9965 GNU, provisional designation 1992 EF2, is a background asteroid from the inner regions of the asteroid belt, approximately 4 kilometers (2 miles) in diameter. It was discovered on 5 March 1992, by astronomer of the Spacewatch program at the Kitt Peak National Observatory in Arizona, United States.[1] The uncertain D-type asteroid has a long rotation period of 39.7 hours.[5] It was named for the free-software GNU Project.[1]
Discovery [1] | |
---|---|
Discovered by | Spacewatch |
Discovery site | Kitt Peak National Obs. |
Discovery date | 5 March 1992 |
Designations | |
(9965) GNU | |
Named after | GNU Project [1] (free software project) |
1992 EF2 · 1988 BD4 1993 QR3 | |
main-belt [1][2] · (inner) background [3] | |
Orbital characteristics [2] | |
Epoch 23 March 2018 (JD 2458200.5) | |
Uncertainty parameter 0 | |
Observation arc | 30.17 yr (11,019 d) |
Aphelion | 2.8283 AU |
Perihelion | 2.0080 AU |
2.4181 AU | |
Eccentricity | 0.1696 |
3.76 yr (1,373 d) | |
276.39° | |
0° 15m 43.56s / day | |
Inclination | 12.206° |
156.48° | |
82.938° | |
Physical characteristics | |
Mean diameter | 2.07±0.53 km[4] 4.10 km (calculated)[5] 6.22±2.14 km[6] 6.293±0.159 km[7][8] |
39.720±0.1589 h (R)[9] 39.745±0.1589 h (S)[9] | |
0.102±0.014[7] 0.1022±0.0145[8] 0.105±0.125[6] 0.20 (assumed)[5] 0.53±0.12[4] | |
D (Pan-STARRS)[10] S (SDSS-MOC)[11] S (assumed)[5] | |
14.10[6][8] 14.3[2][5] 14.31±0.14[10] 14.398±0.005 (R)[9] 14.72[4] 14.966±0.011 (S)[9] | |
GNU is a non-family asteroid from the main belt's background population.[3]
It orbits the Sun in the inner asteroid belt at a distance of 2.0–2.8 AU once every 3 years and 9 months (1,373 days; semi-major axis of 2.42 AU). Its orbit has an eccentricity of 0.17 and an inclination of 12° with respect to the ecliptic.[2] The body's observation arc begins with its first observation as 1988 BD4 at La Silla Observatory in January 1988, or 4 years prior to its official discovery observation at Kitt Peak.[1]
GNU has been characterized as a dark D-type asteroid by Pan-STARRS' survey and in the SDSS-based taxonomy.[10][11] It is also an assumed S-type asteroid, the most common type in the inner asteroid belt.[5]
In September and October 2012, two rotational lightcurves of GNU were obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 39.720 and 39.745 hours, with a brightness amplitude of 0.36 and 0.42 magnitude in the R- and S-band, respectively (U=2/2).[9] While not being a slow rotator, GNU' period is significantly longer than the average spin rate of 2 to 20 hours, seen among the majority of asteroids.
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, GNU measures between 2.07 and 6.293 kilometers in diameter and its surface has an albedo between 0.102 and 0.53.[4][6][7][8] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a stony asteroid of 0.20 and calculates a diameter of 4.10 kilometers based on an absolute magnitude of 14.3.[5]
This minor planet was named for the free-software GNU Project, created by Richard Stallman 1984. GNU is the recursive acronym for "GNU is not Unix". The collaborative projects enables programmers to trade and improve upon free software.[1] The official naming citation was published by the Minor Planet Center on 11 November 2000 (M.P.C. 41571).[12]