The meteor observer’s year

Contents

Introduction

Finding out which meteor showers are active each month can be a challenge. Some published lists haven’t been updated for over 20 years and don’t take into account more recent and more accurate video observations. Some more recent lists go too far and extend the activity dates of meteor showers to those detectable using video methods but well beyond those during which the meteor shower will be evident visually.

The list is largely based on the 2014 revision of the International Meteor Organization’s (IMO’s) Working List of Visual Meteor Showers, which itself is based on “A Comprehensive List of Meteor Showers Obtained from 10 Years of Observations with the IMO Video Meteor Network” by Sirko Molau and Jurgen Rendtel.  Amendments continue to be made using reliable data to ensure the information remains as fully up-to-date as possible, since as we have discovered in the last two decades, meteor showers are not fixed things, but are constantly changing, some faster than others.

SPA observers are encouraged to cover these showers because they are known to be genuinely active at the present time, and they produce visually-detectable rates.

Diurnal and Seasonal Variations

In addition to the variations in meteor rates due to major meteor showers listed later, there are also general daily and seasonal trends in meteor rates. In the same way as the front of your coat gets wetter than the back as you walk through the rain, so the side of the Earth facing the direction the Earth is heading its orbit encounters more meteors than the backward looking side. In practice this means that the background sporadic meteor rates are lowest at around 6pm each day and then steadily rise through the night towards their peak at around 6am. The seasonal variation occurs because the direction in which the Earth is moving lies on the ecliptic 90 degrees behind the location of the Sun. Around the spring equinox, this is in Sagittarius and so never gets very high in the sky from the UK and so sporadic meteor rates are low. By the autumn equinox, this has moved to the Taurus/Gemini area, is therefore much higher in the sky, and hence we see higher sporadic meteor rates.

Visual Meteor Showers List

The activity dates given for the major showers in the table below are those between which the shower is likely to be apparent to a naked eye observer. Outlying members of the meteor stream can be detected beyond these dates via imaging techniques.

Shower nameIMO shower
code
Activity
Period
MaximumZHR at
max.
Radiant position at maximum RA DecRadiant Daily motion RA DecSpeed (km/s)
QuadrantidsQUAJan 1-6Jan 3–480-12015h20m49°2.4m-0.2°41 km/s
LyridsLYRApr 18-25Apr 22–231818h04m34°4.4m0.0°49 km/s
η AquaridsETAApr 19-May 28May 5-67022h32m-01°3.5m0.4°66 km/s
June BoötidsJBOJun 22-Jul 2Jun 27?0-100+14h56m48°1.6m-0.2°18 km/s
δ AquaridsSDAJul 15-Aug 20Jul 292022h36m-16°3.0m0.2°40 km/s
α CapricornidsCAPJul 15-Aug 15Aug 1-2520h28m-10°3.2m0.3°23 km/s
PerseidsPERJul 17-Aug 24Aug 12–1360-10003h16m58°5.6m0.2°59 km/s
κ CygnidsKCGAug 3-25Aug 18?319h04m59°1.0m0.1°25 km/s
α AurigidsAURAug 25-Sep 10Aug 31606h04m39°4.3m-0.1°66 km/s
September ε PerseidsSPESep 5-21Sep 9503h12m48°4.3m0.1°64 km/s
Oct CamelopardalidsOCTOct 5-6Oct 5–6var.11h00m78°--47 km/s
DraconidsDRAOct 7-10Oct 8-9var.17h28m54°--20 km/s
ε GeminidsEGEOct 14-27Oct 18306h50m27°4.0m0.0°70 km/s
OrionidsORIOct 14-31Oct 21-232506h20m16°2.6m0.1°66 km/s
Southern TauridsSTAmid Sep - late Novsee notes5see chart2.9m0.2°21 km/s
Northern TauridsNTAmid Oct - early Decsee notes5see chart3.6m0.2°29 km/s
LeonidsLEONov 10-24Nov 17-181510h08m22°2.4m-0.3°71 km/s
Dec Alpha DraconidsDADDec 4-13Dec 7-8113h00m60°--41 km/s
MonocerotidsMONDec 5-20Dec 8206h40m2.5m-0.2°41 km/s
Sigma HydridsHYDDec 3-15Dec 11308h30m3.2m-0.2°58 km/s
GeminidsGEMDec 7-16Dec 13–1411007h28m33°4.0m-0.1°35 km/s
December Leo MinoridsDLMDec 5-Feb 4Dec 20510h44m30°3.5m-0.4°64 km/s
Coma BerenicidsCOMDec 12-23Dec 16311h40m18°2.4m-0.3°65 km/s
UrsidsURSDec 17-25Dec 22-231014h28m76°0.0m-0.4°33 km/s

