The extremely rapid rotational braking of the magnetic helium-strong star HD 37776
Authors | |
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Year of publication | 2009 |
Type | Article in Periodical |
MU Faculty or unit | |
Citation | |
Field | Astronomy and astrophysics |
Keywords | chemically peculiar stars; early type stars; variable stars; individual: \hvezda; stellar rotation; methods of data analysis |
Description | We analyse all available observations of the famous He-strong magnetic chemically peculiar (mCP) star HD~37776 obtained since 1976, namely 1707 photometric measurements, including 550 of our own recent BV observations, and 188 spectrophotometric or spectroscopic measurements of He I spectral lines equivalent widths. All of these individual observations were processed simultaneously by means of specially developed robust codes. We find that the 1.5387 d period of HD 37776 has lengthened by a remarkable 17.7+/-0.7 s over the past 31 years. We also note that a decrease in the rate of the period change is not excluded by the data. The shapes of light curves in all colours were found to be invariable. The period increase is interpreted as a consequence of the momentum loss through events or processes in the extended stellar magnetosphere. |
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