Saremi, E., Abedi, A., Javadi, A., van Loon, J., Khosroshahi, H. (2017). Pulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I. Iranian Journal of Astronomy and Astrophysics, 4(1), 19-36. doi: 10.22128/ijaa.2017.92
Elham Saremi; Abbas Abedi; Atefeh Javadi; Jacco van Loon; Habib Khosroshahi. "Pulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I". Iranian Journal of Astronomy and Astrophysics, 4, 1, 2017, 19-36. doi: 10.22128/ijaa.2017.92
Saremi, E., Abedi, A., Javadi, A., van Loon, J., Khosroshahi, H. (2017). 'Pulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I', Iranian Journal of Astronomy and Astrophysics, 4(1), pp. 19-36. doi: 10.22128/ijaa.2017.92
Saremi, E., Abedi, A., Javadi, A., van Loon, J., Khosroshahi, H. Pulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I. Iranian Journal of Astronomy and Astrophysics, 2017; 4(1): 19-36. doi: 10.22128/ijaa.2017.92
Pulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I
1School of Physics, Birjand University, Birjand, P.O.Box 97175-615, Iran;
2School of Astronomy, Institute for Research in Fundamental Sciences (IPM), Tehran, P.O.Box 19395-5531, Iran;
3Lennard-Jones Laboratories, Keele University, ST5 5BG, UK
Abstract
We have conducted an optical long-term monitoring survey of the majority of dwarf galaxies in the Local Group, with the Isaac Newton Telescope (INT), to identify the long period variable (LPV) stars. LPV stars vary on timescales of months to years, and reach the largest amplitudes of their brightness variations at optical wavelengths, due to the changing temperature. They trace stellar populations as young as ~ 30 Myr to as old as ~ 10 Gyr whose identification is one of the best ways to reconstruct the star formation history. The system of galactic satellites of the large Andromeda spiral galaxy (M31) forms one of the key targets of our monitoring survey. In this first paper in the series, we present the first results from the survey in the form of a census of LPV stars in Andromeda I (And I) dwarf galaxy. Photometry was obtained for 10585 stars in a 0.07 square degree field, of which 116 stars were found to be variable, most of which are Asymptotic Giant Branch (AGB) stars. Our data were matched to mid-infrared photometry from the Spitzer Space Telescope, and to optical catalogues of variable stars from the Hubble Space Telescope.