EMCCD photometry reveals two new variable stars in the crowded central region of the globular cluster NGC 6981

Abstract

Two previously unknown variable stars in the crowded central region of the globular cluster NGC 6981 are presented. The observations were made using the Electron Multiplying CCD (EMCCD) camera at the Danish 1.54m Telescope at La Silla, Chile.The two variables were not previously detected by conventional CCD imaging because of their proximity to a bright star. This discovery demonstrates that EMCCDs are a powerful tool for performing high-precision time-series photometry in crowded fields and near bright stars, especially when combined with difference image analysis (DIA).

4 pages, 3 figures, Submitted to A&A, Version 3 contains the correct celestial coordinates in Table 1

References in corpus (4)

• Lucky Imaging: High Angular Resolution Imaging in the Visible from the Ground
• Light and Motion in SDSS Stripe 82: The Catalogues
• Difference Image Analysis: Extension to a Spatially Varying Photometric Scale Factor and Other Considerations
• High Frame-rate Imaging Based Photometry, Photometric Reduction of Data from Electron-multiplying Charge Coupled Devices (EMCCDs)

Cited by in corpus (16)

• A ring system detected around the Centaur (10199) Chariklo
• High-precision photometry by telescope defocussing. VI. WASP-24, WASP-25 and WASP-26
• High-precision photometry by telescope defocussing. VII. The ultra-short period planet WASP-103
• The Two-Colour EMCCD Instrument for the Danish 1.54m Telescope and SONG
• High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). I. Lucky imaging observations of 101 systems in the southern hemisphere
• A Search for Photometric Variability Towards M71 with the Near-Infrared Transiting ExoplanetS Telescope
• Physical properties of the WASP-67 planetary system from multi-colour photometry
• Searching for variable stars in the cores of five metal rich globular clusters using EMCCD observations
• Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry
• A Census of Variability in Globular Cluster M68 (NGC 4590)
• Larger and faster: revised properties and a shorter orbital period for the WASP-57 planetary system from a pro-am collaboration
• Rotation periods and astrometric motions of the Luhman 16AB brown dwarfs by high-resolution lucky-imaging monitoring
• Many new variable stars discovered in the core of the globular cluster NGC 6715 (M54) with EMCCD observations
• Time-Series BVI Photometry for the Globular Cluster NGC 6981 (M72)
• New variable stars in NGC 6652 and its background Sagittarius stream
• Exploring the crowded central region of 10 Galactic globular clusters using EMCCDs. Variable star searches and new discoveries