(15692) 1984 RA (provisional designation 1984 RA) is a Hungaria asteroid from the innermost regions of the asteroid belt, approximately 2 kilometers (1.2 miles) in diameter. It was discovered on 1 September 1984, by Italian astronomer Maria Barucci at the Palomar Observatory in California, United States.[1] The presumed E-type asteroid has a longer-than average rotation period of 37.4 hours and possibly an elongated shape.[3]
| Discovery[1] | |
|---|---|
| Discovered by | M. Barucci |
| Discovery site | Palomar Obs. |
| Discovery date | 1 September 1984 |
| Designations | |
| (15692) 1984 RA | |
| 1984 RA · 1986 JT1 1992 SZ26 | |
| main-belt · (inner)[2] Hungaria[1][3][4] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 41.44 yr (15,135 d) |
| Aphelion | 2.1225 AU |
| Perihelion | 1.7302 AU |
| 1.9264 AU | |
| Eccentricity | 0.1018 |
| 2.67 yr (977 d) | |
| 138.59° | |
| 0° 22m 6.96s / day | |
| Inclination | 23.217° |
| 142.60° | |
| 273.05° | |
| Physical characteristics | |
Mean diameter | 1.728±0.273 km[5][6] 2.43 km (calculated)[3] |
| 37.44±0.05 h[7][a] | |
| 0.30 (assumed)[3] 0.780±0.146[5][6] | |
| E (assumed)[3] | |
| 14.7[6] 14.85±0.97[8] 14.9[2] 15.0[3] | |
Orbit and classification edit
1984 RA is a bright core member of the Hungaria family (003),[4] a large family of three thousand asteroids located within the dynamical group with the same name.[1][3] Hungarias form the innermost dense concentration of asteroids in the Solar System; they are inside the asteroid belt's core region, sometimes considered a completely independent population.[9]
The asteroid orbits the Sun in the innermost asteroid belt at a distance of 1.7–2.1 AU once every 2 years and 8 months (977 days; semi-major axis of 1.93 AU). Its orbit has an eccentricity of 0.10 and an inclination of 23° with respect to the ecliptic.[2] The body's observation arc begins with a precovery found in the Digitized Sky Survey and taken at the Siding Spring Observatory in November 1977, almost 7 years prior to its official discovery observation at Palomar.[1]
Physical characteristics edit
1984 RA is an assumed E-type asteroid, known for their high albedos, typically around 0.4.[3]
Rotation period edit
In July 2013, a rotational lightcurve of this asteroid was obtained from photometric observations by American astronomer Brian Warner at the Palmer Divide Station (U82) in California. Lightcurve analysis gave a long rotation period of 37.44 hours with a brightness amplitude of 0.66 magnitude, indicative of an elongated shape (U=2).[7][a] While not being a slow rotator, 1984 RA has a significantly longer period than most asteroids, which rotate once every 2 to 20 hours around their axis.
Diameter and albedo edit
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, this asteroid measures 1.728 kilometers in diameter and its surface has an exceptionally high albedo of 0.78.[5][6] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 – a compromise value between the E- (0.40) and S-type (0.20) members of the Hungaria family and group, respectively – and calculates a diameter of 2.43 kilometers based on an absolute magnitude of 15.0.[3]
Numbering and naming edit
This minor planet was numbered by the Minor Planet Center on 26 July 2000 (M.P.C. 40991).[10] As of 2018, it has not been named.[1]
Notes edit
- ^ a b Lightcure plot of (15692) 1984 RA, by B. D. Warner at the Center for Solar System Studies – Palmer Divide Station (U82). Rotation period 37.44±0.05 hours. Observation from 8 Jul 2013 to 1 Aug 2013. Data points: 273. Quality code is 2. Summary figures at the LCDB
References edit
- ^ a b c d e f "15692 (1984 RA)". Minor Planet Center. Retrieved 10 May 2018.
- ^ a b c d "JPL Small-Body Database Browser: 15692 (1984 RA)" (2018-04-26 last obs.). Jet Propulsion Laboratory. Retrieved 10 May 2018.
- ^ a b c d e f g h i "LCDB Data for (15692)". Asteroid Lightcurve Database (LCDB). Retrieved 10 May 2018.
- ^ a b "Asteroid (15692) 1984 RA – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 27 October 2019.
- ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. S2CID 118745497.
- ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. S2CID 118700974. (catalog)
- ^ a b Warner, Brian D. (January 2014). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2013 June- September". The Minor Planet Bulletin. 41 (1): 27–32. Bibcode:2014MPBu...41...27W. ISSN 1052-8091.
- ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID 53493339.
- ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131. S2CID 119280014.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 10 May 2018.
External links edit
- Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
- Discovery Circumstances: Numbered Minor Planets (15001)-(20000) – Minor Planet Center
- (15692) 1984 RA at AstDyS-2, Asteroids—Dynamic Site
- (15692) 1984 RA at the JPL Small-Body Database