C/2023 A1
Not currently visible. Last report 1233 days ago at mag 30.2. Historic peak was mag 17.6. 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
30.2
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
32
Arc unknown
Last observation
1233d ago
Tue, 02 May 2023 20:21:00 GMT · COBS consensus
Perihelion
2023-03-18
1.840 au
Peak window
2023-03-01 → 2023-03-21
COBS peak mag 17.6 on 2023-03-04 · perihelion 2023-03-18. Window is those dates ±3 days — not a light-curve fit.
Historic peak
17.6
COBS / analyzed peak 2023-03-04
Catalog ingest
11h 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.
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
0.9920
i
94.70°
Ω
318.00°
ω
159.00°
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 A1 (Leonard)
Informal: Leonard
C/2023 A1 · 2026-09-14 18:28:01 UTC → current
Discoverer · parsed-name · 2026-09-14 18:28:01 UTC → current
CCD Observer · DEK01 · 11 reports · last 1294d ago
CCD Observer · MAS01 · 4 reports · last 1300d ago
CCD Observer · PAP04 · 3 reports · last 1233d ago
CCD Observer · CAR06 · 3 reports · last 1281d ago
CCD Observer · CAR09 · 3 reports · last 1281d ago
CCD Observer · FRI02 · 3 reports · last 1285d ago
CCD Observer · SHU · 2 reports · last 1254d ago
CCD Observer · QVA · 1 reports · last 1297d ago
CCD Observer · YOS02 · 1 reports · last 1278d ago
CCD Observer · HIL04 · 1 reports · last 1259d ago
CCD Observer · TIR01 · 1 reports · last 1295d ago
Visual Observer · SZA · 1 reports · last 1271d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.