C/2011 L4
Not currently visible. Last report 4114 days ago at mag 28.0. Historic peak was mag 0.5. 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
28.0
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
1090
Arc unknown
Last observation
4114d ago
Fri, 12 Jun 2015 16:33:35 GMT · COBS consensus
Perihelion
2013-03-11
0.303 au
Peak window
2013-03-08 → 2013-03-14
COBS peak mag 0.5 on 2013-03-11 · perihelion 2013-03-11. Window is those dates ±3 days — not a light-curve fit.
Historic peak
0.5
COBS / analyzed peak 2013-03-11
Catalog ingest
9h ago
Venator last wrote this row 2026-09-16 13:20:17 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
0.303 au
e
1.0000
i
84.90°
Ω
65.10°
ω
334.00°
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/2011 L4 (PANSTARRS)
Informal: PANSTARRS
C/2011 L4 · 2026-09-14 18:27:55 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:55 UTC → current
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1–40 of 120
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.