C/1968 H1
Not currently visible. Last report 21289 days ago at mag 34.8. Historic peak was mag 3.8. 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
34.8
Professional survey · COBS consensus
Confidence
33
Class E · priority 60
Observations
45
Arc unknown
Last observation
21289d ago
Mon, 03 Jun 1968 23:02:24 GMT · COBS consensus
Perihelion
1968-04-14
0.687 au
Peak window
1968-04-04 → 1968-04-17
COBS peak mag 3.8 on 1968-04-07 · perihelion 1968-04-14. Window is those dates ±3 days — not a light-curve fit.
Historic peak
3.8
COBS / analyzed peak 1968-04-07
Catalog ingest
15h 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
0.687 au
e
0.9960
i
101.00°
Ω
232.00°
ω
50.20°
a
—
MOID
—
H
—
H0 / n
—
NEO score
—
PHA score
—
RMS
—
Elongation
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COBS comet list
okComet Observation Database magnitudes and perihelion data for the full COBS list (active and inactive).
C/1968 H1 (Tago-Honda-Yamamoto)
Informal: Tago-Honda-Yamamoto
C/1968 H1 · 2026-09-14 18:27:57 UTC → current
Discoverer · parsed-name · 2026-09-14 18:27:57 UTC → current
Visual Observer · SIM · 21 reports · last 21292d ago
Visual Observer · BEY · 9 reports · last 21289d ago
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Visual Observer · MCC03 · 4 reports · last 21305d ago
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Visual Observer · CHE06 · 3 reports · last 21319d ago
Visual Observer · PAN · 2 reports · last 21305d ago
Visual Observer · TAY02 · 1 reports · last 21311d ago
Visual Observer · BOR · 1 reports · last 21316d ago
Visual Observer · DEL · 1 reports · last 21308d ago
Visual Observer · CHU · 1 reports · last 21314d ago
Visual Observer · MIL03 · 1 reports · last 21316d ago
Visual Observer · MIN · 1 reports · last 21322d ago
Visual Observer · VSE · 1 reports · last 21315d ago
Pips are observation weight on this object (log of report count). Hover for catalog-wide weight.