Occultation (Eclipse) of TYC 0032-00866-1 by (261) Prymno on Oct. 7 - Updated 2007 Oct. 8, 18h UT
The DC-area expedition was cancelled due to dew in s. VA
Some plans for the event were made at the Virginia Association of Astronomical Societies meeting on Sat. October 6
The 3rd Astro Meteo forcast showed clouds extending from Richmond, VA south across most of eastern & central N. Carolina; that forecast was appently rather accurate. High relative humidity, with temp. only 1-2 deg. above the dew point, was forcast for areas westward towards the Appalachian Mountains, and those conditions threatened at least patchy low clouds and fog similar to the thick fog we had duriong the previous 2 nights; the National Weather Service forecaster said a slight eastward component remained with the wind that would again bring in moisture from the Atlantic and prevent drying out in the area. With this poor prospect, I decided not to try to observe the occultation from southern Virginia. The IR images at the time show no clouds across the region, but they do not show low clouds. The surface reports said it was mostly cloudy or misty at Richmond and overcast at Petersburg; the automated station at Emporia also said it was overcast. Somewhat better conditions were reported at the automated stations at Lynchburg and Danville, where I was considering going, but they reported high humidity and dew point only a deg. below the temp., conditions ripe for low clouds and fog that probably formed over most adjacent areas; airports with large areas of cleared vegetation tend to be a little drier than most areas. An observer in western N.C. planned to try the event, but didn't read my recent messages in time, thinking the event was a day later (night of Oct. 7 rather than morning) until he realized his mistake later on Sunday. It was clear in northern Alabama, and David Nance observed visually from his home in Madison where he reported a miss. ___________________________________ The file for the presentation that I gave on observing occultations at the meeting of the Virginia Association of Astronomical Societies is here (14.5 megabytes). I showed videos of the occultation of a star whose close duplicity was discovered during the occultation that you can read about and see here, and about the spectacular graze of another close double star, mu Arietis, observed in Texas in June. I also showed one of the video segments of the graze of 59 Leonis during the total lunar eclipse last March recorded from the Virginia part of the Delmarva; that event was also observed by Richmond Astronomical Society members north of Richmond. ___________________________________ The rest of this page gives pre-event information as of Oct. 6 at 3h UT. Help us measure the size and shape of the asteroid (261) Prymno Sunday morning, October 7! Observers across southern Virginia, western N. Carolina, and west to central Texas can find a 10th-mag. star a deg. south of nu Piscium and time its sudden disappearance and reappearance as the 50-km asteroid (261) Prymno covers the star for at least a few seconds. The path passes over s.e. and s.central Virginia at 7:45 UT (3:45 am EDT); then at 7:46 UT over w. North Carolina, s.e. Tenn., the n.w. corner of Georgia, and n. Alabama (Huntsville); at 7:47 UT (2:47 am CDT), over n. Miss., the s.e. corner of Arkansas, n. Louisiana (Shreveport), and easternmost Texas (Nacogdoches); at 7:48 UT, over central Texas between Austin and Waco (with path uncertainties, either city could have an occultation) and n. of Del Rio; at 7:49 UT (1:49 am MDT), over Big Bend Park, TX and n. Mexico just s. of Chihuahua; and at 7:50 UT, over Baja California sur near Loreto. Maps of the path are in pages 2-4 of this Power Point file, including Steve Preston's North American path map (view as seen from the asteroid), then more detailed Google maps generated from Derek Breit's web site showing the path across the USA, and in more detail across Virginia. On Oct. 6, Sat., I plan to give a talk/workshop on occultations at this year's meeting of the Virginia Association of Astronomical Societies (VAAS), hosted this Saturday, Oct. 6, by the Northern Virginia Astronomy