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(meteorobs) Meteor Activity Outlook for May 16-22, 2003

The moon is full on Thursday May 15 and will undergo a total eclipse during
the evening hours for observers in North and South America. I have seen many
meteors during total eclipses at all hours of the night. It's also
interesting to see
how the moonlight affects your limiting magnitude during the different
phases of
the eclipse. The antihelion source will only be fifteen degrees east of the
moon so
it will be easy to monitor both the eclipse and this source simultaneously.
This
weekend and beyond, the moon will be present in the morning sky, limiting
the
activity seen during this time of night. The sources of meteors listed below
are
active during this period but will be difficult to observe. If your sky is
transparent
and the limiting magnitude exceeds +5.0, then you may be able to achieve
some
success at observing during this period. The estimated total hourly rates
for
evening observers this week should be near 2 for northern viewers and 3 for
those located south of the equator. For morning observers the estimated
total hourly rates should be near 3 for those located in the Northern
Hemisphere and 5 for those in the Southern Hemisphere. These rates assume
that you are watching from rural areas away from all 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 meteor activity. Moonlight greatly reduces the
activity
seen during the morning hours during this period.

The positions listed below are exact for Saturday night/Sunday morning May
17/18. The positions do not change greatly day to day so these positions may
be used during this entire period. Most star atlases (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 detailed descriptions of each shower will return next week when
moonlight becomes less of a factor.

Antihelion (Sagittarids)       16:44 (251)  -22
Beta Corona Australids      19:08 (287)  -40
Northern Apex                  21:44 (326)  +03
Southern Apex                  21:44 (326)  -27
Eta Aquarids                     21:32 (323)   -07

Clear Skies!
Robert Lunsford
AMS Operations Manager

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