P/2007 R1
P/2007 R1 (Larson)
Not currently visible. Last report 1998 days ago at mag 20.8. Historic peak was mag 17.1. 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
20.8
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
2
Arc unknown
Last observation
1998d ago
Mon, 29 Mar 2021 04:04:48 GMT · COBS consensus
Perihelion
2036-01-23
4.380 au
Peak window
2035-08-07 → 2036-01-26
COBS peak mag 17.1 on 2035-08-10 · perihelion 2036-01-23. Window is those dates ±3 days — not a light-curve fit.
Historic peak
17.1
COBS / analyzed peak 2035-08-10
Catalog ingest
23m ago
Venator last wrote this row 2026-09-17 04:00:04 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
4.380 au
e
0.2560
i
8.35°
Ω
169.00°
ω
163.00°
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/2007 R1 (Larson)
Informal: Larson
P/2007 R1 · 2026-09-14 18:27:53 UTC → current
Discoverers
Discoverer · parsed-name · 2026-09-14 18:27:53 UTC → current
Contributors
CCD Observer · PAP04 · 1 reports · last 1998d ago
CCD Observer · TSU02 · 1 reports · last 6911d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.