Club (NOVAC) at C. M. Crockett State Park west of Manassas, VA; for details, see http://www.novac.com/vaas/ . The current weather forecast is good, and if that continues, after my talk I plan to drive to southern Virginia to set up stations from near Richmond to the North Carolina border to record the relatively good (261) Prymno occultation that night (actually, Sun. am, Oct. 7). I hope that other observers in s. Virginia, w. North Carolina, and elsewhere along the path west to Texas and maybe event Baja can try this reasonably good event as well; let me know if you plan to observe so I can avoid duplicating your line and we can obtain the best coverage across Prymno. A central occultation by the 51-km asteroid would last 4.6s with an easily-seen 2.5-mag. drop to the 12.7-mag. of Prymno. The 14% sunlit crescent Moon will be 125 deg. away from the target and thus no problem, with the event occurring before moonrise for most observers. The target star will be more than 45 deg. above the horizon along the path in North America. In any case, please let me know if you might try to observe this occultation from at or near home, or if you might be mobile, so we can effectively target mobile observers to avoid duplication of observations by fixed-site observers. I'll update the long station list below to show plans with a future message after receiving responses from potential observers. Even better, I recommend installing new software called Occult Watcher, where you input your position and it searches Steve Preston's predition Web site, informing you of all asteroidal occultations in your region during the next 4-5 weeks, giving probabilities and other details. Whenever a path is updated, the software lets you know. It also has provision for you to specify your observing intentions, and these are displayed along with those of other observers to help plan the overall coverage for the event. Hristo Pavlov in Sydney, Australia wrote this program; you can get it here. FINDING THE TARGET STAR The star is at J2000 RA 1h 41m 19.7s, Dec +4 deg. 14' 4", 1 1/4 deg. s. of 4th-mag. nu Piscium and about 5 deg. west of 3rd-mag. alpha Piscium (Alrescha). Detailed finder charts of different scales and a map showing the path across the USA are at Steve Preston's page for the event here. I have put Steve Preston's charts in this Power Point file, which for some may be easier to view and print. Additional useful information is on Derek Breit's Web site - scroll down to the line for this event on UT Oct. 7 at 7h UT, then click on "GoogleMap" for the interactive Google map of the path that you can zoom in on it to great detail. If you double-click inside the map on the place where you want to observe, the coordinates and distance from center of the location will appear at the bottom of the map (with + for north and - for south). Click on "Sites" for a long list of stations sorted by distance from the central line, giving the predicted time of the occultation at the site, and the Sun & star altitudes at the time, and the probability for an occultation there (if your site is not in the list, either you are not within 3-sigma of having an occultation, or you may not be in the master list - to check the latter, contact Derek Breit at breit_ideas@hotmail.com). The list uses accurate coordinates provided to us for the calculations, but the list only displays the coordinates to the nearest 5' for privacy concerns. A shortened version of the list is below. Let me know if your station is not on the list; if you can provide coordinates or a postal address, we can add your location. Clicking on "stars" gives a list of stars that can be used to pre- point a stationary telescope to the direction of the occultation star before the event. It gives offset times relative to (before) the time of the occultation. I've applied those offset times to 7h 45m 44s UT, the time that the occultation is predicted to occur in Richmond, VA and other sites along I-95 in s. VA, to create this list where also I've added the identifications of stars with Flamsteed numbers and Bayer greek letters. WEATHER The 2nd Astro Meteo cloud cover, transparency, and relative humidity