comets.venator.space

Venator

Early warning for newly discovered comets and unconfirmed objects.

Back to Contributors

C/2004 S1

C/2004 S1 (Van Ness)

CometClass Ecatalogued
Unknown

Not currently visible. Last report 8051 days ago at mag 41.1. Historic peak was mag 15.0. 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

JSONCSV

Right ascension

—

J2000

Declination

—

J2000

Estimated magnitude

41.1

Professional survey · COBS consensus

Confidence

33

Class E · priority 60

Observations

12

Arc unknown

Last observation

8051d ago

Thu, 21 Oct 2004 20:38:23 GMT · COBS consensus

Perihelion

2004-12-08

—

Peak window

2004-10-14 → 2004-12-11

COBS peak mag 15.0 on 2004-10-17 · perihelion 2004-12-08. Window is those dates ±3 days — not a light-curve fit.

Historic peak

15.0

COBS / analyzed peak 2004-10-17

Catalog ingest

13h ago

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

—

e

—

i

—

Ω

—

ω

—

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/2004 S1 (Van Ness)

    Informal: Van Ness

    C/2004 S1 · 2026-09-14 18:27:57 UTC → current

Discoverers

  • Van Ness

    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.