IOTA/IOTA-ES occultation update for (806) Gyldenia / TYC 7401-01637-1 event on 2008 May 15, 03:21 UT Visible from N Brazil Summary ------- On 2008 May 15 UT, the 63 km diameter asteroid (806) Gyldenia will occult a 10.6 mag star in the constellation Sagittarius for observers along a path across N Brazil. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.2 mag to 15.8 mag (the magnitude of the asteroid) for at most 6.8 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: 54 * date and approx. time of event: 2008 May 15, 03:16 - 2008 May 15, 03:27 UT * magnitude of target star: 10.6 * magnitude drop [mag]: 5.2 * estimated maximum duration [s]: 6.8 * Moon: 79 % sunlit, 95° distance * Sun: 138° distance * rough path description: N Brazil The occultation path -------------------- * approximate projected width [km]: 127 * 1 sigma uncertainty interval [path widths]: +/- 1.18 * 1 sigma uncertainty interval [seconds]: +/- 7.3 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .051 +/- .031) * 1 sigma uncertainty ellipse (major, minor, PA): ( .051", .031", 94° ) * approx speed of asteroid's shadow [km/s]: 9.1766 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 7401-01637-1 by 806 Gyldenia on 2008 May 15 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 ' " Longitude Longitude Longitude Longitude - 34 44 58 51 0 0 3 16 11 0 157 -19 ... .. .. - 33 44 56 ... .. .. ... .. .. - 34 6 29 50 0 0 3 16 11 1 157 -20 - 35 5 48 - 33 8 37 - 37 32 26 ... .. .. - 33 33 14 49 0 0 3 16 12 2 158 -21 - 34 30 31 - 32 37 17 - 36 51 43 ... .. .. - 33 4 43 48 0 0 3 16 13 3 158 -22 - 34 0 12 - 32 10 29 - 36 16 39 ... .. .. - 32 40 31 47 0 0 3 16 14 4 158 -22 - 33 34 24 - 31 47 47 - 35 46 39 ... .. .. - 32 20 16 46 0 0 3 16 16 5 159 -23 - 33 12 43 - 31 28 53 - 35 21 16 ... .. .. - 32 3 39 45 0 0 3 16 19 6 159 -24 - 32 54 50 - 31 13 30 - 35 0 5 ... .. .. - 31 50 26 44 0 0 3 16 22 7 159 -25 - 32 40 28 - 31 1 21 - 34 42 46 - 29 9 0 - 31 40 22 43 0 0 3 16 25 8 159 -26 - 32 29 22 - 30 52 16 - 34 29 3 - 29 2 4 - 31 33 16 42 0 0 3 16 29 9 159 -27 - 32 21 21 - 30 46 3 - 34 18 42 - 28 57 47 - 31 28 58 41 0 0 3 16 33 10 159 -28 - 32 16 14 - 30 42 32 - 34 11 29 - 28 56 2 - 31 27 19 40 0 0 3 16 37 11 159 -29 - 32 13 52 - 30 41 36 - 34 7 15 - 28 56 40 - 31 28 13 39 0 0 3 16 42 12 159 -30 - 32 14 6 - 30 43 8 - 34 5 51 - 28 59 36 - 31 31 33 38 0 0 3 16 47 13 159 -31 - 32 16 51 - 30 47 1 - 34 7 8 - 29 4 45 - 31 37 13 37 0 0 3 16 53 14 159 -32 - 32 22 1 - 30 53 11 - 34 11 2 - 29 12 1 - 31 45 9 36 0 0 3 16 59 15 158 -32 - 32 29 30 - 31 1 33 - 34 17 25 - 29 21 22 - 31 55 18 35 0 0 3 17 5 16 158 -33 - 32 39 16 - 31 12 3 - 34 26 14 - 29 32 43 - 32 7 35 34 0 0 3 17 12 17 158 -34 - 32 51 14 - 31 24 40 - 34 37 26 - 29 46 3 - 32 22 0 33 0 0 3 17 19 17 158 -35 - 33 5 23 - 31 39 20 - 34 50 57 - 30 1 18 - 32 38 30 32 0 0 3 17 27 18 157 -36 - 33 21 41 - 31 56 2 - 35 6 46 - 30 18 29 - 32 57 4 31 0 0 3 17 35 19 157 -37 - 33 40 6 - 32 14 45 - 35 24 51 - 30 37 33 - 33 17 41 30 0 0 3 17 43 20 157 -38 - 34 0 38 - 32 35 28 - 35 45 12 - 30 58 31 - 33 40 23 29 0 0 3 17 52 21 156 -40 - 34 23 18 - 32 58 12 - 36 7 49 - 31 21 22 - 34 5 9 28 0 0 3 18 1 21 156 -41 - 34 48 6 - 33 22 57 - 36 32 43 - 31 46 7 - 34 32 0 27 0 0 3 18 11 22 155 -42 - 35 15 3 - 33 49 44 - 36 59 57 - 32 12 46 - 35 1 0 26 0 0 3 18 21 23 155 -43 - 35 44 11 - 34 18 36 - 37 29 32 - 32 41 23 - 35 32 10 25 0 0 3 18 31 24 154 -44 - 36 15 35 - 34 49 35 - 38 1 32 - 33 11 58 - 36 5 35 24 0 0 3 18 42 24 154 -45 - 36 49 17 - 35 22 43 - 38 36 3 - 33 44 35 - 36 41 18 23 0 0 3 18 53 25 153 -46 - 37 25 22 - 35 58 6 - 39 13 9 - 34 19 17 - 37 19 25 22 0 0 3 19 5 26 152 -47 - 38 3 56 - 36 35 49 - 39 52 57 - 34 56 9 - 38 0 3 21 0 0 3 19 18 26 152 -48 - 38 45 6 - 37 15 57 - 40 35 37 - 35 35 15 - 38 43 19 20 0 0 3 19 30 27 151 -49 - 39 29 1 - 37 58 37 - 41 21 18 - 36 16 42 - 39 29 23 19 0 0 3 19 44 27 150 -51 - 40 15 51 - 38 43 59 - 42 10 14 - 37 0 36 - 40 18 26 18 0 0 3 19 58 28 149 -52 - 41 5 48 - 39 32 12 - 43 2 40 - 37 47 8 - 41 10 41 17 0 0 3 20 12 28 148 -53 - 41 59 7 - 40 23 29 - 43 58 56 - 38 36 26 - 42 6 25 16 0 0 3 20 27 29 148 -54 - 42 56 6 - 41 18 5 - 44 59 24 - 39 28 43 - 43 5 59 15 0 0 3 20 43 29 147 -55 - 43 57 7 - 42 16 18 - 46 4 35 - 40 24 13 - 44 9 46 14 0 0 3 20 59 29 146 -56 - 45 2 39 - 43 18 31 - 47 15 7 - 41 23 14 - 45 18 18 13 0 0 3 21 17 30 145 -58 - 46 13 18 - 44 25 10 - 48 31 52 - 42 26 8 - 46 32 15 12 0 0 3 21 35 30 143 -59 - 47 29 48 - 45 36 51 - 49 55 56 - 43 33 20 - 47 52 29 11 0 0 3 21 54 30 142 -60 - 48 53 13 - 46 54 19 - 51 28 59 - 44 45 24 - 49 20 13 10 0 0 3 22 15 30 141 -61 - 50 24 57 - 48 18 34 - 53 13 25 - 46 3 2 - 50 57 5 9 0 0 3 22 36 30 140 -62 - 52 7 6 - 49 50 58 - 55 13 10 - 47 27 11 - 52 45 37 8 0 0 3 23 0 29 138 -63 - 54 2 54 - 51 33 33 - 57 35 24 - 48 59 6 - 54 49 53 7 0 0 3 23 26 29 137 -64 - 56 18 0 - 53 29 22 - 60 36 33 - 50 40 37 Latitude Latitude Latitude Latitude - 56 0 0 6 30 0 3 23 40 28 136 -64 7 7 24 5 53 22 8 38 56 4 29 35 - 57 0 0 6 6 27 3 23 51 28 136 -64 6 43 25 5 30 13 8 13 50 4 7 18 - 58 0 0 5 44 48 3 24 3 27 135 -65 6 21 23 5 8 55 7 50 48 3 46 46 - 59 0 0 5 25 0 3 24 14 27 135 -65 6 1 15 4 49 26 7 29 46 3 27 59 - 60 0 0 5 7 0 3 24 25 27 134 -65 5 42 57 4 31 43 7 10 41 3 10 53 - 61 0 0 4 50 47 3 24 36 26 134 -65 5 26 28 4 15 45 6 53 31 2 55 27 - 62 0 0 4 36 19 3 24 46 25 133 -65 5 11 46 4 1 30 6 38 13 2 41 40 - 63 0 0 4 23 33 3 24 56 25 133 -64 4 58 49 3 48 56 6 24 45 2 29 30 - 64 0 0 4 12 30 3 25 6 24 132 -64 4 47 36 3 38 2 6 13 6 2 18 57 - 65 0 0 4 3 8 3 25 16 24 132 -64 4 38 5 3 28 47 6 3 15 2 9 59 - 66 0 0 3 55 25 3 25 25 23 131 -63 4 30 16 3 21 10 5 55 10 2 2 35 - 67 0 0 3 49 22 3 25 34 22 131 -63 4 24 9 3 15 11 5 48 50 1 56 45 - 68 0 0 3 44 58 3 25 43 22 131 -63 4 19 41 3 10 50 5 44 16 1 52 29 - 69 0 0 3 42 12 3 25 52 21 130 -62 4 16 55 3 8 5 5 41 27 1 49 47 - 70 0 0 3 41 5 3 26 0 20 130 -62 4 15 49 3 6 58 5 40 22 1 48 38 - 71 0 0 3 41 38 3 26 8 20 130 -61 4 16 23 3 7 28 5 41 3 1 49 3 - 72 0 0 3 43 49 3 26 16 19 130 -60 4 18 