Meteor Activity Outlook for February 13-19, 2010

February offers the meteor observer in the northern hemisphere a couple of weak
showers plus falling sporadic rates. This may not seem too exiting but you never
know when surprises are in store. An errant earthgrazer from the Centaurid complex
may shoot northward. Better yet, a bright fireball may light up the sky. February
is the start of the fireball season, when an abundance of fireballs seem to occur.
This lasts well into April and seems to occur mostly during the early evening hours.

Observers in the southern hemisphere are treated to the Alpha Centaurid peak on
the 8th plus the entire Centaurid complex of radiants is active all month long.
Sporadic rates are slightly less than those seen in January, but still stronger
than those witnessed north of the equator.

During this period the moon reaches its new phase
on Sunday February 14th. At this time the moon lies near the sun and is invisible
at night. Next week the waxing crescent moon will enter the evening sky but will
set long before the more productive morning hours arrive. The estimated total
hourly rates for evening observers this week is near two for northern observers
and three for those viewing from south of the equator. For morning observers the
estimated total hourly rates should be near fourteen from the northern hemisphere
and twenty as seen from the 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.

The radiant positions and rates listed below are exact
for Saturday night/Sunday morning February 13/14. 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 showers are expected to be active this week:

The wide Antihelion (ANT) radiant is now centered at 10:32 (158) +07. This
area of the sky lies in southwestern Leo, seven degrees southeast of the first
magnitude star Regulus (Alpha Leonis). This radiant is best placed near 0100 LST
when it lies on the meridian and is located highest in the sky. Due to the large
size of this radiant, any meteor radiating from western Leo, Cancer, Sextans, or
extreme western Hydra could be a candidate for this shower. Rates at this time
should be near two per hour no matter your location. With an entry velocity of
30 km/sec., the average Antihelion meteor would be of medium-slow speed.

The Alpha Centaurids (ACE) reached maximum activity on Monday February 8th.
This shower is only visible south of thirty degrees north latitude. The further
one is located south (down to 60S) the better the radiant is situated in the sky.
Expected rates from the southern hemisphere is now less than five per hour, even
with the radiant located high in the sky. The current radiant position lies at
14:28 (217) -61. This position lies in southeastern Centaurus, directly
between the brilliant stars Rigel Kentaurus (Alpha Centauri) and Hadar (Beta
Centauri). The radiant is best placed during the last dark hour before dawn, when
it lies highest above the horizon in a dark sky. At 56km/sec. the Alpha Centaurids
would produce mostly swift meteors.

Studies by Sirko Molau and Juergen Rendtel of video radiants has revealed a radiant
active in Hercules this time of year. The Beta Herculids (BHE) are only active
for five nights and reach maximum activity on Friday February 12th. Hourly rates on
that morning should be near one shower member per hour as seen from the northern
hemisphere. Those situated south of the equator should average slightly
less than one meteor per hour. The radiant position on the 14th lies at 16:32
(248) +22. This position lies in western Hercules, just north of the third
magnitude star Beta Herculis. The radiant is best placed during the last dark hour
before dawn, when it lies highest above the horizon in a dark sky. At 56km/sec. the
Beta Herculids would produce mostly swift meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately
eleven Sporadic meteors per hour during the last hour before dawn as seen
from rural observing sites. Evening rates would be near two per hour. As seen from
the mid-southern hemisphere (45S), morning rates would be near fourteen per hour
as seen from rural observing sites and three 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.