First EURONEAR NEA discoveries from La Palma using the INT★

Abstract

Since 2006, the EURONEAR project has been contributing to the research of near Earth asteroids (NEAs) within an European network. One of the main aims is the amelioration of the orbits of NEAs, and starting in February 2014 we focus on the recovery of one-opposition NEAs using the Isaac Newton Telescope (INT) in La Palma in override mode. Part of this NEA recovery project, since June 2014 EURONEAR serendipitously started to discover and secure the first NEAs from La Palma and using the INT, thanks to the team-work including amateurs and students who promptly reduce the data, report discoveries and secure new objects recovered with the INT and few other telescopes from the EURONEAR network. Five NEAs were discovered with the INT, including 2014 LU14, 2014 NL52 (one very fast rotator), 2014 OL339 (the fourth known Earth quasi-satellite), 2014 SG143 (a quite large NEA) and 2014 VP. Another very fast moving NEA was discovered but was unfortunately lost due to lack of follow-up time. Additionally, another 14 NEA candidates were identified based on two models, all being rapidly followed-up using the INT and another 11 telescopes within the EURONEAR network. They include one object discovered by Pan-STARRS, two Mars crossers, two Hungarias, one Jupiter trojan, and other few inner MBAs. Using the INT and Sierra Nevada 1.5 m for photometry, then the Gran Telescopio de Canarias (GTC) for spectroscopy, we derived the very rapid rotation of 2014 NL52, then its albedo, magnitude, size, and its spectral class. Based on the total sky coverage in dark conditions, we evaluate the actual survey discovery rate using 2-m class telescopes. One NEA is possible to be discovered randomly within minimum 2.8 square degrees and maximum 5.5 square degrees. These findings update our past statistics, being based on double sky coverage and taking into account the recent increase in discovery.

Asteroid (469219) 2016 HO3, the smallest and closest Earth quasi-satellite

“…Earth quasi-satellites have not been the target subject of specific surveys. For instance, the discovery of 2014 OL 339 (Vaduvescu et al 2014(Vaduvescu et al , 2015 was the by-product of a standard NEO survey, EU-RONEAR (Vaduvescu et al 2008); the others also were serendipitous, not planned, findings. Therefore, the identification by chance in less than a year of two objects moving in similar orbits, 2015 SO 2 and 469219, that also exhibit matching orbital evolution within several thousand years backwards and forward in time, strongly suggests that these two and other -yet to be discovered-NEOs may be part of a group of dynamical origin as the ones described in e.g.…”

Dynamical evolution of near-Earth asteroid 1991 VG

“…The list of NEOs has been retrieved from JPL's Solar System Dynamics Group (SSDG) Small-Body Database (SBDB). 2 Considering the currently available data on NEOs, the orbit of 1991 VG is neither the (overall) most Earth-like known -the current record holder is 2006 RH 120 (Bressi et al 2008a;Kwiatkowski et al 2009) which has the lowest values of the D-criteria, but it has not been observed since 2007 June 22-nor the one with the orbital period closest to one Earth year -which is 2014 OL 339 with a=0.9992 au or an orbital period of 364.83227±0.00002 d (Vaduvescu et al 2014(Vaduvescu et al , 2015de la Fuente Marcos & de la Fuente Marcos 2014;Holmes et al 2015)-nor the least eccentric -which is 2002 AA 29 with e=0.01296 (Connors et al 2002;Smalley et al 2002), followed by 2003 YN 107 with e=0.01395 (McNaught et al 2003;Connors et al 2004)-nor the one with the lowest inclination -which is probably 2009 BD with i=0. • 38 (Buzzi et al 2009;Micheli, Tholen & Elliott 2012), followed by 2013 BS 45 with i=0.…”

Infrequent visitors of the Kozai kind: the dynamical lives of 2012 FC71, 2014 EK24, 2014 QD364, and 2014 UR

“…comm. ) from the EURONEAR network (Vaduvescu et al 2008(Vaduvescu et al , 2015 have reported a rotation period of 6 min. Its very fast rotation is also characterised by a large amplitude of 0.79 mag.…”