A1 Refereed original research article in a scientific journal

A pulsation analysis of K2 observations of the subdwarf B star PG 1142-037 during Campaign 1: A subsynchronously rotating ellipsoidal variable




AuthorsM. D. Reed, A. S. Baran, R. H. Ostensen, J. H. Telting, J. W. Kern, S. Bloemen, P. Blay, T. Pursimo, T. Kuutma, D. Slumstrup, M. Saajasto, L.D. Nielsen, J. Harmanen, A. J. Winans, H. M. Foster, L. Rowe

PublisherOXFORD UNIV PRESS

Publication year2016

JournalMonthly Notices of the Royal Astronomical Society

Journal name in sourceMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

Journal acronymMON NOT R ASTRON SOC

Volume458

Issue2

First page 1417

Last page1426

Number of pages10

ISSN0035-8711

DOIhttps://doi.org/10.1093/mnras/stw348


Abstract
We report a new subdwarf B pulsator, PG 1142-037, discovered during the first full-length campaign of K2, the two-gyro mission of the Kepler space telescope. 14 periodicities have been detected between 0.9 and 2.5 hr with amplitudes below 0.35 parts-per-thousand. We have been able to associate all of the pulsations with low-degree, 1 <= 2 modes. Follow-up spectroscopy of PG 1142 has revealed it to be in a binary with a period of 0.54 d. Phase-folding the K2 photometry reveals a two-component variation including both Doppler boosting and ellipsoidal deformation. Perhaps the most surprising and interesting result is the detection of an ellipsoidal, tidally distorted variable with no indication of rotationally induced pulsation multiplets. This indicates that the rotation period is longer than 45 d, even though the binary period is near 13 h.



Last updated on 2024-26-11 at 20:07