17365 Thymbraeus

17365 Thymbraeus (provisional designation 1978 VF₁₁) is a Jupiter trojan from the Trojan camp, which is located in Jupiter's trailing L₅ Lagrangian point.

17365 Thymbraeus

Discovery[1]
Discovered by	Eleanor F. Helin Schelte J. Bus
Discovery site	Palomar Obs.
Discovery date	7 November 1978
Designations
MPC designation	(17365) Thymbraeus
Alternative designations	1978 VF11 · 1998 MM49 · 1999 RE121[2]
Minor planet category	Jupiter trojan[2][1] Trojan (L5)[3]
Orbital characteristics [1]
Epoch 13 September 2023 (JD 2460200.5)
Uncertainty parameter 0
Observation arc	68.79 yr (25,125 days)
Earliest precovery date	23 November 1954
Aphelion	5.683 AU
Perihelion	4.856 AU
Semi-major axis	5.270 AU
Eccentricity	0.0785
Orbital period (sidereal)	12.10 yr (4,418 days)
Mean anomaly	321.875°
Mean motion	0° 4m 53.321s / day
Inclination	11.644°
Longitude of ascending node	252.124°
Argument of perihelion	117.711°
Physical characteristics[4]: 3
Mean diameter	44.904±0.525 km[1]
Mean density	0.830±0.050 g/cm3[4]: 3
Synodic rotation period	12.671821 h (retrograde) or 12.672607 h (prograde)[4]: 3
North pole right ascension	92°±2° (retrograde) or 268°±2° (prograde)[4]: 3
North pole declination	−77°±2° (retrograde) or +77°±2° (prograde)[4]: 3
Geometric albedo	0.066±0.009[1]
Absolute magnitude (H)	10.59±0.04[1]

Background

It was discovered by Eleanor Helin and Schelte Bus at Palomar Observatory on 7 November 1978.^[2] Thymbraeus is 45 kilometres (28 mi) in diameter and has an elongated dumbbell shape that is on the verge of splitting apart due to centrifugal forces of its rapid rotation.^[4] The asteroid's density is less than that of water, indicating that it has a highly porous interior structure similar to a rubble pile.^[5][6][4] It was given the name Thymbraeus on 27 February 2023, after one of the two sons of the Trojan priest Laocoön who was attacked by sea serpents for attempting to warn the Trojans about the Trojan horse in Greek mythology.^[7]

References

1. "JPL Small-Body Database Browser: 17365 Thymbraeus (1978 VF11)" (2023-09-07 last obs.). Jet Propulsion Laboratory. Retrieved 4 November 2023.
2. "(17365) Thymbraeus = 1998 MM49 = 1978 VF11 = 1999 RE121". Minor Planet Center. Retrieved 4 November 2023.
3. "List of Jupiter Trojans". Minor Planet Center. 26 September 2023. Retrieved 4 November 2023.
4. Carry, B.; Descamps, P.; Ferrais, M.; Rivet, J.-P.; Berthier, J.; Jehin, E.; et al. (2023). "Close-to-fission dumbbell Jupiter-Trojan (17365) Thymbraeus". Astronomy & Astrophysics. 680: 6. arXiv:2309.15537. Bibcode:2023A&A...680A..21C. doi:10.1051/0004-6361/202347158.
5. Mann, Rita K.; Jewitt, David; Lacerda, Pedro (September 2007). "Fraction of Contact Binary Trojan Asteroids". The Astronomical Journal. 134 (3): 1133–1144. arXiv:0706.0233. Bibcode:2007AJ....134.1133M. doi:10.1086/520328.
6. Noll, K. S.; Benecchi, S. D.; Ryan, E. L.; Grundy, W. M. (March 2014). Ultra-Slow Rotating Outer Main Belt and Trojan Asteroids: Search for Binaries (PDF). 45th Lunar and Planetary Science Conference. Vol. 45. The Woodlands, Texas. p. 1703. Bibcode:2014LPI....45.1703N.
7. "WGSBN Bulletin 3, #3" (PDF). WGSBN Bulletin. 3 (3). International Astronomical Union: 22. 27 February 2023. Retrieved 4 November 2023.

External links

• 17365 Thymbraeus at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 17365 Thymbraeus at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters