Occultation of TYC 0613-00905-1 by (231) Vindobona on Aug. 2 - New 2007 Aug. 6, 21h UT
This pre-event notice was distributed only by e-mail late the evening of 2007 July 31 and is posted here now for the first time
Please help us Wednesday (tomorrow) night, actually early Thursday morning, about 5:05 am EDT August 2, to measure the size and shape of the medium-sized (about 86 km) asteroid (231) Vindobona by observing and at least approximately timing its occultation of an 11.6-mag. star southeast of the great square of Pegasus, 27 deg. east-northeast of the Moon, and 1.3 deg. north of 6th-mag. zeta Piscium. The first Astro Meteo forecast (45h prognosis) is good for the path from North Carolina to the Delmarva Peninsula. The path passes over Raleigh and Fayetteville, NC at 5:04 am EDT; over Richmond, VA just before 5:05; then just after 5:05 over Point Lookout and the Maryland eastern shore (with Kent Is. at the n. limit and Salisbury at the s. limit), and Delaware, with Wilmington at the n. limit and the Sun alt. -11 deg.; the path also crosses New Jersey and New York City, but bright twilight will make it hard to monitor the 11.6-mag. star there, and clouds are currently forecast there, too. The prediction for the path, which projects to 91 km wide, is rather uncertain, the 1-sigma expected error being 0.62 path widths or 56 km, so observers in Charlotte, NC; Washington, DC; Baltimore; and the n.w. suburbs of Philadelphia, being near or just inside the 1-sigma n. limit, have a good chance for an occultation and are strongly encouraged to try to observe this event. Similarly, Hampton Roads is within the 1-sigma southern limit, and since shifts of even more than 1 sigma have been more common than expected, observers within the 2-sigma limits at places such as Norfolk, Charlottesville, and northern Virginia, and central Maryland, are also encouraged to observe. Although moonlight may hinder directly locating the target star, there is an easy way to get on target just by pre-pointing your telescope to Altair at the right time (about 11:43 pm EDT; see below for details). The path, including some expanded static maps showing major highways and cities, as well as finder charts of different scales and the first Astro Meteo forecast maps, are in a power point file here. All other asteroidal occultations in the region since the one by Papagena on May 24 have been clouded out, so if you have an 8-inch or larger telescope, please try to observe this event from a convenient location at or near home (Go to bed a little early Wed. evening, then get up a couple of hours earlier than usual to make this observation; then follow your usual routine with breakfast and travel to work). If you feel more adventuresome, join our mobile effort to the eastern Shore (sites near US 50; if later forecasts aren't as good there, alternate sites would be near US 17 in Virginia from Port Royal (s.e. of Fredericksburg) almost to Yorktown. Timing methods are described here. 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 If an occultation occurs, there will be a 3-mag. drop lasting about 15 seconds for a central event. The star is at J2000 RA 1h 13m 05.3s, Dec +8 deg. 56' 37", only about 10' west-southwest of 8.8-mag. SAO 109738, which in turn is 1.4 deg. north of 5th-mag. zeta Piscium. Path maps and detailed finder charts of different scales are on Steve Preston's Web page for the event. With the rather bright moonlight (the Moon will be 86% sunlit, 27 deg. west of the target star), locating zeta Piscium might be difficult. With an equatorial mount, you can use setting circles to offset from the bright 2nd-mag. star Hamal (alpha Arietis) to zeta Piscium. Hamal is at declination +23.4 deg. while zeta Piscium is at +7.6 deg. (or 15.8 deg. s. of Hamal); zeta's RA is 53 min. less than (west of) Hamal's. Using those offsets with a polar axis aligned to Polaris within a couple of degrees should put zeta near the center of your finder scope field of view. Additional useful information is on Derek Breit's Web site - scroll down to the line for this event on UT Aug. 2 at 9h UT, then click on "GoogleMap" for the interactive Google map of the path that you can zoom in on it to great detail, and put in different values for the "offset" gray lines until they go over a desired location to find out that's location north or south (-) of the predicted line; 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, which can be used by anyone, not just by those trying to run remote stations. The list gives offset times from the time of the occultation to prepoint your telescope; I've applied those offset times to 9:05:26 UT (4:05:26 am EDT) to obtain the actual times for sites on the Maryland eastern shore in this plain text file. In the station list below, you can get the predicted UT of the occultation at your station, then subtract 9:05:26 UT from it to get the small correction that you will need to apply to the times in the file with the link just given, to make the times valid for your site. USING ALTAIR TO FIND THE TARGET STAR Altair (alpha Aquilae) and the target star have nearly the same declination, but have an RA difference of over 5h 21m. If you aim your telescope at Altair, the target star will be 5.7 arc minutes north of where Altair was 5h 21m 27s later, if you keep the telescope firmly pointed in that direction (no tracking, clock drive or GO TO system off). If you have a narrow video field of view, put Altair near the south edge of the field of view, and the target star should track across the northern part of the field at the time of the occultation. For the eastern shore of Maryland, the occultation is predicted to occur at 4:05:26 am EDT, so the pre-pointing to Altair should be done there at 11:43:59 pm. It will be a little earlier for locations in N.Car. and Va.; apply the event time difference, UT at your station (from the list below) - 9:05:26 UT to get the small correction to apply to the Altair pre-point time. Of course, you need to time the pre-point to within 10s or so, so the clock that you use should