(meteorobs) Meteor Activity Outlook for July 30-August 5, 2004

Robert Lunsford lunro.imo.usa at cox.net
Wed Jul 28 17:15:00 EDT 2004


The moon reaches its full phase on Saturday July 31. At this time it is
located 180 degrees from the sun and rises as the sun sets and sets as the
sun rises. This weekend and for the remainder of this period, the moon will
be present in the early morning sky, limiting the meteor activity to be
seen. 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 is near two for those in the Northern Hemisphere and two
for those located in the Southern Hemisphere. For morning observers the
estimated total hourly rates should be near thirteen for those located in
the Northern Hemisphere and thirteen 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. Rates are reduced this
week due to intense moonlight.

The positions listed below are exact for Saturday night/Sunday morning July
31/August 1. 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.

Alpha Capricornids             20:40  (310)   -09   Hourly Rate = 1 Northern
Hemisphere, 2 Southern

Anthelion                            21:32  (323)   -13   Hourly Rate = 1
Northern Hemisphere, 2 Southern

N. Delta Aquarids (NDA)    21:56  (329)  -08  Hourly Rate = 0 Northern
Hemisphere, 1 Southern

S. Iota Aquarids (SIA)         22:00  (330)  -16  Hourly Rate = 0 Northern
Hemisphere, 1 Southern

S. Delta Aquarids (SDA)     22:48  (342)   -16  Hourly Rate = 3 Northern
Hemisphere, 5 Southern

Piscis Austrinids (PAU)       23:00  (345)   -29  Hourly Rate = 0 Northern
Hemisphere, 1 Southern

Perseids (PER)                   02:08  (032)   +55  Hourly Rate = 5
Northern Hemisphere, 0 Southern

Northern Apex                   02:32  (038)   +29  Hourly Rate = 2 Northern
Hemisphere, 0 Southern

Southern Apex                   02:32  (038)   -01   Hourly Rate = 1
Northern Hemisphere, 1 Southern


Clear Skies!
Robert Lunsford
AMS Operations Manager



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