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Celestial object
C/1999 S2 (McNaught-Watson)
1999 S2, C/1999 S2 (McNaught-Watson), McNaught-Watson
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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 designation1999 S2
JPL SPK-ID1000274
Orbit classHYP
Orbit IDJPL 55
Near-Earth objectNo
Potentially hazardousNo
Epoch · JD2451620.5
Eccentricity1.005270827129
Semi-major axis-1227.083164839 AU
Perihelion distance6.467743234 AU
Orbital period—
Earth MOID5.662960000 AU
Jupiter Tisserand—
Inclination65.82021989°
Absolute magnitude · H—
Comet total magnitude · M18.0000 · K1 4.5000
Diameter—
Albedo—
Last catalogue sync2026-09-18 08:00:02
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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