The positions listed below are e xact for Saturday night/Sunday morning June 15/16. 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 18:36 (279) -23. This area of the sky is located in northern Sagittarius near the famous globular cluster M22. 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 northwestern Sagittarius 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 than 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 Sagittarids (SAG).
The June Lyrids/Xi Draconids reach
maximum activity in mid June. While recent June Lyrid activity has been
strong enough to place it back on the IMO's working list, some of this activity
can be attributed to another radiant exactly 20 degrees north of the June
Lyrids. After its discovery back in 1966, the June Lyrids produced some modest
activity for the next several years. During the early 70's reports of this
activity waned as did interest in this shower. Then after more than two decades
of poor activity two teams of observers in the USA and The Netherlands discovered
a sharp radiant near Draco's head in 1996, active between June 11 and the
17th. These meteors were much more numerous than the June Lyrids that year
and have continued to provide more activity than its southerly neighbor
ever since. The current radiant positions for the June Lyrids is 18:32 (278)
+35. and 18:32 (278) +55 for the Xi Draconids. These positions lie on the
in central Lyra, 4 degrees south of the brilliant zero magnitude star Vega
(Alpha Lyrae) and in southern Draco, 5 degrees northeast of the 2th magnitude
star Eltanin (Gamma Draconis), the southernmost
star in the "Lozenge" (head) of Draco. As seen from the Northern Hemisphere
these radiants lie high in the sky passing nearly overhead during the short
nights that occur this time of year. They are well placed between 0100 and
0200 when they lie highest above the horizon. They lie much lower in the sky
as seen from the Southern Hemisphere and are not well seen. While some activity
may be seen this weekend, better results may be obtained later next week
and into the following weekend. Meteors from both radiants are somewhat swift
unless seen near the radiant or low in the sky. Please keep an eye out for
this activity and let us know which radiant is active for you.
The Northern Apex radiant is now located
at 23:36 (354) +13. This position lies in southern Pegasus close to the 4th
magnitude star 70 Pegasi. 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 Pegasus or western
Pisces 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 23:36 (354) -17 . This position lies in southeastern Aquarius, close to the faint naked eye double star Omega Aquarii. Any activity from southern Aquarius or western Cetus could be a candidate from this source. Due to the southern declination (celestial latitude) rates would be now close to 2 per hour from the Southern Hemisphere and 1 per hour from the Northern Hemisphere.
The Arietids are active from a radiant
located just west of the sun. Being located there, the radiant rises just
before the start of morning twilight and any activity would be seen shooting
upwards from the northeastern horizon. These meteors are of medium velocity
and usually last several seconds as they skim the outer regions of the earth's
atmosphere. The current radiant position is located at
03:28 (052) +29 which is located on the Aries/Taurus border some 5 degrees
northwest of the Pleiades star cluster. This shower peaked on June 6 with
a ZHR of 60. Even with such strong rates the unfavorable altitude at the
time of daybreak makes seeing this activity a difficult challenge. On the
other hand, those with radio meteor equipment can easily detect this activity
as it is the strongest annual radio meteor shower of the year.
The Sporadic rates for the Northern
Hemisphere have now bottomed out and will slowly begin to rise during June
and July. One would expect to see perhaps 4 random meteors per hour during
the last hours before dawn from rural observing sites. During the evening
hours perhaps 1 random meteor can be seen per hour. These estimates and
the morning estimates for the Southern Hemisphere do not include the apex
meteors listed above. 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.