(meteorobs) Meteor Activity Outlook for November 17-23, 2012

[skywayinc at aol.com]

Bob --

Re: your comment regarding the Leonids: "As the weekend passes, these rates will fall to only 2-3 per hour." 

Any thoughts on the interaction of the Earth with a dust trail ejected by Comet 55/P dating back to AD 1400 that both Jerimie Vauballion and Mikhail Maslov have forecast will interact with Earth during the early hours of next Tuesday morning?  While nothing extraordinary is expected regarding ZHRs (Mikhail is thinking 15-20), it is my contention that debris that is this old (18-revolutions/600+ years) might carry a few larger-than-normal particles that may give rise to some outstandingly bright meteors.  

-- joe rao




-----Original Message-----
From: Robert Lunsford <lunro.imo.usa at cox.net>
To: meteorobs <meteorobs at meteorobs.org>
Sent: Fri, Nov 16, 2012 3:21 pm
Subject: (meteorobs) Meteor Activity Outlook for November 17-23, 2012


During this period the moon reaches its first quarter phase on Tuesday November 
0th. At this time the moon is located ninety degrees east of the sun and will 
et near 2300 (1100pm) local standard time (LST). This weekend the waxing 
rescent moon will set during the early evening hours and will pose no problems 
o meteor watchers. Later in the week the gibbous moon will limit good meteor 
bserving to the late morning morning before dawn. The estimated total hourly 
eteor rates for evening observers this week is near four for observers located 
t mid-northern latitudes and three for observers in mid-southern latitudes. For 
orning observers the estimated total hourly rates should be near twenty eight 
rom the mid-northern hemisphere and twenty three from the mid-southern 
emisphere. The actual rates will also depend on factors such as personal light 
nd motion perception, local weather conditions, alertness and experience in 
atching meteor activity. Rates are reduced during t
he evening hours due to moonlight.
The radiant (the area of the sky where meteors appear to shoot from) positions 
nd rates listed below are exact for Saturday night/Sunday morning November 
7/18. These positions do not change greatly day to day so the listed 
oordinates may be used during this entire period. Most star atlases (available 
t science stores and planetariums) will provide maps with grid lines of the 
elestial coordinates so that you may find out exactly where these positions are 
ocated in the sky. A planisphere or computer planetarium program is also useful 
n showing the sky at any time of night on any date of the year. Activity from 
ach radiant is best seen when it is positioned highest in the sky, either due 
orth or south along the meridian, depending on your latitude. It must be 
emembered that meteor activity is rarely seen at the radiant position. Rather 
hey shoot outwards from the radiant so it is best to center your field of view 
o 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 
he radiant (if it is a shower member) or in another direction if it is a 
poradic. Meteor activity is not seen from radiants that are located below the 
orizon. The positions below are listed in a west to east manner in order of 
ight ascension (celestial longitude). The positions listed first are located 
urther west therefore are accessible earlier in the night while those listed 
urther down the list rise later in the night.
The following radiants are expected to be active this week:
Remnants from the famous Andromedid (AND) shower, noted for intense storms 
uring the 19th century, may still be seen throughout November. The current 
osition of this large radiant is 01:36 (024) +37. This position lies in eastern 
ndromeda, three degrees east of the second magnitude star Mirach (Beta 
ndromedae). The radiant is so diffuse that Andromedid meteors may be seen 
oming from Triangulum, northern Pisces, as well as Andromeda. Visual activity 
s expected to be low, but detectable. An inconspicuous maximum occurred on 
ovember 9, when this source was the 5th most active radiant in the sky. The 
ndromedid meteors are best seen near 2200 (10pm) local standard time (LST), 
hen the radiant lies on the meridian and lies highest in the sky. At 19km/sec., 
he average Andromedid will appear as a very slow moving meteor.
Studies of the IMO video database by Sirko Molau and Juergen Rendtel has 
evealed another active radiant in Taurus this time of year. Now that the 
outhern Taurids are no longer detectable, the Gamma Taurids (GTA) may be 
istinguished within the Taurid complex. The Gamma Taurid radiant is centered at 
4:04 (061) +15. This area of the sky lies in western Taurus, three degrees west 
f the the 4th magnitude star Hyadum I (Gamma Tauri). The radiant is best placed 
ear 0100 LST, when it lies highest above the horizon. Maximum activity occurred 
n November 10th so current rates would be near one shower member per hour, no 
atter your location.  Meteors from the Gamma Taurids strike the atmosphere at 
7km/sec., which would produce meteors of slow velocity.
