C/2019 Y4
Not currently visible. Last report 2309 days ago at mag 37.3. Historic peak was mag 2.4. 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
37.3
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
728
Arc unknown
Last observation
2309d ago
Thu, 21 May 2020 21:35:59 GMT · COBS consensus
Perihelion
2020-05-29
0.257 au
Peak window
2020-05-25 → 2020-06-01
COBS peak mag 2.4 on 2020-05-28 · perihelion 2020-05-29. Window is those dates ±3 days — not a light-curve fit.
Historic peak
2.4
COBS / analyzed peak 2020-05-28
Catalog ingest
9h 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
0.257 au
e
0.9990
i
44.90°
Ω
121.00°
ω
177.00°
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/2019 Y4 (ATLAS)
Informal: ATLAS
C/2019 Y4 · 2026-09-14 18:27:59 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:59 UTC → current
CCD Observer · LEH02 · 59 reports · last 2309d ago
CCD Observer · YOS02 · 51 reports · last 2318d ago
CCD Observer · FRI02 · 48 reports · last 2312d ago
Visual Observer · GUZ · 42 reports · last 2316d ago
Visual Observer · HAR11 · 41 reports · last 2314d ago
CCD Observer · DEK01 · 40 reports · last 2311d ago
CCD Observer · BUC01 · 34 reports · last 2336d ago
Visual Observer · MEY · 33 reports · last 2319d ago
CCD Observer · NOV01 · 29 reports · last 2329d ago
Visual Observer · DIJ · 28 reports · last 2316d ago
Visual Observer · KWI · 28 reports · last 2316d ago
CCD Observer · MAS01 · 28 reports · last 2312d ago
Visual Observer · SCH04 · 25 reports · last 2317d ago
CCD Observer · HER02 · 25 reports · last 2331d ago
Visual Observer · GET · 25 reports · last 2310d ago
Visual Observer · SHA02 · 24 reports · last 2334d ago
Visual Observer · HER02 · 22 reports · last 2318d ago
Visual Observer · COL02 · 21 reports · last 2319d ago
Visual Observer · SCH19 · 19 reports · last 2324d ago
Visual Observer · BIV · 18 reports · last 2312d ago
CCD Observer · JAM02 · 17 reports · last 2321d ago
Visual Observer · WAR01 · 14 reports · last 2319d ago
Visual Observer · MOR03 · 14 reports · last 2318d ago
Visual Observer · BOH02 · 13 reports · last 2338d ago
Visual Observer · SCI · 13 reports · last 2339d ago
CCD Observer · KII · 12 reports · last 2336d ago
Visual Observer · LEH · 11 reports · last 2334d ago
Visual Observer · SZA · 11 reports · last 2313d ago
Visual Observer · KAM01 · 9 reports · last 2335d ago
Visual Observer · POW01 · 9 reports · last 2343d ago
CCD Observer · SWA01 · 8 reports · last 2326d ago
CCD Observer · HAR10 · 8 reports · last 2336d ago
Visual Observer · FIL04 · 8 reports · last 2339d ago
Visual Observer · DEC · 8 reports · last 2345d ago
Visual Observer · HEG01 · 7 reports · last 2346d ago
Visual Observer · CSO · 7 reports · last 2335d ago
Visual Observer · KAR02 · 7 reports · last 2334d ago
Visual Observer · KAS01 · 7 reports · last 2338d ago
Visual Observer · BIE02 · 6 reports · last 2310d ago
Visual Observer · PIL01 · 6 reports · last 2343d ago
1–40 of 94
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.