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Geology topics

Matthew W. Collier

Publications and source records attributed to Matthew W. Collier.

1 recordsLinked to original sources

Photometric studies of δ Scuti stars. I. IP Virginis

We report 15 new times of maximum light for the δ Scuti star IP Virginis (formerly known as SA 106‐1024). An analysis of all times of maximum light indicates that IP Vir has been decreasing in period at a constant rate of − days day −1 . Evidence is also presented that IP Vir is a double‐mode variable with a period ratio of . This period ratio predicts a [Fe/H] value of −0.3. From photometric ( uvby β) observations, we find a foreground reddening of .008 mag and a metallicity of [Fe/H] = +0.05. It is shown that [Fe/H] = −0.3 is most likely the correct value. Intrinsic ‐ and c 1 ‐values, plotted in a model atmosphere grid, indicate a mean effective temperature, K, and a mean surface gravity, . All of these physical parameters support Landolt's initial conclusion that IP Vir is an ordinary δ Sct star.

Publications of the Astronomical Society of the Pa