C/2011 F1
Not currently visible. Last report 4563 days ago at mag 27.2. Historic peak was mag 9.9. 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
27.2
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
291
Arc unknown
Last observation
4563d ago
Fri, 21 Mar 2014 10:04:48 GMT · COBS consensus
Perihelion
2013-01-07
1.840 au
Peak window
2013-01-04 → 2013-01-10
COBS peak mag 9.9 on 2013-01-07 · perihelion 2013-01-07. Window is those dates ±3 days — not a light-curve fit.
Historic peak
9.9
COBS / analyzed peak 2013-01-07
Catalog ingest
11h ago
Venator last wrote this row 2026-09-16 13:20:16 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
1.840 au
e
1.0000
i
56.50°
Ω
85.10°
ω
193.00°
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 F1 (LINEAR)
Informal: LINEAR
C/2011 F1 · 2026-09-14 18:27:54 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:54 UTC → current
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CCD Observer · TSU02 · 10 reports · last 5091d ago
CCD Observer · SHU · 10 reports · last 5143d ago
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CCD Observer · YOS02 · 7 reports · last 5241d ago
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Visual Observer · NOV01 · 3 reports · last 5114d ago
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CCD Observer · HAR10 · 3 reports · last 5234d ago
Visual Observer · PAR03 · 3 reports · last 5233d ago
Visual Observer · KUT · 3 reports · last 5113d ago
CCD Observer · NAG08 · 3 reports · last 5156d ago
Visual Observer · NAG08 · 3 reports · last 5170d ago
CCD Observer · CER01 · 2 reports · last 5137d ago
Visual Observer · GUZ · 2 reports · last 5141d ago
CCD Observer · DYM · 2 reports · last 5187d ago
Visual Observer · CSO · 2 reports · last 5205d ago
Visual Observer · HAS02 · 2 reports · last 5141d ago
Visual Observer · SCH18 · 1 reports · last 5167d ago
Visual Observer · MAS01 · 1 reports · last 5233d ago
Visual Observer · AGU01 · 1 reports · last 5149d ago
Visual Observer · YOS04 · 1 reports · last 5143d ago
CCD Observer · YUS · 1 reports · last 5196d ago
CCD Observer · KUT · 1 reports · last 5148d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.