C/1983 H1
Not currently visible. Last report 15775 days ago at mag 36.0. Historic peak was mag 4.4. 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
36.0
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
320
Arc unknown
Last observation
15775d ago
Sun, 10 Jul 1983 11:16:48 GMT · COBS consensus
Perihelion
1983-05-26
1.010 au
Peak window
1983-05-13 → 1983-05-29
COBS peak mag 4.4 on 1983-05-16 · perihelion 1983-05-26. Window is those dates ±3 days — not a light-curve fit.
Historic peak
4.4
COBS / analyzed peak 1983-05-16
Catalog ingest
11h ago
Venator last wrote this row 2026-09-16 13:20:17 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
1.010 au
e
0.9900
i
72.50°
Ω
49.20°
ω
193.00°
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/1983 H1 (IRAS-Araki-Alcock)
Informal: IRAS-Araki-Alcock
C/1983 H1 · 2026-09-14 18:27:57 UTC → current
Discoverer · parsed-name · 2026-09-16 13:20:17 UTC → current
Discoverer · parsed-name · 2026-09-16 13:20:17 UTC → current
Discoverer · parsed-name · 2026-09-16 13:20:17 UTC → current
Discoverer · parsed-name · 2026-09-16 13:20:17 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:57 UTC → 2026-09-16 13:20:17 UTC
Visual Observer · PEA · 43 reports · last 15775d ago
Visual Observer · JON · 23 reports · last 15798d ago
Visual Observer · CLA · 21 reports · last 15781d ago
Visual Observer · SHA02 · 19 reports · last 15833d ago
Visual Observer · BOU · 17 reports · last 15811d ago
Visual Observer · SEA · 15 reports · last 15802d ago
Visual Observer · MOR · 14 reports · last 15834d ago
Visual Observer · GRE · 14 reports · last 15833d ago
Visual Observer · CAM · 14 reports · last 15803d ago
Visual Observer · LOV · 12 reports · last 15804d ago
Visual Observer · HUR · 11 reports · last 15835d ago
Visual Observer · POI · 11 reports · last 15807d ago
Visual Observer · BUS01 · 11 reports · last 15835d ago
Visual Observer · BOR · 10 reports · last 15833d ago
Visual Observer · WEG · 9 reports · last 15835d ago
Visual Observer · OME · 9 reports · last 15834d ago
Visual Observer · COM · 8 reports · last 15834d ago
Visual Observer · KEI · 8 reports · last 15834d ago
Visual Observer · SIM · 8 reports · last 15831d ago
Visual Observer · DEA · 8 reports · last 15802d ago
Visual Observer · SPR · 7 reports · last 15834d ago
Visual Observer · KRO02 · 7 reports · last 15835d ago
Visual Observer · MER · 7 reports · last 15834d ago
Visual Observer · YUS · 7 reports · last 15834d ago
CCD Observer · PEA · 6 reports · last 15784d ago
Visual Observer · MAC · 6 reports · last 15834d ago
Visual Observer · KEE · 6 reports · last 15835d ago
Visual Observer · KOR01 · 6 reports · last 15833d ago
Visual Observer · NAK01 · 5 reports · last 15835d ago
Visual Observer · KAM01 · 5 reports · last 15834d ago
Visual Observer · VEN01 · 5 reports · last 15832d ago
Visual Observer · ASP · 5 reports · last 15834d ago
Visual Observer · DEY · 5 reports · last 15834d ago
Visual Observer · BLA04 · 5 reports · last 15834d ago
Visual Observer · KAN · 5 reports · last 15836d ago
Visual Observer · MCN · 5 reports · last 15836d ago
Visual Observer · SIM01 · 5 reports · last 15832d ago
Visual Observer · ISH02 · 4 reports · last 15836d ago
Visual Observer · MAR01 · 4 reports · last 15836d ago
Visual Observer · CHE03 · 4 reports · last 15834d ago
1–40 of 74
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.