Back to Contributors

221P

221P/LINEAR

CometClass Ecatalogued
Unknown

Not currently visible. Last report 1955 days ago at mag 24.2. 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.

Active comet in COBS

Right ascension

J2000

Declination

J2000

Estimated magnitude

24.2

Professional survey · COBS consensus

Confidence

33

Class E · priority 60

Observations

10

Arc unknown

Last observation

1955d ago

Mon, 10 May 2021 18:14:23 GMT · COBS consensus

Perihelion

2028-04-04

1.620 au

Peak window

2028-04-01 → 2028-04-12

COBS peak mag 17.6 on 2028-04-09 · perihelion 2028-04-04. Window is those dates ±3 days — not a light-curve fit.

Historic peak

17.6

COBS / analyzed peak 2028-04-09

Catalog ingest

11h 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

1.620 au

e

0.5210

i

10.30°

Ω

220.00°

ω

48.20°

a

MOID

H

H0 / n

NEO score

PHA score

RMS

Elongation

Reporting sources

  • COBS comet list

    ok

    Comet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).

Name history

  • 221P/LINEAR

    221P · 2026-09-14 18:27:55 UTC → current

Discoverers

  • LINEAR

    Discoverer · parsed-name · 2026-09-14 18:27:55 UTC → current

Contributors

Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.