Aspasia Occultation Wide Path This Evening, Ariz. to NJ - New 2005 Sept. 28
The weather forecast is good for the Mid-Atlantic States, with the path crossing most of Maryland, Virginia, and DC
We could still use some help for the occultation by (409) Aspasia this evening. Below is the station list of observers who have said that they will try the occultation. The data for many more stations can be found on Derek Breit's Web site; you can get the time of closest approach, and altitudes of the star and Sun above and below your horizon there. Search for your, or your location's, name to get your information. A Word version of Derek's station list, possibly for easier searching and printing, is here. As noted in last night's message, you can see in great detail where lines of different distances (that you can specify in km from the predicted central line) cross local highways on Charlie Ridgway's interactive Web page. See that message (below) for other links, information about the star, etc. The Clear Sky Clock (CSC) forecast is similar to what I described yesterday, but better in central Tennessee and some of Texas around Dallas and west of there; and a little worse in Arkansas. A small front is approaching the Mid-Atlantic States from the northwest and is supposed to bring some rain to the DC area later in the night, but it will be mostly over West Virginia at the time of the Aspasia event, with still mostly clear skies for most of Virginia and most of Maryland. A new forecast will become available on the Environment Canada site (on which CSC is based) by about 17h UT (1 pm EDT) and I will check that and the visual satellite loop to make a final decision about deploying. After 19h UT, I'll only be reachable by cell phone at 301-526-5590 until a few hours after the occultation. I plan to set up at sites along MD5 and MD235 southeast of Washington, DC, but could switch to the Eastern Shore along US 50, or Virginia along I-95, if the weather prospects look better either east or west. Note that the 10 deg. altitude in the DC region makes it difficult to find sites with a good view, also away from light pollution. I will check this e-mail about last at 13h UT, then can be reached at my office at david.dunham@jhuapl.edu. I hope to check my mail here one last time at about 19h UT (3 pm EDT) before driving to the sites. In the list below, M is a mobile video observer, m is mobile visual, V is fixed-site video, * is fixed-site visual, ? means uncertain that an observation will be made for weather or other various reasons, and W or w means CSC is predicting mostly cloudy skies for the area, for a video or visual observer, respectively. Steve Preston's 08/20/05 Update Occultation of TYC 6219-00862-1 by 409 Aspasia on 2005 Sep 29 UT Dist.Proba- U.T. Alt Sun Location Longitude Latitude km bility h m o o o ' o ' 228-- 16% ** Northern limit plus 1-sigma ** 215 V 19% 1 41.2 25 -18 STILLWAT OK ART LUCAS - 97 8.2 36 3.6 122-- 49% *** Predicted Northern limit *** 100 V 57% 1 41.7 10 -32 Marston MD Obs.,Curt Roelle - 77 4.8 39 30.3 87 V 61% 1 41.7 11 -31 StephnsC VA John Brooks - 78 11.7 39 5.2 12 W 75% 1 40.8 32 -10 Rincon NM mobile R Richins -106 59.8 +32 43.7 0-- 75% **** Centre Line **** -5 ? 75% 1 41.5 19 -26 SPOT Obs M Manner - 87 33.0 35 53.4 -8 ? 75% 1 40.7 35 -7 TUCSON AZ CRAWFORD~ROBERT W. -110 45.0 32 11.3 -20 M 74% 1 41.8 10 -33 David Dunham mobile -32 * 73% 1 41.7 13 -31 Fincastl VA John Goss RVAS - 79 58.2 37 28.4 -34 V 73% 1 41.6 18 -27 Murfreesboro, TN S Degenhardt - 86 21.3 35 53.8 -35 W 73% 1 40.9 33 -10 LasCrucs NM Robert A. James -106 47.7 32 19.4 -55 M 69% 1 41.8 10 -33 unlikely MD Dunham remote #2 -076 19.2 +38 02.5 -75 M 64% 1 41.8 10 -33 Point Lookout, MD Dunham remote -076 19.2 +38 02.5 -122-- 49% *** Predicted Southern limit *** -123 ? 49% 1 41.7 14 -30 BlueRidgeNC D.Caton,DarkSkyObs - 81 24.7 36 15.1 -228-- 16% ** Southern limit plus 1-sigma ** _____________________________________ David Dunham, 2005 Sept. 28 am phones home 301-474-4722; office 240-228-5609; cell 301-526-5590 office email david.dunham@jhuapl.edu ******************************************************************** Message with more information from Tuesday morning, Sept. 27: I need your help to determine the size and shape of the relatively large (about 160 km) asteroid (409) Aspasia when it occults an 11.0-mag. star 3 deg. east of 2.5-mag. eta Ophiuchi (Sabik) Wednesday evening from southern Arizona to Virginia/Maryland/Delaware/DC. Please let me know if you can try to observe the occultation from either fixed locations or with mobile