be at least that accurate; any of the (now common) watches or small clocks that automatically reset themselves to WWVB time can be used for this purpose. Doing this will avoid a possibly difficult starhop in rather bright moonlight to find the target star (but if you miss Altair, Hamal, zeta Piscium, then SAO 109738, then the target should not be too difficult, see above). Below is a partial list of stations, similar to station lists that I've distributed for previous events. This (Tues.) evening, I'll distribute an update of this list with notations indicating observers who have said they will try the event - claim your "chord" (distance from the central line) now so that mobile observers can avoid your line. In the list below, "north" or positive distanced from center are more to the east, or northeast, of center, while "south" or negative distances are more to the west, or southwest, of center. I plan to set up 2 or 3 stations in the eastern half of the path across southern New Jersey, mainly near US 40; maybe a couple of other DC-region observers could travel to northeastern Maryland to fill in some gaps in the western side of the path. Let us know what you can do to help. For all locations, the target star's altitude will be between 55 and 65 deg. above the southern horizon, so it should be easy to find an unobstructed view. The Sun's altitude is given since for locations northeast of Delaware, twilight will be stronger than moonlight, preventing effective monitoring of the relatively faint target star for most observers from New Jersey and locations farther northeast. Occultation of TYC 0613-00905-1 by 231 Vindobona on 2007 Aug 02 Prediction by Steve Preston on July 8.2 The 2nd column gives the probability that an occultation will occur at the location. You need to use a fixed-space font such as Courier for the table to display properly. All observers especially within the "2-sigma" limits are encouraged to observe, at least from convenient near-home locations. Unfortunately, the weather forecast is poor from southern S. Carolina to Florida. NOTE THAT THIS IS ONLY 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. P r Dist. o U.T. from b 9h Sun center. Location, observer and Alt km % m s o 212 0 ** Northern limit plus 3-Sigma ** 210 0 Athens GA Scott Shaw 2 54 -19 197 0 Millvill PA Mike Sheppard 5 56 -10 196 0 Greenvil SC Furman Univ. 3 19 -18 196 0 Fincastl VA John Goss RVAS 4 26 -15 194 0 GEORGETO GA TONY P. MURRAY 2 2 -22 186 1 Roanoke VA Michael Good RVAS 4 21 -15 185 1 Carlisle PA Dcknson College Obs 5 36 -11 183 1 Hagerstown MD Rod Martin 5 22 -12 179 1 STEPHENS CITY VA BROOKS~JOHN 5 9 -12 177 1 Verona VA Karaffa & Wine 4 47 -14 175 1 FountnIn SC David Anderson 3 18 -18 174 1 Front Royal, VA - Dave Skillman 5 7 -13 163 2 842 Gettysburg College Observat 5 30 -11 161 2 Lewisbry PA AST.SOC.OF HARRSBRG 5 38 -11 156 2 ** Northern limit plus 2-Sigma ** 150 3 w. N. Carolina Mike Bruce 4 7 -16 144 4 Hanover PA Joe Carlson 5 32 -11 143 4 Centerville, GA K9 Obs. George 2 30 -20 138 5 