maps are shown in the last 3 pages of this Power Point file. The best area will be northern Mexico and Baja, but a Bermuda high will also be centered over Tennessee so that it should be relatively clear from the Atlantic shore of the Delmarva Peninsula to the Mississippi River, except for a patch of cloud predicted to cover south-central Virginia (up to Richmond) and the central and eastern Carolinas. Much cloudiness is forecast from Dallas to Houston, with relatively clear sky from I-35 to Del Rio (but the forecast might not take into account the adiabatic cooling clouds that often form over central Texas) and partly cloudy skies over n. Louisiana. If the clouds in s. central VA are still predicted with later forecasts, I may switch my planned stations eastward to either along US 17 or to the Delmarva, trying to observe from the "M" equivalent distant from the central line sites as given in the station list below, except that I would not be able to do the southernmost one then (too close to Norfolk). The mornings have been quite moist recently with heavy fog, but it's supposed to dry out a little over the weekend. But I'll check to see what happens Sat. morning relative to the forecast, and will also ask the National Weather Service forecaster tomorrow afternoon about the possibility of fog & low clouds developing by the time of the occultation, and I may scale back my effort if fog is expected to be widespread. Note that a new Astro Meteo forecast will become available Sat. afternoon. _________________________________ Those well away from the path might also watch for a possible occultation by a possible satellite; in general, there's some chance for this within 10 path-widths of the central line, and for 10 times the central duration (almost a minute in this case) before and after the predicted time of closest approach for your location (you can see that for your location in the station list, or you can estimate it well enough from the path description above, or from Steve Preston's North American map; the 1-sigma uncertainty in the occultation time is less than 0.1 minute. Any event should be timed, even if only approximately, but do the best you can; timing methods are described here. Much more information about asteroidal occultations in general is here. Please go to that link to get information for your site and help us measure the sizes and shapes of these asteroids. For reporting observations, even if the star is monitored and no occultation is seen, you should use the new report forms that you can get here and click on "Templates for Report Forms". Completed reports should be sent to reports@asteroidoccultation.com and copied to Jan Manek at jan.manek@worldonline.cz . _________________________________ STATION LIST Below is a partial list of stations, similar to station lists that I've distributed for previous events. So far, I know of no other observers who have definite plans to observe this occultation, so I include places where I will probably observe, and "?" for the locations of some others who I hope will try to observe this event from the indicated location. I use "M" (mobile video) for my possible locations. All observers especially within the "2-sigma" limits are encouraged to observe, at least from convenient near-home locations, and of course much farther away for checking for satellites. NOTE THAT THIS IS MOSTLY A LIST OF POTENTIAL OBSERVERS AND POSSIBLE OBSERVING STATIONS; I'M SURE THAT NO OBSERVATION WILL BE MADE FROM MOST OF THESE LOCATIONS, SO ANY OBSERVATION THAT YOU CAN MAKE WILL BE VALUABLE. Below, codes between the "Probability (Prob.)" column and the location, observer is * for visual observers, V for video, m for mobile visual, and M for mobile video. w is for a visual observer likely to be clouded out while W is similar for a video observers. So far, apparently no observers have claimed any lines with Occult Watcher. Occultation of TYC 0032-00866-1 by 261 Prymno on 2007 Oct 07 Distance from center of occultation path - in km [Prediction of 2007 Sep 25.2] P r Dist. o U.T. from b 7h center. Location, observer and km % m s 112 0 ** Northern limit plus 3-Sigma ** 108 0 Fan Mtn Obs