IOTA/IOTA-ES occultation update for (925) Alphonsina / TYC 0251-00899-1 event on 2008 Dec 07, 00:22 UT Visible from Russia Summary ------- On 2008 Dec 07 UT, the 54 km diameter asteroid (925) Alphonsina will occult a 10.0 mag star in the constellation Sextans for observers along a path across Russia. In the case of an occultation, the combined light of the asteroid and the star will drop by 3.1 mag to 13.0 mag (the magnitude of the asteroid) for at most 4.0 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: 78 * date and approx. time of event: 2008 Dec 07, 00:15 - 2008 Dec 07, 00:20 UT * magnitude of target star: 10.0 * magnitude drop [mag]: 3.1 * estimated maximum duration [s]: 4.0 * Moon: 61 % sunlit, 154° distance * Sun: 103° distance * rough path description: Russia The occultation path -------------------- * approximate projected width [km]: 62 * 1 sigma uncertainty interval [path widths]: +/- 0.71 * 1 sigma uncertainty interval [seconds]: +/- 2.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .028 +/- .024) * 1 sigma uncertainty ellipse (major, minor, PA): ( .028", .023", 110° ) * approx speed of asteroid's shadow [km/s]: 13.5380 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 0251-00899-1 by 925 Alphonsina on 2008 Dec 7 Centre Star Star Sun Path Limit1 Path Limit2 Error Limit1 Error Limit2 E. Longitude Latitude U.T. Alt Az Alt o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " o ' " o ' " o ' " o ' " Longitude Latitude Longitude Latitude Longitude Latitude Longitude Latitude 101 35 58 86 58 21 0 15 20 9 209 -22 115 16 54 87 31 53 92 55 20 86 22 6 149 45 31 87 59 5 85 2 47 85 30 38 87 24 58 81 45 57 0 15 30 14 195 -22 89 52 31 82 12 29 85 14 22 81 19 49 93 59 29 82 50 46 82 32 11 80 43 28 85 40 37 77 54 44 0 15 40 18 193 -22 87 8 8 78 16 4 84 18 45 77 33 39 89 23 33 78 46 44 82 30 57 77 4 7 85 18 19 74 42 40 0 15 51 21 193 -21 86 23 47 75 0 59 84 15 43 74 24 31 88 2 15 75 27 14 82 51 21 73 58 59 85 20 34 71 54 23 0 16 1 24 194 -21 86 14 23 72 10 42 84 28 33 71 38 11 87 34 9 72 34 1 83 17 33 71 15 21 85 32 56 69 22 27 0 16 11 26 194 -20 86 19 25 69 37 19 84 47 41 69 7 40 87 27 43 69 58 32 83 45 27 68 46 48 85 50 9 67 2 37 0 16 21 29 195 -20 86 31 34 67 16 22 85 9 40 66 48 56 87 32 2 67 35 59 84 13 42 66 29 34 86 9 56 64 52 11 0 16 32 31 196 -19 86 47 35 65 5 3 85 33 0 64 39 21 87 42 21 65 23 23 84 41 45 64 21 13 86 31 8 62 49 17 0 16 42 33 197 -19 87 5 52 63 1 26 85 56 59 62 37 11 87 56 15 63 18 44 85 9 26 62 20 2 86 53 9 60 52 38 0 16 52 34 197 -18 87 25 34 61 4 10 86 21 13 60 41 7 88 12 27 61 20 36 85 36 41 60 24 48 87 15 38 59 1 12 0 17 2 36 198 -17 87 46 8 59 12 14 86 45 32 58 50 12 88 30 11 59 27 56 86 3 29 58 34 36 87 38 23 57 14 16 0 17 13 38 199 -17 88 7 17 57 24 51 87 9 49 57 3 42 88 48 58 57 39 54 86 29 52 56 48 43 88 1 17 55 31 12 0 17 23 39 200 -16 88 28 50 55 41 24 87 34 2 55 21 1 89 8 30 55 55 54 86 55 53 55 6 35 88 24 16 53 51 32 0 17 33 41 201 -15 88 50 39 54 1 23 87 58 10 53 41 41 89 28 36 54 15 23 87 21 33 53 27 44 88 47 18 52 14 51 0 17 43 42 202 -14 89 12 39 52 24 24 88 22 11 52 5 19 89 49 6 52 37 58 87 46 56 51 51 47 89 10 21 50 40 51 0 17 54 43 203 -14 89 34 49 50 50 7 88 46 7 50 31 35 90 9 57 51 3 18 88 12 4 50 18 26 89 33 26 49 9 14 0 18 4 45 205 -13 89 57 6 49 18 15 89 9 58 49 0 12 90 31 3 49 31 5 88 36 59 48 47 24 