C/1998 M3
Not currently visible. Last report 10038 days ago at mag 31.6. 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
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J2000
Declination
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J2000
Estimated magnitude
31.6
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
11
Arc unknown
Last observation
10039d ago
Fri, 14 May 1999 17:02:24 GMT · COBS consensus
Perihelion
1998-07-14
5.750 au
Peak window
1998-06-24 → 1998-07-17
COBS peak mag 17.6 on 1998-06-27 · perihelion 1998-07-14. Window is those dates ±3 days — not a light-curve fit.
Historic peak
17.6
COBS / analyzed peak 1998-06-27
Catalog ingest
15h ago
Venator last wrote this row 2026-11-06 14:20:21 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
5.750 au
e
0.9990
i
113.00°
Ω
256.00°
ω
20.70°
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/1998 M3 (Larsen)
Informal: Larsen
C/1998 M3 · 2026-09-14 18:27:58 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:58 UTC → current
CCD Observer · NAK01 · 5 reports · last 10039d ago
Visual Observer · SCO01 · 3 reports · last 10300d ago
Seiichi Yoshida and KenIchi Kadota
CCD Observer · YOS05 · 3 reports · last 10070d ago
CCD Observer · YOS04 · 2 reports · last 10091d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.