A rival for Babcock's star: the extreme 30-kG variable magnetic field in the Ap star HD 75049 - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




A rival for Babcock's star: the extreme 30-kG variable magnetic field in the Ap star HD 75049 - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The extraordinary magnetic Ap star HD75049 has been studied with dataobtained with the ESO VLT and 2.2-m telescopes. Direct measurements reveal thatthe magnetic field modulus at maximum reaches 30kG. The star shows photometric,spectral and magnetic variability with a rotation period of 4.049d. Variationsof the mean longitudinal magnetic field can be described to first order by acentred dipole model with an inclination i = 25 degrees, an obliquity beta = 60degrees, and a polar field B p = 42kG.The combination of the longitudinal and surface magnetic field measurementsimply a radius of R = 1.7 R sun, suggesting the star is close to the zero-agemain sequence. HD75049 displays moderate overabundances of Si, Ti, Cr, Fe andlarge overabundances of rare earth elements. This star has the second strongestmagnetic field of any main sequence star after Babcock-s star, HD215441, whichit rivals.



Author: V.G.Elkin, G.Mathys, D.W.Kurtz, S. Hubrig, L.M.Freyhammer

Source: https://arxiv.org/







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