Astro-Observer

Meteor showers

Alpha Monocerotid Meteor Shower

By Astro-Observer · Last reviewed November 8, 2026

Active
November 15 – November 25
Peak
Around November 21–22
Peak rate (ZHR)
Variable (up to 400 in the 1995 outburst)
Radiant
Canis Minor (7h 48m, +1°)
Speed
65 km/s (fast)
Best seen from
Both hemispheres
Best time
After midnight, best in the hours before dawn

Next peaks

Expected peak (UTC)Moon at peakMoonlight
November 22, 2026, around 0h Waxing gibbous, 91% lit Bright Moon
November 22, 2027, around 6h Waning crescent, 36% lit Some

Recent outbursts have lasted less than an hour, and they come only in rare years, so the exact hour matters.

Computed from the shower's peak solar longitude (λ☉ 239.32°). Real peaks can come a few hours early or late, and you will see meteors on the nights either side. The peak hour may be in daylight where you are; watch the darkest hours of the nearest night.

The Alpha Monocerotids are a shower of surprises. In most years it is almost silent. But a few times in the past hundred years Earth has crossed a narrow, dense ribbon of dust, and for a short while fast meteors poured from a point near Procyon.

Where the meteors come from

No parent body has been identified. Astronomers who measured meteoroid orbits during the 1995 outburst concluded that the dust came from a narrow trail in the orbit of a long-period comet that has not been found. Only when the planets' pull shifts that trail into Earth's path do we get an outburst.

When to watch

The shower is active from November 15 to 25, with the peak around November 22; the table above gives the expected time and the Moon. Outside forecast outburst years, the peak night is no better than any other. The radiant rises in the east in the late evening and is highest in the small hours.

How to find the radiant

The shower is named after Monoceros, the faint Unicorn, but the radiant falls just over the border in Canis Minor, about 5° south of Procyon. Procyon is the bright star east of Orion; dim Monoceros lies just to its south. The radiant lies almost on the celestial equator, so it is well placed from both hemispheres.

What to expect

In most years the shower is barely detectable by eye. Outbursts are another story: in 2019 most observers counted 10 to 20 meteors in under half an hour. The meteors are fast, at 65 km/s, and a population index of 2.4 means a good share are bright.

Viewing tips

  • Make a special effort only in a year with a published outburst prediction.
  • Be outside an hour before the predicted time, in case it comes early.
  • Count in five-minute blocks and note the times.
  • Dress for a long, cold wait in the small hours.

History and notable displays

Outbursts were seen in 1925, 1935, 1985 and 1995. The 1995 event lasted about 40 minutes with a ZHR up to 400. For 2019, Esko Lyytinen and Peter Jenniskens predicted a short outburst on November 22 near 04h50m UT, possibly close to 1995 levels. It came on time, around 04h57m UT, but weaker, with a ZHR of about 80 to 100.

About the numbers. The ZHR (zenithal hourly rate) is how many meteors one observer would see in an hour under a perfectly dark sky with the radiant straight overhead. Real counts are almost always lower: under suburban skies, or with the radiant low, expect a half to a quarter of it, or less.

Sources

Checked November 8, 2026.