96P/Machholz

96P/Machholz
96P/Machholz as seen by STEREO-A in April 2007
Discovery
Discovered byDonald Machholz[1]
Discovery dateMay 12, 1986
Designations
96P, Machholz, Machholz 1, 1986 J2, 1991 XII, 1986e, 1986 VII
Orbital characteristics
Epoch2028-May-29
(JD 2461920.5)[2]
Aphelion5.944 AU
Perihelion0.1160 AU
(38% of Mercury's perihelion)
Semi-major axis3.030 AU
Eccentricity0.9617
Orbital period5.27 yr
Max. orbital speed122 km/s (440,000 km/h)[3]
Inclination57.49°
Last perihelionJanuary 31, 2023, 02:02 UTC[2]
October 27, 2017, 23:03 UTC[2]
Next perihelion≈May 12, 2028[3]

Comet 96P/Machholz or 96P/Machholz 1[4] is a short-period sungrazing comet discovered on May 12, 1986, by amateur astronomer Donald Machholz on Loma Prieta peak, in central California using 130 millimetres (5.1 in) binoculars.[4][5] On June 6, 1986, 96P/Machholz passed 0.404 AU (60,400,000 km; 37,600,000 mi) from the Earth.[1] 96P/Machholz last came to perihelion on January 31, 2023.[2] The comet has an estimated diameter of around 6.4 km (4.0 mi).[6]

This comet is a parent body of 96P-family sungrazing comets.

96P/Machholz is unusual among comets in several respects. Other than small SOHO comets, its highly eccentric 5.29 year orbit has the smallest perihelion distance known among numbered/regular short-period comets,[7] bringing it considerably closer to the Sun than the orbit of Mercury. It is also the only known short-period comet with both high orbital inclination and high eccentricity.[6] In 2007, 96P/Machholz was found to be both carbon-depleted and cyanogen-depleted, a chemical composition nearly unique among comets with known compositions.[8][9] The chemical composition implies a different and possible extrasolar origin.[10][11]

  1. ^ a b Cite error: The named reference jpldata was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference MPC was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Horizons2028 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Cometography was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Machholz-podcast-2007 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Schleicher2008 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SBDB-numbered was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference IAU8842 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Langland-Shula2007 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference S&T-2008-12-05 was invoked but never defined (see the help page).
  11. ^ Ferreira, Becky (February 3, 2023). "We May Have Had an Interstellar Visitor for Eons and Scientists Are Stumped - "I think it's going to be inconclusive, if not impossible to demonstrate conclusively," one physicist said of the possible interstellar comet". Vice. Retrieved February 4, 2023.