C/2013 N4
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.
Right ascension
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J2000
Declination
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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
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.
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
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COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/2013 N4 (Borisov)
Informal: Borisov
C/2013 N4 · 2026-09-14 18:27:56 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:56 UTC → current
Visual Observer · WOL01 · 3 reports · last 4664d ago
Visual Observer · GON05 · 2 reports · last 4778d ago
Visual Observer · BIV · 2 reports · last 4756d ago
CCD Observer · PAP04 · 1 reports · last 4688d ago
CCD Observer · YOS02 · 1 reports · last 4734d ago
Visual Observer · YOS04 · 1 reports · last 4722d ago
CCD Observer · PRY01 · 1 reports · last 4637d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.