(meteorobs) Meteor Activity Outlook for March1-7, 2014

Robert Lunsford lunro.imo.usa at cox.net
Fri Feb 28 13:51:20 EST 2014


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 new phase on Saturday March 1st. At this time the moon will lie near the sun and will be invisible at night. Next week the waxing crescent moon will emerge in the evening sky but will not cause any problems to meteor observers viewing during the more active morning hours. 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 5 for observers situated at mid-northern latitudes and 11 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. 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 1/2. 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:

The center of the large Anthelion (ANT) radiant is currently located at 11:36 (174) +01. This position lies in western Virgo, 3 degrees west of the fourth magnitude star Zavijava (Beta Virginis). These meteors may be seen all night long but the radiant is best placed near 0100 Local Standard Time (LST) when it lies on the meridian and is highest in the sky. 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 slow velocity.

The Gamma Normids (GNO) are active from a radiant located at 15:08 (227) -51. This position lies in southeastern Lupus, 3 degrees northwest of the third magnitude star Zeta Lupi.  Due to the southerly declination (celestial latitude) these meteors cannot be seen north of the northern tropical regions. They are best seen from mid-southern latitudes where the radiant lies high in the sky near 0500 local summer time. This shower peaks on March 13 so current hourly rates would still be less than one no matter you location. At 56km/sec. the Gamma Normids would produce mostly swift meteors.

IMO shower #37 is active Wednesday March 5th through March 10th. Maximum activity is expected on the 5th from a radiant located at 15:43 (236) +42. This position is located in a extreme northeastern Bootes. The closest bright star is second magnitude Alphecca (Alpha Coronae Borealis), which lies fifteen degrees to the southwest. 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 less than one shower member per hour, no matter your location. Observers in the northern hemisphere have an advantage in that the radiant lies higher in the sky during the morning hours. At 42 km/sec. these meteors would have a medium velocity.

IMO shower #35 is active through Wednesday from a radiant located at 16:39 (250) +49. This position is located in a remote area of northwestern Hercules. The closest bright star is Eltanin (Gamma Draconis), which lies twenty degrees to the east.  Peak activity is expected on the morning of March 4th. 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 less than one shower member per hour, no matter your location. Observers in the northern hemisphere have an advantage in that the radiant lies higher in the sky during the morning hours. At 40 km/sec. these meteors would have a medium 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 12 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.

The list 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.

 
Anthelions (ANT) - 11:08 (167) +04   Velocity - 29km/sec. 
Northern Hemisphere - 1 per hr.   Southern Hemisphere - 1 per hr 
 
Gamma Normids (GNO) - 15:32 (233) -52  Velocity - 56km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr.

 IMO #37 - 15:43 (236) +42   Velocity - 42km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr.
 
IMO #35 - 16:39 (250) +49  Velocity - 40km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr.
 
Clear Skies! 
Robert Lunsford 	 
American Meteor Society   	 
 	 	 	 	 	 	 



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