278P
278P/McNaught
Not currently visible. Last report 1829 days ago at mag 22.3. Historic peak was mag 18.2. 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
22.3
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
10
Arc unknown
Last observation
1829d ago
Mon, 13 Sep 2021 23:45:36 GMT · COBS consensus
Perihelion
2027-09-16
1.970 au
Peak window
2027-05-05 → 2027-09-19
COBS peak mag 18.2 on 2027-05-08 · perihelion 2027-09-16. Window is those dates ±3 days — not a light-curve fit.
Historic peak
18.2
COBS / analyzed peak 2027-05-08
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
1.970 au
e
0.4550
i
6.66°
Ω
10.40°
ω
244.00°
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
278P/McNaught
278P · 2026-09-14 18:27:55 UTC → current
Discoverers
Discoverer · parsed-name · 2026-09-14 18:27:55 UTC → current
Contributors
CCD Observer · HIL04 · 7 reports · last 1829d ago
CCD Observer · PAP04 · 2 reports · last 1965d ago
CCD Observer · PRY01 · 1 reports · last 4887d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.