IOTA/IOTA-ES occultation update for (2570) Porphyro / TYC 5777-00022-1 event on 2012 Nov 26, 11:33 UT Visible from Philippines, Indonesia Summary ------- On 2012 Nov 26 UT, the 24 km diameter asteroid (2570) Porphyro will occult a 10.1 mag star in the constellation Aquarius for observers along a path across Philippines, Indonesia. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.5 mag to 17.6 mag (the magnitude of the asteroid) for at most 1.0 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: 22 * date and approx. time of event: 2012 Nov 26, 11:34 - 2012 Nov 26, 11:37 UT * geocentric midpoint of event [JD]: 2456257.98139167 * magnitude of target star: 10.1 * magnitude drop [mag]: 7.5 * estimated maximum duration [s]: 1.0 * Moon: 96 % sunlit, 82° distance * Sun: 75° distance * rough path description: Philippines, Indonesia Additional comments ------------------- close double star The occultation path -------------------- * approximate projected width [km]: 24 * 1 sigma uncertainty interval [path widths]: +/- 3.13 * 1 sigma uncertainty interval [seconds]: +/- 4.9 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .054 +/- .044) * 1 sigma uncertainty ellipse (major, minor, PA): ( .059", .037", 58° ) * approx speed of asteroid's shadow [km/s]: 24.0918 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5777-00022-1 by 2570 Porphyro on 2012 Nov 26 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 96 0 0 - 4 13 2 11 34 26 74 245 -1 - 4 20 24 - 4 5 40 - 5 6 30 - 3 19 35 97 0 0 - 3 41 11 11 34 31 73 245 -2 - 3 48 33 - 3 33 49 - 4 34 41 - 2 47 42 98 0 0 - 3 9 15 11 34 36 71 245 -3 - 3 16 37 - 3 1 53 - 4 2 46 - 2 15 45 99 0 0 - 2 37 15 11 34 41 70 244 -4 - 2 44 37 - 2 29 52 - 3 30 47 - 1 43 43 100 0 0 - 2 5 11 11 34 46 69 244 -6 - 2 12 33 - 1 57 48 - 2 58 44 - 1 11 39 101 0 0 - 1 33 5 11 34 51 68 244 -7 - 1 40 28 - 1 25 42 - 2 26 38 - 0 39 32 102 0 0 - 1 0 58 11 34 56 67 244 -8 - 1 8 20 - 0 53 35 - 1 54 31 - 0 7 25 103 0 0 - 0 28 50 11 35 1 66 244 -9 - 0 36 12 - 0 21 27 - 1 22 23 0 24 43 104 0 0 0 3 17 11 35 5 65 244 -10 - 0 4 5 0 10 40 - 0 50 16 0 56 50 105 0 0 0 35 23 11 35 10 63 244 -11 0 28 0 0 42 45 - 0 18 10 1 28 54 106 0 0 1 7 26 11 35 15 62 244 -12 1 0 4 1 14 48 0 13 54 2 0 56 107 0 0 1 39 25 11 35 20 61 244 -14 1 32 3 1 46 47 0 45 55 2 32 55 108 0 0 2 11 20 11 35 24 60 244 -15 2 3 59 2 18 42 1 17 52 3 4 48 109 0 0 2 43 10 11 35 29 59 244 -16 2 35 49 2 50 32 1 49 43 3 36 36 110 0 0 3 14 54 11 35 33 58 244 -17 3 7 32 3 22 15 2 21 29 4 8 17 111 0 0 3 46 30 11 35 38 57 244 -18 3 39 9 3 53 51 2 53 8 4 39 51 112 0 0 4 17 58 11 35 42 55 244 -19 4 10 37 4 25 18 3 24 38 5 11 16 113 0 0 4 49 17 11 35 46 54 244 -20 4 41 56 4 56 37 3 56 0 5 42 32 114 0 0 5 20 26 11 35 51 53 244 -22 5 13 6 5 27 45 4 27 13 6 13 38 115 0 0 5 51 24 11 35 55 52 244 -23 5 44 5 5 58 43 4 58 14 6 44 33 116 0 0 6 22 11 11 35 59 51 244 -24 6 14 52 6 29 29 5 29 5 7 15 16 117 0 0 6 52 45 11 36 3 50 244 -25 6 45 27 7 0 3 5 59 43 7 45 46 118 0 0 7 23 6 11 36 7 49 244 -26 7 15 48 7 30 23 6 30 8 8 16 2 119 0 0 7 53 13 11 36 11 47 244 -27 7 45 56 8 0 30 7 0 19 8 46 5 120 0 0 8 23 5 11 36 14 46 245 -28 8 15 48 8 30 21 7 30 16 9 15 52 121 0 0 8 52 41 11 36 18 45 245 -29 8 45 26 8 59 57 7 59 57 9 45 24 122 0 0 9 22 2 11 36 22 44 245 -31 9 14 47 9 29 17 8 29 23 10 14 40 123 0 0 9 51 5 11 36 25 43 245 -32 9 43 51 9 58 20 8 58 32 10 43 38 124 0 0 10 19 51 11 36 29 42 245 -33 10 12 38 10 27 5 9 27 23 11 12 18 125 0 0 10 48 19 11 36 32 41 245 -34 10 41 6 10 55 32 9 55 56 11 40 41 126 0 0 11 16 28 11 36 35 40 246 -35 11 9 16 11 23 40 10 24 11 12 8 44 127 0 0 11 44 17 11 36 39 39 246 -36 11 37 6 11 51 29 10 52 6 12 36 28 128 0 0 12 11 47 11 36 42 38 246 -37 12 4 37 12 18 57 11 19 42 13 3 51 129 0 0 12 38 56 11 36 45 36 246 -38 12 31 46 12 46 6 11 46 57 13 30 54 130 0 0 13 5 44 11 36 48 35 246 -39 12 58 35 13 12 53 12 13 51 13 57 36 131 0 0 13 32 11 11 36 50 34 247 -40 13 25 3 13 39 19 12 40 24 14 23 56 132 0 0 13 58 15 11 36 53 33 247 -41 13 51 8 14 5 22 13 6 35 14 49 55 133 0 0 14 23 58 11 36 56 32 247 -42 14 16 52 14 31 4 13 32 24 15 15 30 134 0 0 14 49 17 11 36 58 31 247 -43 14 42 12 14 56 22 13 57 50 15 40 43 135 0 0 15 14 14 11 37 1 30 248 -45 15 7 9 15 21 18 14 22 53 16 5 33 136 0 0 15 38 47 11 37 3 29 248 -46 15 31 43 15 45 50 14 47 33 16 29 59 137 0 0 16 2 56 11 37 6 28 248 -47 15 55 53 16 9 58 15 11 48 16 54 2 138 0 0 16 26 41 11 37 8 27 248 -48 16 19 39 16 33 42 15 35 40 17 17 40 139 0 0 16 50 1 11 37 10 26 249 -49 16 43 0 16 57 1 15 59 7 17 40 54 140 0 0 17 12 57 11 37 12 25 249 -50 17 5 57 17 19 56 16 22 10 18 3 43 141 0 0 17 35 27 11 37 14 24 249 -51 17 28 29 17 42 26 16 44 47 18 26 7 142 0 0 17 57 33 11 37 16 23 250 -52 17 50 35 18 4 31 17 6 59 18 48 5 143 0 0 18 19 13 11 37 18 22 250 -53 18 12 16 18 26 10 17 28 46 19 9 39 144 0 0 18 40 27 11 37 19 21 250 -54 18 33 32 18 47 23 17 50 8 19 30 46 145 0 0 19 1 16 11 37 21 20 251 -55 18 54 21 19 8 11 18 11 3 19 51 28 146 0 0 19 21 39 11 37 22 19 251 -56 19 14 45 19 28 33 18 31 32 20 11 44 147 0 0 19 41 36 11 37 24 18 251 -57 19 34 42 19 48 29 18 51 36 20 31 35 148 0 0 20 1 6 11 37 25 17 252 -58 19 54 14 20 7 58 19 11 13 20 50 58 149 0 0 20 20 10 11 37 27 16 252 -59 20 13 19 20 27 1 19 30 23 21 9 56 150 0 0 20 38 48 11 37 28 15 252 -60 20 31 57 20 45 38 19 49 7 21 28 27 151 0 0 20 56 59 11 37 29 14 253 -61 20 