Astronomy:(15692) 1984 RA
| 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 | |
| Minor planet category | 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) |
| |{{{apsis}}}|helion}} | 2.1225 AU |
| |{{{apsis}}}|helion}} | 1.7302 AU |
| 1.9264 AU | |
| Eccentricity | 0.1018 |
| Orbital period | 2.67 yr (977 d) |
| Mean anomaly | 138.59° |
| Mean motion | 0° 22m 6.96s / day |
| Inclination | 23.217° |
| Longitude of ascending node | 142.60° |
| 273.05° | |
| Physical characteristics | |
| Mean diameter | 1.728±0.273 km[5][6] 2.43 km (calculated)[3] |
| Rotation period | 37.44±0.05 h[7][lower-alpha 1] |
| Geometric albedo | 0.30 (assumed)[3] 0.780±0.146[5][6] |
| E (assumed)[3] | |
| Absolute magnitude (H) | 14.7[6] 14.85±0.97[8] 14.9[2] 15.0[3] |
(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]
Orbit and classification
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
1984 RA is an assumed E-type asteroid, known for their high albedos, typically around 0.4.[3]
Rotation period
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 ({{{1}}}).[7][lower-alpha 1] 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
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
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
- ↑ 1.0 1.1 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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "15692 (1984 RA)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=15692.
- ↑ 2.0 2.1 2.2 2.3 "JPL Small-Body Database Browser: 15692 (1984 RA)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2015692.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 "LCDB Data for (15692)". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=15692%7C.
- ↑ 4.0 4.1 "Asteroid (15692) 1984 RA – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=15692#Asteroid%2015692EAR-A-VARGBDET-5-NESVORNYFAM-V3.0.
- ↑ 5.0 5.1 5.2 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. doi:10.1088/0004-637X/741/2/68. Bibcode: 2011ApJ...741...68M.
- ↑ 6.0 6.1 6.2 6.3 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. doi:10.1088/0004-637X/741/2/90. Bibcode: 2011ApJ...741...90M. (catalog)
- ↑ 7.0 7.1 Warner, Brian D. (January 2014). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2013 June- September". The Minor Planet Bulletin 41 (1): 27–32. ISSN 1052-8091. Bibcode: 2014MPBu...41...27W.
- ↑ 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. doi:10.1016/j.icarus.2015.08.007. Bibcode: 2015Icar..261...34V.
- ↑ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131. Bibcode: 2015aste.book..297N.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html.
External links
- Asteroid Lightcurve Database (LCDB), query form (info )
- 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
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