1996 PW
Discovery images of 1996 PW from NEAT-GEODSS in August 1996
Discovery[1][2]
Discovered byNEAT
Discovery siteHaleakala Obs.
Discovery date9 August 1996
Designations
1996 PW
TNO[3] · damocloid[4][5]
distant[1] · unusual[6]
Orbital characteristics[3]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 2
Observation arc1.39 yr (506 d)
Aphelion504.23 AU
Perihelion2.4933 AU
253.36 AU
Eccentricity0.9902
4033 yr (1,473,017 d)
2.0281°
0° 0m 0.72s / day
Inclination29.956°
144.38°
181.60°
TJupiter1.7130
Physical characteristics
Mean diameter
7 km[4]
8 km (est. at 0.15)[2]
15 km (est. at 0.04)[2]
35.44 h[7][8]
Ld (SMASS)[3][7][9]
D[8][10]
B–R = 0.56±0.04
V–I = 1.03±0.06
V–J = 1.80±0.05
V–H = 2.19±0.05
V–K = 2.32±0.05[8]
14.0[1][3]

    1996 PW is an exceptionally eccentric trans-Neptunian object and damocloid on an orbit typical of long-period comets but one that showed no sign of cometary activity around the time it was discovered.[8] The unusual object measures approximately 10 kilometers (6 miles) in diameter and has a rotation period of 35.4 hours and likely an elongated shape.[7]

    Description

    1996 PW orbits the Sun at a distance of 2.5–504 AU once every 4,033 years (semi-major axis of 253 AU). Its orbit has an eccentricity of 0.99 and an inclination of 30° with respect to the ecliptic.[3]

    Simulations indicate that it has most likely come from the Oort cloud, with a roughly equal probability of being an extinct comet and a rocky body that was originally scattered into the Oort cloud. The discovery of 1996 PW prompted theoretical research that suggests that roughly 1 to 2 percent of the Oort cloud objects are rocky.[2][10]

    1996 PW was first observed on 9 August 1996 by the Near-Earth Asteroid Tracking (NEAT) automated search camera on Haleakala Observatory, Hawaii. It is the first object that is not an active comet discovered on an orbit typical of long-period comets.[2]

    1996 PW has a rotation period of 35.44±0.02 hours and a double-peaked lightcurve with a high amplitude of 0.44±0.03 magnitude (U=3).[7][8] Its spectrum is moderately red and featureless,[11] typical of D-type asteroids and bare comet nuclei.[8][10][11] Its spectrum suggests an extinct comet.[11] The upper limit on 1996 PW's dust production is 0.03 kg/s.[8]

    See also

    References

    1. 1 2 3 "1996 PW". Minor Planet Center. Retrieved 17 January 2018.
    2. 1 2 3 4 5 Weissman, Paul R.; Lecison, Harold F. (March 1997). "Origin and evolution of the unusual object 1996 PW". The Astrophysical Journal. 488 (2): 529. Bibcode:1997LPI....28.1529W. doi:10.1086/310940.
    3. 1 2 3 4 5 "JPL Small-Body Database Browser: (1996 PW)" (1997-12-28 last obs.). Jet Propulsion Laboratory. Retrieved 17 January 2018.
    4. 1 2 Johnston, Wm. Robert (15 October 2017). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 17 January 2018.
    5. ↑ Akimasa Nakamura (2 May 2009). "Table of Damocloid objects, or Oort cloud asteroids". Lowell Observatory. Retrieved 17 January 2018.
    6. ↑ "List Of Other Unusual Objects". Minor Planet Center. Retrieved 14 November 2018.
    7. 1 2 3 4 "LCDB Data for (1996+PW)". Asteroid Lightcurve Database (LCDB). Retrieved 20 November 2018.
    8. 1 2 3 4 5 6 7 Davies, John K.; McBride, Neil; Green, Simon F.; Mottola, Stefano; Carsenty, Uri; Basran, Devinder; et al. (April 1998). "The Lightcurve and Colors of Unusual Minor Planet 1996 PW". Icarus. 132 (2): 418–430. Bibcode:1998Icar..132..418D. doi:10.1006/icar.1998.5888.
    9. ↑ Bus, Schelte J.; Binzel, Richard P. (July 2002). "Phase II of the Small Main-Belt Asteroid Spectroscopic Survey. A Feature-Based Taxonomy" (PDF). Icarus. 158 (1): 146–177. Bibcode:2002Icar..158..146B. doi:10.1006/icar.2002.6856. Archived from the original (PDF) on 23 September 2015. Retrieved 20 November 2018.
    10. 1 2 3 Toth, Imre (December 2005). "Connections between asteroids and cometary nuclei". Asteroids. 1: 67–96. Bibcode:2006IAUS..229...67T. doi:10.1017/S174392130500668X.
    11. 1 2 3 Hicks, M. D.; Buratti, B. J.; Newburn, R. L.; Rabinowitz, D. L. (February 2000). "Physical Observations of 1996 PW and 1997 SE5: Extinct Comets or D-Type Asteroids?". Icarus. 143 (2): 354–359. Bibcode:2000Icar..143..354H. doi:10.1006/icar.1999.6258.
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