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C/2013 N4

C/2013 N4 (Borisov)

CometClass Ecatalogued
Unknown

Not currently visible. Last report 4637 days ago at mag 33.7. Historic peak was mag 14.4. 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

33.7

Professional survey · COBS consensus

Confidence

33

Class E · priority 60

Observations

11

Arc unknown

Last observation

4637d ago

Sun, 05 Jan 2014 17:16:47 GMT · COBS consensus

Perihelion

2013-08-19

1.200 au

Peak window

2013-08-16 → 2013-08-22

COBS peak mag 14.4 on 2013-08-19 · perihelion 2013-08-19. Window is those dates ±3 days — not a light-curve fit.

Historic peak

14.4

COBS / analyzed peak 2013-08-19

Catalog ingest

12h ago

Venator last wrote this row 2026-09-16 13:20:17 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.

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

1.200 au

e

0.9740

i

37.00°

Ω

323.00°

ω

142.00°

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/2013 N4 (Borisov)

    Informal: Borisov

    C/2013 N4 · 2026-09-14 18:27:56 UTC → current

Discoverers

  • Borisov

    Discoverer · parsed-name · 2026-09-14 18:27:56 UTC → current

Contributors

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