Exploring the crowded central region of ten Galactic globular clusters using EMCCDs : variable star searches and new discoveries
Date
04/2016Author
Grant ID
UF100010 / UF130581
ST/M001296/1
Keywords
Metadata
Show full item recordAbstract
Aims: We aim to obtain time-series photometry of the very crowded central regions of Galactic globular clusters; to obtain better angular resolution than has been previously achieved with conventional CCDs onground-based telescopes; and to complete, or improve, the census of the variable star population in those stellar systems. Methods: Images were taken using the Danish 1.54-m Telescope at the ESO observatory at La Silla in Chile. The telescope was equipped with an electron-multiplying CCD, and the short-exposure-time images obtained (ten images per second) were stacked using the shift-and-add technique to produce the normal-exposure-time images (minutes). Photometry was performed via difference image analysis. Automatic detection of variable stars in the field was attempted.Results: The light curves of 12541 stars in the cores of ten globular clusters were statistically analysed to automatically extract the variable stars. We obtained light curves for 31 previously known variable stars (3 long-period irregular,2 semi-regular, 20 RR Lyrae, 1 SX Phoenicis, 3 cataclysmic variables, 1W Ursae Majoris-type and 1 unclassified) and we discovered 30 new variables (16 long-period irregular, 7 semi-regular, 4 RR Lyrae, 1 SX Phoenicis and 2 unclassified). Fluxes and photometric measurements for these stars are available in electronic form through the Strasbourg astronomical Data Center.
Citation
Figuera Jaimes , R , Bramich , D M , Skottfelt , J , Kains , N , Jørgensen , U G , Horne , K , Dominik , M , Alsubai , K A , Bozza , V , Calchi Novati , S , Ciceri , S , D'Ago , G , Galianni , P , Gu , S-H , Harpsøe , K B W , Haugbølle , T , Hinse , T C , Hundertmark , M , Juncher , D , Korhonen , H , Mancini , L , Popovas , A , Rabus , M , Rahvar , S , Scarpetta , G , Schmidt , R W , Snodgrass , C , Southworth , J , Starkey , D , Street , R A , Surdej , J , Wang , X-B & Wertz , O 2016 , ' Exploring the crowded central region of ten Galactic globular clusters using EMCCDs : variable star searches and new discoveries ' , Astronomy & Astrophysics , vol. 588 , A128 , pp. 1-22 . https://doi.org/10.1051/0004-6361/201527641
Publication
Astronomy & Astrophysics
Status
Peer reviewed
ISSN
0004-6361Type
Journal article
Rights
© 2016, ESO. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at www.aanda.org / https://dx.doi.org/10.1051/0004-6361/201527641
Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.