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C/1999 E1

C/1999 E1 (Li)

CometClass Ecatalogued
Unknown

Not currently visible. Last report 9361 days ago at mag 28.3. Historic peak was mag 14.8. 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

28.3

Professional survey · COBS consensus

Confidence

33

Class E · priority 60

Observations

42

Arc unknown

Last observation

9361d ago

Wed, 21 Mar 2001 18:00:00 GMT · COBS consensus

Perihelion

1999-02-06

3.900 au

Peak window

1999-01-06 → 1999-02-09

COBS peak mag 14.8 on 1999-01-09 · perihelion 1999-02-06. Window is those dates ±3 days — not a light-curve fit.

Historic peak

14.8

COBS / analyzed peak 1999-01-09

Catalog ingest

14h ago

Venator last wrote this row 2026-11-06 14:20:18 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

3.900 au

e

0.7610

i

47.00°

Ω

128.00°

ω

330.00°

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

  • C/1999 E1 (Li)

    Informal: Li

    C/1999 E1 · 2026-09-14 18:27:54 UTC → current

Discoverers

  • Li

    Discoverer · parsed-name · 2026-09-14 18:27:54 UTC → current

Contributors

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