P/2010 H2 (Vales)

P/2010 H2 (Vales)
Discovery[1]
Discovered byJan Vales
Discovery siteČrni Vrh Observatory
Discovery date16 April 2010
Orbital characteristics[4]
Epoch8 May 2010 (JD 2455324.5)
Observation arc141 days
Earliest precovery date15 April 2010[2]
Number of
observations
1,631
Aphelion4.593 AU
Perihelion3.108 AU
Semi-major axis3.851 AU
Eccentricity0.19291
Orbital period7.556 years
Inclination14.253°
64.309°
Argument of
periapsis
130.12°
Mean anomaly7.781°
Last perihelion10 March 2025
(unobserved)
Next perihelion19 September 2032[3]
TJupiter2.988
Earth MOID2.129 AU
Jupiter MOID0.613 AU
Physical characteristics[5]
Mean radius
0.25 km (0.16 mi)
0.04 (assumed)
Comet total
magnitude
(M1)
7.0[4]
Comet nuclear
magnitude (M2)
20.6

P/2010 H2 (Vales), is a distant Jupiter-family comet with a 7.5-year orbit around the Sun. Its frequent encounters with Jupiter also classify it as a quasi-Hilda comet.[6] As of 2025, it is the only comet discovered so far by Slovenian astronomer, Jan Vales. It last came to perihelion in March 2025 and will next come to perihelion in September 2032.[3] The comet has not been observed since the outburst during its discovery year of 2010.[5]

Observational history

The comet underwent a massive outburst when it was discovered by Jan Vales on 16 April 2010.[1] No prediscovery observations earlier than 15 April 2010 were found.[2] Later analysis of data from the Catalina Sky Survey indicated that the outburst may have been ongoing for 15 hours at the time, resulting in its brightness increased by a thousand-fold.[6]

Observations conducted on the day after discovery noted that its coma had undergone a significant increase in size, from 24–26 arcseconds to 34–38 arcseconds across.[7]

Although calculated to have a relatively short orbital period, it was not recovered during its next apparition in 2017.[8] On 17 March 2023, Toni Scarmato reported the observation of an object close to the predicted position of P/2010 H2, indicating a possible recovery of the comet.[9] Further analysis in 2024 did not match the position of the initial reports, concluding that Scarmato's find is likely a different object.[10]

Further search attempts in 2015 and 2025 from the Lowell Discovery Telescope failed to recover the comet, indicating a possible absolute nuclear magnitude fainter than 20.6, and a nucleus smaller than 0.5 km (0.31 mi) in diameter assuming a geometric albedo of 0.04.[5] However it is still likely that it may have become inactive after the 2010 outburst instead of simply disintegrating.[5]

References

  1. ^ a b J. Vales; R. A. Kowalski; W. Ryan; et al. (17 April 2010). B. G. Marsden (ed.). "Comet P/2010 H2 (Vales)". Central Bureau for Astronomical Telegrams. 2249. Bibcode:2010CBET.2249....1V.
  2. ^ a b P. Balanutsa; D. Zimnukhov; E. Gorbovskoy; et al. (22 April 2010). "Prediscovery detection of the Comet P/2010 H2 by MASTER Robotic Net". The Astronomer's Telegram. 2578: 1. Bibcode:2010ATel.2578....1B.
  3. ^ a b "Horizons Batch for Vales (P/2010 H2) (90004090) on 2032-Sep-19" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 27 February 2026. (JPL#26 Soln.date: 2021-Apr-15)
  4. ^ a b "P/2010 H2 (Vales) – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 20 November 2025.
  5. ^ a b c d Q. Z. Ye; T. L. Farnham; P. Cai; L. Feaga (2026). "A Search for the Lost Comet P/2010 H2 (Vales)". arXiv:2603.16579 [astro-ph.EP].
  6. ^ a b D. C. Jewitt; Y. Kim (2020). "Outbursting Quasi-Hilda Asteroid P/2010 H2 (Vales)". The Planetary Science Journal. 1 (3): 77–89. arXiv:2010.05012. Bibcode:2020PSJ.....1...77J. doi:10.3847/PSJ/abbef6.
  7. ^ P. Birtwhistle; K. Hornoch; A. Novichonok; D. Chestnov (19 April 2010). B. G. Marsden (ed.). "Comet P/2010 H2 (Vales)". Central Bureau for Astronomical Telegrams. 2253. Bibcode:2010CBET.2253....1B.
  8. ^ S. Yoshida (6 January 2024). "P/2010 H2 (Vales)". aerith.net. Retrieved 20 November 2025.
  9. ^ T. Scarmoto (28 March 2023). "Possible Recovery of Comet P/2010 H2". Facebook. ICQ Comet Observations. Retrieved 20 November 2025.
  10. ^ A. Coffinet; B. J. Gray; P. Birtwhistle (26 March 2024). "Recovery of P/2010 H2 (Vales)?". Groups.io. Retrieved 20 November 2025.