The discovery of two new rapidly oscillating Ap stars, HD92499 and HD143487

Autor: Elkin, V., Kurtz, Donald, Mathys, R., Freyhammer, Lars
Přispěvatelé: Observational Astronomy
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Popis: We report the discovery of short periodic radial velocity variations in the stars HD92499 and HD143487. Both stars show strong magnetic fields and large overabundances of rare earth elements and belong to the class of cool chemically peculiar stars of the main sequence. They are therefore new rapidly oscillating Ap stars. Pulsations were detected from analysis of high time resolution spectra obtained with the European Southern Observatory Very Large Telescope by using a cross-correlation method for large spectral bands and from combinations of lines belonging to rare earth elements. The amplitudes of the pulsations are small and do not exceed several dozens of ms-1 with periods of around 10min. The detection of such low amplitudes is important for the determination of which magnetic Ap stars pulsate, and which are constant, a distinction important for the understanding of the pulsation driving mechanism in these stars.
Databáze: OpenAIRE