The Two-Colour EMCCD Instrument for the Danish 1.54m Telescope and SONG

Abstract

We report on the implemented design of a two-colour instrument based on electron multiplying CCD (EMCCD) detectors. This instrument is currently installed at the Danish 1.54m telescope at ESO's La Silla Observatory in Chile, and will be available at the SONG (Stellar Observations Network Group) 1m telescope node at Tenerife and at other SONG nodes as well. We present the software system for controlling the two-colour instrument and calibrating the high frame-rate imaging data delivered by the EMCCD cameras. An analysis of the performance of the Two-Colour Instrument at the Danish telescope shows an improvement in spatial resolution of up to a factor of two when doing shift-and-add compared with conventional imaging, and that it is possible to do high-precision photometry of EMCCD data in crowded fields. The Danish telescope, which was commissioned in 1979, is limited by a triangular coma at spatial resolutions below 0.5" and better results will thus be achieved at the near diffraction limited optical system on the SONG telescopes, where spatial resolutions close to 0.2" have been achieved. Regular EMCCD operations have been running at the Danish telescope for several years and have produced a number of scientific discoveries, including microlensing detected exoplanets, the detection of previously unknown variable stars in dense globular clusters and the discovery of two rings around the small asteroid-like object (10199) Chariklo.

Accepted to A&A, 17 pages, 15 figures

References in corpus (9)

• The ACS Survey of Galactic Globular Clusters. I. Overview and Clusters Without Previous HST Photometry
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• A ring system detected around the Centaur (10199) Chariklo
• Lucky Imaging: High Angular Resolution Imaging in the Visible from the Ground
• A New Algorithm For Difference Image Analysis
• High-precision photometry by telescope defocussing. VI. WASP-24, WASP-25 and WASP-26
• Physical properties of the WASP-67 planetary system from multi-colour photometry
• High Frame-rate Imaging Based Photometry, Photometric Reduction of Data from Electron-multiplying Charge Coupled Devices (EMCCDs)
• Searching for variable stars in the cores of five metal rich globular clusters using EMCCD observations

Cited by in corpus (17)

• Refined physical parameters for Chariklo's body and rings from stellar occultations observed between 2013 and 2020
• Contamination from a nearby star cannot explain the anomalous transmission spectrum of the ultra-short period giant planet WASP-103b
• OGLE-2016-BLG-1190Lb: First Spitzer Bulge Planet Lies Near the Planet/Brown-Dwarf Boundary
• The EBLM Project VI. The mass and radius of five low-mass stars in F+M binaries discovered by the WASP survey
• Searching for variable stars in the cores of five metal rich globular clusters using EMCCD observations
• The EBLM project X. Benchmark masses, radii and temperatures for two fully convective M-dwarfs using K2
• OGLE-2018-BLG-0022: A Nearby M-dwarf Binary
• Precision measurement of a brown dwarf mass in a binary system in the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035
• An analysis of binary microlensing event OGLE-2015-BLG-0060
• PyTorchDIA: A flexible, GPU-accelerated numerical approach to Difference Image Analysis
• A white dwarf bound to the transiting planetary system WASP-98
• Observing the changing surface structures of the active K giant sigma Gem with SONG
• The Thresher: Lucky Imaging without the Waste
• Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk
• OGLE-2015-BLG-1609Lb: Sub-jovian planet orbiting a low-mass stellar or brown dwarf host
• Digging deeper into the dense Galactic globular cluster Terzan 5 with Electron-Multiplying CCDs. Variable star detection and new discoveries
• Variation of the stellar color in high-magnification and caustic-crossing microlensing events