IOTA/IOTA-ES occultation update for (2474) Ruby / TYC 5517-00783-1 event on 2009 Jan 03, 08:14 UT Visible from Summary ------- On 2009 Jan 03 UT, the 18 km diameter asteroid (2474) Ruby will occult a 9.8 mag star in the constellation Crater for observers along a path across . In the case of an occultation, the combined light of the asteroid and the star will drop by 6.8 mag to 16.6 mag (the magnitude of the asteroid) for at most 1.3 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: 15 * date and approx. time of event: 2009 Jan 03, 08:07 - 2009 Jan 03, 08:15 UT * magnitude of target star: 9.8 * magnitude drop [mag]: 6.8 * estimated maximum duration [s]: 1.3 * Moon: 38 % sunlit, 175° distance * Sun: 101° distance * rough path description: The occultation path -------------------- * approximate projected width [km]: 20 * 1 sigma uncertainty interval [path widths]: +/- 4.40 * 1 sigma uncertainty interval [seconds]: +/- 7.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .059 +/- .047) * 1 sigma uncertainty ellipse (major, minor, PA): ( .060", .046", 105° ) * approx speed of asteroid's shadow [km/s]: 13.1996 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5517-00783-1 by 2474 Ruby on 2009 Jan 3 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 -119 6 59 61 0 0 8 7 22 1 109 -52 -119 41 18 -118 33 16 ... .. .. -113 58 41 -113 44 20 60 0 0 8 7 23 3 114 -52 -114 12 45 -113 16 16 ... .. .. -109 22 17 Latitude Latitude Latitude Latitude -113 0 0 59 50 46 8 7 23 4 114 -53 59 44 57 59 56 35 58 53 57 60 48 4 -112 0 0 59 37 52 8 7 23 4 115 -53 59 32 1 59 43 43 58 40 48 60 35 26 -111 0 0 59 24 30 8 7 24 5 116 -53 59 18 38 59 30 23 58 27 11 60 22 20 -110 0 0 59 10 40 8 7 24 5 117 -53 59 4 46 59 16 34 58 13 5 60 8 46 -109 0 0 58 56 21 8 7 25 6 118 -53 58 50 25 59 2 17 57 58 29 59 54 44 -108 0 0 58 41 32 8 7 25 7 119 -53 58 35 35 58 47 30 57 43 24 59 40 12 -107 0 0 58 26 14 8 7 26 7 120 -53 58 20 15 58 32 13 57 27 49 59 25 11 -106 0 0 58 10 25 8 7 27 8 120 -53 58 4 24 58 16 26 57 11 42 59 9 39 -105 0 0 57 54 4 8 7 27 8 121 -53 57 48 1 58 0 7 56 55 4 58 53 37 -104 0 0 57 37 12 8 7 28 9 122 -53 57 31 7 57 43 17 56 37 53 58 37 3 -103 0 0 57 19 47 8 7 29 10 123 -53 57 13 41 57 25 54 56 20 10 58 19 58 -102 0 0 57 1 49 8 7 30 10 124 -53 56 55 41 57 7 58 56 1 54 58 2 19 -101 0 0 56 43 18 8 7 31 11 125 -53 56 37 8 56 49 29 55 43 4 57 44 7 -100 0 0 56 24 12 8 7 32 11 126 -53 56 18 0 56 30 25 55 23 39 57 25 22 - 99 0 0 56 4 32 8 7 34 12 126 -53 55 58 18 56 10 47 55 3 39 57 6 1 - 98 0 0 55 44 16 8 7 35 13 127 -53 55 37 59 55 50 33 54 43 3 56 46 6 - 97 0 0 55 23 24 8 7 36 13 128 -53 55 17 5 55 29 42 54 21 50 56 25 34 - 96 0 0 55 1 54 8 7 38 14 129 -53 54 55 34 55 8 15 54 0 1 56 4 26 - 95 0 0 54 39 48 8 7 39 15 130 -53 54 33 25 54 46 11 53 37 33 55 42 40 - 94 0 0 54 17 3 8 7 41 15 131 -53 54 10 38 54 23 28 53 14 28 55 20 17 - 93 0 0 53 53 39 8 7 43 16 132 -52 53 47 12 54 0 7 52 50 43 54 57 15 - 92 0 0 53 29 36 8 7 45 17 132 -52 53 23 7 53 36 6 52 26 19 54 33 33 - 91 0 0 53 4 53 8 7 47 18 133 -52 52 58 22 53 11 25 52 1 15 54 9 12 - 90 0 0 52 39 29 8 7 49 18 134 -52 52 32 56 52 46 3 51 35 30 53 44 10 - 89 0 0 52 13 24 8 7 51 19 135 -52 52 6 48 52 20 0 51 9 3 53 18 27 - 88 0 0 51 46 37 8 7 54 20 136 -52 51 39 59 51 53 16 50 41 55 52 52 2 - 87 0 0 51 19 8 8 7 56 21 137 -51 51 12 27 51 25 48 50 14 4 52 24 54 - 86 0 0 50 50 55 8 7 59 21 137 -51 50 44 13 50 57 38 49 45 30 51 57 4 - 85 0 0 50 21 59 8 8 1 22 138 -51 50 15 15 50 28 44 49 16 13 51 28 30 - 84 0 0 49 52 19 8 8 4 23 139 -50 49 45 32 49 59 7 48 46 12 50 59 12 - 83 0 0 49 21 55 8 8 7 24 140 -50 49 15 6 49 28 44 48 15 27 50 29 9 - 82 0 0 48 50 46 8 8 11 25 141 -50 48 43 55 48 57 37 47 43 57 49 58 21 - 81 0 0 48 18 51 8 8 14 25 142 -49 48 11 58 48 25 45 47 11 42 49 26 48 - 80 0 0 47 46 12 8 8 18 26 142 -49 47 39 16 47 53 8 46 38 42 48 54 29 - 79 0 0 47 12 46 8 8 21 27 143 -49 47 5 49 47 19 44 46 4 57 48 21 24 - 78 0 0 46 38 35 8 8 25 28 144 -48 46 31 35 46 45 35 45 30 26 47 47 33 - 77 0 0 46 3 38 8 8 29 29 145 -48 45 56 36 46 10 39 44 55 10 47 12 55 - 76 0 0 45 27 54 8 8 34 30 146 -47 45 20 51 45 34 58 44 19 8 46 37 31 - 75 0 0 44 51 25 8 8 38 31 147 -47 44 44 20 44 58 31 43 42 20 46 1 20 - 74 0 0 44 14 10 8 8 43 32 148 -46 44 7 3 44 21 17 43 4 47 45 24 23 - 73 0 0 43 36 9 8 8 47 33 149 -45 43 29 0 43 43 18 42 26 30 44 46 40 - 72 0 0 42 57 23 8 8 52 33 149 -45 42 50 12 43 4 34 41 47 27 44 8 11 - 71 0 0 42 17 51 8 8 58 34 150 -44 42 10 39 42 25 4 41 7 40 43 28 55 - 70 0 0 41 37 36 8 9 3 35 151 -44 41 30 22 41 44 50 40 27 10 42 48 55 - 69 0 0 40 56 36 8 9 9 36 152 -43 40 49 21 41 3 52 39 45 57 42 8 10 - 68 0 0 40 14 54 8 9 14 37 153 -42 40 7 37 40 22 11 39 4 1 41 26 41 - 67 0 0 39 32 29 8 9 21 38 154 -41 39 25 11 39 39 47 38 21 24 40 44 29 - 66 0 0 38 49 23 8 9 27 39 155 -41 38 42 4 38 56 42 37 38 7 40 1 34 - 65 0 0 38 5 36 8 9 33 40 156 -40 37 58 17 38 12 57 36 54 10 39 17 59 - 64 0 0 37 21 11 8 9 40 41 157 -39 37 13 50 37 28 32 36 9 35 38 33 43 - 63 0 0 36 36 8 8 9 47 42 158 -38 36 28 46 36 43 30 35 24 24 37 48 48 - 62 0 0 35 50 29 8 9 54 43 159 -37 35 43 6 35 57 52 34 38 38 37 3 16 - 61 0 0 35 4 14 8 10 1 44 160 -37 34 56 51 35 11 38 33 52 18 36 17 8 - 60 0 0 34 17 27 8 10 9 45 161 -36 34 10 4 34 24 51 33 5 26 35 30 26 - 59 0 0 33 30 9 8 10 17 46 163 -35 33 22 45 33 37 33 32 18 4 34 43 11 - 58 0 0 32 42 21 8 10 25 47 164 -34 32 34 57 32 49 46 31 30 13 33 55 26 - 57 0 0 31 54 6 8 10 33 48 165 -33 31 46 41 32 1 31 30 41 57 33 7 12 - 56 0 0 31 5 25 8 10 41 49 166 -32 30 58 1 31 12 50 29 53 17 32 18 32 - 55 0 0 30 16 22 8 10 50 50 168 -31 30 8 58 30 23 47 29 4 14 31 29 27 - 54 0 0 29 26 58 8 10 59 51 169 -30 29 19 34 29 34 22 28 14 53 30 40 0 - 53 0 0 28 37 15 8 11 8 52 171 -29 28 29 52 28 44 39 27 25 14 29 50 14 - 52 0 0 27 47 17 8 11 17 53 172 -28 27 39 54 27 54 40 26 35 20 29 0 10 - 51 0 0 26 57 5 8 11 27 54 174 -26 26 49 43 27 4 28 25 45 15 28 9 52 - 50 0 0 26 6 42 8 11 36 55 175 -25 25 59 21 26 14 5 24 54 59 27 19 22 - 49 0 0 25 16 12 8 11 46 56 177 -24 25 8 51 25 23 33 24 4 37 26 28 43 - 48 0 0 24 25 35 8 11 56 57 179 -23 24 18 15 24 32 55 23 14 10 25 37 56 - 47 0 0 23 34 56 8 12 6 58 