VA Univ.ofVA 32in 45 52 104 0 841 Martin Observatory, Blacksb 46 5 102 0 * FincastleVA John Goss RVAS 46 1 83 2 ** Northern limit plus 2-Sigma ** 77 4 ? Roanoke VA Michael Good RVAS 46 2 77 4 Abingdon VA 46 15 75 4 Salisbury MD 45 33 73 5 ? Oliver VA Robert Oldham 45 45 71 6 Chihuahua MX 49 30 70 6 KnoxvilleTN Nick Cook 46 28 66 9 ? Konnarock VA 46 12 63 10 Mike Fleenor 46 30 63 10 ? Ashland VA - Keeble Obs 45 45 55 16 ** Northern limit plus 1-Sigma ** 54 17 M Hanover C.H. VA Shell gas D. D 45 44 48 23 H34 Chapel Hill 47 56 47 24 ? Richmond VA Randy Tatum vid. 45 45 44 27 Mchncsvl VA Ken Wilson 45 44 43 29 BELVIDER TN C.Smith c/oDegenhar 46 45 42 29 850 Cordell-Lorenz Observatory, 46 43 40 31 WACO TX MCANALLY~JOHN W 48 13 35 38 Cold Harbor VA Ed's Nursery D 45 43 31 43 Richmond Airpt V w.I295 45 44 30 44 Blanchrd A CLaude Baines 47 45 27 47 *** Northern limit *** 26 49 922 Timberland Observatory, Dec 46 53 25 51 M Varina Grove VA w.I295 & VA5 45 44 22 53 LORENA TX BARTON~JOHNNY 48 12 16 60 ? Ashevill NC D.Caton,DarkSkyObs 46 11 15 60 Shreveport, LA Terry Atwood 47 44 15 61 Huntsville AL 46 49 12 63 ? Madison AL David Nance 46 48 9 65 ? MSFC Huntsville AL Bill Cooke 46 49 8 65 Loreto, Baja, Coughlin 50 21 7 66 Chattanooga TN 46 39 4 66 Redstone AL Dave Lanteigne 46 48 4 67 PETERSBURG VA possible site 45 44 3 67 843 Emerald Lane Observatory, D 46 51 3 67 w. N. Carolina Mike Bruce 46 4 0 67 **** Centre Line **** -2 67 New Bohemia VA e.I295 & US460 45 44 -3 67 Shreveport LA 47 39 -4 67 Rossville, GA Paul Thennes 46 39 -4 66 WILDWOOD GA SMITH~NED 46 40 -8 65 BrysonCy NC Simon Skiles 46 26 -10 64 Wiliamsb VA William&Mary Col. 45 40 -11 63 Templeton VA w.I95 & VA35 45 44 -16 60 M Carson VA I95 exit 45 44 -19 56 ? Asheville NC John C 46 20 -25 50 Stony Creek VA I95 n.exit 45 44 -25 50 1983_529 R. Nacogdoches, TX 47 54 -26 49 s. Ligui, rd.goes W., Coughlin 50 21 -27 48 740 SFA Observatory, Nacogdoche 47 53 -27 47 *** Southern limit *** -32 42 ? Yorktown VA Michael Klosterman 45 38 -34 39 WinstonSalem NC 46 4 -37 36 Cullman AL Scott Smith 46 51 -37 36 Hampton VA - Dave Kratz 45 38 -38 34 ? Langley VA Hampton 16in pe 45 38 -39 34 CRANE HILL AL SMITH~SCOTT AND 46 52 -43 28 J. Petersen 48 24 -43 28 ? Smithfield VA - H $ K Abramson 45 39 -43 28 n. Emporia, VA D. Dunham remo 45 45 -46 25 Emporia VA w.I95 & n.US58 45 46 -46 25 SanAnton TX Jack Petersen Aud 48 25 -46 25 FrnchCA MS c/o Scott Degenhard 47 11 -48 23 757 High Point 46 2 -50 21 752 Puckett Observatory, Mounta 46 34 -53 18 Austin, TX Jim Walker, 8cm R 48 21 -54 17 ELLIJAY GA JOHNSON~RUSSELL 46 34 -55 16 ** Southern limit plus 1-Sigma ** -56 16 1983_529 J. P. Powell, Nacogdoc 47 53 -56 15 Suffolk VA Tidewater CC Ob via 45 38 -57 15 M Skippers VA e.I95 & Moores 45 46 -62 11 19991025 McCants, Bee Caves RC, 48 21 -63 10 ? CHESAPEK VI DENNIS A. ROWLEY 45 38 -63 10 Sexton TX HARPER~ROCKY 47 48 -64 10 Austin TX Kirchhof, Rick 8in. 48 20 -64 10 Austin, TX MikeMcCants8in 48 20 -65 9 Norfolk VA 45 37 -66 8 ? Greensbo NC David Connor,10mi.s 46 0 -70 6 Salisbry NC Catawba C.Ob,Wilson 46 5 -73 5 Chesapeake VA Glendon Howell 45 38 -80 3 ? s Burlin NC 3CollegesObs.Danfor 46 5 -80 3 C. Constitucion, Baja, Coughlin 50 27 -83 2 ** Southern limit plus 2-Sigma ** -88 2 ChapelHl NC MoreheadOb. Melvin 45 56 -89 1 H32 Texas A&M Physics Observato 48 9 -89 1 Dallas NC - TAS 46 10 -90 1 725 Fair Oaks Ranch 48 28 -90 1 SAN ANTONIO TX SLATER~DAVID 48 28 -93 1 Raleigh NC Jerry Watson 45 55 -102 0 ? Concord NC Roger Harvey 46 6 -103 0 Greenvil SC Furman Univ. 46 19 -103 0 Moyock, NC possible site 45 37 -104 0 H47 Vicksburg 47 23 -105 0 Spartanburg SC 46 16 -106 0 Birmingham AL 46 52 -107 0 ? CARY NC LANG~MARK 45 54 -107 0 915 River Oaks Observatory, New 48 24 -112 0 ** Southern limit plus 3-Sigma ** __________________ David Dunham, 2007 Oct. 8, 18h UT cell phone 301-526-5590, e-mail dunham@starpower.net office e-mail david.dunham@jhuapl.edu I will be reachable by cell phone, but my e-mail is not working on my Blackberry, so I won't be able to get e-mail messages possibly starting Sat. morning (I'll try to find wifi to get messages in the afternoon, maybe they'll have it at or near the VAAS meeting)