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Venator

Early warning for newly discovered comets and unconfirmed objects.

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128P

128P/Shoemaker-Holt

CometClass Ecatalogued
Northern hemisphere

Difficult — CCD / large telescope. Around mag 15.8. A large amateur CCD or a professional telescope is required.

Active comet in COBS

JSONCSV

Right ascension

06h 28m 32s

J2000

Declination

+20° 17′ 53″

J2000

Estimated magnitude

15.8

CCD / citizen telescope · COBS consensus

Confidence

33

Class E · priority 66

Observations

59

80.00 d arc

Last observation

8d ago

Tue, 08 Sep 2026 19:57:21 GMT · COBS consensus

Perihelion

2026-07-17

3.040 au

Peak window

2026-07-14 → 2026-12-22

COBS peak mag 15.2 on 2026-12-19 · perihelion 2026-07-17. Window is those dates ±3 days — not a light-curve fit.

Historic peak

15.2

COBS / analyzed peak 2026-12-19

Catalog ingest

13m ago

Venator last wrote this row 2026-09-16 22:00:03 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

3.040 au

e

0.3220

i

4.37°

Ω

214.00°

ω

211.00°

a

4.480 au

MOID

—

H

—

H0 / n

8.5 / 4

NEO score

—

PHA score

—

RMS

—

Elongation

77°

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

  • 128P/Shoemaker-Holt

    128P · 2026-09-08 02:09:56 UTC → current

Discoverers

  • Shoemaker-Holt

    Discoverer · parsed-name · 2026-09-08 17:27:23 UTC → current

Contributors

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