"During this period the moon reaches its full phase on Friday February
14th. At this time the moon will lie opposite the sun and will remain
above the horizon all night long as seen from mid-northern latitudes.
This weekend the waxing gibbous moon will set during the early morning
hours and will allow several hours of viewing under optimal conditions
before the onset of dawn. This window of opportunity will shrink by
approximately 45 minutes with each passing day until the moon lies above
the horizon all night long toward the end of the week. The estimated
total hourly meteor rates for evening observers this week is near 3 for
observers situated at mid-northern latitudes and 4 for observers viewing
from the southern tropics (latitude 25 S.). For morning observers the
estimated total hourly rates should be near 9 for observers situated at
mid-northern latitudes and 20 for observers viewing from the southern
tropics. 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. Evening rates are reduced during
this period due to moonlight. Note that the hourly rates listed below
are estimates as viewed from dark sky sites away from urban light
sources. Observers viewing from urban areas will see less activity as
only the brightest meteors will be visible from such locations.
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 February 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 sources of meteoric activity are expected to be active this week:
According to Sergei Shanov, there is the possibility that the Earth may
encounter some debris from comet 45P/Honda-Mrkos-Pajusakova on February
11, near 9:37 Universal Time. Activity is expected to be weak and even
worse than that, the position of 21:54 (328) -15 places it in
northeastern Capricornus, just a few degrees from the sun! This
situation makes visual sightings nearly impossible but observers may
attempt to listen for any activity near the time of maximum activity. At
the time of maximum activity the sun will be above the horizon for
nearly the entire eastern hemisphere, therefore radio observers in the
eastern hemisphere might attempt to verify any activity. These meteors
would have a slow entry velocity of 23 km/sec.
The center of the large Anthelion (ANT) radiant is currently located at
10:20 (155) +09. This position lies in southwestern Leo, 3 degrees
southeast of the 1st magnitude star known as Regulus (Alpha Leonis). Due
to the large size of this radiant, Anthelion activity may also appear
from Cancer, Sextans, northwestern Hydra as well as Leo. This radiant is
best placed near 0100 local standard time (LST), when it lies on the
meridian and is located highest in the sky. Rates at this time should be
near 1 no matter your location. With an entry velocity of 30 km/sec.,
the average Anthelion meteor would be of slow velocity.
The Alpha Centaurids (ACE) are active from January 28 though February
21, with maximum activity occurring on February 8. The radiant is
currently located at 14:04 (211) -59. This position lies in southeastern
Centaurus just north of the brilliant 1st magnitude star known as Hadar
(Beta Centauri). Due to the southern declination of this radiant, these
meteors are not visible beyond tropical latitudes in the northern
hemisphere. Current rates would be near 5 per hour as seen from the
southern hemisphere and less than 1 from the northern hemisphere. These
meteors are best seen near 0400 LST when the radiant lies highest above
the horizon. At 56 km/sec. the Alpha Centaurids would produce mostly
swift meteors.
Activity from the Beta Herculids begins on Thursday morning February
13th. This also happens to be the morning of maximum activity. This
shower was discovered by Juergen Rendtel and Sirko Molau using data from
the IMO video database. This shower is active from the 13th through the
19th. On the 13th the radiant is located at 16:27 (247) +24. This
position is located in western Hercules, three degrees north of the
third magnitude star Kornephoros (Beta Herculis). These meteors are best
seen near during the last dark hour before dawn when the radiant lies
highest above the horizon in a dark sky. Rates would mostly likely be
near one shower member per hour, no matter your location. At 56 km/sec.
the Beta Herculids would produce mostly swift meteors.
As seen from the mid-northern hemisphere (45N) one would expect to see
approximately 7 sporadic meteors per hour during the last hour before
dawn as seen from rural observing sites. Evening rates would be near 2
per hour. As seen from the tropical southern latitudes (25S), morning
rates would be near 14 per hour as seen from rural observing sites and 3
per hour during the evening hours. Locations between these two extremes
would see activity between the listed figures. Evening rates are
reduced due to interfering moonlight.
The table below presents a list of radiants that are expected to be active this
week. Rates and positions are exact for Saturday night/Sunday morning except
where noted in the shower descriptions.
45Pids -21:54 (328) -15 Velocity - 23km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr
Anthelions (ANT) - 10:20 (155) +09 Velocity - 29km/sec.
Northern Hemisphere - 1 per hr. Southern Hemisphere - 1 per hr
Alpha Centaurids (ACE) - 14:04 (211) -59 Velocity - 56km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - 5 per hr
Beta Herculids (BHE) - 16:27 (247) +24 Velocity - 56km/sec.
Northern Hemisphere - 1 per hr. Southern Hemisphere - 1 per hr
Clear Skies!
Robert Lunsford
American Meteor Society"
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