CodorusP PA MasonDixonStarParty 5 33 -11 137 5 York PA J.Jones&P.De Rosa 5 37 -11 134 5 Bonaire GA Ron Dawes 2 30 -20 134 5 Wstmnstr MD WAS BearBrchNatCtr 5 30 -11 133 6 Fan Mtn Obs VA Univ.ofVA 32in 4 46 -14 132 6 Barnesville MD John Menke 5 20 -12 132 6 780 Leander McCormick Observato 4 50 -13 131 6 Jim Thorpe PA Tom Bash 6 2 -10 131 6 Marston MD Obs.,Curt Roelle 5 27 -11 130 6 Haymarkt VA Hopewell Obs. 5 11 -12 128 7 Mt Airy MD George Varros 5 24 -12 128 7 Wstmnstr MD Brian Eney WAS 5 29 -11 127 7 935 Wyrick Observatory, Haymark 5 12 -12 126 7 Pulpit Rock, PA LVAAS site 5 55 -10 125 8 Damascus MD Hands On Optics 5 23 -12 123 8 Hampsted MD Marc Damashek 5 31 -11 122 8 Sterling VA Patrick Lowry 5 17 -12 121 8 Woodbine MD Ray Sterner 5 26 -12 120 9 STERLING VA ROBERT STEWART 5 17 -12 119 9 NewFredm PA Harry Bates Mapsonu 5 35 -11 119 9 Sterling VA Peter Gural 5 17 -12 118 10 Gaithrsb MD Pan; Gemeny, etc. 5 20 -12 114 11 Eldrsbrg MD Vince Pearman 5 27 -11 114 11 Lancastr PA Weaver & Seeds 5 43 -11 114 11 Salisbry NC Catawba C.Ob,Wilson 3 54 -16 113 11 Gaithersburg, MD Jim Vail 5 20 -12 113 11 Ldersbrg MD Ken Adcock 5 28 -11 112 11 Eldersbu MD 2003_428GeorgeSaute 5 27 -11 111 12 Kutztown PA John Loomis 5 56 -10 110 12 Nokesvil VA Sam Somers 5 10 -12 108 13 REISTERSTOWN MD PEARMAN~VINCE 5 30 -11 106 13 Dayton MD Gary Frishkorn 5 24 -12 106 13 AlphaRdg MD Howard Ast League 5 26 -12 104 14 Vienna VA 2003_428J. Guerber 5 17 -12 102 15 757 High Point 4 4 -16 102 15 Ashton MD Greg Mort 5 23 -12 101 15 s Burlin NC 3CollegesObs.Danfor 3 54 -16 101 15 Bethesda, MD Vince Sempronio 5 20 -12 101 15 ** Northern limit plus 1-Sigma ** 100 16 BETHESDA MD JAY H. MILLER 5 20 -12 98 16 Concord NC Roger Harvey 3 48 -16 98 17 Silver Spring, MD Ed Abel 5 22 -12 97 17 Nicklasn VA NOVAC via Stewart 5 13 -12 97 17 Bethesda MD John Wetmore 5 20 -12 97 17 AUGUSTA GA VENABLE~ROGER J 2 54 -19 95 18 A P L MD N. field AC site 5 25 -12 95 18 Fulton MD 5 24 -12 94 18 Columbia MD Peter Chen 5 26 -12 94 19 Narvon PA Dick Sauder 5 48 -10 93 19 H85 Silver Spring 5 22 -12 93 19 Allentown PA S.Mt,Deterline,etc 6 0 -10 92 19 Columbia, MD Don Gardner 5 25 -12 91 20 450 Carla Jane Observatory, Cha 3 43 -17 91 20 Towson, MD Alex Storrs 5 30 -11 91 20 Douglsvl PA Peter DetterlineObs 5 54 -10 90 20 WASHNGTN DC MASON~BRIAN U.S.N.O 5 19 -12 90 20 775 Sayre Observatory, South Be 6 1 -10 90 21 TAKOMA P MD HAROLD WILLIAMS 5 21 -12 88 21 ColegPrk MD UMD Ob.,E. Warner 5 22 -12 88 22 454 Maryland Space Grant Consor 5 30 -11 87 22 Arlngton VA Scott Fearing 5 18 -12 87 22 295 Catholic University Observa 5 20 -12 85 23 WOODBRIDGE VA BROWN~BRIAN W. 5 13 -12 84 23 Charlott NC Gayle Riggsbee 3 40 -17 84 23 ALEXANDRIA VA BOLSTER~ROBERT 5 17 -12 84 24 Hanover MD - Jose Guzman 5 26 -11 83 24 E.Baltmr MD Jonathan Anderson 5 31 -11 82 24 Greenbelt, MD Northway Field 5 23 -12 82 24 Bel Air MD HCAS L. Hubble 5 36 -11 81 25 GREENBELT MD - Dunham/Warren 5 22 -12 81 25 GORF16IN Be Wayne H. Warren Jr. 5 23 -12 80 26 462 Mount Belleview Observatory 5 21 -12 78 27 