(meteorobs) Meteor Activity Outlook for December 13-19, 2014

Fri Dec 12 22:10:17 EST 2014

During this period the moon reaches its full phase on Sunday December 14th.
Hmmmm . . . methinks you're about 90-degrees off on the moon's phase, Bob.

-- joe rao

-----Original Message-----
From: Robert Lunsford <lunro.imo.usa at cox.net>
To: Meteor science and meteor observing <meteorobs at meteorobs.org>
Sent: Fri, Dec 12, 2014 6:17 pm
Subject: (meteorobs) Meteor Activity Outlook for December 13-19, 2014

During this period the moon reaches its full phase on Sunday December 14th. At 
this time the moon rises near midnight local standard time (LST) and will remain 
in the sky the remainder of the night. Viewing conditions improve with each 
passing night as the moon wanes and rises later each morning. The estimated 
total hourly meteor rates for evening observers this week is near 4 as seen from 
the northern hemisphere (45N) and 3 as seen from southern tropical latitudes 
(25S). For morning observers the estimated total hourly rates should be near 65 
as seen from the northern hemisphere and 30 as seen from below the equator. 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 brightes
 t meteors will be visible from such locations. Morning rates are reduced during 
this period due to the bright moon.

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 December 
13/14. 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.

Now that the activity from particles produced by comet 2P/Encke has ceased 
encountering the Earth, the Taurid showers for 2014 are over and we resume 
reporting activity from the Anthelion (ANT) radiant. This is not a true radiant 
but rather activity caused by the Earth's motion through space. As the Earth 
revolves around the sun it encounters particles orbiting in a prograde motion 
that are approaching their perihelion point. They all appear to be radiating 
from an area near the opposition point of the sun, hence the name Anti-helion. 
These were once recorded as separate showers throughout the year but it is now 
suggested to bin them into their category separate from true showers and 
sporadics. This radiant is a very large oval some thirty degrees wide by fifteen 
degrees high. Activity from this radiant can appear from more than one 
constellation. The position listed here is for the center of the radiant which 
is currently located at 06:20 (095) +23. This position lies in wes
 tern Gemini, 5 degrees west of the third magnitude star known as Mebsuta 
(Epsilon Geminorum). Anthelion activity may also appear from eastern Taurus, 
northeastern Orion, or southern Auriga. This radiant is best placed near 
midnight LST when it lies on the meridian and is highest in the sky. Rates at 
this time should be near 2 per hour as seen from the northern hemisphere and 1 
per hour from south of the equator. With an entry velocity of 30 km/sec., the 
average Anthelion meteor would be of slow velocity.

The Monocerotids (MON) are active from November 27th through December 17th. Peak 
activity occurred on December 9th so current rates should be near 1 per hour no 
matter your location. The radiant is located at 07:00 (105) +07. This position 
lies in eastern Monoceros, 10 degrees west of the zero magnitude star Procyon 
(Alpha Canis Minoris).  The Monocerotids are best seen near 0100 LST when the 
radiant lies highest above the horizon. At 41 km/sec. the Monocerotids produce 
mostly meteors of medium velocity.

The Geminids (GEM) will peak on Saturday evening/Sunday morning December 13/14 
from a radiant located at 07:37 (113.3) +32. This position is located very close 
to the bright 2nd magnitude star known as Castor (Alpha Geminorum). Expected 
maximum rates depend on your location and sky transparency. The half-illuminated 
moon will also compromise rates seen after midnight. Midnight rates should be 
near 20 per hour for urban observers. Those viewing from suburbs should see 30 
Geminids per hour near midnight. Rural observers should be treated to at least 
50 Geminids per hour. These rates should hold from midnight through 2am before 
falling as the radiant sets and the moonlight intensifies.    Geminid activity 
can be seen from the southern hemisphere but at much reduced rate. As seen from 
south of the equator, Geminid activity could only be seen for a few hours before 
and after 0200 LST. Rates will fall drastically with each passing night no more 
will be seen after the 17th. At 34 km
 /sec. the Geminids produce mostly meteors of medium velocity.

The Sigma Hydrids (HYD) are active from November 24 through December 21, with 
maximum activity occurring on December 6. The radiant is currently located at 
08:40 (130) +01 , which places it in western Hydra, 2 degrees south of the 4th 
magnitude star known as Sigma Hydrae. These meteors are best seen near 0400 LST 
when the radiant lies highest above the horizon. Current rates should be near 2 
per hour no matter your location. With an entry velocity of 61 km/sec., most 
activity from this radiant would be of swift speed.

The Eta Hydrids (EHY) were recently discovered by members of of the Croatian 
Meteor Network. This radiant is active from December 10-18 with maximum activity 
occurring on December 12. The radiant is currently located at 09:00 (135) +02 , 
which places it in western Hydra, 2 degrees west of the 4th magnitude star known 
as Theta Hydrae. This position is close to the Sigma Hydrids so care must be 
taken to separate the two sources. These meteors are best seen near 0400 LST 
when the radiant lies highest above the horizon. Current rates should be less 
than 1 per hour no matter your location. With an entry velocity of 63 km/sec., 
most activity from this radiant would be of swift speed.

