P/2009 Y2
P/2009 Y2 (Kowalski)
Not currently visible. Last report 6065 days ago at mag 18.6. Historic peak was mag 17.5. 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
18.6
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
2
Arc unknown
Last observation
6065d ago
Sun, 07 Feb 2010 19:11:59 GMT · COBS consensus
Perihelion
2026-12-13
2.370 au
Peak window
2026-12-06 → 2026-12-16
COBS peak mag 17.5 on 2026-12-09 · perihelion 2026-12-13. Window is those dates ±3 days — not a light-curve fit.
Historic peak
17.5
COBS / analyzed peak 2026-12-09
Catalog ingest
12m ago
Venator last wrote this row 2026-09-17 01:55:25 UTC
Light curve
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.
Orbital elements
q
2.370 au
e
0.6380
i
30.00°
Ω
262.00°
ω
172.00°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
—
Reporting sources
COBS comet list
downComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
Name history
P/2009 Y2 (Kowalski)
Informal: Kowalski
P/2009 Y2 · 2026-09-13 22:21:22 UTC → current
Discoverers
Discoverer · parsed-name · 2026-09-13 22:21:22 UTC → current
Contributors
CCD Observer · HAE · 1 reports · last 6065d ago
CCD Observer · HAU · 1 reports · last 6087d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.