Astronomy:1184 Gaea
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 5 September 1926 |
| Designations | |
| (1184) Gaea | |
| Pronunciation | /ˈdʒiːə/[5] |
| Named after | Gaea (Gaia)[2] (Greek mythology) |
| 1926 RE · 1930 OE 1931 XG | |
| Minor planet category | main-belt · (middle)[3] Aeria[4] |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 91.06 yr (33,260 days) |
| |{{{apsis}}}|helion}} | 2.8555 AU |
| |{{{apsis}}}|helion}} | 2.4804 AU |
| 2.6680 AU | |
| Eccentricity | 0.0703 |
| Orbital period | 4.36 yr (1,592 days) |
| Mean anomaly | 0.0836° |
| Mean motion | 0° 13m 34.32s / day |
| Inclination | 11.315° |
| Longitude of ascending node | 355.75° |
| 311.34° | |
| Physical characteristics | |
| Dimensions | 11.783±0.296 km[6] 12.048±0.146 km[7] 26.52 km (calculated)[3] |
| Rotation period | 2.94±0.06 h[8] |
| Geometric albedo | 0.10 (assumed)[3][lower-alpha 1] 0.4512±0.0298[7] 0.462±0.061[6] |
| S/C (assumed)[3][lower-alpha 1] | |
| Absolute magnitude (H) | 11.0[1][3] · 11.1[7] · 11.42±0.31[9] |
1184 Gaea, provisional designation 1926 RE, is an Aerian asteroid from the central regions of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 5 September 1926, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany.[10] The asteroid was named after the goddess of Earth, Gaea (Gaia), from Greek mythology.[2]
Orbit and classification
Gaea is a member of the small Aeria family (539),[4] named after its parent body 369 Aeria.[11]:23 It orbits the Sun in the central main-belt at a distance of 2.5–2.9 AU once every 4 years and 4 months (1,592 days). Its orbit has an eccentricity of 0.07 and an inclination of 11° with respect to the ecliptic.[1]
The body's observation arc begins at Heidelberg in November 1925, more than 2 months after its official discovery observation.[10]
Physical characteristics
The asteroid's spectral type is unknown. The LCDB assumes a stony (S) or carbonaceous (C) composition to be equally likely,[lower-alpha 1] while the overall spectral type for members of the Aeria family is that of an X-type.[11]:23 The high albedo figures obtained from observations with the WISE telescope do not agree with neither of these spectral types (see below).[7]
Rotation period
In January 2011, a rotational lightcurve of Gaea was obtained from photometric observations by French amateur astronomer René Roy. Lightcurve analysis gave a short rotation period of 2.94 hours with a brightness amplitude of 0.09 magnitude ({{{1}}}).[8] A low brightness amplitude also indicates that the body might have a spheroidal rather than an irregular shape.
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Gaea measures 11.783 and 12.048 kilometers in diameter and its surface has a high albedo of 0.462 and 0.4512, respectively.[6][7]
The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 – a compromise value between the stony (0.20) and carbonaceous (0.057) asteroids, both found abundantly in this region of the asteroid belt – and consequently calculates a much larger diameter of 26.52 kilometers based on an absolute magnitude of 11.0.[3]
Naming
This minor planet was named after Gaia (or Gaea), the goddess of Earth in Greek mythology. Her son and husband was Uranus, the god of the sky. Uranus and Gaia were the parents of the first generation of Titans (six males and six females), and the ancestors of most of the Greek gods. The asteroid's name was proposed by German ARI-astronomer Gustav Stracke after whom the asteroid 1019 Strackea was named.[2]
Notes
- ↑ 1.0 1.1 1.2 Generic stony/carbonaceous composition with a compromise albedo of 0.10, for asteroids with an semi-major axis of 2.6–2.7 AU, according to LCDB's – 2. Taxonomic Class, orbital class, and albedo
References
- ↑ 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 1184 Gaea (1926 RE)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001184. Retrieved 24 October 2017.
- ↑ 2.0 2.1 2.2 Schmadel, Lutz D. (2007). "(1184) Gaea". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 99. doi:10.1007/978-3-540-29925-7_1185. ISBN 978-3-540-00238-3.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 "LCDB Data for (1184) Gaea". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1184%7CGaea. Retrieved 24 October 2017.
- ↑ 4.0 4.1 "Asteroid 1184 Gaea – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1184+Gaea#Asteroid%201184%20GaeaEAR-A-VARGBDET-5-NESVORNYFAM-V3.0. Retrieved 26 October 2019.
- ↑ "Gaea". Merriam-Webster Dictionary. https://www.merriam-webster.com/dictionary/Gaea.
- ↑ 6.0 6.1 6.2 Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R. et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal 791 (2): 11. doi:10.1088/0004-637X/791/2/121. Bibcode: 2014ApJ...791..121M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M. Retrieved 24 October 2017.
- ↑ 7.0 7.1 7.2 7.3 7.4 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.
- ↑ 8.0 8.1 Behrend, Raoul. "Asteroids and comets rotation curves – (1184) Gaea". Geneva Observatory. http://obswww.unige.ch/~behrend/page3cou.html#001184. Retrieved 24 October 2017.
- ↑ 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. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V. Retrieved 24 October 2017.
- ↑ 10.0 10.1 "1184 Gaea (1926 RE)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=1184. Retrieved 24 October 2017.
- ↑ 11.0 11.1 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.
External links
- Asteroid Lightcurve Database (LCDB), query form (info )
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 1184 Gaea at AstDyS-2, Asteroids—Dynamic Site
- 1184 Gaea at the JPL Small-Body Database
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