C/2011 K1
C/2011 K1 (Schwartz-Holvorcem)
Not currently visible. Last report 5634 days ago at mag 34.5. Historic peak was mag 19.3. 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
34.5
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
1
Arc unknown
Last observation
5634d ago
Sun, 05 Jun 2011 07:26:23 GMT · COBS consensus
Perihelion
2011-04-20
3.410 au
Peak window
2011-04-17 → 2011-05-25
COBS peak mag 19.3 on 2011-05-22 · perihelion 2011-04-20. Window is those dates ±3 days — not a light-curve fit.
Historic peak
19.3
COBS / analyzed peak 2011-05-22
Catalog ingest
14h ago
Venator last wrote this row 2026-11-06 14:20:19 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
3.410 au
e
1.0000
i
123.00°
Ω
70.80°
ω
167.00°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
—
Reporting sources
COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
Name history
C/2011 K1 (Schwartz-Holvorcem)
Informal: Schwartz-Holvorcem
C/2011 K1 · 2026-09-14 18:27:55 UTC → current
Discoverers
Discoverer · parsed-name · 2026-09-14 18:27:55 UTC → current
Contributors
CCD Observer · NOV01 · 1 reports · last 5634d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.