Shower Notes

Follow the links below for additional information about the main meteor showers and radiant location charts:

 

Major Showers

Quadrantids

Lyrids

Eta Aquarids

Delta Aquarids and Alpha Capricornids

Perseids

Draconids

Orionids

Taurids

Leonids

Geminids

Ursids

 

Minor Showers

June Bootids

Kappa Cygnids

Alpha Aurigids and September Perseids

October Camelopardalids 

December Alpha Draconids

Other Meteor Showers of Note

Tau Herculids  This minor meteor shower is associated with the remnants of comet 73P/Schwassmann-Wachmann 3.  In most years it produces little or no activity.  However, occasionally the Earth will encounter one of the denser filaments of particles within the meteor stream and this can lead to somewhat higher activity.  The next likely occasion will be on 2022 May 31 when the Earth is predicted to pass through the centre of a filament left by the comet in 1995.  The location of the Tau Herculid radiant does seem to vary from outburst to outburst, but is generally near RA 14h05m, Dec +30 – within the constellation of Bootes, and somewhat distant from Hercules.

Sigma Hydrids  This minor shower is active in early to mid-December and only produces low activity rates but, over its two-week activity period, produces a significant overall number of meteors. Peak rates occur around Dec 11th.  The radiant is located below the head of Hydra. Note that the radiant doesn’t rise above the horizon until mid-evening and so no Sigma Hydrids will be seen before this time. The best observed rates occur after midnight, when the radiant is climbing higher in the sky. There will be no moonlight interference for the 2018 Sigma Hydrids, with the waxing crescent Moon setting before the radiant rises on Dec 10-11.

December Leo Minorids and Coma Berenicids: The minor Coma Berenicid shower underwent a degree of confusion in recent times, after IMO video results found apparently identically very swift, mostly faint, meteors radiating from an area about 15° west of where previous visual observations had suggested it should be, as well as from the anticipated radiant. It now seems there may be two minor showers active here, of which the December Leo Minorids is marginally the stronger, and apparently the longer-lasting. Initially thought that both peaked around December 20, the Coma shower is now believed to reach its weak maximum a few days sooner (and from a somewhat different position than earlier indicated). It may be that visual observers will struggle to identify the sources as separate, given previous apparent difficulties in this respect. The December Leo Minorid radiant is usefully observable after 22:30 UT, while the Coma Berenicid radiant area is so placed only after 01h.

 

Antihelion Source (ANT) Radiant Centre Locations

The use of the “Antihelion Source” relates to the problem of distinguishing between a large number of minor shower radiants that are active around the anti-solar position on the ecliptic throughout the year. With the radiants involved often being close together, it has been virtually impossible for visual observers to reliably assign a given meteor to the correct minor shower. Hence, rather than maintain an unreliable list of minor showers along the ecliptic, the solution has been to assign all such meteors to this “antihelion source”. The only exceptions to this have been those showers that are strong enough to clearly stand out above the background levels, these being the Delta Aquarids and Alpha Capricornids in the summer and the Taurids in the autumn.

Source is active all year except during STA & NTA; Better ZHRs (3-4) likely in March-April, early & late May & June, and early July; Radiant area is about 30° in RA by 15° in Dec.

DateRADec
January 107h32m21°
January 1508h28m17°
February 109h40m12°
February 1510h36m07°
March 111h32m02°
March 1512h28m-04°
April 113h36m-10°
April 1514h32m-15°
May 115h32m-19°
May 1516h28m-22°
June 117h35m-23°
June 1518h24m-23°
July 119h28m-21°
July 1520h20m-18°
August 121h24m-13°
August 1522h20m-08°
September 123h24m-02°
September 15STA only
October 1STA only
October 15NTA & STA
November 1NTA & STA
November 15NTA & STA
December 1NTA only
December 15