IOTA/IOTA-ES occultation update for (207) Hedda / TYC 1884-00081-1 event on 2008 May 13, 17:44 UT Visible from S Russia, SW Asia Summary ------- On 2008 May 13 UT, the 66 km diameter asteroid (207) Hedda will occult a 11.3 mag star in the constellation Gemini for observers along a path across S Russia, SW Asia. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.7 mag to 15.0 mag (the magnitude of the asteroid) for at most 1.7 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 56 * date and approx. time of event: 2008 May 13, 17:45 - 2008 May 13, 17:46 UT * midpoint of event [JD]: 2454600.238925 * magnitude of target star: 11.3 * magnitude drop [mag]: 3.7 * estimated maximum duration [s]: 1.7 * Moon: 67 % sunlit, 64° distance * Sun: 46° distance * rough path description: S Russia, SW Asia The occultation path -------------------- * approximate projected width [km]: 84 * 1 sigma uncertainty interval [path widths]: +/- 1.11 * 1 sigma uncertainty interval [seconds]: +/- 1.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .021 +/- .036) * 1 sigma uncertainty ellipse (major, minor, PA): ( .036", .021", 0° ) * approx speed of asteroid's shadow [km/s]: 38.7025 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1884-00081-1 by 207 Hedda on 2008 May 13 Centre Star Star Sun Path Limits Error Limits E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " Latitude Latitude Latitude Latitude 27 0 0 50 35 27 17 45 30 35 269 0 50 7 59 51 3 8 49 7 43 52 5 22 28 0 0 50 9 24 17 45 31 35 270 -1 49 41 53 50 37 8 48 41 30 51 39 30 29 0 0 49 42 58 17 45 33 34 271 -2 49 15 24 50 10 46 48 14 55 51 13 14 30 0 0 49 16 10 17 45 34 33 272 -2 48 48 32 49 44 0 47 47 58 50 46 35 31 0 0 48 48 58 17 45 36 33 273 -3 48 21 19 49 16 51 47 20 38 50 19 32 32 0 0 48 21 25 17 45 38 32 275 -4 47 53 43 48 49 20 46 52 58 49 52 7 33 0 0 47 53 31 17 45 39 31 276 -5 47 25 46 48 21 28 46 24 57 49 24 19 34 0 0 47 25 15 17 45 41 31 276 -6 46 57 29 47 53 14 45 56 35 48 56 10 35 0 0 46 56 39 17 45 42 30 277 -7 46 28 52 47 24 40 45 27 55 48 27 40 36 0 0 46 27 44 17 45 44 29 278 -7 45 59 55 46 55 46 44 58 55 47 58 49 37 0 0 45 58 30 17 45 45 28 279 -8 45 30 40 46 26 33 44 29 37 47 29 39 38 0 0 45 28 57 17 45 47 28 280 -9 45 1 7 45 57 2 44 0 2 47 0 9 39 0 0 44 59 8 17 45 48 27 281 -10 44 31 16 45 27 12 43 30 10 46 30 22 40 0 0 44 29 1 17 45 50 26 282 -11 44 1 9 44 57 6 43 0 3 46 0 16 41 0 0 43 58 39 17 45 51 25 283 -12 43 30 47 44 26 44 42 29 40 45 29 54 42 0 0 43 28 1 17 45 53 24 284 -13 43 0 10 43 56 6 41 59 3 44 59 16 43 0 0 42 57 10 17 45 54 24 285 -14 42 29 19 43 25 15 41 28 14 44 28 24 44 0 0 42 26 6 17 45 55 23 285 -14 41 58 15 42 54 10 40 57 11 43 57 17 45 0 0 41 54 49 17 45 57 22 286 -15 41 26 59 42 22 52 40 25 58 43 25 57 46 0 0 41 23 21 17 45 58 21 287 -16 40 55 33 41 51 23 39 54 34 42 54 25 47 0 0 40 51 43 17 45 59 20 288 -17 40 23 56 41 19 44 39 23 0 42 22 43 48 0 0 40 19 56 17 46 0 19 288 -18 39 52 11 40 47 55 38 51 18 41 50 50 49 0 0 39 48 1 17 46 1 18 289 -19 39 20 18 40 15 58 38 19 29 41 18 48 50 0 0 39 15 59 17 46 2 17 290 -20 38 