Bulg. J. Phys. vol.27 no.S1 (2000), pp. 081-084



Unusual Variable Star in Dwarf Galaxy IC1613

R. Kurtev1, J. Borissova2, W. Li3, A. Filipenko3, L. Georgiev4
1Department of Astronomy, Sofia University, Bulgaria
2Institute of Astronomy, BAN, Bulgaria
3University of California at Berkeley, USA
4Insituto de Astronomia, UNAM, Mexico
Abstract. Recently King et al. (1999) discovered Nova 1999 in IC1613 with 0.8 m KAIT of Lick Observatory. The new object is located at α = 104m48s.97, δ = +2°05′28″.8 (J2000.0). On the IR frames taken on Oct. 15 1998 at the National Mexican Astronomical Observatory at "San Pedro Martir" the Nova 1999 has (J-K) = 1.14 and K = 14.69 m. Its presence on the images taken one year before the discovery and its brightness questioned its classification as a nova. The light curve based on 92 archive KAIT images was constructed and remarkably resembles that of Mira-type variable. The obtained period is 508 ± 10 days. The star is over-luminous with respect to the PL relation derived by Feast et al. (1989) for LMC Miras. At longer periods (P > 400 days) many LMC Miras show such kind of behavior and the relation appears to break down. It is possible that the situation in IC1613 is similar.

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