C/1984 S1
Not currently visible. Last report 15330 days ago at mag 36.4. Historic peak was mag 9.1. 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
36.4
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
7
Arc unknown
Last observation
15330d ago
Thu, 27 Sep 1984 03:07:11 GMT · COBS consensus
Perihelion
1984-10-13
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Peak window
1984-08-24 → 1984-10-16
COBS peak mag 9.1 on 1984-08-27 · perihelion 1984-10-13. Window is those dates ±3 days — not a light-curve fit.
Historic peak
9.1
COBS / analyzed peak 1984-08-27
Catalog ingest
11h ago
Venator last wrote this row 2026-09-16 13:20:18 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
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e
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i
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Ω
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ω
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a
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MOID
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H
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H0 / n
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NEO score
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PHA score
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RMS
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Elongation
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COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/1984 S1 (Meier)
Informal: Meier
C/1984 S1 · 2026-09-14 18:27:58 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:58 UTC → current
Visual Observer · MOR · 2 reports · last 15330d ago
Visual Observer · HAL · 1 reports · last 15337d ago
CCD Observer · PEA · 1 reports · last 15332d ago
Visual Observer · GRE · 1 reports · last 15338d ago
Visual Observer · KEI · 1 reports · last 15332d ago
Visual Observer · BOR · 1 reports · last 15335d ago
Visual Observer · OME · 1 reports · last 15338d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.