300P
Not currently visible. Last report 1359 days ago at mag 24.1. Historic peak was mag 13.8. 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
24.1
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
28
Arc unknown
Last observation
1359d ago
Fri, 17 Feb 2023 03:43:00 GMT · COBS consensus
Perihelion
2027-09-13
0.827 au
Peak window
2027-09-10 → 2027-09-17
COBS peak mag 13.8 on 2027-09-14 · perihelion 2027-09-13. Window is those dates ±3 days — not a light-curve fit.
Historic peak
13.8
COBS / analyzed peak 2027-09-14
Catalog ingest
14h ago
Venator last wrote this row 2026-11-06 14:20:20 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
0.827 au
e
0.6930
i
5.67°
Ω
95.60°
ω
223.00°
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).
300P/Catalina
300P · 2026-09-14 18:27:56 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:56 UTC → current
CCD Observer · SRB · 3 reports · last 7806d ago
CCD Observer · TSU02 · 3 reports · last 7805d ago
Visual Observer · YOS04 · 3 reports · last 7762d ago
CCD Observer · PRY01 · 3 reports · last 4538d ago
Visual Observer · WOL01 · 2 reports · last 4542d ago
Visual Observer · GON05 · 2 reports · last 7803d ago
CCD Observer · HIL04 · 2 reports · last 4523d ago
CCD Observer · MAS01 · 2 reports · last 2890d ago
CCD Observer · NAK01 · 1 reports · last 7826d ago
Visual Observer · WYA · 1 reports · last 4545d ago
CCD Observer · PAP04 · 1 reports · last 1359d ago
CCD Observer · WAR01 · 1 reports · last 2868d ago
CCD Observer · HOR02 · 1 reports · last 7828d ago
CCD Observer · MAT08 · 1 reports · last 2934d ago
Visual Observer · MAT08 · 1 reports · last 7803d ago
CCD Observer · OHS · 1 reports · last 7763d ago
Visual Observer · TOT03 · 1 reports · last 7833d ago
Visual Observer · URB01 · 1 reports · last 7735d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.