C/1983 O1
Not currently visible. Last report 15319 days ago at mag 33.7. Historic peak was mag 13.8. Typical backyard telescopes will not show it. HST, JWST, or an 8–10 m class telescope might recover it with a good ephemeris.
Right ascension
—
J2000
Declination
—
J2000
Estimated magnitude
33.7
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
269
Arc unknown
Last observation
15319d ago
Wed, 28 Nov 1984 12:14:24 GMT · COBS consensus
Perihelion
1983-07-24
3.370 au
Peak window
1983-07-21 → 1983-10-24
COBS peak mag 13.8 on 1983-10-21 · perihelion 1983-07-24. Window is those dates ±3 days — not a light-curve fit.
Historic peak
13.8
COBS / analyzed peak 1983-10-21
Catalog ingest
13h ago
Venator last wrote this row 2026-11-06 14:20:20 UTC
Brightness over time (V mag)
Gold = reported observations. Steel dashed family = ensemble (nominal / outburst / fade / disruption).
Tail length
Converted to degrees from COBS (d / arcmin / arcsec). Empty until analysis has pulled the archive.
Ensemble is a first-pass H0/n photometric model plus observed samples — not a trained ML forecast yet. The background analyzer walks the catalog one object at a time so COBS is not flooded. Disruption track rises after perihelion to stand in for solar-wind stripping.
q
3.370 au
e
1.0000
i
135.00°
Ω
210.00°
ω
187.00°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
—
COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/1983 O1 (Cernis)
Informal: Cernis
C/1983 O1 · 2026-09-14 18:27:57 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:57 UTC → current
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Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.