Volume 468, Number 3, June IV 2007Extended baselines for the IRAM Plateau de Bure interferometer: First results
|Page(s)||1039 - 1044|
|Section||Stellar structure and evolution|
|Published online||24 April 2007|
Rotational period of GQ Lupi *,**
Astrophysikalisches Institut und Universitäts-Sternwarte Jena, Schillergäßchen 2-3, 07745 Jena, Germany e-mail: firstname.lastname@example.org
2 Thüringer Landessternwarte, Sternwarte 5, 07778 Tautenburg, Germany
3 Max-Planck Institute for extraterrestrial Physics, Giessenbachstrasse, Garching, 85741, Germany
4 Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany
5 Department of Physics and Astronomy, Stony Brook University, NY 11794-3800, USA
Accepted: 20 March 2007
Aims. We wanted to determine the rotation parameters of GQ Lup A, thereby constraining the evolutionary history of the GQ Lup system.
Methods.We have undertaken a photometric monitoring campaign on GQ Lup A consisting of two epochs spaced one year apart. We also searched the photometric archives to enlarge the data set.
Results.We were able to determine the photometric period ( days) in both epochs in several photometric bands. This periodicity could also be found in some of the archival data. The combined false-alarm probability is 0.015. The variation is most likely caused by hot spots on the surface of GQ Lup A. This, combined with high-resolution spectra () allows calculation of GQ Lup A's inclination (). Radial velocity data also contains this period but is inconclusive. Nevertheless, the RV data supports the interpretation that hot spots cause the photometric variation. We use the known K-band variability, amplitude, and phase of GQ Lup A together with a new image of GQ Lup A+b, taken quasi-simultaneously with our monitoring of the star, to confirm the magnitude and, hence, luminosity of the companion.
Key words: stars: rotation / stars: fundamental parameters / stars: starspots
Based on observations obtained on Cerro Paranal, Chile, in ESO program 075.C-0710(C) and on La Silla, Chile, in ESO programs 074.C-0034(A),075.C-0710(E), 075.C-0710(F), 075.C-0202(A), 076.C-0010(A) as well as with ANDICAM of the SMARTS consortium.
© ESO, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.