The extremely rapid rotational braking of the magnetic helium-strong star HD 37776
| Authors | |
|---|---|
| Year of publication | 2008 |
| Type | Article in Periodical |
| Magazine / Source | Astronomy and Astrophysics |
| MU Faculty or unit | |
| Citation | |
| Field | Astronomy and astrophysics |
| Keywords | stars: chemically peculiar; stars: early type; stars: variables: general; stars: individual: HD 37776 |
| Description | We attempt to confirm the possible period change of HD 37776 and discuss a possible origin of this change as a consequence of i) duplicity; ii) precession; iii) evolutionary changes; and iv) continuous/discrete/transient angular momentum loss. We analyse 1895 individual observations obtained by various techniques were processed simultaneously by means of specially developed robust codes. We confirm the previously suspected gradual increase in the period of HD 37776 and find that it 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. We interpret this ongoing period increase as a braking of the star's rotation, at least in its surface layers, due to the momentum loss through events or processes in the extended stellar magnetosphere. |
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