and they are also indicated in the finding chart. MaxI - MinI = -0.67 and MaxI - MinII = -0.6 in R filter.

2. The new variable star GSC 04516-02121 (indicated as V in the finding chart) is inside the field of view of the known variable star V405 Cep. GSC 4516-01706 and GSC 4516-01124 were used as comparison (C) and check (K) stars, respectively, and they are also indicated in the finding chart. MaxI - MinI = -0.55 and MaxI - MinII = -0.4 in R filter.

3. The new variable star 2MASS J07083972+1214429 (indicated as V1 in the finding chart) is inside the field of view of the known variable star AV CMi. GSC 0757-00435 and GSC 0757-00134 were used as comparison (C1) and check (K1) stars, respectively, and they are also indicated in the finding chart. MaxI - MinI = -0.20 and MaxI - MinII = -0.20 in R filter.

4. The variable star 2MASS GSC 00770-00523 (indicated as V2 in the finding chart) is inside the field of view of the known variable star AV CMi. GSC 0770-00929 and GSC 0770-00911 were used as comparison (C2) and check (K2) stars, respectively, and they are also indicated in the finding chart. MaxI - MinI = -0.1, MaxI - MinII = -0.09 and MaxII - MinII = -0.08 in R filter.

5. The new variable star GSC 01025-01841 (indicated as V in the finding chart) is inside the field of view of the known variable star V456 Oph. GSC 1025-01618 and GSC 1025-00331 were used as comparison (C) and check (K) stars, respectively, and they are also indicated in the finding chart. MaxI - MinI = -0.08 and MaxI - MinII = -0.05 in B filter.

Remarks:
In this study we present the first photometric elements of five newly discovered variables. Their variability was detected for the first time as by-product during our observations of other eclipsing binaries, except for the case of GSC 00770-00523 for which only one time of minimum has been published by Zejda et al. (2006), but no other information of its variability exists so far.

The observations were carried out at the Gerostathopoulion Observatory of the University of Athens from 2007 to 2009, using a 40-cm Cassegrain telescope equipped with ST-8XMEi and ST-10XME CCD cameras and the BVRI Bessell photometric filters. Differential magnitudes were obtained for all systems using the software Muniwin v.1.1.26 (Hroch 1998).

All the systems presented in the present study need follow-up observations in order to confirm the type of their variability, while more photometric and spectroscopic observations, using larger telescopes, are needed in order to obtain more accurate light curves and determine their spectral characteristics. Then, it would be possible to obtain absolute elements of the systems and enrich the bibliography of this type of stars.

Acknowledgments: This work has been financially supported by the Special Account for Research Grants No 70/4/9709 of the National and Kapodistrian University of Athens, Greece.

References:
Hroch, F., 1998, Proceedings of the 29th Conference on Variable Star Research, Brno, Czech Republic; eds.: Dušek, J. and Zejda, M., p. 30
Zejda, M., Mikulasek, Z., Wolf, M., 2006, IBVS, 5741, 1