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By Robert Lunsford AMS Visual Program Coordinator
The
moon reaches its first quarter phase on Sunday April 1.
This means that it will rise near local noon and set near
midnight on this particular day. The moon will be a nuisance
for those observing prior to midnight but will have set
for morning observers.
The
estimated total hourly rates for evening observers this
week should be near 1 for those located in the Northern
Hemisphere and 2 for those located in the Southern Hemisphere.
Rates are reduced due to moonlight. For morning observers
the estimated total hourly rates would be near 7 for the
Northern Hemisphere and 12 for those located in the Southern
Hemisphere. These morning rates assume that you are watching
from rural areas away from sources of light pollution.
The
actual rates will also depend on factors such as personal
light and motion perception, local weather conditions, alertness
and experience in watching for meteor activity. The positions
listed below are exact for Saturday night/Sunday morning
March 31/April 1. The positions do not change greatly day
to day so these positions may be used during this entire
period.
The
Antihelion radiant is now located at 13:40 (205) -10. This
area of the sky is located in central Virgo just 5 degrees
east of the bright first magnitude star Spica (Alpha Virginis).
Any slow to medium speed meteor from this general area is
a good candidate for this shower. This area of the sky is
best placed near 0100 local time when it lies on the meridian.
At this
time expect to see perhaps 1 to 2 meteors per hour from
this source. Those who share reports with the IMO should
label these meteors as Virginids (VIR).
The
Northern Apex radiant is now located at 18:40 (280) -08.
This position lies in Scutum very close to the 4th magnitude
star Epsilon Scuti. 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 Scutum, Serpens
Cauda, southwestern Aquila, or extreme northern Sagittarius
could be a good candidate.
As seen
from the Northern Hemisphere this source should produce
at least 1 meteor per hour during the last few hours before
dawn. Rates seen from the Southern Hemisphere should be
better with perhaps 2 of these meteor being seen per hour.
The
Southern Apex source lies exactly 30 degrees south of its
northern counterpart at 18:40 (240) -38. This position lies
in northern Corona Australis very close to the 5th magnitude
star Lambda Coronae Australis. 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
eastern Scorpius, Corona Australis, or southern Sagittarius
could possibly be a candidate from this source.
As seen
from the Northern Hemisphere this source now lies so low
in the southeastern sky that chances are little or no activity
will be seen. With the radiant being situated much higher
in the sky, rates seen from the Southern Hemisphere should
be better with perhaps 2-3 of these meteor being seen per
hour.
The
Delta Pavonids is a far southern shower listed among the
radiants of the Dutch Meteor Society. It reached maximum
activity on March 29 with a predicted ZHR of 5. Current
rates are most likely 1-2 per hour at best. The radiant
position lies at 20:52 (313) -64.
This
area of the sky is located in eastern Pavo 3 degrees northeast
of the 3rd magnitude star Beta Pavonis. I would not expect
any activity from this radiant to be visible north of 25
degrees north latitude. This radiant is better seen from
a location far south of the equator during the last hour
before morning twilight.
These
meteors have a geocentric velocity of 35 km/sec. which means
they would appear to move slowly if seen near the radiant
or near the horizon. If seen far from the radiant and high
in the sky then they would travel with medium speeds much
like the Geminids of December.
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 random meteor can be seen per
hour. Rates seen from the Southern Hemisphere would now
be slightly better than those seen in the Northern Hemisphere
with perhaps 6 random meteors being seen per hour during
the late morning hours and 2 per hour during the evening.
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