(48639) 1995 TL8

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(48639) 1995 TL8
Discovered by A. Gleason (Spacewatch)
Discovery date October 15, 1995 and
November 9, 2002 (moon)
MPC designation (48639) 1995 TL8
Alternative names none
Minor planet category Classical (DES)[1]
Orbital characteristics[2]
Epoch November 30, 2008 (JD 2454800.5)
Aphelion 65.086 AU
9,736 Gm (Q)
Perihelion 39.980 AU
5,980 Gm (q)
Semi-major axis 52.533 AU
7,858 Gm (a)
Eccentricity 0.23894
Orbital period 380.77 a (139077 d)
Average orbital speed 4.06 km/s
Mean anomaly 35.705°
Inclination 0.24686°
Longitude of ascending node 260.30°
Argument of perihelion 84.104°
Known satellites 1
Physical characteristics
Dimensions ≈350 (primary)
and ≈160 km (secondary)
Albedo 0.09 (assumed)
Temperature ≈38 K
Absolute magnitude (H) 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 km is derived from an albedo guess of 0.09, being typical for trans-Neptunian objects.[3]


Discovered in 1995 by Arianna E. 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 November 9, 2002, and announced on October 5, 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 km to the primary at the time of discovery, with a possible orbital period of about half a day and an estimated diameter of 161 km.[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] Though if Neptune migrated outward, there would have been a period when Neptune had a higher eccentricity.

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 near 3:7 resonance pattern of 1995 TL8 with Neptune only marches clockwise. It never halts and reverses course (i.e. librates).
The orbital period of 1995 TL8 missing the 7:3 (2.333) resonance of Neptune.

To see a proper 3:7 resonance with Neptune, see: (131696) 2001 XT254.

See also[edit]

  • 3753 Cruithne (orbital circulations due to near resonant perturbations with Earth)


  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]