C/2009 F6
Not currently visible. Last report 6200 days ago at mag 29.4. Historic peak was mag 8.3. 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
29.4
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
117
Arc unknown
Last observation
6200d ago
Sat, 26 Sep 2009 07:40:48 GMT · COBS consensus
Perihelion
2009-05-09
1.250 au
Peak window
2009-04-22 → 2009-05-12
COBS peak mag 8.3 on 2009-04-25 · perihelion 2009-05-09. Window is those dates ±3 days — not a light-curve fit.
Historic peak
8.3
COBS / analyzed peak 2009-04-25
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
1.250 au
e
0.9970
i
85.70°
Ω
279.00°
ω
129.00°
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/2009 F6 (Yi-SWAN)
Informal: Yi-SWAN
C/2009 F6 · 2026-09-14 18:27:53 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:53 UTC → current
Visual Observer · LEH · 13 reports · last 6350d ago
Visual Observer · RES · 10 reports · last 6350d ago
Visual Observer · GET · 10 reports · last 6329d ago
Visual Observer · CER01 · 8 reports · last 6332d ago
Visual Observer · DIJ · 7 reports · last 6354d ago
Visual Observer · SHA02 · 6 reports · last 6353d ago
Visual Observer · BOU · 6 reports · last 6329d ago
Visual Observer · MEY · 5 reports · last 6358d ago
Visual Observer · MOR03 · 5 reports · last 6350d ago
Visual Observer · CHR · 4 reports · last 6334d ago
Visual Observer · FRA01 · 3 reports · last 6357d ago
CCD Observer · SRB · 3 reports · last 6357d ago
Visual Observer · FIL04 · 3 reports · last 6352d ago
Visual Observer · HAH · 3 reports · last 6338d ago
Visual Observer · PAR03 · 3 reports · last 6353d ago
CCD Observer · YUS · 3 reports · last 6323d ago
Visual Observer · SCH04 · 2 reports · last 6357d ago
Visual Observer · GRA04 · 2 reports · last 6367d ago
Visual Observer · LAB02 · 2 reports · last 6331d ago
Visual Observer · QVA · 2 reports · last 6368d ago
Visual Observer · GON05 · 2 reports · last 6322d ago
CCD Observer · YOS02 · 2 reports · last 6331d ago
Visual Observer · GOI · 2 reports · last 6200d ago
Visual Observer · PIL01 · 2 reports · last 6336d ago
Visual Observer · KAM01 · 1 reports · last 6368d ago
Visual Observer · KUO · 1 reports · last 6368d ago
CCD Observer · OKS01 · 1 reports · last 6370d ago
Visual Observer · NOV01 · 1 reports · last 6370d ago
Visual Observer · GIL01 · 1 reports · last 6360d ago
Visual Observer · HOR02 · 1 reports · last 6353d ago
Visual Observer · NAG04 · 1 reports · last 6362d ago
Visual Observer · CHU06 · 1 reports · last 6365d ago
Visual Observer · BUS01 · 1 reports · last 6361d ago
Visual Observer · GUZ · 1 reports · last 6353d ago
Visual Observer · HEG01 · 1 reports · last 6367d ago
CCD Observer · SHU · 1 reports · last 6371d ago
Visual Observer · KAR02 · 1 reports · last 6361d ago
Visual Observer · SCI · 1 reports · last 6351d ago
Visual Observer · HAS02 · 1 reports · last 6365d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.