(48639) 1995 TL8

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(48639) 1995 TL8
Discovered by A. Gleason (Spacewatch)
Discovery date 15 October 1995 and
9 November 2002 (moon)
MPC designation (48639) 1995 TL8
Classical (DES)[1]
Orbital characteristics[2]
Epoch 30 November 2008 (JD 2454800.5)
Aphelion 65.086 AU
9,736 Gm (Q)
Perihelion 39.980 AU
5,980 Gm (q)
52.533 AU
7,858 Gm (a)
Eccentricity 0.23894
380.77 a (139077 d)
4.06 km/s
Inclination 0.24686°
Known satellites 1
Physical characteristics
Dimensions ≈ 350 (primary)
and ≈160 km (secondary)
Albedo 0.09 (assumed)
Temperature ≈ 38 K
5.28 and 6.98

(48639) 1995 TL8 (also written (48639) 1995 TL8) is a classical Kuiper belt object possessing a relatively large satellite.

The assumed diameter of 352 kilometres (219 mi) is derived from an albedo guess of 0.09, being typical for trans-Neptunian objects.[3]


Discovered in 1995 by Arianna Gleason as part of the Spacewatch project, it was the first of the bodies presently classified as a scattered-disc object (SDO) to be discovered, preceding the SDO prototype (15874) 1996 TL66 by almost a year.


A relative size and distance comparison of the (48639) 1995 TL8 system with the EarthMoon system. The scale of the Earth–Moon system has been reduced so Earth appears the same size as the (48639) 1995 TL8 primary.

A companion was discovered by Denise C. Stephens and Keith S. Noll, from observations with the Hubble Space Telescope taken on 9 November 2002, and announced on 5 October 2005. The satellite, designated S/2002 (48639) 1, is relatively large, having a likely mass of about 10% of the primary. Its orbit has not been determined, but it was at a separation of only about 420 kilometres (260 mi) to the primary at the time of discovery, with a possible orbital period of about half a day and an estimated diameter of 161 kilometres (100 mi).[4]

Scattered–extended object[edit]

(48639) 1995 TL8 is classified as scattered–extended by the Deep Ecliptic Survey (DES), since its orbit appears to be beyond significant gravitational interactions with Neptune's current orbit.[1] However, if Neptune migrated outward, there would have been a period when Neptune had a higher eccentricity.

The near 3:7 resonance pattern of 1995 TL8 with Neptune only moves clockwise. It never halts and reverses course (i.e. librates).

Simulations by Emel’yanenko and Kiseleva in 2007 show that (48639) 1995 TL8 appears to have less than a 1% chance of being in a 3:7 resonance with Neptune, but it does execute circulations near this resonance.[5]

It has been observed 48 times and has an orbit quality code of 4 (0 being best; 9 being worst).[2]

The orbital period of 1995 TL8 missing the 7:3 (2.333) resonance of Neptune.

See also[edit]


  1. ^ a b Marc W. Buie (2003-10-22). "Orbit Fit and Astrometric record for 48639". SwRI (Space Science Department). Retrieved 2009-01-26. 
  2. ^ a b "JPL Small-Body Database Browser: 48639 (1995 TL8)" (last obs). 2008-08-29. Retrieved 2009-01-26. 
  3. ^ Wm. Robert Johnston (22 August 2008). "List of Known Trans-Neptunian Objects". Johnston's Archive. Archived from the original on 13 February 2009. Retrieved 2009-01-26. 
  4. ^ Wm. Robert Johnston (2005-10-09). "(48639) 1995 TL8". Johnston's Archive. Archived from the original on 10 December 2005. Retrieved 2006-02-07. 
  5. ^ Emel’yanenko, V. V; Kiseleva, E. L. (2008). "Resonant motion of trans-Neptunian objects in high-eccentricity orbits". Astronomy Letters 34 (4): 271–279. Bibcode:2008AstL...34..271E. doi:10.1134/S1063773708040075. 

External links[edit]