(meteorobs) Meteor Activity Outlook for August 4-10, 2012

Fri Aug 10 16:03:10 EDT 2012

Would you mind if I forwarded this to the AAAP(_www.3ap.org_ 
(http://www.3ap.org)  ) Yahoo Group, as a reference for the  sporadics that will be seen 
during tomorrow's Persied observation at the public  star party?

Thanks.

Kathy DeSantis

In a message dated 8/4/2012 8:13:13 P.M. Eastern Daylight Time,  
lunro.imo.usa at cox.net writes:

Meteor  activity kicks into high gear in August as seen from the northern 
hemisphere.  The main reason for all this activity is the Perseid shower that 
peaks on  August 12. This shower is active most of the month and remains 
above the level  of the sporadic background for a week centered on August 12. 
The sporadic  activity is also near maximum as seen from the northern 
hemisphere and is now  more than double the rates from just three months ago. As 
seen from south of  the equator, meteor rates are still decent but falling 
rapidly. The sporadic  rates continue their downward slide and the Perseid 
radiant does not rise high  into the sky as seen in the southern hemisphere so 
rates from this shower are  greatly reduced when compared to the northern 
hemisphere.

During this  period the moon reaches its last quarter phase on Thursday 
August 9th. This  weekend the bright waning gibbous moon will rise during the 
late evening hours  and will effectively ruin the sky for meteor watching the 
remainder of the  night. The estimated total hourly rates for evening 
observers this week is  near four for observers located in the northern 
hemisphere and two for  observers south of the equator. For morning observers the 
estimated total  hourly rates should be near fifteen for those located in the 
mid-northern  hemisphere (45 N) and ten for those viewing from the 
mid-southern hemisphere  (45 S). Locations between these two extremes would see 
activity between the  listed figures. These rates assume that you are watching 
from rural areas away  from all sources of light pollution. 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. Morning  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 
August 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. Vi
ewing 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  list below presents a summary of the expected activity this week. 
Rates and  positions are exact for Saturday night/Sunday morning August 4/5, but 
may be  used all week. The full descriptions of each radiant will continue 
next week  when the moon becomes less of a nuisance to observers.

Kappa Cygnids  (KCG) - 18:06 (274) +46   Velocity 23km/sec
Northern Hemisphere -  <1 per hr    Southern Hemisphere - <1 per hour

Alpha  Capricornids (CAP) - 20:36 (309) -09   Velocity 25km/sec
Northern  Hemisphere - 1 per hr    Southern Hemisphere - 1 per  hour

Antihelions (ANT) - 21:40 (325) -12   Velocity  30km/sec
Northern Hemisphere - <1 per hr   Southern Hemisphere  - 1 per hour

Delta Aquariids (SDA) - 22:42 (346) -14    Velocity 42km/sec
Northern Hemisphere - 2 per hr   Southern  Hemisphere - 3 per hour

Piscids Austrinids (PAU) - 23:12 (348)  -27   Velocity 35km/sec
Northern Hemisphere - <1 per  hr   Southern Hemisphere - 1 per hour

Perseids (PER) - 02:28  (037) +56   Velocity 61km/sec
Northern Hemisphere - 6 per  hr   Southern Hemisphere - 3 per hour

Alpha Triangulids (ATR)  - 02:40 (040) +37   Velocity 67km/sec
Northern Hemisphere - <1  per hr   Southern Hemisphere - <1 per hour

Eta Eridanids  (ERI) - 02:52 (043) -13   Velocity 64km/sec
Northern Hemisphere -  <1 per hr   Southern Hemisphere - <1 per hour

Clear  Skies!
Robert Lunsford
American Meteor Society

_______________________________________________
meteorobs mailing  list
meteorobs at meteorobs.org
http://lists.meteorobs.org/mailman/listinfo/meteorobs

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.meteorobs.org/pipermail/meteorobs/attachments/20120810/00bb063c/attachment.html 