Meteor Activity Outlook for September 8-14, 2012

During this period the moon reaches its last quarter phase on Saturday September
8th. At this time the moon is located ninety degrees west of the sun and will
rise near midnight local daylight time (LDT) for observers located in the
mid-northern latitudes. As the week progresses the moon’s phase will wane and it
will rise later in the morning, creating more favorable viewing conditions for
meteor observers. The estimated total hourly meteor rates for evening observers
this week is near four for observers located at mid-northern latitudes and three
for observers in mid-southern latitudes. For morning observers the estimated
total hourly rates should be near thirteen from the mid-northern hemisphere and
four from the mid-southern hemisphere. 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 reduced
during this period due to moonlight.

The radiant (the area of the sky where meteors appear
to shoot from) positions and rates listed below are exact for Saturday night/Sunday
morning September 8/9. 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. It must be
remembered that meteor activity is rarely seen at the radiant position. Rather
they shoot outwards from the radiant so it is best to center your field of view
so that the radiant lies at the edge and not the center.
Viewing there will allow you to easily trace the path of each meteor back to
the radiant (if it is a shower member) or in another direction if it is a
sporadic. 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 following radiants are expected to be active this week:

The Southern Taurid (STA) radiant becomes active this week and will replace the
Antihelion radiant until December. These two radiants are superimposed upon each
other in the sky and impossible to separate. The center of the large STA
radiant is currently located at 00:24 (006) +01. This position lies in blank
area of southern Pisces, midday between the bright stars Deneb Kaitos (Beta
Ceti) and Algenib (Gamma Pegasi). These two stars also roughly mark the southern
and northern boundaries of the STA radiant. Southern Taurid activity may also
appear from eastern Aquarius as well as Pisces, Cetus, and Pegasus. This radiant
is best placed near 0200 LDT, when it lies on the meridian and is located
highest in the sky. Rates at this time are expected to be near two per hour no
matter your location. With an entry velocity of 29 km/sec., the average Southern
Taurid meteor would be of slow velocity.

The September Epsilon Perseids (SPE) is the strongest shower of the month. They
are active from September 4th through the 12th with maximum activity occurring
on the 9th. The radiant position is currently located at 03:08 (047) +41. This
position lies in western Perseus, very close to the famous eclipsing variable
star known as Algol (Beta Persei). The radiant is also best placed near 0500
LDT, when it lies highest above the horizon. Rates at maximum are near five
shower members per hour. This shower experienced an outburst in 2008 with ZHR’s
near 25 for a short time. Many bright meteors were produced during this outburst
with the brightest estimated at magnitude -8. With an entry velocity of 66
km/sec., most activity from this radiant would be swift. This activity is
visible from the tropical regions of the southern hemisphere, but further south
the radiant becomes too low in the sky to produce much activity.

Studies of the IMO’s video database by Sirko Molau and Juergen Rendtel has
revealed a new radiant active in Lynx this time of year. The September Lyncids
(SLY) are active from September 6th through the October 5th with maximum
activity occurring on September 27th. The radiant position is currently located
at 07:04 (106) +56. This position lies in northwestern Lynx, a dozen degrees
northeast of the second magnitude star Menkalinan (Beta Aurigae) . The radiant
is best placed during the last dark hour before dawn, when it lies highest above
the horizon in a dark sky. Rates are variable for this radiant throughout the
activity period. Current rates are expected to be 1-2 shower members per hour as
seen from mid-northern latitudes. This radiant is not well placed to be viewed
from the southern hemisphere. With an entry velocity of 64 km/sec., most
activity from this radiant would be swift.

As seen from the mid-northern hemisphere (45N) one would expect to see
approximately seven sporadic meteors per hour during the last hour before dawn
as seen from rural observing sites. Evening rates would be near three per hour.
As seen from the mid-southern hemisphere (45S), morning rates would be near
three per hour as seen from rural observing sites and two per hour during the
evening hours. Locations between these two extremes would see activity between
the listed figures. Morning rates are reduced due to to moonlight during this
period.

The table below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning.