Another morning meteor shower - Saturday morning 9/1/07

[Jane H Jones]

Here is another reason to wake up early on Saturday morning - a rare 
meteor shower!  Bright shooting stars should be visible even with a 
big old bright moon, and our city light pollution.  Look to the East 
and Northeast.

"Some time in the 40 years or so around 4 A.D., comet Kiess (C/1911 
N1) passed by the Sun, ejecting a cloud of dust particles. The comet 
returned in 1911, after completing one orbit. The dust particles were 
pushed by the Sun's light into slightly wider orbits and have been 
returning ever since, forming a thin ongoing stream of dust that 
usually passes just outside Earth's orbit. On occasion, the combined 
gravity of the solar system's planets moves this dust trail into 
Earth's path. Earth encountered this 2000-year-old dust in 1935, 
1986, and 1994, causing a meteor shower known as the Aurigids." 
http://aurigids.seti.org/

Best viewing direction:
Best viewing: Keep Moon out of field of view (best to block behind 
obstruction such as telephone pole, then watch whole sky), avoid city 
haze that scatters moonlight
Best direction: East and Northeast
Best time: Start one hour before peak, then see the rate of meteors 
increase and decrease while Earth travels through the shower

When:
Date: 2007 September 1
Peak time: about 11:33 +/- 20 minutes UT (= 04:33 a.m. Pacific 
Daylight Savings Time).
Duration: about 1.5-hour
Width: 25 minutes above half the peak rate

What:
Peak rate: ZHR (Zenithal Hourly Rate) = 200 per hour (10-minute interval)
Meteor brightness: mostly -3 to +3 magnitude
Shower radiant: constellation Auriga (Radiant at RA = 92, Decl. = +39)
Entry speed: Vinf = 67 km/s

Where:
Visible from: California, Oregon, Hawaii, Alaska, Mexico [see flux 
applet for visibility from your location]

Moon:
4 days past Full Moon, high in the sky

Important because:
Once in a lifetime crossing of the dust trail of a known long period 
comet (comet Kiess).

Public interest:
When you make a wish, consider that each meteoroid was released at 
some unknown moment during the period 36 B.C. - A.D. 45.

Links: NASA Ames News Release: 
http://www.nasa.gov/centers/ames/news/releases/2007/07_59AR.html

-- 
Jane Houston Jones
Senior Outreach Specialist, Cassini Program
JPL - 4800 Oak Grove Drive, MS 230-205
Pasadena, CA  91109  818-393-6435
jane.h.jones at jpl.nasa.gov
Cassini SOC http://soc.jpl.nasa.gov/index.cfm
What's Up? http://education.jpl.nasa.gov/amateurastronomy/index.html
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