(meteorobs) Meteor Activity Outlook for May 26-June 1, 2006

Kim Youmans meteorsga at bellsouth.net
Sat May 27 09:53:41 EDT 2006


David,
             I always use the Alpo list, set up by Bob Lunsford, at 
http://www.lpl.arizona.edu/~rhill/alpo/meteorstuff/metshwr.html.

Kim Y.
----- Original Message ----- 
From: "David Stine" <david at exposquare.com>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: Friday, May 26, 2006 5:07 PM
Subject: RE: (meteorobs) Meteor Activity Outlook for May 26-June 1, 2006


Robert,

Is there a site that has all of the meteor showers set up in order of
their activity dates.  I could take the alphabetized list and do it
myself by date, but whoever has this original, IMO, if it is an excel
sheet should be able to do it by one click on the activity date.  Just a
thought.

David
Comet-1

-----Original Message-----
From: meteorobs-bounces at meteorobs.org
[mailto:meteorobs-bounces at meteorobs.org] On Behalf Of Robert Lunsford
Sent: Friday, May 26, 2006 3:50 PM
To: meteorobs at meteorobs.org
Subject: (meteorobs) Meteor Activity Outlook for May 26-June 1, 2006

During May the Antihelion radiant moves from eastern Libra, through
northern
Scorpius and into southern Ophiuchus. These areas of the sky are south
of
the celestial equator, favoring observers watching from south of the
equator. Northern observers still suffer with low sporadic rates,
especially
during the evening hours. This situation will not improve until
mid-July,
when sporadic rates dramatically rise for northern observers. The
overall
meteor activity is much like April, possibly slightly better in the
south
and slightly worse in the north. The most favorable time to view meteor
activity this month would be during the first week of the month, when
the
Eta Aquarids are near maximum activity.

During this period the moon will reach its new phase on Saturday May 27.
At
this time the moon will rise and set with the sun and will not casue any
interference. As the week progresses the waxing crescent moon enter the
evening sky but will set long before the more active morning hours
arrive.
The estimated total hourly rates for evening observers this week is near
two
for observers in the northern hemisphere and three for those south of
the
equator. For morning observers the estimated total hourly rates should
be
near seven for those in the northern hemisphere and ten for those south
of
the equator. 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.

The radiant positions listed below are exact for Saturday night/Sunday
morning May 27/28. These positions do not change greatly day to day so
the
listed coordinates may be used during this entire period. Most star
atlases
(available at science stores and planetariums) 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 latitude. Meteor activity is not seen from radiants
that
are located below the horizon. The positions below are listed in a west
to
east manner in order of right ascension (celestial longitude). The
positions
listed first are located further west therefore are accessible earlier
in
the night while those listed further down the list rise later in the
night.

The Tau Herculids (THE) are produced by comet 73P/Schwassmann-Wachmann ,
which is currently making headlines as it passes close to the Earth.
This
shower was once included in many shower lists. As our understanding of
the
shower dynamics increased with this shower it became apparent that this
shower is visible only on rare occasions when the Earth passes through
the
trails of debris produce by this comet. Therefore the Tau Herculids have
been removed from most lists and are only rarely discussed. With the
close
approach of 73P/Schwassmann-Wachmann to the Earth in 2006, there exists
the
small possibility that some activity may be seen from this shower during
the
next two weeks. The Earth passes closest to the largest fragment of this
comet near 20:00 Universal Time on May 31. This is not a particularly
close
approach so very low numbers, if any at all, are expected to appear
then, or
during the remainder of this encounter. Using the IMO's shower
parameters
listed at: http://www.imo.net/files/data/vmdb/vmdbrad.txt, I have
calculated
that the radiant for this shower will be located near 15:16 (229) +34
this
weekend. This area of the sky is located in eastern Bootes near the
position
of the fourth magnitude star Delta Bootis. The actual radiant of shower
members may differ significantly due to the fragmentation of this comet
and
the very slow entry velocity. The best time to view possible activity is
near midnight when the radiant lies highest in the sky. This shower is
well
placed for viewing in the northern hemisphere as it passes through the
zenith for those located at 40N latitude. At extreme northern latitudes
the
length of the night is shortened appreciably, limiting the time one can
view
activity. As one progresses southward the length of night increases but
the
radiant altitude decreases. South of the equator the radiant altitude
becomes a major factor, reducing the possibility of seeing any activity
from
this source. The radiant does not rise above the horizon south of 50S
latitude. With an entry velocity of only 15 kilometers per second, these
meteors will appear to move slowly, helping to aid in their
identification.
A great majority of these meteors will possess an angular velocity less
than
5 degrees per second with the highest possible angular velocity
certainly
being less than 10 degrees per second. Please report any positive
sightings
to the AMS, the IMO News list, or Meteorobs as soon as possible after
your
observation.

The Antihelion (ANT) radiant is now centered at 17:16 (259) -23. This
area
of the sky is located in southeastern Ophiuchus, two degrees northwest
of
the third magnitude star Theta Ophiuchi. This radiant is best placed
near
0200 local daylight time when it lies on the meridian and is highest in
the
sky. Rates at this time should be near two per hour for those north of
the
equator and three per hour south of the equator. With an entry velocity
of
30 km/sec., the average Antihelion meteor would be of medium-slow speed.

The Daytime Arietids (DAR) are active from a radiant located
approximately
thirty degrees west of the sun. 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 02:28 (037) +17, which is
located
in central Aries seven degrees east of the second magnitude star Hamal
(Alpha Arietis). This shower peaks on June 7 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 are now nearing their
annual
minimum activity. One would expect to see perhaps five random meteors
per
hour during the last hours before dawn from rural observing sites.
During
the evening hours perhaps two random meteors can be seen per hour.
Sporadic
rates seen from the southern hemisphere are now increasing toward a
secondary maximum in July. One would see approximately eight random
meteors
per hour during the late morning hours and three per hour during the
evening.

Tau Herculids (THE) 15:16 (229) +34   North >1 - South 0

Antihelion (ANT) 17:16 (259) -23   North 2 - South 3

Daytime Arietids (DAR)  02:28 (037) +17   North >1 - South >1

*For a detailed explanation on the different classes of meteor showers
and
other astronomical terms, please visit:
http://www.amsmeteors.org/showers.html#X2006

Clear Skies!
Robert Lunsford
American Meteor Society

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