P/2021 U3
P/2021 U3 (Attard-Maury)
Not currently visible. Last report 1813 days ago at mag 27.8. 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
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J2000
Estimated magnitude
27.8
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
1
Arc unknown
Last observation
1813d ago
Fri, 19 Nov 2021 21:50:24 GMT · COBS consensus
Perihelion
2021-10-24
1.890 au
Peak window
2021-10-21 → 2021-12-05
COBS peak mag 18.2 on 2021-12-02 · perihelion 2021-10-24. Window is those dates ±3 days — not a light-curve fit.
Historic peak
18.2
COBS / analyzed peak 2021-12-02
Catalog ingest
14h ago
Venator last wrote this row 2026-11-06 14:20:23 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
1.890 au
e
0.5490
i
70.00°
Ω
75.10°
ω
335.00°
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
P/2021 U3 (Attard-Maury)
Informal: Attard-Maury
P/2021 U3 · 2026-09-14 18:28:01 UTC → current
Discoverers
Discoverer · parsed-name · 2026-09-14 18:28:01 UTC → current
Contributors
CCD Observer · PAP04 · 1 reports · last 1813d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.