89 56 32 47 39 46 0 18 14 46 206 -12 90 19 29 47 48 34 89 33 45 47 30 58 90 52 24 48 1 4 89 1 44 47 18 28 90 19 39 46 12 14 0 18 24 47 207 -11 90 41 58 46 20 50 89 57 30 46 3 38 91 13 57 46 33 3 89 26 20 45 51 26 90 42 48 44 46 28 0 18 35 48 209 -11 91 4 33 44 54 53 90 21 13 44 38 4 91 35 42 45 6 50 89 50 51 44 26 7 91 6 1 43 22 19 0 18 45 49 210 -10 91 27 14 43 30 34 90 44 57 43 14 5 91 57 37 43 42 16 90 15 16 43 2 23 91 29 17 41 59 38 0 18 55 50 211 -9 91 50 2 42 7 43 91 8 41 41 51 33 92 19 44 42 19 12 90 39 39 41 40 5 91 52 39 40 38 18 0 19 5 51 213 -8 92 12 57 40 46 14 91 32 28 40 30 22 92 42 1 40 57 31 91 4 1 40 19 6 92 16 6 39 18 12 0 19 16 52 214 -7 92 36 0 39 26 0 91 56 18 39 10 24 93 4 30 39 37 5 91 28 24 38 59 19 92 39 40 37 59 15 0 19 26 53 216 -7 92 59 13 38 6 55 92 20 14 37 51 34 93 27 10 38 17 49 91 52 50 37 40 40 93 3 22 36 41 20 0 19 36 54 218 -6 93 22 35 36 48 54 92 44 15 36 33 46 93 50 3 36 59 38 92 17 19 36 23 2 93 27 13 35 24 24 0 19 46 55 220 -5 93 46 7 35 31 51 93 8 25 35 16 56 94 13 9 35 42 25 92 41 54 35 6 21 93 51 14 34 8 20 0 19 57 56 221 -4 94 9 52 34 15 41 93 32 43 34 0 59 94 36 29 34 26 7 93 6 35 33 50 33 94 15 27 32 53 7 0 20 7 56 223 -3 94 33 49 33 0 22 93 57 12 32 45 51 95 0 3 33 10 40 93 31 25 32 35 33 94 39 53 31 38 39 0 20 17 57 225 -2 94 58 0 31 45 48 94 21 52 31 31 28 95 23 53 31 55 59 93 56 25 31 21 17 95 4 33 30 24 53 0 20 27 57 227 -1 95 22 26 30 31 57 94 46 44 30 17 47 95 47 59 30 42 0 94 21 37 30 7 43 95 29 27 29 11 45 0 20 38 58 229 0 95 47 8 29 18 46 95 11 52 29 4 45 96 12 24 29 28 42 94 47 1 28 54 47 Uncertainty in time = +/- 3 secs [Prediction of 2008 Nov 26.0] Data for the target star ------------------------ * name: TYC 0251-00899-1 * constellation : Sextans * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 10 11 15.8247 DE: +06 19 30.594 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .021, .021 ) * V mag [mag]: 10.0 * B mag [mag]: 11.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (925) Alphonsina approx. diameter [km]: 54 approx. diameter ["]: .036 distance from Earth [AU]: 2.07700 * orbital information: orbit source: Preston date of fit: 2008 Nov 26 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 808 number of rejected observations: 84 time covered by the observations: 1902 Mar 06 - 2008 Nov 23 1 sigma uncertainty ellipse (major, minor, PA): 0.021, 0.012, 130° remarks: * orbital elements for (925) Alphonsina : Mean anomaly = 350.73043096 deg Arg. of pericenter = 201.58828627 deg Long. of node = 299.72926439 deg Inclination = 21.06795494 deg Eccentricity = 0.08103399 Semimajor axis = 2.70095305 AU Perihelion dist = 2.48208405 AU Mag: H = 8.19, G = 0.15 Epoch of elements : MJD 54807.01500000 TDT (2008 Dec 07.015) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Dec 7 925 Alphonsina 0h 22.0m UT 10.0 10 11 15.825 6 19 30.59TYC 0251-00899-1 11.0 13.0 54 4.0 2.077 1.054 -28.27 71.1636 6.333 172.36 -22.63 0.3666 0.43808 0.24246 3.71474 -6.67749 -0.00526 0.00211 2000 349.17283020081130.00000201.588286299.729264 21.0679550.08103399 2.7009531 2.4820840 8.3 5.00.15 RATE 2.2203860 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.028 0.023 110 1.71 0.026 0 54796.5020081207_0899-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Nov 26, 23:48 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org