C/2020 R4
Not visible to typical instruments. Current estimate mag 31.8. Historic peak was mag 7.7. Visual and most CCD amateur setups will not see it. Space telescopes or large ground telescopes are the remaining path.
Right ascension
—
J2000
Declination
—
J2000
Estimated magnitude
31.8
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
302
Arc unknown
Last observation
5d ago
Fri, 11 Sep 2026 23:45:36 GMT · COBS consensus
Perihelion
2021-03-02
1.020 au
Peak window
2021-02-27 → 2021-04-23
COBS peak mag 7.7 on 2021-04-20 · perihelion 2021-03-02. Window is those dates ±3 days — not a light-curve fit.
Historic peak
7.7
COBS / analyzed peak 2021-04-20
Catalog ingest
14h ago
Venator last wrote this row 2026-09-16 13:20:18 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
1.020 au
e
0.9890
i
164.00°
Ω
323.00°
ω
46.50°
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/2020 R4 (ATLAS)
Informal: ATLAS
C/2020 R4 · 2026-09-14 18:28:00 UTC → current
Discoverer · parsed-name · 2026-09-14 18:28:00 UTC → current
Jose Guilherme de Souza Aguiar
Visual Observer · DES01 · 31 reports · last 1971d ago
CCD Observer · LEH02 · 28 reports · last 1896d ago
Visual Observer · COL02 · 16 reports · last 1949d ago
CCD Observer · DEK01 · 16 reports · last 1934d ago
CCD Observer · FRI02 · 15 reports · last 1934d ago
Visual Observer · GON05 · 14 reports · last 1925d ago
CCD Observer · CAR06 · 14 reports · last 1926d ago
Visual Observer · KWI · 13 reports · last 1949d ago
CCD Observer · YOS02 · 11 reports · last 1961d ago
Visual Observer · WYA · 9 reports · last 1929d ago
Visual Observer · DIJ · 9 reports · last 1951d ago
CCD Observer · HAR10 · 9 reports · last 1974d ago
Visual Observer · HAR11 · 8 reports · last 1951d ago
CCD Observer · PAP04 · 7 reports · last 1949d ago
Visual Observer · WOL01 · 7 reports · last 1973d ago
Visual Observer · FIL04 · 7 reports · last 1949d ago
Visual Observer · SCH04 · 6 reports · last 1958d ago
Visual Observer · LAB02 · 6 reports · last 1954d ago
Visual Observer · GOI · 6 reports · last 1975d ago
CCD Observer · MAS01 · 6 reports · last 1955d ago
Visual Observer · TSU02 · 6 reports · last 1957d ago
Visual Observer · MOR03 · 6 reports · last 1953d ago
Visual Observer · BIV · 5 reports · last 1927d ago
Visual Observer · MIY01 · 5 reports · last 1951d ago
CCD Observer · HIL04 · 4 reports · last 1974d ago
Visual Observer · GET · 4 reports · last 1974d ago
Visual Observer · KAR02 · 4 reports · last 1959d ago
Visual Observer · KUT · 4 reports · last 1934d ago
Visual Observer · AMO01 · 3 reports · last 1991d ago
CCD Observer · NOV01 · 3 reports · last 1956d ago
Visual Observer · HER02 · 3 reports · last 1965d ago
Visual Observer · SHA02 · 3 reports · last 1960d ago
Visual Observer · MAT08 · 3 reports · last 2000d ago
Visual Observer · DEC · 3 reports · last 1982d ago
CCD Observer · PAR03 · 3 reports · last 1954d ago
CCD Observer · SHU · 3 reports · last 5d ago
Visual Observer · HAS02 · 3 reports · last 1933d ago
Visual Observer · NOV01 · 2 reports · last 1961d ago
CCD Observer · BRY04 · 2 reports · last 1958d ago
Visual Observer · BUI01 · 2 reports · last 1958d ago
1–40 of 58
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.