C/1989 R1
Not currently visible. Last report 13503 days ago at mag 38.3. Historic peak was mag 11.9. 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
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J2000
Declination
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J2000
Estimated magnitude
38.3
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
4
Arc unknown
Last observation
13503d ago
Thu, 28 Sep 1989 02:52:48 GMT · COBS consensus
Perihelion
1989-08-31
1.330 au
Peak window
1989-08-28 → 1989-09-03
COBS peak mag 11.9 on 1989-08-31 · perihelion 1989-08-31. Window is those dates ±3 days — not a light-curve fit.
Historic peak
11.9
COBS / analyzed peak 1989-08-31
Catalog ingest
2d ago
Venator last wrote this row 2026-09-14 20:00:18 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.
No tail measures stored yet for this object.
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
1.330 au
e
0.9870
i
128.00°
Ω
129.00°
ω
155.00°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
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RMS
—
Elongation
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COBS comet list
downComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/1989 R1 (Helin-Roman)
Informal: Helin-Roman
C/1989 R1 · 2026-09-14 18:27:57 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:57 UTC → current
Visual Observer · HAL · 2 reports · last 13503d ago
Visual Observer · MOR · 1 reports · last 13524d ago
Visual Observer · EIS · 1 reports · last 13524d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.