C/2015 C2
Not currently visible. Last report 4084 days ago at mag 35.7. Historic peak was mag 13.2. 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
35.7
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
15
Arc unknown
Last observation
4084d ago
Sun, 12 Jul 2015 20:52:47 GMT · COBS consensus
Perihelion
2015-03-04
0.705 au
Peak window
2015-02-24 → 2015-03-07
COBS peak mag 13.2 on 2015-02-27 · perihelion 2015-03-04. Window is those dates ±3 days — not a light-curve fit.
Historic peak
13.2
COBS / analyzed peak 2015-02-27
Catalog ingest
14h 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.
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.
q
0.705 au
e
0.9980
i
94.80°
Ω
49.10°
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/2015 C2 (SWAN)
Informal: SWAN
C/2015 C2 · 2026-09-14 18:27:56 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:56 UTC → current
Visual Observer · BIE02 · 3 reports · last 4139d ago
CCD Observer · MAT08 · 3 reports · last 4216d ago
Visual Observer · GON05 · 2 reports · last 4142d ago
Visual Observer · GUZ · 2 reports · last 4163d ago
CCD Observer · PRY01 · 2 reports · last 4084d ago
Visual Observer · MAT08 · 1 reports · last 4221d ago
Visual Observer · SZA · 1 reports · last 4200d ago
Visual Observer · YOS04 · 1 reports · last 4156d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.