Variable Yellow and Red Stragglers in the Old Open Cluster NGC 6791

• Autorzy: Kaluzny J.
• Języki publikacji: EN

Abstrakty

EN

Two sets of archive time series observations of an old open cluster NGC 6791 were reanalyzed using an image subtraction technique. We report identification of four new variable stars. Proper motion data are available for three of them and indicate that they are likely cluster members. Photometry of these stars is discussed along with the data for two earlier identified variables. The sample analyzed includes one yellow and three red stragglers. An eclipsing red straggler V9 is of particular interest. Cluster membership of this RS Cvn type binary would imply that its cooler component is in a stage of thermal inequilibrium. One of variables is a K type red giant showing low-amplitude variability with a period of about 0.33 d.

Słowa kluczowe

EN

open clusters: individual: NGC 6791; associations: individual: NGC 6791; Hertzsprung-Russel; HR; C-M diagrams; binaries: eclipsing

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2003
• Tom: Vol. 53, No. 1
• Strony: 51--62
• Opis fizyczny: Bibliogr. 30 poz., rys., tab., wykr.

Twórcy

autor

Kaluzny J.

• Copernicus Astronomical Center, Bartycka 18, 00-716 Warsaw, Poland

Bibliografia

• Alard, C., and Lupton, R. 1998, Astrophys. J., 503, 325.
• Alard, C. 2000, Astron. Astrophys. Suppl. Ser., 144, 363.
• Albrow, M.D., et al. 2000, Astrophys. J., 534, 894.
• Chaboyer, B., Green, E.M., and Liebert, J. 1999, Astron. J., 117, 1360.
• Edmonds, P.D., and Gilliland, R.I. 1996, Astrophys. J. Letters, 464, L157.
• Ferraro, F.R., Possenti, A., D’Amico, N., and Sabbi, E. 2001, Astrophys. J. Letters, 561, L93.
• Frandsen, S., et al. 2002, Astron. Astrophys., 349, L5.
• Gilliland, R.L. et al. 2000, Astrophys. J. Letters, 545, L47.
• Hatzes, A.P., and Cohran, W.D. 1994, Astrophys. J., 432, 763.
• Henry, G.W., Fekel, F.C., and Henry, S.M. 2000, Astrophys. J. Suppl. Ser., 130, 201.
• Kaluzny, J., and Udalski, A. 1992, Acta Astron., 42, 29.
• Kaluzny, J., and Ruciński, S.M. 1993, MNRAS, 265, 34.
• Kaluzny, J., Stanek, K.Z., Garnavich, P.M., and Challis, P. 1997, Astrophys. J., 491, 153.
• Kjeldsen, H., et al. 2002, IAU Coll. No. 185, Eds. C. Aerts, T.R. Bedding, and J. Christensen-Salsgaard, ASP Conference Proceedings, p. 470.
• Konacki, M., Torres, G., Jha, S., and Sasselov, D.D. 2003, Nature, 421, 507.
• Kovács, G., Zucker, S., and Mazeh, T. 2002, Astron. Astrophys., 391, 369.
• Liebert, J., Saffer, R. A., and Green, E.M. 1994, Astron. J., 107, 1408.
• Mathieu, R.D, van den Berg, M., Torres, G., Latham, D., Varbunt, F., and Stassun, K. 2003, Astron. J., 125, 246.
• Mochejska, B.J., Stanek, K.Z., Sasselov, D.D., and Szentgyorgyi, A.H. 2002, Astron. J., 123, 3460.
• Mochejska, B.J., Stanek, K.Z., and Kaluzny, J. 2003, AJ, in press (astro-ph/0303002).
• Monet, D., et al. 1998, USNO-A2.0, U.S. Naval Observatory, Washington DC.
• Padmakar, and Pandey, S.K. 1999, Astron. Astrophys., 138, 203.
• Ruciński, S.M., Kaluzny, J., and Hilditch, R.W. 1996, MNRAS, 282, 705.
• Schwarzenberg-Czerny, A. 1996, Astrophys. J. Letters, 460, L107.
• Stetson, P.B. 1987, P.A.S.P., 99, 191.
• Stetson, P.B. 2000, P.A.S.P., 112, 925.
• Udalski, A., et al. 2002a, Acta Astron., 52, 1.
• Udalski, A., et al. 2002b, Acta Astron., 52, 115.
• Udalski, A., et al. 2002c, Acta Astron., 52, 317.
• Worthley, G., and Jowett, K.J. 2003, P.A.S.P., 115, 96.