238P/Read

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238P/Read
P/2005 U1
Discovery
Discovered by Spacewatch
(M. Read)
Discovery date 24 October 2005
Designations
Main-belt comet[1][2]
Encke-type comet[3]
Orbital characteristics[3]
Epoch 7 January 2006
Uncertainty parameter 1
Aphelion 3.9645 AU (Q)
Perihelion 2.3647 AU (q)
3.1646 AU (a)
Eccentricity 0.25277
5.63 yr
28.566° (M)
Inclination 1.2662°
51.647°
325.76°
TJupiter 3.153
Physical characteristics
Mean diameter
0.6 km (approx.)[4]
Mean density
1.0 g/cm3 (assumed)[4]
Albedo 0.04 (assumed)[4]
Surface temp. min mean max
Kelvin[4] 142 K 159 K 184 K
19.62 to 23.41
20.1±0.4R[4]

238P/Read (P/2005 U1) is a main-belt comet[1][2] discovered on 24 October 2005 by astronomer Michael T. Read using the Spacewatch 36-inch telescope on Kitt Peak National Observatory. It has an orbit within the asteroid belt and has displayed the coma of a traditional comet. It fits the definition of an Encke-type comet with (TJupiter > 3; a < aJupiter).[3]

Description[edit]

Before it was discovered 238P came to perihelion on 2005 July 27.[3] When it was discovered on 2005 October 24, it showed vigorous cometary activity until 2005 December 27.[4] Outgassing likely began at least 2 months before discovery.[4] The activity of 238P is much stronger than 133P/Elst-Pizarro and 176P/LINEAR.[4] This may indicate that the impact assumed to have triggered 238P's activity occurred very recently.[4]

Observations of 238P when it was inactive in 2007 suggests that it has a small nucleus only about 0.6 km in diameter.[4]

It last came to perihelion on 2011 March 10,[4] and will next come to perihelion on 2016 October 22.[5][6]

238P/Read was the target of a mission proposal in NASA's Discovery Program in the 2010s called Proteus, however it was not selected for further development.[7] Discovery program's founding mission was to an asteroid, but it went to a Near-Earth asteroid.[8] A mission to a main-belt asteroid was proposed in the 1990s (also see Deep Impact (spacecraft)).[9]

References[edit]

  1. ^ a b Henry H. Hsieh (May 2010). "Main Belt Comets". Hawaii. Archived from the original on 2011-08-06. Retrieved 2010-12-15. (older 2010 site) Archived August 10, 2009, at the Wayback Machine.
  2. ^ a b David Jewitt. "Main Belt Comets". UCLA, Department of Earth and Space Sciences. Retrieved 2010-12-15.
  3. ^ a b c d "JPL Small-Body Database Browser: 238P/Read (2005 U1)" (last observation: 2011-09-14). Archived from the original on 2012-08-09. Retrieved 2012-08-08.
  4. ^ a b c d e f g h i j k Hsieh, Henry H.; Jewitt; David C.; Ishiguro, Masateru (2009). "Physical Properties of Main-Belt Comet P/2005 U1 (Read)". The Astronomical Journal. 137 (1): 157–168. arXiv:0810.1351. Bibcode:2009AJ....137..157H. doi:10.1088/0004-6256/137/1/157. Retrieved 2010-12-18.
  5. ^ Syuichi Nakano (2010-08-20). "P/Read (2005 U1 = 2010 N2)". OAA Computing and Minor Planet Sections. Retrieved 2011-07-25.
  6. ^ "238P/Read Orbit". Minor Planet Center. Retrieved 2014-06-20.
  7. ^ "PROTEUS – A MISSION TO INVESTIGATE THE ORIGIN OF EARTH'S WATER: CREATING HABITABLE WORLDS" (PDF). Astrobiology Science Conference 2015. Retrieved January 11, 2016.
  8. ^ [1]
  9. ^ Discover 95 : MISSIONS TO THE MOON, SUN, VENUS AND A COMET PICKED FOR DISCOVERY - NASA

See also[edit]

External links[edit]

Numbered comets
Previous
237P/LINEAR
238P/Read Next
239P/LINEAR