V 1162 Ori: A multiperiodic delta Scuti star with variable period and amplitude
Makaleler > Tam Makale · 2001
Yazarlar: T Arentoft, C Sterken, G Handler, LM Freyhammer, A Bruch, P Niarchos, K Gazeas, V Manimanis, P Van Cauteren, E Poretti, DW Dawson, ZL Liu, AY Zhou, BT Du, RR Shobbrock, R Garrido, R Fried, MC Akan, C Ibanoglu, Mustafa Serdar EVREN, G Tas, D Johnson, C Blake, DW Kurtz
ASTRONOMY & ASTROPHYSICS, SCI Expanded İndekslerine Giren Dergi, Uluslararası, 2001, cilt 374, ss 1056-1070
DOI: 10.1021/0004-6361:20010794
Özet
We present the results of multisite observations of the delta Scuti star V1162 Ori. The observations were done in the period October 1999 - May 2000, when 18 telescopes at 15 observatories were used to collect 253 light extrema during a total of 290 hours of time-series observations. The purpose of the observations was to investigate amplitude and period variability previously observed in this star, and to search for low-amplitude frequencies. We detect, apart from the main frequency and its two first harmonics, four additional frequencies in the light curves, all with low amplitudes (1-3 mmag). Combining the present data set with data obtained in 1998-99 at ESO confirms the new frequencies and reveals the probable presence of yet another pulsational frequency. All five low-amplitude frequencies are statistically significant in the data, but at least one of them (f(5)) suffers from uncertainty due to aliasing. Using colour photometry we find evidence for a radial main frequency (f(1)), while most or all low-amplitude frequencies are likely non-radial. We show that the main frequency of V1162 Ori has variable amplitude and period/phase, the latter is also displayed in the O-C diagram from light extrema. The amplitude variability in our data is cyclic with a period of 282 d and a range of nearly 20 mmag, but earlier amplitude values quoted in the literature cannot be explained by this cyclic variation. O-C analysis including data from the literature show that the period of V1162 Ori displays a linear period change as well as sudden or cyclic variations on a time scale similar to that of the amplitude variations.