48 18 39 43 54 37 47 34 40 46 39 51 0 0 38 43 51 17 46 3 16 291 -21 38 16 12 39 11 43 37 15 34 40 14 23 52 0 0 38 11 38 17 46 4 16 291 -22 37 44 2 38 39 28 36 43 29 39 42 1 53 0 0 37 39 22 17 46 5 15 292 -23 37 11 49 38 7 8 36 11 21 39 9 35 54 0 0 37 7 3 17 46 6 14 293 -24 36 39 33 37 34 46 35 39 12 38 37 6 55 0 0 36 34 43 17 46 7 13 293 -25 36 7 15 37 2 22 35 7 2 38 4 35 56 0 0 36 2 22 17 46 8 12 294 -25 35 34 58 36 29 58 34 34 52 37 32 2 57 0 0 35 30 2 17 46 8 11 294 -26 35 2 42 35 57 35 34 2 44 36 59 30 58 0 0 34 57 44 17 46 9 10 295 -27 34 30 28 35 25 13 33 30 38 36 27 0 59 0 0 34 25 30 17 46 10 9 296 -28 33 58 17 34 52 54 32 58 35 35 54 32 60 0 0 33 53 19 17 46 10 8 296 -29 33 26 11 34 20 40 32 26 38 35 22 7 61 0 0 33 21 14 17 46 11 7 297 -30 32 54 10 33 48 30 31 54 46 34 49 48 62 0 0 32 49 16 17 46 11 6 297 -31 32 22 16 33 16 27 .. .. .. 34 17 34 63 0 0 32 17 25 17 46 11 5 298 -32 31 50 30 32 44 32 .. .. .. 33 45 28 64 0 0 31 45 43 17 46 12 4 298 -33 31 18 52 32 12 45 .. .. .. 33 13 30 65 0 0 31 14 10 17 46 12 3 299 -34 30 47 25 31 41 8 .. .. .. 32 41 42 66 0 0 30 42 49 17 46 12 2 299 -35 30 16 8 31 9 41 .. .. .. 32 10 4 67 0 0 30 11 39 17 46 12 1 300 -35 29 45 4 30 38 27 .. .. .. 31 38 37 Uncertainty in time = +/- 2 secs [Prediction of 2008 Apr 9.0] Data for the target star ------------------------ * name: TYC 1884-00081-1 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 06 39 57.7099 DE: +26 09 15.588 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .017, .035 ) * V mag [mag]: 11.3 * B mag [mag]: 11.7 * Apparent position with proper motion RA(deg): 100.1188616729 DE(deg): 26.1484995612 * Equation of equinoxes (radians) : 0.000040872863018 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (207) Hedda approx. diameter [km]: 66 approx. diameter ["]: .032 distance from Earth [AU]: 2.88500 * orbital information: orbit source: Preston date of fit: 2008 Apr 08 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 809 number of rejected observations: 111 time covered by the observations: 1903 Sep 23 - 2008 Feb 18 1 sigma uncertainty ellipse (major, minor, PA): 0.012, 0.008, 93° remarks: * orbital elements for (207) Hedda : Mean anomaly = 258.81903512 deg Arg. of pericenter = 192.45043187 deg Long. of node = 29.28160634 deg Inclination = 3.80225892 deg Eccentricity = 0.02839860 Semimajor axis = 2.28423232 AU Perihelion dist = 2.21936332 AU Mag: H = 9.92, G = 0.15 Epoch of elements : MJD 54599.73900000 TDT (2008 May 13.739) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 13 207 Hedda 17h 44.0m UT 11.3 6 39 57.710 26 9 15.59TYC 1884-00081-1 11.7 15.0 66 1.7 2.885 4.925 -5.92 -37.8731 26.156 -86.92 18.61 17.7342 0.05453 0.61892 21.75830 -1.94195 0.00384 -0.00007 2000 256.0386302008 5 4.00000192.450432 29.281606 3.8022590.02839860 2.2842323 2.2193633 9.9 5.00.15 RATE 2.8549180 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.036 0.021 0 2.11 0.036 0 54565.5020080513_0081-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 09, 17:08 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org