The positions listed below are exact for Saturday night/Sunday morning July 20/21. 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 which constellations are in 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. 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 Alpha Capricornid radiant is located at 20:00 (300) -12. The area of the sky is located in extreme northeastern Sagittarius, just 4 degrees west of the naked eye double star Alpha Capricorni. The velocity of the Alpha Caps is 25 km/sec., which is slower than your average meteor. The radiant is best placed near 0100 local daylight time when it lies on the meridian. The Alpha Caps are known for their brightly colored fireballs which increase in frequency as we approach the July 29 maximum for this shower.
The Alpha Cygnids are listed as the Psi Cygnids in the list of radiants published by the Dutch Meteor Society. No matter what you call them they are often overlooked by the many other better known radiants active at this time. This radiant was well represented in the studies coordinated by Dr. Peter Jenniskens between 1980 and 1991. Their studies indicate a ZHR near 3 at maximum activity on July 18. The radiant position is currently located at 20:28 (307) +48. This position is located in northern Cygnus, 4 degrees northwest of the bright star Deneb (Alpha Cygni). With an entry velocity of 37 km/sec. these meteors are of average velocity. The radiant is best placed near 0200 LDT when it lies nearly overhead for much of the Northern Hemisphere. Due to its high northern declination this activity is not well seen from the Southern Hemisphere.The Antihelion radiant is now located at 20:52 (313) -16. This area of the sky is located in north central Capricornus near the 3rd magnitude star Theta Capricorni. Any slow to medium speed meteor from central Capricornus or western Aquarius could be a candidate for this shower. The radiant 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 shower member per hour from locations north of the equator and 2 an hour from areas south of the equator.
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 than material 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 facing the direction from which this activity appears. 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.
The North Delta Aquarids are currently barely active as the date of maximum activity is not until August 8. This low rate of activity will prevail throughout most of July. The radiant is currently located at 21:20 (320) -09. This area of the sky is located in western Aquarius, 4 degrees southwest of the 3rd magnitude star Beta Aquarii. This position is close to the antihelion radiant and unless you plot the meteors you see, these meteors will be indistinguishable from one another. At 42 km/sec. the NDA's are a bit faster than the antihelion meteors. This radiant is most active between 0200 and 0300 LDT when it lies highest in the southern sky. Like many of the radiants active this time of year the NDA's are better seen from areas south of the northern tropics or 30 degrees north latitude.
The South Delta Aquarids radiant provides the strongest activity in July. This radiant peaks in strength on July 27 with an average ZHR of 20. At this time rates are only 2-3 per hour but this will quickly rise as we approach late July. The current radiant position lies at 22:16 (334) -18. This area of the sky is located in a remote area of southern Aquarius, some 10 degrees southwest of the 3rd magnitude star Delta Aquarii. The radiant lies low in the southeast at dusk and is not well seen until it approaches the meridian near 0300 LDT. These meteors encounter the earth at a speed of 41 km/sec. which is a bit faster than average. These meteors are also best seen from the Southern Hemisphere where the radiant passes high overhead.
The Pisces Austrinids are barely active with a current ZHR of 1. Don't expect to see 1 an hour unless you live near 30 degrees south latitude where the radiant passes high overhead between the hours of 0200 and 0300 LDT. The current radiant position lies at 22:20 (335) -32 which places it in central Pisces Austrinus some 8 degrees southwest of the bright 1st magnitude star Fomalhaut (Alpha Piscis Austrini). These meteors are of average velocity, slower than the Aquarids but faster than the Alpha Caps and the antihelion meteors.The Northern Apex radiant is now located at 01:52 (028) +26. This position lies in southwestern Triangulum only 2 degrees south of the 3rd magnitude star Alpha Trianguli . 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 northern Pisces, northwestern Aries or Triangulum could be a good candidate for this shower. This source should provide at least 2 meteors per hour for those in the Northern Hemisphere and 1 per hour for those in the Southern Hemisphere.
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 "sweeps 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 01:52 (028) -04 . This position lies in central Cetus 5 degrees west of the rapidly brightening variable star Mira (Omicron Ceti). 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 north central Cetus or southern Pisces could be a candidate from this source. Rates would be now close to 2 per hour regardless of your location.
Perseid activity is just now beginning
to appear. Don't look for these meteors to radiant from Perseus at this time.
The current radiant position is actually a bit west of Perseus at 01:16 (019)
+52. This area of the sky is located in southern Cassiopeia some 7 degrees
southeast of the 2nd magnitude star Shedar (Alpha Cassiopeiae). The radiant
is well placed for those in the Northern Hemisphere during the last few hours
before dawn. Due to the high northern declination (celestial latitude) of
the radiant, rates seen from the Southern Hemisphere are very low or non-existent.
Current Perseid rates for those north of the equator would also be low, near
1 shower member per hour. Rates will gradually increase as we approach the
August 12 maximum. At 59 km/sec., Perseid meteors are swift, often exhibiting
persistent trains.
The Sporadic rates for the Northern Hemisphere are now increasing. One would expect to see perhaps 5 random meteors per hour during the last hours before dawn from rural observing sites. This estimate and the morning estimate for the Southern Hemisphere does not include the apex meteors listed above. During the evening hours perhaps 1 random meteors can be seen per hour from the Northern Hemisphere. Rates seen from the Southern Hemisphere are at their highest level of the year with perhaps 8 random meteor being seen per hour during the early morning hours and 1 per hour during the evening. Southern observers had better enjoy these strong rates now as rates will soon plummet to far below those seen from the Northern Hemisphere. Evening rates are reduced due to moonlight.