The December Leonis Minorids (DLM) are active from December 6th through January 
18th. The radiant is currently located at 10:25 (156) +33. This position lies in 
central Leo Minor, approximately 10 degrees northeast of the third magnitude 
star Zeta Leonis. These meteors are best seen near 0500 LST when the radiant 
lies highest above the horizon. This shower peaks on December 21st so current 
rates would be near 2 per hour as seen from the northern hemisphere and 1 per 
hour as seen from south of the equator. At 63 km/sec. the December Leonis 
Minorids produce mostly swift meteors.

The last of the Psi Ursa Majorids (PSU) will be seen this week from a radiant 
located at 12:00 (180) +39. This position lies in a remote area of southeastern 
Ursa Major, 15 degrees south of the 2nd magnitude star known as Phecda (Gamma 
Ursae Majoris). This area of the sky is best placed during the last hour before 
dawn, when it lies highest above the horizon in a dark sky. Current rates would 
most likely be less than one per hour no matter your location. At 61km/sec., the 
average Psi Ursa Majorid meteor would be swift.

The December Chi Virginids (XVI) were discovered by members of SonotaCo based on 
video observations obtained in 2007 and 2008. This radiant is active from 
December 8-24 with maximum activity occurring on the 17th. The radiant is 
currently located at 12:43 (191) -10. This area of the sky is located in 
southern Virgo, 10 degrees west of the bright, 1st magnitude star known as Spica 
(Alpha Virginis). Rates would most likely be less than 1 per hour no matter your 
location. At 69km/sec., the average December Chi Virginid meteor would be swift.

The December Sigma Virginids (DSV) were discovered by John Greaves using data 
from SonotoCo.  This radiant is active from December 6-31 with maximum occurring 
on the 24th. The current radiant location is 13:04 (196) +06, which places it in 
central Virgo, 5 degrees south of the third magnitude star Vindemiatrix (Epsilon 
Virginis). These meteors are best seen during the last dark hour before dawn, 
when the radiant lies highest above the horizon in a dark sky. At 68 km/sec. the 
December Sigma Virginids would produce mostly swift meteors.

Activity from the Ursids (URS) should begin to appear during the late-week 
period from a radiant located at 13:58 (210) +76. This position lies in eastern 
Ursa Minor, fifteen degrees east of the second magnitude star Kochab (Beta Ursa 
Minoris). It must be remembered that the length of degrees are smaller in high 
declinations so the radiant is actually closer to this star than these figures 
imply. These meteors are best seen during the last dark hour before dawn, when 
the radiant lies highest above the horizon in a dark sky. This shower is not 
well seen from the southern hemisphere. Maximum activity is not expected until 
Monday December 22th, so current hourly rates this week would probably be less 
than one. On the morning of maximum, hourly rates of between 5-10 Ursids may be 
seen. At 30 km/sec. the Ursids produce mostly medium-slow meteors.

As seen from the mid-northern hemisphere (45N) one would expect to see 
approximately 8 sporadic meteors per hour during the last hour before dawn as 
seen from rural observing sites. Evening rates would be near 3 per hour. As seen 
from the tropical southern latitudes (25S), morning rates would be near 5 per 
hour as seen from rural observing sites and 2 per hour during the evening hours. 
Locations between these two extremes would see activity between the listed 
figures. Morning rates are reduced during this period due to moonlight.

Anthelion (ANT) - 06:20 (095) +23  Velocity - 30km/sec. 
Northern Hemisphere - 2 per hr.   Southern Hemisphere - 1 per hr. 

Monocerotids (MON) - 07:00 (105) +07  Velocity - 41km/sec. 
Northern Hemisphere - 1 per hr.   Southern Hemisphere - 1 per hr. 

Geminids (GEM) - 07:37 (113) +32  Velocity - 34km/sec. 
Northern Hemisphere - 50 per hr.   Southern Hemisphere - 20 per hr. 

Sigma Hydrids (HYD) -08:40 (130) +01	  Velocity - 61km/sec. 
Northern Hemisphere - 2 per hr.   Southern Hemisphere - 2 per hr. 

Eta Hydrids (EHY) - 09:00 (135) +02  Velocity - 63km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr 

Dec. Leonis Minorids (DLM) - 10:25 (156) +33  Velocity - 63km/sec. 
Northern Hemisphere - 2 per hr.   Southern Hemisphere - 1 per hr. 

Psi Ursa Majorids (PSU) - 12:00 (180) +39  Velocity - 61km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr. 

Dec. Chi Virginids (XVI) - 12:43 (191) -10  Velocity - 69km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr 

Dec. Sigma Virginids (DSV) - 13:04 (196) +06 Velocity - 68km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr 

Ursids (URS) - 13:58 (210) +76  Velocity - 30km/sec. 
Northern Hemisphere - <1 per hr.   Southern Hemisphere - <1 per hr 

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/20141212/4784e987/attachment-0001.html 