181 -22 23 27 37 23 42 15 22 23 41 24 47 6 - 46 0 0 22 44 16 8 12 16 59 183 -21 22 36 59 22 51 34 21 33 13 23 56 14 - 45 0 0 21 53 39 8 12 26 59 185 -20 21 46 23 22 0 55 20 42 49 23 5 24 - 44 0 0 21 3 6 8 12 36 60 187 -18 20 55 52 21 10 22 19 52 30 22 14 37 - 43 0 0 20 12 42 8 12 47 61 189 -17 20 5 29 20 19 56 19 2 20 21 23 58 - 42 0 0 19 22 27 8 12 57 61 192 -16 19 15 16 19 29 40 18 12 21 20 33 27 - 41 0 0 18 32 26 8 13 8 62 194 -15 18 25 16 18 39 36 17 22 36 19 43 9 - 40 0 0 17 42 40 8 13 19 63 197 -14 17 35 32 17 49 48 16 33 7 18 53 5 - 39 0 0 16 53 11 8 13 29 63 200 -12 16 46 5 17 0 18 15 43 56 18 3 18 - 38 0 0 16 4 3 8 13 40 63 202 -11 15 56 58 16 11 8 14 55 7 17 13 50 - 37 0 0 15 15 17 8 13 51 64 205 -10 15 8 14 15 22 20 14 6 40 16 24 44 - 36 0 0 14 26 55 8 14 2 64 208 -9 14 19 55 14 33 56 13 18 38 15 36 2 - 35 0 0 13 39 1 8 14 13 64 211 -8 13 32 2 13 45 59 12 31 4 14 47 47 - 34 0 0 12 51 35 8 14 23 64 214 -6 12 44 38 12 58 31 11 43 59 13 59 59 - 33 0 0 12 4 39 8 14 34 64 217 -5 11 57 45 12 11 34 10 57 24 13 12 42 - 32 0 0 11 18 16 8 14 45 64 219 -4 11 11 25 11 25 9 10 11 23 12 25 57 - 31 0 0 10 32 28 8 14 56 64 222 -3 10 25 38 10 39 18 9 25 56 11 39 46 - 30 0 0 9 47 15 8 15 7 64 225 -1 9 40 28 9 54 3 8 41 6 10 54 11 - 29 0 0 9 2 40 8 15 17 64 228 0 8 55 55 9 9 25 7 56 53 10 9 12 Uncertainty in time = +/- 7 secs [Prediction of 2008 Nov 4.0] Data for the target star ------------------------ * name: TYC 5517-00783-1 * constellation : Crater * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 11 54 05.8310 DE: -08 42 18.443 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .020, .020 ) * V mag [mag]: 9.8 * B mag [mag]: 10.4 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2474) Ruby approx. diameter [km]: 18 approx. diameter ["]: .011 distance from Earth [AU]: 2.21300 * orbital information: orbit source: Preston date of fit: 2008 Apr 24 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 738 number of rejected observations: 26 time covered by the observations: 1953 Sep 16 - 2008 Mar 10 1 sigma uncertainty ellipse (major, minor, PA): 0.057, 0.042, 107° remarks: * orbital elements for (2474) Ruby : Mean anomaly = 292.56095739 deg Arg. of pericenter = 14.03492566 deg Long. of node = 238.00312715 deg Inclination = 7.49428709 deg Eccentricity = 0.21616360 Semimajor axis = 2.68739030 AU Perihelion dist = 2.10647434 AU Mag: H = 11.71, G = 0.15 Epoch of elements : MJD 54834.34300000 TDT (2009 Jan 03.343) ------ occelmnt file for Occult BEGIN ----------------------------------- 2009 Jan 3 2474 Ruby 8h 14.6m UT 9.8 11 54 5.831- 8 42 18.44TYC 5517-00783-1 10.4 16.6 18 1.3 2.213 1.603 -17.64 -48.2172 -8.700 57.48 -22.80 8.2435 0.25841 0.34635 5.98298 -4.43955 -0.00523 0.00248 2000 291.58933420081230.00000 14.034926238.003127 7.4942870.21616360 2.6873903 2.106474311.8 5.00.15 RATE 2.2372160 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.060 0.046 105 5.40 0.049 0 54774.5020090103_0783-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Nov 04, 05:09 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org