Astro Corner
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Celestial object
117P/Helin-Roman-Alu 1
117P, 117P/Helin-Roman-Alu 1, Helin-Roman-Alu
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Reference data
RADate-dependentMoving object · use an ephemeris
DecDate-dependentMoving object · use an ephemeris
Magnitude—
Angular size—
Position angle—
Distance—
Constellation—
Solar System catalogue
JPL SBDBMoving-object reference
Comets and minor planets move against the background sky. Astro Corner therefore keeps their orbital catalogue record separately and does not pretend a single RA/Dec is permanently correct.
Primary designation117P
JPL SPK-ID1000121
Orbit classJFc
Orbit IDJPL K223/3
Near-Earth objectNo
Potentially hazardousNo
Epoch · JD2456714.5
Eccentricity0.253835625431
Semi-major axis4.096078241 AU
Perihelion distance3.056347659 AU
Orbital period3,028.0 days
Earth MOID2.046170000 AU
Jupiter Tisserand2.967000
Inclination8.69753418°
Absolute magnitude · H—
Comet total magnitude · M15.7000 · K1 15.0000
Diameter9.000000 km
Albedo—
Last catalogue sync2026-09-18 07:40:03
Planning coordinates are intentionally separate.A later Horizons ephemeris layer can calculate the object's apparent position for a specific date, time and observing location. Until then, static-sky tools are hidden for this record rather than showing misleading coordinates.
Open JPL Small-Body Database 
Reference transparencySources & data provenanceSee where catalogue identities and imported reference fields came from.4 records
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Images of this object
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