AUGUSTA GA CRUTE~TOM 3 2 -19 77 27 PHILLIPS NJ DAVID C. MILNE 6 4 -10 76 27 Essex MD Dale Lehman 5 31 -11 76 28 FredericksburgVA 5 6 -12 76 28 GlennDale MD Joe Sedlak 5 23 -12 76 28 New Cut Rd, MD Sedlak mobile 5 26 -11 75 28 BOWIE MD ANDREW W. SEACORD I 5 24 -12 74 29 Greensbo NC David Connor,10mi.s 4 7 -15 73 29 Woodmore MD Chuck Quintero 5 22 -12 72 30 Bowie MD Glenn Bock 5 24 -12 71 30 H88 Hope Observatory, Belcamp 5 36 -11 70 31 TEMPL HL MD RICHARD J. TAIBI 5 19 -12 70 31 SEVERNA PARK MD LEONARD~BOBBY 5 27 -11 70 31 Abbevill GA George Burke 2 24 -21 69 32 Aberdeen MD Phil Dykstra 5 38 -11 66 33 Bowie MD John Wood 5 23 -12 65 34 W. Chester PA EDWIN LURCOTT 5 51 -10 62 35 459 Smith River Observatory, Da 7 18 -6 62 36 Nanjemoy MD S. MD. Astro. Soc. 5 12 -12 62 36 HighBrdg NJ Robinson Obs. 6 7 -9 60 37 WEST CHE PA CLIFFORD J. BADER 5 50 -10 58 38 KENNETT SQUAREPA KAUER~JAMES CHA 5 48 -10 56 39 ChadsFrd PA Alfred Webber 5 49 -10 55 40 791 Flower and Cook Observatory 5 52 -10 55 40 866 U.S. Naval Academy, Michels 5 26 -11 55 40 Annapolis MD - L Koscianiski 5 26 -11 52 41 Newark DE Dan Dunlap 5 44 -11 52 41 Plymouth PA ColonialObs.D'Egidio 5 55 -10 51 42 923 The Bradstreet Observatory, 5 54 -10 51 42 788 Mount Cuba Observatory, Wil 5 47 -10 50 43 Oliver VA Robert Oldham 4 59 -13 48 43 Port Royal VA - Dunham mobile 5 7 -12 48 44 Hughesvl MD MICHAEL CAPOBIANCO 5 17 -12 46 45 Garrison NY Frank Suits 6 28 -8 45 45 *** Northern limit *** 44 46 Media PA John Kemtz 5 52 -10 42 47 Springfield, PA Don D'Egidio, 5 52 -10 41 47 ChrlotHl MD Jeff Hunt 5 17 -12 40 48 Ashland VA - Keeble Obs 4 58 -13 40 48 COLUMBIA SC UNIVERSITY OF SOUTH 3 22 -18 37 49 Monsey NY Ben Wymore 6 23 -9 36 50 Wilmsbrg MA Bryce Babcock 6 54 -7 34 51 Richmond VA Randy Tatum vid. 4 55 -13 33 51 WCaldwel NJ Jack Gavin 6 17 -9 31 52 Harlington, NJ Robert Vanderbei 6 7 -9 30 52 Philadelphia PA Deborah Goldader 5 55 -10 29 53 NewMlfrd CT TIMOTHY HAGER 6 36 -8 27 54 Ewing, NJ - Herb Johnson 6 3 -10 26 54 ChapelHl NC MoreheadOb. Melvin 4 13 -15 26 54 438 Smith College Observatory, 6 54 -7 25 54 Wye Mill MD mobile site Dunham 5 31 -11 25 54 Princetn NJ Mikkelsen, David 6 6 -9 23 55 Mchncsvl VA Ken Wilson 4 57 -13 23 55 785 Fitz-Randolph Observatory, 6 6 -9 22 55 Durham NC Joe Mack 4 16 -15 21 56 292 Burlington, New Jersey 5 59 -10 20 56 Vidalia GA Jeff Lackmeyer 2 38 -20 20 56 Chapaqua NY Robert Davidson 6 26 -8 17 57 Cary NC JeffBarschaw/Lang 4 12 -15 17 57 449 Griffin Hunter Observatory 3 35 -17 16 57 Tuckahoe MD St.Park star party 5 33 -11 14 57 Raleigh NC Jerry Watson 4 15 -15 11 58 Easton MD 5 28 -11 11 58 Ridgefield CT Sander Pool 6 31 -8 11 58 Cold Harbor VA Ed's Nursery D 4 58 -13 7 58 New York NY 6 18 -9 5 59 Monroe NJ Schwartz~Mark 6 9 -9 5 59 Milford DE Eric Rick Barnes 5 41 -11 4 59 NEW YORK NY VELIZ~CLAUDIO 6 18 -9 3 59 STAMFORD CT FAIRFIELD CTY.A.S. 6 28 -8 1 59 Dover DE 5 40 -11 1 59 RYE NY DARELIUS~JOEL T 6 25 -8 1 59 Cheswold DE GARY KISER 5 42 -11 0 59 CARY NC LANG~MARK 4 15 -15 0 59 **** Centre Line **** -5 59 Bayside NY