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(meteorobs) Meteor Activity Outlook for April 18-24, 2003

The moon reaches its last quarter phase on Wednesday April 23. For this
entire period 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 as stated above, 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.
Morning rates are significantly reduced by moonlight during this period.
Rates will increase slightly on the mornings of April 22 and 23, when the
Lyrid shower reaches maximum activity.
The positions listed below are exact for Saturday night/Sunday morning April
19/20. 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.
Pi Puppids                          07:16 (109)  -45
Antihelion (Sagittarids)   14:56 (224)  -16
Lyrids                                  14:08 (269)  +34
Northern Apex                  15:44 (299)  -05
Southern Apex                 15:44 (299)  -35
Eta Aquarids                     21:32 (323)  -07



Clear Skies!
Robert Lunsford
AMS Operations Manager

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