TY - JOUR
TI - NELIOTA: The wide-field, high-cadence, lunar monitoring system at the prime focus of the Kryoneri telescope
AU - Xilouris, E.M.
AU - Bonanos, A.Z.
AU - Bellas-Velidis, I.
AU - Boumis, P.
AU - Dapergolas, A.
AU - Maroussis, A.
AU - Liakos, A.
AU - Alikakos, I.
AU - Charmandaris, V.
AU - Dimou, G.
AU - Fytsilis, A.
AU - Kelley, M.
AU - Koschny, D.
AU - Navarro, V.
AU - Tsiganis, K.
AU - Tsinganos, K.
JO - Chinese Astronomy and Astrophysics
PY - 2018
VL - 619
TODO - null
SP - null
PB - EDP Sciences
SN - 0275-1062
TODO - 10.1051/0004-6361/201833499
TODO - CMOS integrated circuits;  Metals;  MOS devices;  Oxide semiconductors;  Photometry;  Semiconductor detectors;  Signal to noise ratio;  Surveying;  Telescopes, Complementary metal oxide semiconductors;  Instrumentation: detectors;  Near earth objects;  Signal to noise (S/N) ratios;  Simultaneous observation;  Size-frequency distributions;  Technical specifications;  Techniques: Miscellaneous, Moon
TODO - We present the technical specifications and first results of the ESA-funded, lunar monitoring project "NELIOTA" (NEO Lunar Impacts and Optical TrAnsients) at the National Observatory of Athens, which aims to determine the size-frequency distribution of small near-Earth objects (NEOs) via detection of impact flashes on the surface of the Moon. For the purposes of this project a twin camera instrument was specially designed and installed at the 1.2 m Kryoneri telescope utilizing the fast-frame capabilities of scientific Complementary Metal-Oxide Semiconductor detectors (sCMOS). The system provides a wide field-of-view (17.0′ × 14.4′) and simultaneous observations in two photometric bands (R and I), reaching limiting magnitudes of 18.7 mag in 10 s in both bands at a 2.5 signal-to-noise ratio (S/N) level. This makes it a unique instrument that can be used for the detection of NEO impacts on the Moon, as well as for any astronomy projects that demand high-cadence multicolor observations. The wide field-of-view ensures that a large portion of the Moon is observed, while the simultaneous, high-cadence, monitoring in two photometric bands makes possible the determination of the temperatures of the impacts on the Moon's surface and the validation of the impact flashes from a single site. Considering the varying background level on the Moon's surface we demonstrate that the NELIOTA system can detect NEO impact flashes at a 2.5 S/N level of ∼12.4 mag in the I-band and R-band for observations made at low lunar phases (∼0.1). We report 31 NEO impact flashes detected during the first year of the NELIOTA campaign. The faintest flash was at 11.24 mag in the R-band (about two magnitudes fainter than ever observed before) at lunar phase 0.32. Our observations suggest a detection rate of 1.96×10-7 events km-2 h-1. © 2018 ESO.
ER -