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Four winters of photometry with ASTEP South at Dome C, Antarctica

Authors :
S. Bonhomme
Carole Gouvret
Jean-Baptiste Daban
Francois Fressin
Jean-Pierre Rivet
Zalpha Challita
François-Xavier Schmider
A. Blazit
E. Chapellier
A. Agabi
Lyu Abe
F. Valbousquet
Yan Fanteï-Caujolle
Tristan Guillot
C. Pouzenc
Djamel Mékarnia
Nicolas Crouzet
E. Bondoux
Daniel Bayliss
Joseph Louis LAGRANGE (LAGRANGE)
Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS)
COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur
COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Observatoire de la Côte d'Azur (OCA)
Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Observatoire Midi-Pyrénées (OMP)
Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)
Source :
Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2018, 619, pp.A116. ⟨10.1051/0004-6361/201732565⟩
Publication Year :
2018
Publisher :
HAL CCSD, 2018.

Abstract

Dome C in Antarctica is a promising site for photometric observations thanks to the continuous night during the Antarctic winter and favorable weather conditions. We developed instruments to assess the quality of this site for photometry in the visible and to detect and characterize variable objects through the Antarctic Search for Transiting ExoPlanets (ASTEP) project. We present the full analysis of four winters of data collected with ASTEP South, a 10 cm refractor pointing continuously toward the celestial south pole. We improved the instrument over the years and developed specific data reduction methods. We achieved nearly continuous observations over the winters. We measure an average sky background of 20 mag arcsec$^{-2}$ in the 579-642 nm bandpass. We built the lightcurves of 6000 stars and developed a model to infer the photometric quality of Dome C from the lightcurves themselves. The weather is photometric $67.1\pm4.2$ % of the time and veiled $21.8\pm2.0$ % of the time. The remaining time corresponds to poor quality data or winter storms. We analyzed the lightcurves of $\sigma$ Oct and HD 184465 and find that the amplitude of their main frequency varies by a factor of 3.5 and 6.7 over the four years, respectively. We also identify 34 new variable stars and eight new eclipsing binaries with periods ranging from 0.17 to 81 days. The phase coverage that we achieved with ASTEP South is exceptional for a ground-based instrument and the data quality enables the detection and study of variable objects. These results demonstrate the high quality of Dome C for photometry in the visible and for time series observations in general.<br />Comment: 23 pages, 23 figures, A&A in press

Details

Language :
English
ISSN :
00046361
Database :
OpenAIRE
Journal :
Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2018, 619, pp.A116. ⟨10.1051/0004-6361/201732565⟩
Accession number :
edsair.doi.dedup.....2db4897dc09fdd88ad97f2537414c4de
Full Text :
https://doi.org/10.1051/0004-6361/201732565⟩