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Title: 117P/Helin–Roman–Alu  
Author: World Heritage Encyclopedia
Language: English
Subject: Comets, Antitail, Comet Ikeya–Murakami, C/1989 X1, 68P/Klemola
Collection: Astronomical Objects Discovered in 1989, Comets, Discoveries by Eleanor F. Helin, Periodic Comets
Publisher: World Heritage Encyclopedia


Discovered by Eleanor F. Helin
Brian P. Roman
Jeff Alu
Discovery date October 2, 1989
Orbital characteristics A
Epoch March 6, 2006
Aphelion 5.123 AU
Perihelion 3.037 AU
Semi-major axis 4.08 AU
Eccentricity 0.2556
Orbital period 8.24 a
Inclination 8.7080°
Last perihelion March 27, 2014[1]
December 19, 2005
Next perihelion 2022-Jul-07[2]

117P/Helin–Roman–Alu, also known as Helin-Roman-Alu 1, is a periodic comet in the Solar System. It is a Quasi-Hilda comet.[3]


  1. ^  
  2. ^ "117P/Helin-Roman-Alu Orbit".  
  3. ^ Toth, I. (March 2006). "The quasi-Hilda subgroup of ecliptic comets - an update".  

External links

  • Orbital simulation from JPL (Java) / Horizons Ephemeris
  • 117P/Helin-Roman-Alu 1 – Seiichi Yoshida @
  • Elements and Ephemeris for 117P/Helin-Roman-Alu – Minor Planet Center
  • 117P at Kronk's Cometography
Periodic comets (by number)
117P/Helin–Roman–Alu Next
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