Grazing Occultations in DC region last night & Sat. pm, Mar. 2 & 4, 2006
Detailed maps for tomorrow (Saturday) evening's graze
Updated: 2006 March 3, 11 pm EST
Astro Meteo is forecasting clear skies across most of the Mid- Atlantic region, including along Sat. evening's graze path across northern Virginia. Conditions probably were not as good for last night's graze, which as far as I know was not observed; see information about it here. Charlie Ridgway and Kiwi Geoff solved the software problems mentioned yesterday, so I used Charlie's Web site to produce the detailed maps of the graze zone around Thornburg, VA (NOT Ladysmith, as I thought before) below. He has the offsets set properly to show the graze zone between the two gray lines. I've put his maps, as well as two detailed aerial views of the graze areas we might use, in this Word file. If you plan to come to the graze, please open that Word file; if you have trouble with it, let me know. Some of the figures are given separately below, but not the ones of the Orrock Lane area that might be the best; they are only in the Word file. Thornburg map overview showing US 1, I-95, and the Thornburg exit 118. We can meet at the gas station at the northwest corner of the exit at 9 pm (or call me on my cell phone when you are in the area; hopefully, it will work). Satellite view of above. Detailed map of the path across I-95 and US 1 as well as Malland Rd. just east of I-95. Aerial view of above. Trees will block the view of the graze in most areas. There seem to be three possible sites where the graze could be observed: 1. Along US 1. There are probably homes where we might need to get permission, and the southernmost part of the zone (less critical) is blocked by trees. However, it might be necessary to get on private roads to get off of US 1. 2. Along Malland Rd., which seems to have no houses, maybe a couple of closed businesses, in the graze zone. The aerial image, however, shows what may be a line of trees between Malland Rd. and I-95 that might block the view for the whole southern half of the graze zone. 3. Along Orrock Lane, and the driveway that goes south of the sharp bend to access the southern half of the graze zone. This open area looks best, but it depends on the long driveway where permission will need to be secured. So each of these have potential problems; I won't know which will work best until I go to the area before the graze. This is a relatively faint star but occurs under good conditions so that it should be easy with a 6-inch scope, and even a 5-inch scope with a Supercircuits PC164C camera, of which I have a couple of extra if you don't have one and want to try with your scope. Especially if we do the Saturday evening graze, I won't be trying either of the more distant (from DC area) grazes on Monday evening, for which the weather forecast is currently uncertain. Click here for the Grazereg limit predictions with observer scan. Click here for the ACLPPP profile. AND DON'T FORGET Saturday evening, April 1, for the graze of 4th-mag. Maia during the Pleiades passage on the dark side of the thin crescent Moon, a spectacular binoculars graze, with path similar to the one tonight across the northern DC suburbs. It's the best graze we've had in the region since the Pleiades passage 37 years ago (March 1969) so it's worth making room in your calendar for it. _______________________________________________________________ Grazing Occultations DATE Day EST Star Mag % alt CA Location Mar 2 Thu 20:35 ZC 209 7.2 12+ 10 1S SterlngVA;Bethsda,Woodmore,MD Mar 4 Sat 22:28 ZC 474 9.0 31+ 15 5N Frostburg, MD; Ladysmith, VA Mar 6 Mon 21:40 ZC 771 6.0 52+ 47 6N LewsbryPA;StantonDE;SomrsPtNJ Mar 6 Mon 21:40 SAO 76991 8.6 52+ 47 6N Logansville,PA; North East,MD Notes: The March 6th grazes are of a double-double system; 8.6-mag. SAO 76991 (the secondary star & second-listed graze) is 11.8" from ZC 771 in PA 27 deg., and both stars are in turn close doubles (each sep. 0.2") with 9th-mag. companions. Charlie Ridgway will produce an interactive Google Maps overlay of all of the April 1st graze paths that will be set up in about a week. He might be able to set this up for the March 2 (3rd UT) and 4 (5th UT) grazes, or Kiwi Geoff may do it; if so, I'll try to post an exact link at the top of my Web site at http://iota.jhuapl.edu late this afternoon. Charlie's link for the Pleiades events is here. You can use it to zoom in to see the graze lines plotted in great detail on maps and aerial imagery of your area when they are posted. _____________________________________ David Dunham, 2006 March 3 11 pm phones home 301-474-4722; office 240-228-5609; cell 301-526-5590 (use before this graze) office e-mail david.dunham@jhuapl.edu home e-mail dunham@starpower.net