Wikipedia

311P/PanSTARRS

For other comets of the same name, see List of Pan-STARRS discoveries.

311P/PanSTARRS
Comet 311P/PanSTARRS imaged by the Hubble Space Telescope on 10–23 September 2013
Discovery[1]
Discovered byBryce T. Bolin
Discovery siteHaleakala Observatory
(Pan-STARRS)
Discovery date27 August 2013
Designations
P/2013 P5
Orbital characteristics[2]
Epoch29 April 2017 (JD 2457872.5)
Observation arc20.29 years
Earliest precovery date17 January 2005
Number of
observations		272
Aphelion2.442 AU
Perihelion1.936 AU
Semi-major axis2.189 AU
Eccentricity0.11567
Orbital period3.238 years
Avg. orbital speed0.304°/d
Inclination4.966°
279.26°
Argument of
periapsis		143.99°
Mean anomaly337.88°
Last perihelion1 January 2024
Next perihelion30 March 2027
TJupiter3.661
Earth MOID0.949 AU
Jupiter MOID2.818 AU
Physical characteristics
Mean diameter
~0.48 km (0.30 mi)[3]
Mean density
3.3±0.2 g/cm3[3]
~0.240 m/s[3]
≥ 5.4 hours[4]
0.29±0.09[5]
Comet total
magnitude (M1)		18.98±0.10[5]

311P/PanSTARRS, also known as P/2013 P5 (PanSTARRS), is an active asteroid and Encke-type comet discovered by Bryce T. Bolin using the Pan-STARRS telescope on 27 August 2013.[1][6] Observations made by the Hubble Space Telescope revealed that it had six comet-like tails.[7] The tails are suspected to be streams of material ejected by the asteroid as a result of a rubble pile asteroid spinning fast enough to remove material from it.[3] This is similar to 331P/Gibbs, which was found to be a quickly-spinning rubble pile as well.

Three-dimensional models constructed by Jessica Agarwal of the Max Planck Institute for Solar System Research in Lindau, Germany, showed that the tails could have formed by a series of periodic impulsive dust-ejection events,[a] radiation pressure from the Sun then stretched the dust into streams.[7]

Precovery images from the Sloan Digital Sky Survey from 2005 were found, showing negligible cometary activity in 2005.[citation needed]

Physical characteristics

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The asteroid has a radius of about 240 m (790 ft).[3] The first images taken by Pan-STARRS revealed that the object had an unusual appearance: asteroids generally appear as small points of light, but P/2013 P5 was identified as a fuzzy-looking object by astronomers.[6] The multiple tails were observed by the Hubble Space Telescope on 10 September 2013, Hubble later returned to the asteroid on 23 September, its appearance had totally changed. It looked as if the entire structure had swung around.[6] The Hubble Space Telescope continued to track the object through 11 February 2014.[8] The comet-like appearance has resulted in the asteroid being named as a comet. The object has a low orbital inclination and always stays outside the orbit of Mars.[2]

Possible satellite

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On 19 April 2018, observations based on light curvature suggested a possible satellite around 311P/PANSTARRS approaching 200 meters.[9] If true this would be one of the few minor planets designated as a comet known to harbor a satellite.

Exploration

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Main article: Tianwen-2

The Tianwen-2 spacecraft is planned to get in orbit around 311P/PanSTARRS in the mid-2030s. It was launched on 28 May 2025 and it will first visit and take samples from asteroid 469219 Kamoʻoalewa from late 2026 to early 2027.[10] After returning them to Earth, it will use its close encounter with Earth for a gravity assist towards 311P/PanSTARRS. When it arrives there, it will get into orbit and conduct a remote sensing study.[11]

See also

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Notes

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  1. ^ "She calculated that dust-ejection events occurred on April 15, July 18, July 24, Aug. 8, Aug. 26 and Sept. 4"

References

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  1. ^ a b B. T. Bolin; L. Denneau; M. Micheli; et al. (27 August 2013). D. W. Green (ed.). "Comet P/2013 P5 (PanSTARRS)". Central Bureau for Astronomical Telegrams. 3639. Bibcode:2013CBET.3639....1B.
  2. ^ a b "311P/PanSTARRS – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 9 November 2013.
  3. ^ a b c d e D. C. Jewitt; J. Agarwal; H. Weaver; M. Mutchler; S. Larson (2013). "The Extraordinary Multi-Tailed Main-Belt Comet P/2013 P5". The Astrophysical Journal Letters. 778 (1): 21–25. arXiv:1311.1483. Bibcode:2013ApJ...778L..21J. doi:10.1088/2041-8205/778/1/L21. S2CID 67795816.
  4. ^ D. C. Jewitt; H. Weaver; M. Mutchler; et al. (2018). "The Nucleus of Active Asteroid 311P/(2013 P5) PanSTARRS". The Astronomical Journal. 155 (6): 231–242. arXiv:1804.05897. Bibcode:2018AJ....155..231J. doi:10.3847/1538-3881/aabdee.
  5. ^ a b D. C. Jewitt; J. Agarwal; H. Weaver; M. Mutchler; S. Larson (2015). "Episodic Ejection from Active Asteroid 311P/PanSTARRS". The Astrophysical Journal. 798 (2): 109–121. arXiv:1410.8573. Bibcode:2015ApJ...798..109J. doi:10.1088/0004-637X/798/2/109.
  6. ^ a b c D. C. Jewitt; N. Guttridge (7 November 2013). "When is a comet not a comet?". esahubble.org. European Space Agency. Retrieved 12 November 2025.
  7. ^ a b J. D. Harrington (7 November 2013). "NASA's Hubble Sees Asteroid Spouting Six Comet-Like Tails". nasa.gov. NASA. Retrieved 12 November 2025.
  8. ^ "311P/PanSTARRS Orbit". Minor Planet Center. Retrieved 13 September 2014.
  9. ^ W. R. Johnston (4 October 2025). "Other reports of asteroid/TNO companions". Johnston's Archive. Retrieved 12 November 2025.
  10. ^ A. Jones (28 May 2025). "China launches Tianwen 2 mission to snag samples of a near-Earth asteroid (video)". Space.com. Retrieved 12 November 2025.
  11. ^ A. Jones (13 January 2023). "Tianwen-2: China's Near-Earth asteroid and comet double-header". The Planetary Society. Retrieved 10 February 2025.
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