29
Aug
2012

Meteor Activity Outlook for September 1-7, 2012

September offers longer nights in the northern hemisphere that tend to be less hazy than those experienced in mid-summer. In the sky, no major showers are visible from either hemisphere but the northern hemisphere enjoys the advantage of higher sporadic rates. Most of the shower activity this month is produced from the Perseus-Aurigid complex active this time of year. These showers rarely produce more than five meteors per hour but still manage to produce most of the shower activity seen this month. Unfortunately the Perseus-Aurigid complex lies too low in the northern sky for southern hemisphere observers to view very well. Video studies have shown that the Southern Taurids are visible as early as
September 7th, therefore after this date the Antihelion radiant will no longer be listed until the Taurid showers end in December. The Antihelion meteors are still active but their radiant is superimposed upon that of the more numerous Taurids, therefore it is impossible to properly separate these meteors. Observers in the southern hemisphere suffer from some of their lowest rates of the year this month. The Southern Taurid radiant is not too badly placed so observers south can expect to see a little of this activity this month.

During this period the moon wanes from its full phase to nearly last quarter. These are the worst circumstances possible for meteor watchers as the moon will interfere with observing all week long as it will be present in the morning sky when meteor rates are at their best. The bright glare of the moonlight will obscure all but the brightest meteors reducing rates significantly. The estimated total hourly meteor rates for evening observers this week is near three for observers located at mid-northern latitudes and two for observers in mid-southern latitudes. For morning observers the estimated total hourly rates should be near eight from the mid-northern hemisphere and four from the mid-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. Rates are reduced during this period due to the intense moonlight.

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 September 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 radiants are expected to be active this week. Detailed descriptions of each source will continue next week when moonlight will not be such a problem.

SHOWER DATE OF MAXIMUM ACTIVITY CELESTIAL POSITION ENTRY VELOCITY CULMINATION HOURLY RATE CLASS
RA (RA in Deg.) DEC Km/Sec Local Daylight Time North-South
Antihelions (ANT) - 23:28 (352) -02 30 01:00 1 – 1 II
September Epsilon Perseids (SPE) Aug 24 03:52 (043) +41 66 05:00 1 – <1 IV
IMO #149 Sep 03 04:52 (073) +45 70 06:00 <1 – <1 IV
Aurigids (AUR) Aug 31 06:16 (094) +40 67 08:00 <1 – <1 II

About Robert Lunsford

Bob has been interested in the stars as far back as he can recall His first experience with meteors was a biggie, the 1966 Leonid shower. In 1980, a major awaking occurred. He received a sample copy of Meteor News. He was amazed to learn there was a group actually devoted strictly to meteor observing! He joined the group also started to view some of the minor showers list among the pages of Meteor News. Lastly, he was contracted by Springer Publishing in 2007 to write a book on observing meteors. The book is now available and hopefully will be a useful guide to all interested in the enjoyable field of meteor observing. More info about Robert Lunsford →
3 Responses
  1. Is a fireball a meteor that is just closer to your position or concordance making it appear larger compared to the numerous others that is farther away,…?
    Meteor,astroids,&other types of debris,man made or natural, falling stars,fireballs,what is the difference in the types of objects that light up on entering the atmosphere :,if its all debris, what makes one or the other by name?
    I saw a fireball in 1976 ,December, it was a warm day in central Alabama, aboutt 35 miles south of Bham,noone but kids saw this thing,,we were 6-7 yrs old,it whizzed by overhead, big&bright,in comparison it was bigger than the evening autumn sun&could actually hear it kinda sizzling as it shreeked by,the remains were found some several miles SSE of the place we saw it,our elementary school principal took us to the site&the local news took our pic examining the remains, i still have the clippings, i wished i knew what became of the remains,it looked like a lava rock with molten iron mixed through out it,thought I’d share


    • Jay and All,

      A fireball is not necessarily closer, but is larger in comparison to your average meteor. It all depends on the size of the object as to what it is called with meteors being the smallest and asteroids the largest.

      I hope this helps!

      Robert Lunsford
      American Meteor Society


  2. i am from the midlands of ireland myself and yhree friends were out walking friday last when i looked up and saw 2 big fireballs followed by 8 to 10 smaller ones flying from left too right it was spectacular ,it dident seem to be coming down too earth just headin across the sky we watched for nearly a minute and a half as it went over the horison wow


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