C/2021 E3
Not currently visible. Last report 1274 days ago at mag 25.4. Historic peak was mag 11.4. 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
25.4
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
130
Arc unknown
Last observation
1274d ago
Wed, 22 Mar 2023 20:24:00 GMT · COBS consensus
Perihelion
2022-06-10
1.780 au
Peak window
2022-05-31 → 2022-06-13
COBS peak mag 11.4 on 2022-06-03 · perihelion 2022-06-10. Window is those dates ±3 days — not a light-curve fit.
Historic peak
11.4
COBS / analyzed peak 2022-06-03
Catalog ingest
10h ago
Venator last wrote this row 2026-09-16 13:20:19 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
1.780 au
e
0.9990
i
113.00°
Ω
104.00°
ω
229.00°
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/2021 E3 (ZTF)
Informal: ZTF
C/2021 E3 · 2026-09-14 18:28:01 UTC → current
Discoverer · parsed-name · 2026-09-14 18:28:01 UTC → current
CCD Observer · LEH02 · 29 reports · last 1308d ago
Jose Guilherme de Souza Aguiar
Visual Observer · DES01 · 19 reports · last 1553d ago
CCD Observer · CAR06 · 10 reports · last 1301d ago
Visual Observer · WYA · 8 reports · last 1418d ago
CCD Observer · HIL04 · 8 reports · last 1274d ago
CCD Observer · DEK01 · 7 reports · last 1296d ago
CCD Observer · PEA · 5 reports · last 1358d ago
CCD Observer · PAP04 · 5 reports · last 1347d ago
CCD Observer · CHA03 · 5 reports · last 1516d ago
CCD Observer · FRI02 · 5 reports · last 1788d ago
Visual Observer · GOI · 4 reports · last 1544d ago
CCD Observer · SHU · 4 reports · last 1833d ago
Visual Observer · AMO01 · 3 reports · last 1549d ago
CCD Observer · HER02 · 3 reports · last 1592d ago
Visual Observer · MAT08 · 3 reports · last 1545d ago
Visual Observer · CAM03 · 2 reports · last 1601d ago
CCD Observer · RAM02 · 2 reports · last 1629d ago
Visual Observer · SZA · 2 reports · last 1596d ago
CCD Observer · YOU04 · 1 reports · last 1359d ago
Visual Observer · HAR11 · 1 reports · last 1456d ago
CCD Observer · DEM03 · 1 reports · last 1352d ago
CCD Observer · BUI01 · 1 reports · last 1840d ago
CCD Observer · HAR10 · 1 reports · last 1621d ago
CCD Observer · MAS01 · 1 reports · last 1474d ago
CCD Observer · CAR09 · 1 reports · last 1301d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.