39 3 9 36 5 43 30 1 51 3 - 73 0 0 3 47 41 3 26 23 18 129 -60 4 22 37 3 13 22 5 47 43 1 54 36 - 74 0 0 3 53 13 3 26 31 17 129 -59 4 28 17 3 18 47 5 53 43 1 59 46 - 75 0 0 4 0 27 3 26 37 16 129 -58 4 35 41 3 25 52 6 1 32 2 6 31 - 76 0 0 4 9 25 3 26 44 16 129 -57 4 44 50 3 34 39 6 11 11 2 14 54 - 77 0 0 4 20 8 3 26 50 15 128 -57 4 55 46 3 45 8 6 22 43 2 24 56 - 78 0 0 4 32 37 3 26 56 14 128 -56 5 8 31 3 57 23 6 36 9 2 36 39 - 79 0 0 4 46 55 3 27 2 13 128 -55 5 23 7 4 11 24 6 51 32 2 50 3 - 80 0 0 5 3 4 3 27 7 12 128 -54 5 39 37 4 27 14 7 8 55 3 5 12 - 81 0 0 5 21 7 3 27 12 11 128 -53 5 58 3 4 44 55 7 28 21 3 22 7 - 82 0 0 5 41 8 3 27 17 10 128 -52 6 18 29 5 4 32 7 49 56 3 40 51 - 83 0 0 6 3 10 3 27 21 9 127 -51 6 40 59 5 26 6 8 13 42 4 1 28 - 84 0 0 6 27 16 3 27 25 8 127 -50 7 5 38 5 49 43 8 39 45 4 24 0 - 85 0 0 6 53 32 3 27 28 7 127 -49 7 32 30 6 15 25 9 8 12 4 48 32 - 86 0 0 7 22 3 3 27 31 6 127 -48 8 1 40 6 43 19 9 39 8 .. .. .. - 87 0 0 7 52 54 3 27 34 5 127 -47 8 33 16 7 13 29 10 12 42 .. .. .. - 88 0 0 8 26 13 3 27 36 4 127 -46 9 7 24 7 46 2 10 49 3 .. .. .. - 89 0 0 9 2 7 3 27 37 3 127 -45 9 44 13 8 21 6 11 28 21 .. .. .. - 90 0 0 9 40 45 3 27 38 1 126 -44 10 23 52 8 58 47 .. .. .. .. .. .. - 91 0 0 10 22 18 3 27 39 0 126 -42 .. .. .. 9 39 15 .. .. .. .. .. .. Uncertainty in time = +/- 10 secs [Prediction of 2008 May 8.0] Data for the target star ------------------------ * name: TYC 7401-01637-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 25 22.9056 DE: -35 27 41.110 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .032, .022 ) * V mag [mag]: 10.6 * B mag [mag]: 11.5 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (806) Gyldenia approx. diameter [km]: 63 approx. diameter ["]: .036 distance from Earth [AU]: 2.44000 * orbital information: orbit source: Preston date of fit: 2008 May 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 583 number of rejected observations: 38 time covered by the observations: 1915 May 01 - 2008 May 05 1 sigma uncertainty ellipse (major, minor, PA): 0.040, 0.022, 96° remarks: * orbital elements for (806) Gyldenia : Mean anomaly = 97.13624564 deg Arg. of pericenter = 114.82679486 deg Long. of node = 44.52588113 deg Inclination = 14.22539378 deg Eccentricity = 0.07002634 Semimajor axis = 3.21713527 AU Perihelion dist = 2.99185107 AU Mag: H = 10.13, G = 0.15 Epoch of elements : MJD 54601.14000000 TDT (2008 May 15.140) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 15 806 Gyldenia 3h 21.9m UT 10.6 18 25 22.906-35 27 41.11TYC 7401-01637-1 11.6 15.8 63 6.8 2.440 -1.035 -13.74 -7.3572 -35.457 128.62 18.94 3.3647 -0.63849 0.58772 -3.50519 -3.81325 -0.00374 0.00075 2000 96.9415292008 514.00000114.826795 44.525881 14.2253940.07002634 3.2171353 2.991851110.6 5.00.15 RATE 1.7080480 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.051 0.031 94 2.18 0.042 0 54594.5020080515_1637-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 08, 03:19 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org