Good Gudrun Occultation Tonight in e. N. America

Mostly clear skies forecast from Virginia to New England

New: 2005 Aug. 10

     After several days of cloudy and hazy summer skies, Clear Sky 
Clock is forecasting mostly clear conditions for Thursday morning, 
August 11th's occultation under good conditions of an 11.7-mag. star 
in southwest Auriga by the relatively large 123-km asteroid (328) 
Gudrun.  The event will occur at 3:44 am EDT (7:44 UT; you only need 
to observe from 7:44.0 to 7:45.5 UT to catch the occultation) for 
the predicted clear area in the path from northern Virginia and 
southern Maryland across eastern Penn., western & northern N.J., 
N.Y.C. at east edge, s.e. New York, w. Conn., w. & central? Mass. 
(Boston is just east of the eastern 1-sigma line), & s. Vermont & s. 
N.H.  Areas farther south, across the central Carolinas, Georgia, & 
Fla. panhandle, and northern New England to Gaspe Peninsula, are 
predicted to be partly cloudy, but with some breaks possibly 
allowing observation.  In the path extending north of Washington, 
DC, average transparency is expected, hopefully good enough to 
observe the 11.7-mag. star with 8-inch telescopes.  

     The target star, TYC 2382-01036-1, is at J2000 RA 4h 39m 14.5s,
Dec. +35 deg. 12' 55" in a rather sparse area 4 deg. west-northwest 
of 3.5-mag. iota Aurigae, 12' east of a 9.5-mag. star, and 32' 
northeast of an 8.5-mag. rather wide double star. Finder charts of 
different scales are on Steve Preston's Web site.
The star will be at rather high altitude, mostly above 40 deg., for 
most observers, with no twilight or moonlight until Labrador 
(nautical twilight there).  If an occultation occurs, there will be 
a 3-mag. drop lasting about 4 sec. 


     A list of stations for this occultation, sorted by distance 
from the central line, giving the time of closest approach, 
distance in km from the predicted central line, probability for an 
occultation, etc., is on Derek Breit's Web site.
He also has some maps of the event, but more detailed maps can be 
found at Charlie Ridgway's interactive Google maps site.
This includes the usual limits for this event (green line for the 
center, blue lines for the predicted limits, and orange ones for the 
1-sigma limits) and you can zoom in to get any desired detail, 
including satellite images. 

     Normally I would try to set up two or 3 systems across the path 
for this, but I'm too busy getting ready for the Julia occultation 
Sat. morning (see next item), so I plan to just try to observe this 
event from my backyard in Greenbelt, which is rather close to the 
center.  Other observers in the Mid-Atlantic and New England areas 
with 8-inch or larger scopes are strongly encouraged to try to 
observe this occultation so we can obtain some good coverage across 
the path.  So far I don't know of anyone planning mobile 
observations of this event, so I don't think a big effort to try to 
coordinate the coverage will be effective (I'll save that for 
Julia).  But let me know your plans, just in case someone plans 
mobile observations, and we can use Derek Breit's Web site given 
above to determine distances in km from the center to assess the 
coverage.

David Dunham, IOTA, 2005 August 10, 19h UT
e-mail home dunham@starpower.net office david.dunham@jhuapl.edu
Phone home 301-474-4722; office 240-228-5609; car 301-526-5590