The Northern Taurids (NTA) are active from a radiant centered at 04:16 (064) 
24. This area of the sky lies in western Taurus just three degrees west of the 
amous naked eye open cluster known as the Pleiades or the Seven Sisters. The 
adiant is best placed near 0100 LST, when it lies highest above the horizon. 
aximum activity occurred on November 13th so current hourly rates would be near 
hree from the northern hemisphere and two from south of the equator. Meteors 
rom the Northern Taurids strike the atmosphere at 29km/sec., which would 
roduce meteors of slow velocity.
The November Orionids (NOO) are active from a radiant located at 05:28 (082) 
16. This area of the sky is located on the Orion/Taurus border, twelve degrees 
ast of the first magnitude orange star Aldebaran (Alpha Tauri).. The peak for 
his radiant is not until November 30th, so rates would be less than than one 
hower member per hour, no matter your location. This location is close to the 
aurid complex, but far enough east to be distinguishable. The faster velocity 
f the November should help distinguish these meteors from the slower, but more 
umerous Taurids. The radiant is best placed for viewing near 0200 LST when it 
ies on the meridian and is highest above the horizon. With an entry velocity of 
4 km/sec., the November Orionids would be of medium speed.
The last few meteors from the Orionids (ORI) will be seen this week. The radiant 
s located at 08:00 (120) +15. This area of the sky is located on the 
emini/Cancer border, twelve degrees northeast of the zero magnitude star 
rocyon (Alpha Canis Minoris). The radiant is best placed for viewing near 0400 
ST when it lies on the meridian and is highest above the horizon. Expected 
ourly rates would be less than one no matter your location With an entry 
elocity of 67 km/sec., most activity from this radiant would be swift.
The Leonids (LEO) are now the most active radiant in the sky, producing a dozen 
hower members per hour during the last couple of hours before dawn. As the 
eekend passes, these rates will fall to only 2-3 per hour. The radiant is 
urrently located at 10:16 (154) +22. This position lies in northwestern Leo, 
ithin the "sickle" of Leo, two degrees northwest of the second magnitude double 
tar Algeiba (Gamma Leonis). The Leonid radiant is best placed during the last 
our before morning twilight when the radiant lies highest in a dark sky. 
eonids may be seen from the southern hemisphere but the viewing conditions are 
ot quite as favorable as those north of the equator.
Studies of the IMO video database by Sirko Molau and Juergen Rendtel has 
evealed an active radiant in Draco this time of year. The November Iota 
raconids (NID) radiant is located at 12:36 (189) +70. This area of the sky lies 
n western Draco close to the position occupied by the fourth magnitude star 
appa Draconis. The radiant is best placed near 0100 LST, when it lies highest 
bove the horizon. Maximum activity occurs on November 26th so current rates 
ould be less than one shower member per hour, no matter your location.  Due to 
he high northerly declination of the radiant these meteors are not visible from 
ost of the southern hemisphere. Only southern equatorial regions would have any 
hance of seeing activity from this source Meteors from the November Iota 
raconids strike the atmosphere at 43km/sec., which would produce meteors of 
edium velocity.
As seen from the mid-northern hemisphere (45N) one would expect to see 
pproximately twelve sporadic meteors per hour during the last hour before dawn 
s seen from rural observing sites. Evening rates would be near three per hour. 
s seen from the mid-southern hemisphere (45S), morning rates would be near six 
er hour as seen from rural observing sites and two per hour during the evening 
ours. Locations between these two extremes would see activity between the 
isted figures. Evening rates are reduced due to moonlight.
The list below presents a condensed version of the expected activity this week.
ates and positions are exact for Saturday night/Sunday morning but may be used
or the entire period.
Andromedids (AND) - 01:36 (024) +37   Velocity - 19km/sec.
orthern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr.
Gamma Taurids (GTA) - 04:04 (061) +15    Velocity - 29km/sec.
orthern Hemisphere - 1 per hr.    Southern Hemisphere - 1 per hr.
Northern Taurids (NTA) - 04:16 (064) +24   Velocity - 29km/sec.
orthern Hemisphere - 3 per hr. Southern Hemisphere - 2 per hr.
November Orionids (NOO) - 05:28 (082) +16   Velocity - 44km/sec.
orthern Hemisphere -<1 per hr.    Southern Hemisphere - <1 per hr.
Leonids (LEO) - 10:16 (154) +22    Velocity - 71km/sec.
orthern Hemisphere - 12 per hr.    Southern Hemisphere - 10 per hr.
Nov. Iota Draconids (NID - 12:36 (189) +70    Velocity - 43km/sec.
orthern Hemisphere -<1 per hr.    Southern Hemisphere - <1 per hr.
Clear Skies!
obert Lunsford
merican Meteor Society
					
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