PAUNZEN E., FROEHLICH H.-E., NETOPIL M., WEISS W.W. and LUEFTINGER T.
Abstract (from CDS):
The magnetic chemically peculiar (CP) stars of the upper main sequence are well-suited laboratories for investigating the influence of local magnetic fields on the stellar surface because they produce inhomogeneities (spots) that can be investigated in detail as the star rotates. We studied the inhomogeneous surface structure of the CP2 star HD49310 based on high-quality CoRoT photometry obtained during 25 days. The data have nearly no gaps. This analysis is similar to a spectroscopic Doppler-imaging analysis, but it is not a tomographic method. We performed detailed light-curve fitting in terms of stationary circular bright spots. Furthermore, we derived astrophysical parameters with which we located HD 49310 within the Hertzsprung-Russell diagram. We also investigated the possible connection of this star to the nearby young open cluster NGC 2264. With a Bayesian technique, we produced a surface map that shows six bright spots. After removing some artefacts, the residuals of the observed and synthetic photometric data are ±0.123mmag. The rotational period of the star is P=1.91909±0.00001-days. Our photometric observations therefore cover about 13 full rotational cycles. Three spots are very large with diameters of ≃40°. The spots are brighter by 40% than the unperturbed stellar photosphere. HD 49310 is a classical silicon (CP2) star with a mass of about 3M☉. It is not a member of NGC 2264. Our analysis shows the potential of using high-quality photometric data to analyse the surface structure of CP stars. A comprehensive analysis of similar archival data, preferrably from space missions, would contribute significantly to our understanding of surface phenomena of CP stars and their temporal evolution.
stars: chemically peculiar - stars: individual: HD 49310