250P
250P/Larson
Not currently visible. Last report 657 days ago at mag 23.4. Historic peak was mag 19.5. 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
—
J2000
Declination
—
J2000
Estimated magnitude
23.4
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
8
Arc unknown
Last observation
657d ago
Fri, 29 Nov 2024 01:12:00 GMT · COBS consensus
Perihelion
2025-05-16
2.270 au
Peak window
2024-12-20 → 2025-05-19
COBS peak mag 19.5 on 2024-12-23 · perihelion 2025-05-16. Window is those dates ±3 days — not a light-curve fit.
Historic peak
19.5
COBS / analyzed peak 2024-12-23
Catalog ingest
15h ago
Venator last wrote this row 2026-09-16 13:20:16 UTC
Light curve
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.
Orbital elements
q
2.270 au
e
0.3980
i
13.20°
Ω
73.30°
ω
45.70°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
—
Reporting sources
COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
Name history
250P/Larson
250P · 2026-09-14 18:27:54 UTC → current
Discoverers
Discoverer · parsed-name · 2026-09-14 18:27:54 UTC → current
Contributors
CCD Observer · NOV01 · 3 reports · last 5683d ago
CCD Observer · HIL04 · 2 reports · last 657d ago
CCD Observer · SHU · 2 reports · last 5712d ago
CCD Observer · MAI01 · 1 reports · last 707d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.