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Czas środkowoeuropejski letni




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Post: 04 marca 2017, 15:00 
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During this period the moon reaches its first quarter phase on Saturday March 4.
At this time the moon is located 90 degrees east of the sun and is located high
in the sky at dusk. It will remain above the horizon until around 0100, when it
sets on the northwestern horizon. The remaining hours of the night will remain
moon-free and good for meteor viewing. As this period progresses the waxing
gibbous moon will set approximately 45 later with each passing night. By the end
of the period the nearly full moon will remain above the horizon nearly all
night long. The estimated total hourly meteor rates for evening observers this
week is near 3 for those viewing from the northern hemisphere and 5 for those
located south of the equator. For morning observers the estimated total hourly
rates should be near 7 as seen from mid-northern latitudes (45N) and 16 as seen
from tropical southern locations (25S). Evening rates are reduced by moonlight
during this period. 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. 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 March 4/5.
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.

These sources of meteoric activity are expected to be active this week.

The center of the large Anthelion (ANT) radiant is currently located at 11:48
(177) +01. This position lies in western Virgo, very close to the area occupied
by the 4th magnitude star known as Zavijava (beta Virginis). Due to the large
size of this radiant, Anthelion activity may also appear from Crater and eastern
Leo as well as western Virgo. 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 2 per hour no matter your location. With
an entry velocity of 30 km/sec., the average Anthelion meteor would be of slow
velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see
approximately 5 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 4 per hour during the evening hours.
Locations between these two extremes would see activity between the listed
figures.

Anthelion (ANT) - 11:48 (177) +01 30 Velocity - 30km/sec.
Northern Hemisphere - 2 per hr. Southern Hemisphere - 2 per hr

Zgodnie z:

Robert Lunsford
International Meteor Organization


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