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Venator

Early warning for newly discovered comets and unconfirmed objects.

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391P

391P/Kowalski

CometClass Ecatalogued
Both hemispheres

Not currently visible. Last report 530 days ago at mag 17.9. Historic peak was mag 16.7. 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

15h 34m 06s

J2000

Declination

−01° 26′ 38″

J2000

Estimated magnitude

17.9

CCD / citizen telescope · COBS consensus

Confidence

33

Class E · priority 66

Observations

6

Arc unknown

Last observation

530d ago

Sat, 05 Apr 2025 01:11:59 GMT · COBS consensus

Perihelion

2028-05-08

4.140 au

Peak window

2028-05-05 → 2028-08-16

COBS peak mag 16.7 on 2028-08-13 · perihelion 2028-05-08. Window is those dates ±3 days — not a light-curve fit.

Historic peak

16.7

COBS / analyzed peak 2028-08-13

Catalog ingest

3m ago

Venator last wrote this row 2026-09-17 05:00:04 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.

No tail measures stored yet for this object.

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

4.140 au

e

0.1180

i

21.30°

Ω

125.00°

ω

187.00°

a

4.700 au

MOID

—

H

—

H0 / n

8.0 / 4

NEO score

—

PHA score

—

RMS

—

Elongation

59°

Reporting sources

  • COBS comet list

    ok

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

  • COBS orbits

    ok

    Osculating elements and photometric parameters (H0, n) for active comets.

Name history

  • 391P/Kowalski

    391P · 2026-09-13 22:21:23 UTC → current

Discoverers

  • Kowalski

    Discoverer · parsed-name · 2026-09-13 22:21:23 UTC → current

Contributors

  • Kevin Hills

    CCD Observer · HIL04 · 4 reports · last 2515d ago

  • Jiri Srba

    CCD Observer · SRB · 1 reports · last 6912d ago

  • Steffen Fritsche

    CCD Observer · FRI02 · 1 reports · last 530d ago

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