C/2009 Y1
Not currently visible. Last report 5499 days ago at mag 31.7. Historic peak was mag 15.2. 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
31.7
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
65
Arc unknown
Last observation
5499d ago
Tue, 18 Oct 2011 11:31:12 GMT · COBS consensus
Perihelion
2011-01-24
2.550 au
Peak window
2010-12-03 → 2011-01-27
COBS peak mag 15.2 on 2010-12-06 · perihelion 2011-01-24. Window is those dates ±3 days — not a light-curve fit.
Historic peak
15.2
COBS / analyzed peak 2010-12-06
Catalog ingest
13h ago
Venator last wrote this row 2026-11-06 14:20:18 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.
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
2.550 au
e
0.9930
i
107.00°
Ω
160.00°
ω
128.00°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
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COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/2009 Y1 (Catalina)
Informal: Catalina
C/2009 Y1 · 2026-09-14 18:27:53 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:53 UTC → current
CCD Observer · NOV01 · 13 reports · last 5533d ago
Visual Observer · HAE · 10 reports · last 5759d ago
Visual Observer · CER01 · 7 reports · last 5545d ago
CCD Observer · TSU02 · 5 reports · last 5499d ago
CCD Observer · SHU · 5 reports · last 5529d ago
CCD Observer · YUS · 5 reports · last 5767d ago
Visual Observer · YOS04 · 4 reports · last 5568d ago
Visual Observer · GON05 · 3 reports · last 5765d ago
CCD Observer · HAE · 2 reports · last 5921d ago
Visual Observer · DIJ · 2 reports · last 5865d ago
Visual Observer · KOU · 2 reports · last 5551d ago
Visual Observer · GET · 2 reports · last 5765d ago
Visual Observer · IVA03 · 2 reports · last 5546d ago
CCD Observer · BRE03 · 1 reports · last 5836d ago
Visual Observer · MAR02 · 1 reports · last 5578d ago
CCD Observer · YOS02 · 1 reports · last 5543d ago
Visual Observer · LEH · 1 reports · last 5823d ago
Visual Observer · PAR03 · 1 reports · last 5520d ago
CCD Observer · KUT · 1 reports · last 5550d ago
Visual Observer · KUT · 1 reports · last 5599d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.