During this period the moon reaches its last quarter phase on Wednesday October 15th. At this time the moon is located 90 degrees west of the sun and will be above the horizon from midnight onward. Although not perfect, these conditions will allow successful meteor observations as long as the observer keeps the moon out of their field of view. This weekend the waning gibbous moon will rise during the late evening hours and will severely impact the number of meteors visible. The estimated total hourly meteor rates for evening observers this week is near 3 as seen from the northern hemisphere and 2 as seen from southern tropical latitudes. For morning observers the estimated total hourly rates should be near 12 for observers located in mid-northern latitudes and 7 for south tropical observers. Rates are reduced during this period due to moonlight. The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brightest meteors will be visible from such locations.
The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning October 11/12. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies at the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.
These sources of meteoric activity are expected to be active this week:
The Gamma Piscids (GPS) are a weak shower active from October 14 through the 21st with maximum activity occurring on the 17th. At maximum the radiant is located at 01:10 (017) +17. This position lies in central Pisces, 5 degrees northwest of the faint star known as Eta Piscium. Rates of less than 1 per hour are expected, even at maximum. With an entry velocity of 21 km/sec., the average Gamma Piscid meteor would be of slow velocity.
The Southern Taurids (STA) are currently active from a radiant located at 02:16 (034) +10. This position lies on the Aries/Cetus border, 3 degrees northwest of the 4th magnitude star known as Xi 2 Ceti. These meteors may be seen all night long but the radiant is best placed near 0200 local daylight time (LDT) when it lies on the meridian and is located highest in the sky. Rates at this time should be near 2 per hour regardless of your location. With an entry velocity of 29 km/sec., the average Southern Taurid meteor would be of slow velocity.
The Orionids (ORI) are active from a radiant at 05:56 (089) +15, which places it in northeastern Orion, 7 degrees north of the orange 1st magnitude star known as Betelgeuse (Alpha Orionis). This area of the sky is best placed near 0500 LDT, when it lies highest above the horizon in a dark sky. Rates this week would be near 2 per hour no matter your location. With an entry velocity of 67 km/sec., most activity from this radiant would be of swift speed.
The Epsilon Geminids (EGE) are active from a radiant located at 06:24 (096) +27. This position is located on the Auriga/Gemini border, lying between the stars Kappa Aurigae and Epsilon Geminorum. This area of the sky is best placed in the sky during the last hour before dawn, when it lies highest above the horizon in a dark sky. Current rates should be near 1 per hour as seen from the northern hemisphere and less than 1 when view south of the equator. With an entry velocity of 70 km/sec., most activity from this radiant would be of swift speed.
The Psi Aurigids (PSA) were discovered among the radiants found by the IMO network of video cameras. This weak shower is active from October 8-18, which maximum activity occurring on the 15th. The radiant is currently located near 07:20 (110) +43. This position lies in a remote area of eastern Auriga, 10 degrees northwest of the 2nd magnitude star known as Castor (Alpha Geminorum). This area of the sky is best placed in the sky during the last hour before dawn, when it lies highest above the horizon in a dark sky. Current rates should be less than 1 per hour no matter your location. With an entry velocity of 68 km/sec., most activity from this radiant would be of swift speed.
The Tau Cancrids (TCA) are active from October 9-25, with maximum activity occurring near the 17th. This shower was discovered by Peter Jenniskens and verified by IMO video data. The radiant currently located at 08:36 (129) +29. This position lies in northern Cancer, close to the 4th magnitude star known as Iota Cancri. This area of the sky is best placed in the sky during the last hour before dawn, when it lies highest above the horizon in a dark sky. Current rates should be near 1 per hour as seen from the northern hemisphere and less than 1 as seen from south of the equator. With an entry velocity of 69 km/sec., most activity from this radiant would be of swift speed.
The October Ursae Majorids (OCU) were first detected by a group of Japanese observers in 2006. This radiant is active from October 14-18, with maximum activity occurring on the 15th. At maximum the radiant is located at 09:36 (144) +64. This position lies in western Ursa Major, near the faint star 23 Ursae Majoris. This area of the sky is best placed during the last hour before morning twilight, when it lies highest above the horizon in a dark sky. At maximum activity rates would most likely be 1 per hour as seen from the northern hemisphere and less than 1 as seen from south of the equator. Due to the high northern location of this radiant, these meteors are not well seen from the southern hemisphere. With an entry velocity of 52km/sec., most activity from this radiant would be medium-swift.
As seen from the mid-northern hemisphere (45N) one would expect to see approximately 5 sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near 2 per hour. As seen from the tropical southern latitudes (25S) morning rates would be near 3 per hour as seen from rural observing sites and 1 per hour during the evening hours. Locations between these two extremes would see activity between the listed figures. Note that sporadic rates are reduced this week during the evening hours due to moonlight.
The list below offers the information from above in tabular form. Rates and positions are exact for Saturday night/Sunday morning except where noted in the shower descriptions.
|SHOWER||DATE OF MAXIMUM ACTIVITY||CELESTIAL POSITION||ENTRY VELOCITY||CULMINATION||HOURLY RATE||CLASS|
|RA (RA in Deg.) DEC||Km/Sec||Local Daylight Time||North-South|
|Gamma Piscids (GPS)||Oct 17||01:10 (017) +17||21||01:00||<1 – <1||IV|
|Southern Taurids (STA)||Oct 10||02:16 (034) +10||29||02:00||2 – 2||II|
|Orionids (ORI)||Oct 22||05:56 (089) +15||67||05:00||2 – 2||I|
|Epsilon Geminids (EGE)||Oct 22||06:24 (096) +27||70||06:00||1 – <1||II|
|Psi Aurigids (PSA)||Oct 15||07:20 (110) +43||68||07:00||<1 – <1||IV|
|Tau Cancrids (TCA)||Oct 17||08:36 (129) +29||69||08:00||1 – <1||IV|
|Oct. Ursae Majorids(OCU)||Oct 15||09:36 (144) +64||52||09:00||1 – <1||IV|