Back to Contributors

C/1999 U1

C/1999 U1 (Ferris)

CometClass Ecatalogued
Unknown

Not currently visible. Last report 9781 days ago at mag 31.7. Historic peak was mag 15.9. 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

31.7

Professional survey · COBS consensus

Confidence

33

Class E · priority 60

Observations

10

Arc unknown

Last observation

9781d ago

Fri, 28 Jan 2000 11:31:12 GMT · COBS consensus

Perihelion

1998-08-20

4.160 au

Peak window

1998-08-17 → 1998-09-14

COBS peak mag 15.9 on 1998-09-11 · perihelion 1998-08-20. Window is those dates ±3 days — not a light-curve fit.

Historic peak

15.9

COBS / analyzed peak 1998-09-11

Catalog ingest

15h ago

Venator last wrote this row 2026-11-07 14:20:17 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

4.160 au

e

0.9980

i

106.00°

Ω

58.00°

ω

291.00°

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 U1 (Ferris)

    Informal: Ferris

    C/1999 U1 · 2026-09-14 18:27:57 UTC → current

Discoverers

  • Ferris

    Discoverer · parsed-name · 2026-09-14 18:27:57 UTC → current

Contributors

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