C/1984 U1
Not currently visible. Last report 14627 days ago at mag 36.9. Historic peak was mag 20.9. 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
—
J2000
Declination
—
J2000
Estimated magnitude
36.9
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
3
Arc unknown
Last observation
14627d ago
Sun, 31 Aug 1986 07:55:11 GMT · COBS consensus
Perihelion
1984-08-13
5.590 au
Peak window
1984-08-10 → 1984-11-17
COBS peak mag 20.9 on 1984-11-14 · perihelion 1984-08-13. Window is those dates ±3 days — not a light-curve fit.
Historic peak
20.9
COBS / analyzed peak 1984-11-14
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
5.590 au
e
0.9920
i
179.00°
Ω
239.00°
ω
184.00°
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/1984 U1 (Shoemaker)
Informal: Shoemaker
C/1984 U1 · 2026-09-14 18:27:57 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:57 UTC → current
CCD Observer · PEA · 2 reports · last 15268d ago
Visual Observer · SCO02 · 1 reports · last 14627d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.