|Discovered by P. Jensen|
MPC designation (5119) 1988 RA1
Observation arc 61.32 yr (22,397 days)
Absolute magnitude 16.994
Discoverer Poul Jensen
Asteroid group Jupiter trojan
|Discovery date 8 September 1988|
Alternative names 1988 RA1
Discovered 8 September 1988
Discovery site Brorfelde Observatory
|Minor planet category Jupiter trojan
People also search for Sun, 10048 Grönbech, (26816) 1986 TS
(5119) 1988 RA1 is a carbonaceous Jupiter trojan from the Trojan camp, approximately 50 kilometers in diameter. It was discovered on 8 September 1988, by Danish astronomer Poul Jensen at the Brorfelde Observatory near Holbæk, Denmark.
The dark C-type Jovian asteroid resides in Jupiter's L5 Lagrangian point (Trojan camp), which lies 60° behind the gas giant's orbit. It orbits the Sun at a distance of 4.6–5.8 AU once every 11 years and 10 months (4,333 days). The Jovian trojan's orbit has an eccentricity of 0.11 and an inclination of 16° with respect to the ecliptic. The first precovery was taken at Palomar Observatory in 1954, extending the asteroid's observation arc by 34 years prior to its discovery.
In February 1994, the Trojan asteroid was observed by astronomers Stefano Mottola and Anders Eriksson with the ESO 1-metre telescope and its DLR MkII CCD-camera at La Silla in Chile. The photometric observations were used to build a light-curve showing a rotation period of 7001128070000000000♠12.807±0.016 hours with a brightness variation of 6999310000000000000♠0.31±0.01 magnitude (U=2+).
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the Trojan asteroid measures 49.3 kilometers in diameter and its surface has a low albedo of 0.061. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 50.8 kilometers, based on an absolute magnitude of 10.2.
On the night this minor planet was discovered at Brorfelde Observatory, Poul Jensen also discovered the Jupiter trojan (6002) 1988 RO, the 12-kilometer size main-belt asteroid (9840) 1988 RQ2, as well as (12689) 1988 RO2, (14364) 1988 RM2, (14837) 1988 RN2, and (24664) 1988 RB1, all main-belt asteroids of inner, middle and outer region of the asteroid belt, respectively.