C/2001 OG108 (LONEOS)
Discovered byM. E. Van Ness[1]
LONEOS telescope at Lowell Observatory
Discovery date28 July 2001[2]
Orbital characteristics A
Epoch15 December 2001[3]
(JD 2452258.5)
Observation arc340 days
Aphelion25.606 AU (Q)
Perihelion0.99404 AU (q)
Semi-major axis13.300 AU (a)
Orbital period48.51 yr
Earth MOID0.3 AU (45 million km)
Dimensions13.6 ± 1.0 km[3]
Last perihelion2002-Mar-15[3]
Next perihelion2050-Jun-06[4]

C/2001 OG108 (LONEOS) is a Halley-type comet with an orbital period of 48.51 years.[3] It was discovered on 28 July 2001 by the LONEOS telescope at Lowell Observatory.[2] Of the short-period comets with known diameters and perihelion inside the orbit of Earth, C/2001 OG108 is the second largest after Comet Swift–Tuttle.[5]

Observations taken in January and February 2002 showed that the "asteroid" had developed a small amount of cometary activity as it approached perihelion.[1] It was subsequently reclassified as a comet.[1] The comet came to perihelion (closest approach to the Sun) on 15 March 2002.[3] It will come to aphelion in 2026 and the next perihelion passage is calculated to be on 6 June 2050.[4] On 23 March 2147 the comet will pass about 0.42 AU (63 million km; 160 LD) from Earth with an uncertainty region of about ±2 million km.[3]

The comet has a rotational period of 2.38 ± 0.02 days (57.12 hr).[1][3]

In 2003, the comet was estimated to have a mean absolute V magnitude (H) of 13.05 ± 0.10, with an albedo of 0.03, giving an effective radius of 8.9 ± 0.7 km.[1] Using data from Fernandez (2004–2005) JPL lists the comet with an albedo of 0.05 and a diameter of 13.6 ± 1.0 km.[3]

This comet probably represents the transition between typical Halley-family/long-period comets and extinct comets.[1] Damocloids have been studied as possible extinct cometary candidates due to the similarity of their orbital parameters with those of Halley-family comets.[1]

See also


  1. ^ a b c d e f g Abell, Paul A.; Fernández, Yanga R.; Pravec, Petr; French, Linda M.; Farnham, Tony L.; Gaffey, Michael J.; Hardersen, Paul S.; Kušnirák, Peter; Šarounová, Lenka; Sheppard, Scott S. (2003). "Physical Characteristics of Asteroid-like Comet Nucleus C/2001 OG108 (LONEOS)". 34th Annual Lunar and Planetary Science Conference. Bibcode:2003LPI....34.1253A.
  2. ^ a b French, Linda M. (2002). "Pre-Activity BVRI Colors of High-Inclination Comet C/2001 OG108 (LONEOS)". American Astronomical Society, DPS Meeting No. 34, #16.01. 34: 868. Bibcode:2002DPS....34.1601F.
  3. ^ a b c d e f g h "JPL Small-Body Database Browser: C/2001 OG108 (LONEOS)" (last observation: 2002-07-03; arc: 340 days). Jet Propulsion Laboratory. Retrieved 18 May 2011.
    (Close approach uncertainty: (MaxDist of 0.434) – (MinDist of 0.408) * 149597870.7 = 3.9 million km)
  4. ^ a b Horizons output. "Observer Table for Comet C/2001 OG108 (LONEOS)" (Soln.date: 2014-Jun-18). Retrieved 2 August 2020. (Observer Location:@sun Perihelion occurs when deldot flips from negative to positive)
  5. ^ "JPL Small-Body Database Search Engine: comets and q < 1 (au) and period < 200 (years)". JPL Solar System Dynamics. Retrieved 24 July 2020.