TY - JOUR
TI - V 1162 Ori: A multiperiodic delta Scuti star with variable period and
amplitude
AU - Arentoft, T
AU - Sterken, C
AU - Handler, G
AU - Freyhammer, LM
AU - Bruch,
AU - A
AU - Niarchos, P
AU - Gazeas, K
AU - Manimanis, V
AU - Van Cauteren, P and
AU - Poretti, E
AU - Dawson, DW
AU - Liu, ZL
AU - Zhou, AY
AU - Du, BT and
AU - Shobbrock, RR
AU - Garrido, R
AU - Fried, R
AU - Akan, MC
AU - Ibanoglu, C
AU - and Evren, S
AU - Tas, G
AU - Johnson, D
AU - Blake, C
AU - Kurtz, DW
JO - Chinese Astronomy and Astrophysics
PY - 2001
VL - 374
TODO - 3
SP - 1056-1070
PB - EDP SCIENCES S A
SN - 0275-1062
TODO - 10.1051/0004-6361:20010794
TODO - stars : variables : delta Scuti; stars : individual : V 1162 Orionis;
techniques : photometric; methods : data analysis
TODO - 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.
ER -