Predictions, Maps, & Plans for the Grazing Occultation of SAO 78233 on May 1, 2006 EDT

Clear for this evening's good grazing occultation

    The latest Astro Meteo (Clear Sky Clock) forecast is very good 
for this evening's good grazing occultation (7.5-mag. close double 
star, Moon a fairly thin crescent only 20% sunlit, high altitude 
above the horizon) in s.e. Pennsylvania and southern New Jersey, so 
I am planning an expedition to try to observe it; see the grazing 
occultation section below for general information about it. 
I plan to observe it near exit 10 of I-295 in s.w. New Jersey, 
10 miles from the Delaware Memorial Bridge.  Let me know if you can 
either join my expedition, or can observe elsewhere in the path, so 
that we might coordinate coverage of this interesting and 
potentially good event.  I would meet anyone else who might be 
interested in joing this effort at 7:45 pm at the intersection of 
Heron Dr. and Harrisonville Rd. about a mile southwest of I-295 exit 
10, but if possible, please call my cell phone, 301-526-5590, 
shortly before you arrive in the area.  Maps showing this area, the 
graze path, and the meeting place are below.  They also will show 
the area where the path crosses US1 in Chadds Ford, Penn., in case 
anyone wants to try to observe the graze there.  The graze observing 
period will be from 8:35 to 8:41 pm EDT near I-295, and a minute 
earlier at US1.  The path also crosses the n.e. corner of Delaware 
n.e. of Wilmington.  

     Below are links to maps of the path, first in .jpg files, then 
in a Power Point file that has some labels for the detailed map of NJ 
and that may be easier to display and print with your computer.  On 
the maps, the 0.6-mile-wide graze zone is between the two pencil-
drawn (gray) lines.

s.w. NJ map shows meeting place, 900 kilobytes.
s.e. PA & n. DE map, 400 kilobytes.
= above showing more to s., 800 kilobytes.

Power Point file with 1st 2 maps above, 4.9 megabytes.
The Power Point file (and only it) includes detailed Google Earth 
aerial photography views of the New Jersey graze zone with the 
meeting place indicated in the lower left corner (and also of the 
area where the path crosses US 1 in Penn. at Chadds Ford).  In 
N.J., the observing sites will be along Heron Dr. extending from 
Harrisonville Rd. for half a mile to the n.e., to about halfway to 
Center Square Rd. (which is at exit 10 from I-295).  If for any 
reason the Heron Dr. sites don't work (but I think they will; there 
are just some fields and commercial buildings with few trees along 
that road), I would use instead sites along Beckett Rd. on the other 
(s.e.) side of I-295. 

I used the Grazereg predictions for this event.  The limit 
predictions, including the list of stations with their distances to 
the path, are here and the ACLPPP profile 
for the graze is here (both are plain text files).
_______ 

General information about just the graze from the expeditions item

                 Grazing Occultations

DATE   Day  EDT     Star    Mag  % alt  CA  Location

May  1 Mon 20:37 SAO 78233  7.5 20+ 42 14N Narvon&ChaddsFord,PA;Sun -7d

Notes:

May 1:  The star may be a close triple, with equal components separated 
by 0.25" in PA 159 deg., and a 9.2-mag. 3rd star 3.1" away in PA 262.
See the top of this message for more about it; the Sun's altitude 
will be -7.6 deg. near I-295 in NJ and experience with past grazes 
shows that the sky will be dark enough with telescopic views to see 
the 7.5-mag. star well then (and o.k. also in s.e. Penn.).  It's a 
total occultation in the Washington, DC area, but will be difficult 
there at -5 deg. altitude.  See above for my expedition plans and 
maps.
_____________________________________

David Dunham, 2006 May 1, 3:30 pm
Phones home 301-474-4722; office 240-228-5609; car 301-526-5590
emails dunham@starpower.net or office david.dunham@jhuapl.edu