17492 Hippasos

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17492 Hippasos
Discovery [1]
Discovered byF. Börngen
Discovery siteKarl Schwarzschild Obs.
Discovery date10 December 1991
Designations
(17492) Hippasos
Pronunciation/ˈhɪpəsəs/[5]
Named after
Hippasus (Hippasos) [1]
(Greek mythology)
1991 XG1 · 1989 UA10
Minor planet category
Jupiter trojan [1][2]
Trojan [3] · Ennomos [4]
Orbital characteristics [2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc40.69 yr (14,862 d)
Aphelion5.4914 AU
Perihelion4.7972 AU
5.1443 AU
Eccentricity0.0675
11.67 yr (4,262 d)
241.97°
0° 5m 4.2s / day
Inclination29.199°
89.019°
218.74°
Jupiter MOID0.2721 AU
TJupiter2.7430
Physical characteristics
Mean diameter
53.98±0.78 km[6]
55.67 km (calculated)[7]
17.75±0.01 h[8][a]
0.057 (assumed)[7]
0.066±0.008[6]
C (assumed)[7]
Absolute magnitude (H)
9.9[6]
10.0[1][2][7]

17492 Hippasos /ˈhɪpəsəs/ is a Jupiter trojan and member of the Ennomos family from the Trojan camp, approximately 54 kilometers (34 miles) in diameter. It was discovered on 10 December 1991, by astronomer Freimut Börngen at the Karl Schwarzschild Observatory in Tautenburg, Germany.[1] The Jovian asteroid belongs to the 80 largest Jupiter trojans has a rotation period of 17.8 hours.[7] It was named after the Trojan prince Hippasus (Hippasos) from Greek mythology.[1]

Orbit and classification[]

Hippasos is a Jovian asteroid in the so-called Trojan camp, located in the L5 Lagrangian point, 60° behind Jupiter, orbiting in a 1:1 resonance with the Gas Giant (see Trojans in astronomy).[3]

It orbits the Sun at a distance of 4.8–5.5 AU once every 11 years and 8 months (4,262 days; semi-major axis of 5.14 AU). Its orbit has an eccentricity of 0.07 and an inclination of 29° with respect to the ecliptic.[2] The body's observation arc begins with a precovery published by the Digitized Sky Survey and taken at the Siding Spring Observatory in September 1977, more than 14 years prior to its official discovery observation at Tautenburg.[1]

Asteroid family[]

Hippasos is a member of the Ennomos family (009),[4] one of few known Jovian asteroid families, named after 4709 Ennomos (also see 4709 Ennomos § Small Ennomos family).[9] A different HCM analysis finds this asteroid to be the parent body of its own Hippasos family,[10] first described by Jakub Rozehnal and Miroslav Brož in 2014. According to the astronomers' model, the Hippasos family consists of 104 known members, and was formed 1 to 2 billion years ago. The extrapolated size of the original body is between 67 and 168 kilometers, which is strongly influenced by the amount of possible interlopers into the family.[11]

Naming[]

This minor planet was named from Greek mythology after the Trojan prince Hippasus (Hippasos). The son of King Priam supported Aeneas in the Trojan War.[1] The official naming citation was published by the Minor Planet Center on 9 March 2001 (M.P.C. 42365).[12]

Physical characteristics[]

Hippasos is an assumed C-type asteroid,[7] while most larger Jupiter trojans are D-type asteroids.

Rotation period[]

In December 2013, a rotational lightcurve of Hippasos was obtained from photometric observations by Robert Stephens at the Center for Solar System Studies in Landers, California. Lightcurve analysis gave a well-defined rotation period of 17.75±0.01 hours with a brightness amplitude of 0.21 magnitude (U=3).[8][a]

Diameter and albedo[]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Hippasos measures 53.98 kilometers in diameter and its surface has an albedo 0.066,[6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 55.67 kilometers based on an absolute magnitude of 10.0.[7]

100+ largest Jupiter trojans

Notes[]

  1. ^ Jump up to: a b Lightcurve plot of (17492) Hippasos from Nov 2013 by Robert Stephens at the Center for Solar System Studies (U81). Quality code is 3- (lightcurve rating at CS3). Summary figures at the LCDB and CS3 website.

References[]

  1. ^ Jump up to: a b c d e f g h "17492 Hippasos (1991 XG1)". Minor Planet Center. Retrieved 18 June 2018.
  2. ^ Jump up to: a b c d "JPL Small-Body Database Browser: 17492 Hippasos (1991 XG1)" (2018-05-25 last obs.). Jet Propulsion Laboratory. Retrieved 18 June 2018.
  3. ^ Jump up to: a b "List of Jupiter Trojans". Minor Planet Center. 1 June 2018. Retrieved 18 June 2018.
  4. ^ Jump up to: a b "Asteroid 17492 Hippasos". Small Bodies Data Ferret. Retrieved 18 June 2018.
  5. ^ 'Hippasus' in Noah Webster (1884) A Practical Dictionary of the English Language
  6. ^ Jump up to: a b c d 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. S2CID 119101711. (online catalog)
  7. ^ Jump up to: a b c d e f g "LCDB Data for (17492) Hippasos". Asteroid Lightcurve Database (LCDB). Retrieved 18 June 2018.
  8. ^ Jump up to: a b Stephens, Robert D.; French, Linda M.; Davitt, Chelsea; Coley, Daniel R. (April 2014). "At the Scaean Gates: Observations Jovian Trojan Asteroids, July- December 2013". The Minor Planet Bulletin. 41 (2): 95–100. Bibcode:2014MPBu...41...95S. ISSN 1052-8091.
  9. ^ 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.
  10. ^ "Asteroid (17492) Hippasos – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 18 June 2018.
  11. ^ Rozehnal, J.; Brož, M. (July 2014). "Long-term evolution of asteroid families among Jovian Trojans" (PDF). Asteroids: 452. Bibcode:2014acm..conf..452R. Retrieved 5 July 2018.
  12. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 18 June 2018.

External links[]

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