4057 Demophon
| Discovery [1] | |
|---|---|
| Discovered by | E. Bowell |
| Discovery site | Anderson Mesa Stn. |
| Discovery date | 15 October 1985 |
| Designations | |
| MPC designation | (4057) Demophon |
| Pronunciation |
/ˈdɛməfən/ DEM-ə-fən |
Named after |
Demophon of Athens [1] (Greek mythology) |
| 1985 TQ | |
|
Jupiter trojan [1][2] Greek [3] · background [4] | |
| Orbital characteristics [2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 32.65 yr (11,927 d) |
| Aphelion | 5.8832 AU |
| Perihelion | 4.6425 AU |
| 5.2628 AU | |
| Eccentricity | 0.1179 |
| 12.07 yr (4,410 d) | |
| 197.56° | |
| 0° 4m 53.76s / day | |
| Inclination | 2.8706° |
| 24.383° | |
| 58.875° | |
| Jupiter MOID | 0.0724 AU |
| TJupiter | 2.9840 |
| Physical characteristics | |
Mean diameter |
45.68±6.58 km[5] 53.16 km (calculated)[6] |
| 29.82±0.24 h[7] | |
|
0.057 (assumed)[6] 0.077±0.015[5] | |
|
C (assumed)[6] V–I = 1.060±0.037[6] | |
| 10.1[1][1][2][5][6] | |
|
| |
4057 Demophon, provisional designation 1985 TQ, is a larger Jupiter trojan from the Greek camp, approximately 46 kilometers (29 miles) in diameter. It was discovered on 15 October 1985 by American astronomer Edward Bowell at the Anderson Mesa Station of the Lowell Observatory near Flagstaff, Arizona.[1] The dark Jovian asteroid has a longer-than-average rotation period of 29.8 hours.[6] It was named after the Athen prince Demophon who fought in the Trojan War.[1]
Orbit and classification
Demophon is a dark Jovian asteroid 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 . It is also a non-family asteroid of the Jovian background population.[4]
It orbits the Sun at a distance of 4.6–5.9 AU once every 12 years and 1 month (4,410 days; semi-major axis of 5.26 AU). Its orbit has an eccentricity of 0.12 and an inclination of 3° with respect to the ecliptic.[2] The body's observation arc begins with a precovery taken at Crimea–Nauchnij in September 1985, just three weeks prior to its official discovery observation at Anderson Mesa.[1]
Physical characteristics
Demophon is an assumed, carbonaceous C-type asteroid. It has a high V–I color index of 1.06.[6] Most larger Jupiter trojans are D-type asteroids.
Rotation period
In June 1994, a first rotational lightcurve of Demophon was obtained from photometric observations by Stefano Mottola and Anders Erikson using the Dutch 0.9-metre Telescope at ESO's La Silla Observatory in Chile. Lightcurve analysis gave a rotation period of 29.31 hours with a brightness variation of 0.23 magnitude (U=2).[8]
In August 2015, photometric observations by the Kepler space telescope rendered another two lightcurves (U=3-/2+).[6][7][9] The best-rated one showed a period of 29.82±0.24 hours and a brightness variation of 0.21 magnitude.[7] Most asteroids have a shorter rotation period between 2 and 20 hours (also see List of slow rotators).
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Demophon measures 45.68 kilometers in diameter and its surface has an albedo of 0.077,[5] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 53.16 kilometers based on an absolute magnitude of 10.1.[6]
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Naming
This minor planet was named from Greek mythology after the Athen prince Demophon, son of King Theseus and Phaedra. After participation in the Trojan War, Demophon married Phyllis, who committed suicide after he had abandoned her.[1] The official naming citation was published by the Minor Planet Center on 22 April 1997 (M.P.C. 29669).[10]
References
- 1 2 3 4 5 6 7 8 9 "4057 Demophon (1985 TQ)". Minor Planet Center. Retrieved 21 June 2018.
- 1 2 3 4 "JPL Small-Body Database Browser: 4057 Demophon (1985 TQ)" (2018-05-19 last obs.). Jet Propulsion Laboratory. Retrieved 21 June 2018.
- ↑ "List of Jupiter Trojans". Minor Planet Center. 1 June 2018. Retrieved 21 June 2018.
- 1 2 "Asteroid (4057) Demophon – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 21 June 2018.
- 1 2 3 4 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. arXiv:1209.1549. Bibcode:2012ApJ...759...49G. doi:10.1088/0004-637X/759/1/49. Retrieved 21 June 2018. (online catalog)
- 1 2 3 4 5 6 7 8 9 "LCDB Data for (4057) Demophon". Asteroid Lightcurve Database (LCDB). Retrieved 21 June 2018.
- 1 2 3 Ryan, Erin Lee; Sharkey, Benjamin N. L.; Woodward, Charles E. (March 2017). "Trojan Asteroids in the Kepler Campaign 6 Field". The Astronomical Journal. 153 (3): 12. Bibcode:2017AJ....153..116R. doi:10.3847/1538-3881/153/3/116. Retrieved 21 June 2018.
- ↑ Mottola, Stefano; Di Martino, Mario; Erikson, Anders; Gonano-Beurer, Maria; Carbognani, Albino; Carsenty, Uri; et al. (May 2011). "Rotational Properties of Jupiter Trojans. I. Light Curves of 80 Objects". The Astronomical Journal. 141 (5): 32. Bibcode:2011AJ....141..170M. doi:10.1088/0004-6256/141/5/170. Retrieved 21 June 2018.
- ↑ Szabó, Gy. M.; Pál, A.; Kiss, Cs.; Kiss, L. L.; Molnár, L.; Hanyecz, O.; et al. (March 2017). "The heart of the swarm: K2 photometry and rotational characteristics of 56 Jovian Trojan asteroids" (PDF). Astronomy and Astrophysics. 599: 13. arXiv:1609.02760. Bibcode:2017A&A...599A..44S. doi:10.1051/0004-6361/201629401. Retrieved 21 June 2018.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 21 June 2018.
External links
- Asteroid Lightcurve Database (LCDB), query form (info)
- Dictionary of Minor Planet Names, Google books
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- Asteroid 4057 Demophon at the Small Bodies Data Ferret
- 4057 Demophon at AstDyS-2, Asteroids—Dynamic Site
- 4057 Demophon at the JPL Small-Body Database
