Astronomy:9694 Lycomedes
![]() Shape model of Lycomedes from its lightcurve | |
Discovery [1] | |
---|---|
Discovered by | C. J. van Houten I. van Houten-G. T. Gehrels |
Discovery site | Palomar Obs. |
Discovery date | 26 September 1960 |
Designations | |
(9694) Lycomedes | |
Pronunciation | /lɪkəˈmiːdiːz/[5] |
Named after | Lycomedes [1] (Greek mythology) |
6581 P-L · 1990 DY1 | |
Minor planet category | Jupiter trojan [1][2] Greek [3] · background [4] |
Orbital characteristics [2] | |
Epoch 23 March 2018 (JD 2458200.5) | |
Uncertainty parameter 0 | |
Observation arc | 57.65 yr (21,058 d) |
|{{{apsis}}}|helion}} | 5.2852 AU |
|{{{apsis}}}|helion}} | 4.9135 AU |
5.0993 AU | |
Eccentricity | 0.0364 |
Orbital period | 11.52 yr (4,206 d) |
Mean anomaly | 226.07° |
Mean motion | 0° 5m 8.16s / day |
Inclination | 4.9436° |
Longitude of ascending node | 350.07° |
53.908° | |
Jupiter MOID | 0.019 AU |
TJupiter | 2.9920 |
Physical characteristics | |
Mean diameter | 31.74±0.24 km[6] 40.33 km (calculated)[7] |
Rotation period | 18.2±0.1 h[8] |
Geometric albedo | 0.057 (assumed)[7] 0.101±0.010[6] |
C (assumed)[7] | |
Absolute magnitude (H) | 10.60[6] 10.7[1][2][7] |
9694 Lycomedes /lɪkəˈmiːdiːz/ is a Jupiter trojan from the Greek camp, approximately 32 kilometers (20 miles) in diameter.[1] It was discovered during the Palomar–Leiden survey at the Palomar Observatory in 1960 and later named after Lycomedes from Greek mythology.[1] The dark Jovian asteroid is likely elongated in shape and has a rotation period of 18.2 hours.[7]
Discovery
Lycomedes was discovered on 26 September 1960, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by astronomer Tom Gehrels at the Palomar Observatory in California.[1] The body's observation arc begins the night after its official discovery observation at Palomar.[1]
Palomar–Leiden survey
Naming
This minor planet was named from Greek mythology after Lycomedes, the Greek king of Scyros. At the request of Thetis, he concealed her son Achilles dressed in girl's clothes among his own daughters to save him from the Trojan War until Odysseus drew him out of his disguise.[1] The official naming citation was published by the Minor Planet Center on 2 April 1999 (M.P.C. 34355).[9]
Orbit and classification
As all Jupiter trojans, Lycomedes is in a 1:1 orbital resonance with Jupiter. It is located in the leading Greek camp at the Gas Giant's L4 Lagrangian point, 60° ahead on its orbit .[3]
It orbits the Sun at a distance of 4.9–5.3 AU once every 11 years and 6 months (4,206 days; semi-major axis of 5.1 AU). Its orbit has an eccentricity of 0.04 and an inclination of 5° with respect to the ecliptic.[2]
Physical characteristics
Lycomedes is an assumed C-type asteroid, while most larger Jupiter trojans are D-types.[7]
Rotation period
In October 2010, a first rotational lightcurve of Lycomedes was obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 18.090±0.0211 hours with a brightness amplitude of 0.38 magnitude ({{{1}}}).[7][10]
In November 2011, follow-up observations over two consecutive nights were made by Daniel Coley at the Goat Mountain Astronomical Research Station (G79) in California. It gave a concurring rotation period of 18.2±0.1 hours with a high brightness amplitude of 0.55 magnitude, indicative of a non-spherical shape ({{{1}}}).[8][lower-alpha 1]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Lycomedes measures between 31.736 and 31.74 kilometers in diameter and its surface has an albedo,[6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 40.33 kilometers based on an absolute magnitude of 10.7.[7]
Notes
References
- ↑ Jump up to: 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 "9694 Lycomedes (6581 P-L)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=9694.
- ↑ Jump up to: 2.0 2.1 2.2 2.3 "JPL Small-Body Database Browser: 9694 Lycomedes (6581 P-L)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009694.
- ↑ Jump up to: 3.0 3.1 "List of Jupiter Trojans". Minor Planet Center. 1 July 2018. https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html.
- ↑ "Asteroid (9694) Lycomedes – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?n=9694&pc=1.1.6.
- ↑ Noah Webster (1884) A Practical Dictionary of the English Language
- ↑ Jump up to: 6.0 6.1 6.2 6.3 Grav, T.; Mainzer, A. K.; Bauer, J. M.; Masiero, J. R.; Nugent, C. R. (November 2012). "WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy". The Astrophysical Journal 759 (1): 10. doi:10.1088/0004-637X/759/1/49. Bibcode: 2012ApJ...759...49G. (online catalog)
- ↑ Jump up to: 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 "LCDB Data for (9694) Lycomedes". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9694.
- ↑ Jump up to: 8.0 8.1 French, Linda M.; Stephens, Robert D.; Coley, Daniel R.; Megna, Ralph; Wasserman, Lawrence H. (July 2012). "Photometry of 17 Jovian Trojan Asteroids". Minor Planet Bulletin 39 (3): 183–187. ISSN 1052-8091. Bibcode: 2012MPBu...39..183F. http://www.minorplanet.info/MPB/issues/MPB_39-3.pdf. Retrieved 23 March 2020.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html.
- ↑ Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal 150 (3): 35. doi:10.1088/0004-6256/150/3/75. Bibcode: 2015AJ....150...75W.
<ref>
tag with name "MPC-discoverers" defined in <references>
is not used in prior text.External links
- Lightcurve Database Query (LCDB), at www.minorplanet.info
- Dictionary of Minor Planet Names, Google books
- Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
- Asteroid 9694 Lycomedes at the Small Bodies Data Ferret
- 9694 Lycomedes at AstDyS-2, Asteroids—Dynamic Site
- 9694 Lycomedes at the JPL Small-Body Database
![]() | Original source: https://en.wikipedia.org/wiki/9694 Lycomedes.
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