1995 SN55

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1995 SN55
Discovery and designation
Discovered by A. Gleason
Discovery date September 20, 1995
Designations
MPC designation 1995 SN55
Minor planet category Centaur[1][2]
Orbital characteristics[1][3]
Epoch September 20 1995 (2449980.5)
Aphelion 39.1 to 91 AU (Q)
Perihelion 7.9 to 8.3 AU (q)
23.5 to 49 AU (a)
Eccentricity 0.66 to 0.83
(Uncertainty=E)[1]
114 to 351 yr
180.2° (M)
Inclination 4.97°
144.6°
49.3°
Physical characteristics
Dimensions 295 km?[4]
276 km[5]
0.08 (assumed)[4][6][7]
6.0[1]

1995 SN55, also written as 1995 SN55, is a lost centaur with a perihelion greater than Jupiter and a semi-major axis that may be less than Neptune's. This object could be the largest known centaur.

Size[edit]

If confirmed to be a centaur, 1995 SN55 would be one of the largest centaurs known. Centaurs typically have an albedo of about 0.08.[6][7] With an absolute magnitude (H) of 6.0,[1] and using an average centaur albedo of 0.08,[6][7] 1995 SN55 could be 295 km in diameter. The two largest known centaurs are 10199 Chariklo (260 km / H=6.6 / albedo = 0.05) and 2060 Chiron (230 km / H=6.2 / albedo = 0.07).

Loss[edit]

1995 SN55 was about 39 AU from the Sun when it was discovered. It was only observed 14 times over 36 days from September 20, 1995 until October 26, 1995.[1][3] Due to this short observation arc, the object has a very poorly known orbit and is considered lost. (See Lost comet or Lost asteroid.)

JPL shows this object having an aphelion distance of only 39.1 AU,[1] whereas the Deep Ecliptic Survey (DES) shows it having an aphelion distance of 91 AU.[3]

References[edit]

  1. ^ a b c d e f g "JPL Small-Body Database Browser: (1995 SN55)" (last observation: 1995-10-26; arc: 36 days and lost). Retrieved 2008-10-21. 
  2. ^ "List Of Centaurs and Scattered-Disk Objects". Minor Planet Center. Retrieved 2008-10-21. 
  3. ^ a b c Marc W. Buie (1995-10-26). "Orbit Fit and Astrometric record for 95SN55". SwRI (Space Science Department). Retrieved 2008-10-21. 
  4. ^ a b assumed to have a typical centaur albedo of 0.08
  5. ^ Michael E. Brown. "How many dwarf planets are there in the outer solar system? (updates daily)". California Institute of Technology. Retrieved 2014-03-26. 
  6. ^ a b c Wm. Robert Johnston (2008-09-17). "TNO/Centaur diameters and albedos". Johnston's Archive. Archived from the original on 22 October 2008. Retrieved 2008-10-21. 
  7. ^ a b c Bauer, James M.; Grav, Tommy; Blauvelt, Erin; Mainzer, Amy (2013). "Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis of WISE/NEOWISE Observations". The Astronomical Journal 773 (1). arXiv:1306.1862. Bibcode:2013DPS....4550806B. doi:10.1088/0004-637X/773/1/22. 

External links[edit]