50 9 21 3 49 20 7 25 21 46 32 152 0 0 21 14 44 11 37 30 13 253 -62 21 7 55 21 21 32 20 25 16 22 4 10 153 0 0 21 32 2 11 37 31 12 253 -63 21 25 14 21 38 49 20 42 40 22 21 22 154 0 0 21 48 53 11 37 32 11 254 -63 21 42 6 21 55 40 20 59 37 22 38 7 155 0 0 22 5 17 11 37 33 10 254 -64 21 58 31 22 12 4 21 16 8 22 54 26 156 0 0 22 21 15 11 37 33 9 254 -65 22 14 30 22 28 0 21 32 11 23 10 18 157 0 0 22 36 46 11 37 34 8 255 -66 22 30 1 22 43 31 21 47 48 23 25 43 158 0 0 22 51 50 11 37 34 7 255 -67 22 45 6 22 58 34 22 2 58 23 40 41 159 0 0 23 6 28 11 37 35 6 256 -68 22 59 44 23 13 11 22 17 41 23 55 13 160 0 0 23 20 38 11 37 35 5 256 -69 23 13 56 23 27 20 22 31 57 24 9 18 161 0 0 23 34 22 11 37 36 4 256 -70 23 27 40 23 41 3 22 45 46 24 22 57 162 0 0 23 47 39 11 37 36 3 257 -71 23 40 58 23 54 20 22 59 8 24 36 9 163 0 0 24 0 29 11 37 36 2 257 -72 23 53 49 24 7 9 23 12 3 24 48 54 164 0 0 24 12 52 11 37 36 1 258 -73 24 6 13 24 19 32 23 24 32 25 1 12 165 0 0 24 24 49 11 37 36 0 258 -73 24 18 10 24 31 28 23 36 33 25 13 4 Uncertainty in time = +/- 5 secs Prediction of 2012 Nov 16.0 Data for the target star ------------------------ * name: TYC 5777-00022-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 21 08.5205 DE: -10 54 37.135 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .022, .022 ) * V mag [mag]: 10.1 * B mag [mag]: 10.8 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2570) Porphyro approx. diameter [km]: 24 approx. diameter ["]: .012 distance from Earth [AU]: 2.77400 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 645 number of rejected observations: 9 time covered by the observations: 1941 Feb 20 - 2012 Sep 16 1 sigma uncertainty ellipse (major, minor, PA): 0.056, 0.031, 54° remarks: * orbital elements for (2570) Porphyro : Mean anomaly = 290.53481061 deg Arg. of pericenter = 97.62151809 deg Long. of node = 324.39647672 deg Inclination = 16.23452302 deg Eccentricity = 0.10645363 Semimajor axis = 2.76522366 AU Perihelion dist = 2.47085555 AU Mag: H = 11.98, G = 0.15 Epoch of elements : MJD 56257.48100000 TDT (2012 Nov 26.481) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 26 2570 Porphyro 11h 33.2m UT 10.1 21 21 8.521-10 54 37.14TYC 5777-00022-1 10.8 17.6 24 1.0 2.774 2.643 18.53 81.1823 -10.915 3.56 -21.06 11.5534 0.00661 -0.00965 12.27761 5.84536 0.00534 0.00184 2000 288.93131320121119.00000 97.621518324.396477 16.2345230.10645363 2.7652237 2.470855612.2 5.00.15 RATE 2.1434270 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.059 0.037 58 4.13 0.037 0 0-5 5 056247.0020121126_0022-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 20:32 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org