Bart Fried 6 21 -9 -6 59 Valdosta GA Martha Leake 2 7 -21 -8 58 Stratfrd CT RolnickOb TomDavis 6 31 -8 -13 58 FAIRFELD CT THOMAS F. DAVIS 6 31 -8 -13 58 798 Yale Observatory, Bethany 6 39 -8 -15 57 UprBrkvl NY Donald Jackson 6 24 -8 -16 57 Millvill NJ Fred Schaaf 5 49 -10 -23 55 Whiting NJ Arcturus Ob P.Gitto 6 3 -9 -25 54 797 Yale Observatory, New Haven 6 38 -8 -25 54 NewHaven CT Pat Maturo 6 38 -8 -26 54 298 Van Vleck Observatory 6 44 -7 -27 54 N Merick NY SAMUEL A. STORCH 6 23 -8 -27 53 928 Moonedge Observatory, North 6 28 -8 -28 53 ATMBostn MA s. of club house 7 10 -6 -28 53 WESTFORD, MA - Wallace Obs 7 10 -6 -28 53 Garner NC Malcolm Smith 4 14 -15 -30 52 Falmouth ME Dunham/Knowles 7 38 -5 -31 52 293 Burlington remote site 6 1 -10 -37 49 Fayettev NC Jan Dabrowski 4 4 -15 -39 48 StonyBrk NY Deane Peterson 6 30 -8 -40 48 E Setakt LI John Greene PC23C 6 31 -8 -41 47 Bethune Obs, SC 3_observatorie 3 35 -17 -45 45 *** Southern limit *** -47 44 Wiliamsb VA William&Mary Col. 5 0 -13 -49 43 Salisbury MD 5 28 -11 -49 43 SomersPt NJ Michael Gille 5 52 -10 -53 41 Sudbury MO Dennis DiCicco 7 8 -6 -54 40 Holtsvil NY Frank Melillo 6 30 -8 -57 39 Cape May NJ planning only 5 44 -10 -61 36 Stedman NC Johnny Horne 4 4 -15 -61 36 RockyMnt NC TRAC via Landen 4 28 -14 -66 33 LUMBERTON NC I95 site 3 54 -16 -68 32 SIMS NC BILLY GLADSON 4 23 -14 -72 30 Brooklin MA Clay Center Obs. 7 10 -6 -73 29 Smithfield VA - H $ K Abramson 4 56 -13 -74 29 Newport VA Jones, Robert C8 4 59 -13 -75 28 Carbuncle Hill Observatory 6 55 -7 -75 28 Yorktown VA Michael Klosterman 5 1 -13 -76 28 Boston MA BATM David Aucoin 7 8 -6 -77 27 South Boston, MA Haldun Menali 7 12 -6 -82 24 Hampton VA - Dave Kratz 5 1 -12 -83 24 Ocean City MD 5 34 -11 -83 24 Langley VA Hampton 16in pe 5 1 -12 -86 22 Savannah GA 2 52 -19 -87 22 Stonngtn CT USCG Academy Obs. 6 50 -7 -92 20 Suffolk VA Tidewater CC Ob via 4 58 -13 -98 17 Gatesvil NC Norfolk A.S.Obs.sit 4 47 -13 -99 16 CHESAPEK VI DENNIS A. ROWLEY 4 57 -13 -101 15 ** Southern limit plus 1-Sigma ** -106 14 Norfolk VA 4 59 -13 -108 13 Chesapeake VA Glendon Howell 4 57 -13 -115 10 GRNVILLE NC FLOYD E. MATTHEIS 4 28 -14 -125 8 Kinston NC J Faircloth 4 20 -14 -156 2 ** Southern limit plus 2-Sigma ** -159 2 831 Rosemary Hill Observatory, 1 52 -22 -159 2 Jacksonville FL - David Crum 2 16 -21 -160 2 Gainesvl FL C.Siopis &S.Fisher 1 59 -21 -165 2 JACKSONVILLE FL CRUM~DAVID A. 2 18 -20 -212 0 ** Southern limit plus 3-Sigma ** For reporting observations, go to http://www.asteroidoccultation.com/observations/NA/ and click on "templates" in the upper right corner; it also gives e-mail addresses to which reports should be sent (of course, I'll be interested in this event, too). Good luck with your observations; hope you can help us measure details of this asteroid! Predictions of other Mid-Atlantic occultations and expeditions through mid September are here. __________________ David Dunham, 2007 July 31, 9pm EDT Phones home 301-474-4722; cell 301-526-5590; office 240-228-5609 office e-mail david.dunham@jhuapl.edu