C/2025 K1
Not currently visible. Last report 237 days ago at mag 22.5. Historic peak was mag 8.0. 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
—
J2000
Declination
—
J2000
Estimated magnitude
22.5
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
710
Arc unknown
Last observation
237d ago
Thu, 22 Jan 2026 18:57:35 GMT · COBS consensus
Perihelion
2025-10-08
0.334 au
Peak window
2025-10-05 → 2025-10-12
COBS peak mag 8.0 on 2025-10-09 · perihelion 2025-10-08. Window is those dates ±3 days — not a light-curve fit.
Historic peak
8.0
COBS / analyzed peak 2025-10-09
Catalog ingest
9h ago
Venator last wrote this row 2026-09-16 13:20:20 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.
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
0.334 au
e
1.0000
i
148.00°
Ω
97.60°
ω
271.00°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
—
COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/2025 K1 (ATLAS)
Informal: ATLAS
C/2025 K1 · 2026-09-14 18:28:02 UTC → current
Discoverer · parsed-name · 2026-09-14 18:28:02 UTC → current
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Jose Guilherme de Souza Aguiar
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CCD Observer · PAP04 · 7 reports · last 294d ago
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Visual Observer · HAS02 · 5 reports · last 281d ago
1–40 of 85
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.