Bright weekend asteroid occ'n, WI,TN,FL,Cuba,s.Brazil
(780) Armenia to cover 8.7-mag. star Sun. am, 2005 July 24
Expedition to Nashville, TN area from DC area planned; the Accuweather forecast is good
New: 2005 July 21
We need your help to cover the path for the occultation of 8.7- mag. SAO 146999 (= HIP 118132) by the 94-km asteroid (780) Armenia Sunday morning, July 24, from 9:34 to 9:52 UT (4:34 to 4:52 am CDT; 5 am EDT). Let me know if you might try to observe this good event so that we can plan coverage of mobile stations to fill in the gaps of the coverage by fixed-site observers who plan to try it. The nearly north-to-south path passes over central Wisconsin (Madison, 9:34 UT), north-central and eastern Illinois (Rockford, Urbana, 9:35), s.w. Indiana, western Kentucky, central Tennessee (Nashville, 9:36), eastern Alabama (Huntsville, Auburn), western Georgia, north- central Florida (Tallahassee, 9:37), western Cuba (Havana, 9:38), central Colombia (w. of Bogota, 9:43), Bolivia (La Paz, 9:47), northeastern Argentina (9:50-9:51), and southernmost Brazil (9:51- 9:52 UT). Charlie Ridgway has set up an interactive Web page for this event that allows you to zoom in on the path, or parts of it, to view it plotted over road maps (USA only) and satellite images (whole path, even Cuba to s. Brazil) to almost whatever detail that you want. Unfortunately, it currently uses an older prediction from late June; the path from Steve Preston's current prediction calculated on July 13 is close to the earlier prediction but perhaps a little east of it. If an occultation occurs, there will be a 5- mag. drop (to Armenia's 13.9 mag.) lasting up to 12 seconds, a relatively slow event facilitating the usefulness of even careful visual timings. Accuweather is forecasting humid conditions (use dew caps!) but mostly clear with mainly scattered cirrus, over the path in central Tenneessee. The predicted cloud cover increases significantly both north and south of that area, but of course the forecast can change, with a better Clear Sky Clock forecast becoming available probably late Friday. If the forecast for the areas mentioned remains good, I plan to drive to the path from the Washington, DC area, leaving early Saturday morning, July 23, and returning late Sunday night. Let me know if you might be interested in joining this expedition. The target star is at J2000 RA 23h 57m 45.9s, Dec -7 deg. 22' 30", in Cetus close to the Aquarius-Cetus-Pisces border 7 deg. west and a little north of 3rd-mag. iota Ceti, 1.6 deg. southwest of 5th- mag. 30 Piscium, and 10' east of a 7.5-mag. star. The star field is fairly sparse, so allow plenty of time to find SAO 146999. Use the finder charts of different scales locating the target star with a cross in the center that are on Steve Preston's Web site. Fortunately, you have most of the night to find it; at the time of the occultation, the star will be over 40 deg. above the horizon for all observers. A station list sorted by distance from the predicted central line, useful for determining the time of closest approach for your location (although you can get a good estimate of that from the maps on Steve Preston's Web site given above) and for planning coverage of the event, will be first distributed either Thurs. or Friday evening, but a first version of it was posted last night by Derek Breit on his Web site. Send me your coordinates, or a careful description of your location, for including in the station list if we might not already have your position. David Dunham, IOTA, 2005 July 21, 5pm EDT (21h UT) Phones home 301-474-4722; office 240-228-5609; cell 301-526-5590 E-mail dunham@starpower.net at home