| Discovery [1] [2] | |
|---|---|
| Discovered by | M. E. Van Ness |
| Discovery site | Lowell Observatory (LONEOS) |
| Discovery date | 28 July 2001 |
| Orbital characteristics [3] | |
| Epoch | 5 December 2001 (JD 2452248.5) |
| Observation arc | 340 days |
| Number of observations | 882 |
| Aphelion | 25.606 AU |
| Perihelion | 0.994 AU |
| Semi-major axis | 13.300 AU |
| Eccentricity | 0.92526 |
| Orbital period | 48.51 years |
| Inclination | 80.245° |
| 10.555° | |
| Argument of periapsis | 116.42° |
| Last perihelion | 15 March 2002 |
| Next perihelion | 7 June 2050 [4] |
| TJupiter | 0.597 |
| Earth MOID | 0.301 AU |
| Jupiter MOID | 0.968 AU |
| Physical characteristics [3] [5] | |
| Dimensions | 13.6 ± 1.0 km (8.45 ± 0.62 mi) |
| 57.2±0.5 hours | |
| 0.054 | |
| (V–R) = 0.46±0.02 | |
| Comet total magnitude (M1) | 13.3 |
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. [6]
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 7 June 2050. [4] On 23 March 2147 the comet will pass about 0.42 AU (63 million km; 160 LD) from Earth [3] with an uncertainty region of about ±2 million km. [7]
| Date & time of closest approach | Earth distance (AU) | Sun distance (AU) | Velocity wrt Earth (km/s) | Velocity wrt Sun (km/s) | Uncertainty region (3-sigma) | Reference |
|---|---|---|---|---|---|---|
| 2147-03-23 11:20 ± 13:38 | 0.42 AU (63 million km ; 39 million mi ; 160 LD ) | 1.35 AU (202 million km; 125 million mi; 530 LD) | 40.3 | 35.3 | ± 2 million km | Horizons |
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]
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 (5.53 ± 0.43 mi). [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 (8.45 ± 0.62 mi) [3]