equipment. Those of us who are mobile don't want to duplicate your chord. The path can be seen on Steve Preston's Web site. It starts in bright twilight over Tucson and other parts of southeastern Arizona, at 1:40 UT of Sept. 29 UT, then over the southern 1/3rd of New Mexico (7:40 pm MDT of the 28th). In the whole path farther east, the event will occur at 1:41 UT (8:41 pm CDT or 9:41 pm EDT), passing over northern Texas with Dallas-Ft. Worth near the s. limit, southern Oklahoma, most of Arkansas, Tennessee and southern Kentucky, southern West Virginia, most of Virginia (maybe not the Norfolk area, but it's possible there), Maryland, Delaware, and Washington, DC. The nothern limit extends farther east, across New Jersey, Long Island, and Cape Cod, with a chance for an event in the populous are north of it (NYC, Conn., Boston), but altitude, less than 9 deg. there, will make observation difficult. Very detailed maps for these events can be found on Charlie Ridgway's interactive Web page with link given above; it links to the very detailed maps and satellite imagery of maps.google.com with overlays of the occultation paths. You can enter an offset distance in km to see individual tracks. On his Web site, the central line is yellow, the northern and southern limits are blue, and the 1-sigma limits are purple/heliotrope. The offset lines are gray. The star, TYC 6219-00862-1, is at J2000 RA 16h 57m 55.2s, Dec. -16 deg. 29' 35". A few 10th and 11th-mag. stars are nearby, with a 6.5-mag. star half a deg. southwest of the target star. Detailed finder charts of different scales are on Steve Preston's Web site given above. If an occultation occurs, a 1.7-magnitude drop lasting up to 6 seconds is predicted. For coverage planning purposes, an extensive list of stations ordered by distance from the predicted central line is on Derek Breit's Web site with link above. You can search for your, or your town's, name to see just when the occultation is predicted for your area (that time should be accurate to within 10 - 15 seconds), and the predicted Sun and star altitudes at the time; the Moon will be below the horizon. If your location is not in the list, and you are within the 3-sigma limits of the occultation, send me information about your location and we'll add it. Clear Sky Clock's forecast now extends out to 0h UT Sept. 29, just 1.7 hours before the event. It shows that it will be clear, or mostly so, in the Mid-Atlantic area east of the Appalachians; partly cloudy across Tenn., Kentucky, & W.Va.; clear over central & s. Arkansas; cloudy from s. Missouri to s.e. Okla. and n.-central Texas north of Dallas/Ft. Worth; clear in central Okla.; mostly cloudy farther west in Texas and over New Mexico; and clear in Arizona. But this could change. As noted above, please let me know your plans; I'll distribute tomorrow night (late Tues. evening) an edited version of D. Breit's list with only observers who have said they'll try to observe this occultation. Mobile observers can use Ridgway's Web site, placing an assigned distance as their offset distance to find and zoom in on locations to observe the event. Especially I want to know who in the Mid-Atlantic region will be trying from fixed locations. The northern limit passes just s. of Hagerstown, MD and York, PA (but those places could very well be within the actual path), while the central line passes north of Fredericksburg, VA and Waldorf, MD, and the southern limit over Chester, VA just south of Richmond. Let me know if you'd be interested in helping my mobile effort south of Washington, DC. I plan to observe from two sites somewhere between Waldorf and Point Lookout, MD, but could run a 3rd video system on someone else's 8-inch or larger scope. We'll need to leave the DC area before afternoon rush hour (before about 3 pm) and set up the telescopes at safe locations in daylight so that the short time of darkness (just under 2 hours from nautical twilight to the event) can be used to find target star fields (west of the target star) and travel between the sites. We can spread out at most over a distance of about 60 miles. _____________________________________ There are more opportunities in the DC region next month and next week - click here for more about them. We will not be trying the good graze over Nags Head, NC Friday morning, Sept. 30, but may be able to provide information for any others who might want to try it. _____________________________________ David Dunham, 2005 Sept. 27 am phones home 301-474-4722; office 240-228-5609; cell 301-526-5590 office email david.dunham@jhuapl.edu