Astronomy:42355 Typhon

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Short description: Scattered disc object
42355 Typhon
Typhon-echidna hst.jpg
Hubble Space Telescope image of Typhon and its moon Echidna, taken in 2006
Discovery
Discovered byNEAT
Discovery date5 February 2002
Designations
(42355) Typhon
Pronunciation/ˈtfɒn/[4]
Named afterΤυφών Typhōn
2002 CR46
Minor planet categorySDO[1][2]
Centaur[3]
7:10 resonance
AdjectivesTyphonian /tˈfniən/[5]
Orbital characteristics[1]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 2
Observation arc9563 days (26.18 yr)
|{{{apsis}}}|helion}}58.982252 astronomical unit|AU (8.8236193 Tm)
|{{{apsis}}}|helion}}17.545721 AU (2.6248025 Tm)
38.263987 AU (5.7242110 Tm)
Eccentricity0.5414560
Orbital period236.70 yr (86453.7 d)
Mean anomaly14.61898075°
Mean motion0° 0m 14.991s / day
Inclination2.4252078°
Longitude of ascending node351.9098598°
159.3215723°
Known satellites1 (Echidna)
TJupiter4.692
Physical characteristics
Mean diameter138±9 km[6]
162±7 km[7]
Mass≈9.082×1017 kg[6]
Mean density0.66+0.09
−0.08
 g/cm3
[6]
Rotation period9.67 h (0.403 d)[6]
Geometric albedo0.044±0.003[7]
0.10±0.02
B−V=0.74±0.02 V−R=0.52±0.01
Absolute magnitude (H)7.5


42355 Typhon (/ˈtfɒn/; provisional designation 2002 CR46) is a scattered disc object that was discovered on February 5, 2002, by the NEAT program. It measures 162±7 km in diameter, and is named after Typhon, a monster in Greek mythology.

Typhon is the first known binary centaur,[8] using an extended definition of a centaur as an object on a non-resonant (unstable) orbit with the perihelion inside the orbit of Neptune.[9]

Moon

Echidna
Discovery
Discovery date2006
Designations
(42355) Typhon I Echidna
Pronunciation/ɪˈkɪdnə/[10]
Named afterΈχιδνα
AdjectivesEchidnian[11]
Echidnean (rarely)[12]
(both /ɪˈkɪdniən/)[13]
Orbital characteristics
~1300 km
Orbital period11 d
Satellite ofTyphon
Physical characteristics
Dimensions89±6 km


A large moon was identified in 2006. It is named Echidna (formal designation (42355) Typhon I Echidna), after the monstrous mate of Typhon. It orbits Typhon at ~1300 km, completing one orbit in about 11 days. Its diameter is estimated to be 89±6 km.

References

  1. 1.0 1.1 "JPL Small-Body Database Browser: (42355 Typhon)". https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=42355. 
  2. "List Of Centaurs and Scattered-Disk Objects". Minor Planet Center. http://www.minorplanetcenter.org/iau/lists/Centaurs.html. 
  3. (42355) Typhon and Echidna
  4. Typhon (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=Typhon  (Subscription or UK public library membership required.)
  5. Typhonian (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=Typhonian  (Subscription or UK public library membership required.)
  6. 6.0 6.1 6.2 6.3 Duffard, R.; Pinilla-Alonso, N.; Santos-Sanz, P.; Vilenius, E.; Ortiz, J. L.; Mueller, T. et al. (April 2014). ""TNOs are Cool": A survey of the trans-Neptunian region. XI. A Herschel-PACS view of 16 Centaurs". Astronomy and Astrophysics 564: 17. doi:10.1051/0004-6361/201322377. Bibcode2014A&A...564A..92D. 
  7. 7.0 7.1 Santos-Sanz, P., Lellouch, E., Fornasier, S., Kiss, C., Pal, A., Müller, T. G., Vilenius, E., Stansberry, J., Mommert, M., Delsanti, A., Mueller, M., Peixinho, N., Henry, F., Ortiz, J. L., Thirouin, A., Protopapa, S., Duffard, R., Szalai, N., Lim, T., Ejeta, C., Hartogh, P., Harris, A. W., & Rengel, M. (2012). “TNOs are Cool”: A Survey of the Transneptunian Region IV - Size/albedo characterization of 15 scattered disk and detached objects observed with Herschel Space Observatory-PACS
  8. K. Noll; H. Levison; W. Grundy; D. Stephens (October 2006). "Discovery of a binary Centaur". Icarus 184 (2): 611. doi:10.1016/j.icarus.2006.05.010. Bibcode2006Icar..184..611N. 
  9. J. L. Elliot; S. D. Kern; K. B. Clancy; A. A. S. Gulbis; R. L. Millis; M. W. Buie et al. (February 2005). "The Deep Ecliptic Survey: A Search for Kuiper Belt Objects and Centaurs. II. Dynamical Classification, the Kuiper Belt Plane, and the Core Population". The Astronomical Journal 129 (2): 1117. doi:10.1086/427395. Bibcode2005AJ....129.1117E. http://occult.mit.edu/_assets/documents/publications/Elliot2005AJ129.1117.pdf. 
  10. Echidna (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=Echidna  (Subscription or UK public library membership required.)
  11. François Hartog (Janet Lloyd, trans., 1988) The Mirror of Herodotus, p. 25
  12. J. A. Weinstock (2014) The Ashgate Encyclopedia of Literary and Cinematic Monsters, p. 79
  13. George Sandys (1669) Ovid's Metamorphosis Englished, 6th ed., p. 134.

External links