Meteor Activity Outlook for October 20-26, 2012

During this period the moon reaches its first quarter phase on Sunday October
21st. At this time the moon is located ninety degrees east of the sun and well
set near 2300 (11pm) local daylight time (LDT). As the week progresses the
waxing gibbous moon will set later and later in the morning, interfering with
meteor observing. The estimated total hourly meteor rates for evening observers
this week is near three for observers located at mid-northern latitudes and two
for observers in mid-southern latitudes. For morning observers the estimated
total hourly rates should be near thirty eight from the mid-northern hemisphere
and twenty seven 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. Rates during
the evening hours are reduced this week 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 October 20/21. 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 Northern Taurids (NTA) are now active from a large radiant centered at 02:40
(040) +19, which lies in central Aries, eight degrees southeast of the second
magnitude star Hamal (Alpha Arietis). The radiant is best placed near 0200 local
daylight time (LDT), when it lies highest above the horizon. Maximum activity is
not expected until November 13, so current rates would be 1-2 per hour, no
matter your location. Meteors from the Northern Taurids strike the atmosphere at
29km/sec., which would produce meteors of slow velocity. You must face in the
general direction of the north and south Taurid radiants in order to tell them
apart.

The Southern Taurid (STA) radiant is currently located at 02:48 (042) +11. This
position lies near on the Cetus/Aries border, very close the the fourth
magnitude star Mu Ceti. This radiant is best placed near 0200 local daylight
time (LDT), when it lies on the meridian and is located highest in the sky.
Maximum occurred on October 9th, so rates would now be near two per hour when
the radiant lies high in the sky. With an entry velocity of 29 km/sec., the
average Southern Taurid meteor would be of slow velocity.

The Orionids (ORI) reach maximum activity on mornings of October 21st and 22nd.
The radiant is currently located at 06:20 (095) +16, which is in the
northeastern Orion, four degrees west of the second magnitude star Alhena (Gamma
Geminorum). The radiant is best placed for viewing near 0500 when it lies on the
meridian and is highest above the horizon. At this time of night one should be
able to count at least 20 shower members per hour from rural locations. Good
rates can actually be seen any time during the morning hours. Orionid meteors
are equally well seen either side of the equator. With an entry velocity of 67
km/sec., most activity from this radiant would be swift. This display does not
have a sharp peak so activity seen after moon set after the 22nd should be good.
Unfortunately the moon will begin to interfere late in the week.

The Epsilon Geminids (EGE) are active all month long with low hourly rates. Even
at maximum activity only three shower members per hour are expected. Recent
research by the IMO has indicated an earlier maximum of October 15th, rather
than October 19th. The radiant position is currently located at 06:56 (104) +28.
This position lies in northern Gemini, four degrees northeast of the fourth
magnitude star Mebsuta (Epsilon Geminorum). The radiant is also best placed
during the last dark hour before dawn, when it lies highest above the horizon in
a dark sky. Rates would be near two per hour as seen from the northern
hemisphere and less than one per hour as seen south of the equator. With an
entry velocity of 70 km/sec., most activity from this radiant would be swift.

The Leonis Minorids (LMI) are active from October 16-27 with maximum activity
occurring on October 23rd. This radiant is currently located at 10:36 (159) +37,
which places it in northeast Leo Minor, four degrees northeast of the fourth
magnitude star Beta Leonis Minoris . The radiant is best placed just before dawn
when it lies highest in a dark sky. This shower is better situated for observers
situated in the northern hemisphere where the radiant rises far higher into the
sky before the start of morning twilight. At 60km/sec., the average Leonis
Minorid is swift.

As seen from the mid-northern hemisphere (45N) one would expect to see
approximately ten 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 five
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.

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