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Post: 29 lutego 2016, 07:25 
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As seen from the northern hemisphere, March is the slowest month for meteor activity. No major annual showers are active and only a few very weak minor showers produce activity this month. The sporadic rates are also near their annual minimum so there is not much to look forward to this month except for the evening fireballs that seem to peak this time of year from the northern hemisphere. This could be due to the fact the Antapex radiant lies highest above the horizon this time of year during the evening hours. From the southern hemisphere, activity from the Centaurid complex begins to wane with only the weak activity visible from Norma and perhaps others areas nearby. At least southern sporadic rates are still strong to make the late summer viewing a bit more pleasurable.

During this period the moon reaches its last quarter phase on Tuesday March 1st. On that date the moon will be located 90 degrees west of the sun and will rise near midnight local standard time (LST) for most observers viewing from mid-northern latitudes. As the week progresses the waning crescent moon will become less of a nuisance with each passing night as it slims and rises later and later. The estimated total hourly meteor rates for evening observers this week is near 3 for observers located in the northern hemisphere and 5 for observers located south of the equator. For morning observers the estimated total hourly rates should be near 5 as seen from mid-northern latitudes (45N) and 10 as seen from tropical southern locations (25S). Morning rates are reduced due to moonlight. 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 February 27/28. 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 11:28 (172) +02. This position lies in southeastern Leo, only 1 degree south of the brilliant planet Jupiter. Due to the large size of this radiant, Anthelion activity may also appear from the nearby constellations of Crater and western Virgo as well as Leo. This radiant is best placed near 0100 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.

The February Mu Virginids (FMV) were discovered by Damir Šegon and colleagues from the Croatian Meteor Network using their data and that of SonotaCo. These meteors are active from February 15 through March 4 with maximum activity occurring on February 26. The current radiant position lies near 16:28 (247) -01, which places it southern Ophuichus, close to the 4th magnitude star known as Lambda Ophiuchi. Rates are expected to be less than 1 per hour no matter your location. These meteors are best seen near 0500 LST when the radiant lies highest above the horizon. At 62 km/sec. the February Mu Virginids would produce mostly swift meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately 3 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 8 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. Morning rates are reduced by moonlight during this period.

The list below offers the information from above in a condensed form. Rates and
positions are exact for Saturday night/Sunday morning except where noted in the
shower descriptions.

Anthelion (ANT) - 11:28 (172) +02 Velocity - 30km/sec.
Northern Hemisphere - 2 per hr. Southern Hemisphere - 2 per hr

February Epsilon Virginids (FEV) - 16:28 (247) -01 Velocity - 62km/sec.
Northern Hemisphere - <1 per hr. Southern Hemisphere - <1 per hr

Zgodnie z:

Robert Lunsford
International Meteor Organization


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