C/2023 A2
Not currently visible. Last report 1295 days ago at mag 29.9. Historic peak was mag 14.5. 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
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J2000
Declination
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J2000
Estimated magnitude
29.9
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
3
Arc unknown
Last observation
1295d ago
Thu, 02 Mar 2023 03:40:00 GMT · COBS consensus
Perihelion
2023-01-20
0.944 au
Peak window
2023-01-13 → 2023-01-23
COBS peak mag 14.5 on 2023-01-16 · perihelion 2023-01-20. Window is those dates ±3 days — not a light-curve fit.
Historic peak
14.5
COBS / analyzed peak 2023-01-16
Catalog ingest
12h ago
Venator last wrote this row 2026-09-16 13:20:19 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
0.944 au
e
0.9980
i
94.70°
Ω
94.50°
ω
142.00°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
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COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/2023 A2 (SWAN)
Informal: SWAN
C/2023 A2 · 2026-09-14 18:28:01 UTC → current
Discoverer · parsed-name · 2026-09-14 18:28:01 UTC → current
CCD Observer · PAP04 · 1 reports · last 1295d ago
CCD Observer · YOS02 · 1 reports · last 1325d ago
CCD Observer · MAS01 · 1 reports · last 1302d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.