2007/12/04 by Z. Mikulasek, Zdeněk Mikulášek, Jiřı́ Krtička +27
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.0712.0524
3 pages, 1 figure, Proceedings of the "CP#AP Workshop", Vienna, 10.-14.Sept.2007, eds.J.Ziznovsky, J.Zverko, E.Paunzen, M.Netopil, will be published in Contrib. Astron. Obs. Skalnate Pleso
arxiv created 2007/12/04 · openalex publication_date 2007/12/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study the long-term light and spectral variations in the He-strong magnetic chemically peculiar star HD 37776 (V901 Ori) to search for changes of its 1.5387 d period in 1976-2007. We analyze all published photometric observations and spectrophotometry in the HeI 4026 A line. The data were supplmented with 506 new (U)VB observations obtained during the last 2 observing seasons, 66 estimates of HeI equivalent widths on 23 CFHT spectrograms and 35 of the 6-m Zeeman spectrograms. All the 1895 particular observations heve been processed simultaneously. We confirm the previously suspected increase of the period in HD 37776 which is a record-breaking among CP stars. The mean rate of the period increase during the last 31 years is 0.541+-0.020 s per year. We interpret this ongoing period increase as the slowing down of the star's surface rotation due to momentum loss through events and processes in its magnetosphere.