The positions listed below are e xact for Saturday night/Sunday morning April 13/14. The positions do not change greatly day to day so these positions may be used during this entire period. Most star atlas's (available at science stores and libraries) 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 location. Meteor activity is not seen from radiants that are located below the horizon. The radiants below are listed in a west to east manner in order of right ascension (celestial longitude). The radiants listed first are located further west therefore are accessible earlier in the night while those listed last rise later in the night. This list also provides the order of ascending velocity for each radiant with those listed first usually being much slower than those last on the list. Velocity should not be the prime factor for shower association as all showers can produce slow meteors. Slow meteors can be produced from normally swift showers, such as the Leonids, when meteors appear near the radiant or close to the horizon. The true velocity is only revealed in shower members seen far from the radiant and high in the sky.
The Antihelion radiant is now located at 14:32 (218) -14. This area of the sky is located in southwestern Libra directly between the stars Lambda Virginis and Zubenelgenubi (Alpha Librae). The radiant lies low in the southeast at dusk and remains above the horizon the remainder of the night. This area of the sky is best placed near 0200 local daylight time when it lies on the meridian and is highest in the sky. At this time expect to see 1 meteor per hour from the Northern Hemisphere and perhaps 2 per hour south of the equator. Any slow to medium speed meteor from southeastern Virgo or southwestern Libra could be a candidate for this shower.
Unlike most of the annual showers the antihelion radiant is produced by debris from unknown sources orbiting in a direct motion, like the earth. These sources are most likely asteroids, which produce stony and metallic debris, whose density is much greater that produced by comets. This debris collides with the earth on the inbound portion of its orbit, before its closest approach to the sun. Therefore we best see them just after midnight when we are directly facing the path of these particles. The antihelion radiant is active all year from an area of the sky nearly opposite that of the sun. The radiant will travel approximately one degree eastward per day and travels through many different constellations over the course of a year. It is easiest to simply list these meteors as "ANT" but a majority of meteor organizations prefer that you list them from the constellation in which the radiant is currently located or the constellation where the shower reaches maximum activity. Those who share reports with the I.M.O. should label these meteors as Sagittarius (SAG).
The Lyrids will begin to show up in
the morning sky this week in limited numbers. The date of maximum activity
is still a week away so rates would be less than 1 shower member per hour.
The radiant is currently located at 17:28
(262) +34 , which would place it in eastern
Hercules just east of the "Keystone" and roughly 10 degrees southwest of
the brilliant zero magnitude star Vega (Alpha Lyrae). The radiant rises during
the late evening hours, as seen from the Northern Hemisphere, but is much
better placed during the morning hours when it lies high in the sky. As seen
from the Southern Hemisphere the radiant rises near midnight but never climbs
very high into the northern sky. At 49 km/sec. the average Lyrid is of medium-swift
velocity.
The Northern Apex radiant is now located at 19:32 (293) -06. This position lies in a remote portion of southern Aquila close to the star Kappa Aquilae. This area of the sky is best placed for viewing during the last dark hour before dawn. Since this radiant is diffuse any meteors from southern Aquila or northern Sagittarius could be a good candidate for this shower. This source should provide 1-2 meteors per hour during the last few hours before dawn regardless of your location.
Like the antihelion radiant both apex radiants are active all year long and travel approximately one degree eastward per day. Unlike the antihelion debris these particles orbit the sun in a retrograde motion opposite that of the earth and are most likely produced by unknown comets. They strike the earth after their closest approach to the sun. Since they are moving in opposite directions these particles strike the earth at tremendous velocities often creating bright meteors with persistent trains. These particles strike the earth on the morning side of earth and are best seen just before morning twilight while the sky is still perfectly dark. There are meteors with a zero inclination that radiate precisely from the apex point on the ecliptic, exactly 90 degrees west of the sun. These meteors are rare though as the earth orbits the sun it has "swept clean" much of the material that shares the same orbit. Much more debris is located just north and south of the earth's orbit with slightly higher or lower inclinations. This creates the northern and southern branches of the apex activity. Meteors from both branches are normally included in the sporadic count but should also be noted in some manner as to which branch of the apex complex they appear to radiate.
The Southern Apex source lies exactly 30 degrees south of its northern counterpart at 19:32 (293) -36 . This position lies in a remote area of southeastern Sagittarius . Like the northern apex these meteors are best seen toward dawn when the radiant lies highest above the horizon in a dark sky. Any meteor from southeastern Sagittarius could be a candidate from this source. Due to the extreme southern declination (celestial latitude) rates would be now close to 3 per hour from the Southern Hemisphere and less 1 per hour from the Northern Hemisphere.
The Delt
a Pavonids are listed among the radiants of the Dutch Meteor Society.
This is a far southern shower that reached maximum activity on March 29,
so current rates would be very low, far less than 1 per hour. The radiant
currently lies at 21:28 (335) -67 which
places it in northern Tucana near the dim star star Delta Tucanae. The activity
is best seen just before the start of morning twilight. This shower is not
visible north of 30 degrees north latitude. At 60 km/sec. the average Delta
Pavonid would appear swift.
The Sporadic rates for the Northern Hemisphere are now in decline and will do so until June. One would expect to see perhaps 5 random meteors per hour during the last hours before dawn from rural observing sites. During the evening hours perhaps 1-2 random meteors can be seen per hour. Rates seen from the Southern Hemisphere would be approximately 6 random meteors being seen per hour during the late morning hours and 2 during the evening hours.