IOTA/IOTA-ES occultation update for (2355) Nei Monggol / TYC 6800-01653-1 event on 2008 May 15, 05:47 UT Visible from USA, Canada Summary ------- On 2008 May 15 UT, the 17 km diameter asteroid (2355) Nei Monggol will occult a 10.2 mag star in the constellation Scorpius for observers along a path across USA, Canada. In the case of an occultation, the combined light of the asteroid and the star will drop by 5.5 mag to 15.7 mag (the magnitude of the asteroid) for at most 1.5 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: 9 * date and approx. time of event: 2008 May 15, 05:43 - 2008 May 15, 05:51 UT * magnitude of target star: 10.2 * magnitude drop [mag]: 5.5 * estimated maximum duration [s]: 1.5 * Moon: 80 % sunlit, 71° distance * Sun: 162° distance * rough path description: USA, Canada The occultation path -------------------- * approximate projected width [km]: 42 * 1 sigma uncertainty interval [path widths]: +/- 7.12 * 1 sigma uncertainty interval [seconds]: +/- 15.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .142 +/- .073) * 1 sigma uncertainty ellipse (major, minor, PA): ( .147", .063", 106° ) * approx speed of asteroid's shadow [km/s]: 11.1412 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6800-01653-1 by 2355 Nei Monggol 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 - 40 36 19 61 0 0 5 43 47 1 205 -2 - 41 3 11 - 40 9 38 - 47 47 26 ... .. .. - 41 37 52 60 0 0 5 43 48 2 204 -3 - 42 4 20 - 41 11 35 - 48 42 55 ... .. .. - 42 42 10 59 0 0 5 43 49 3 203 -4 - 43 8 18 - 42 16 13 - 49 42 23 ... .. .. - 43 49 17 58 0 0 5 43 51 4 202 -5 - 44 15 8 - 43 23 36 - 50 45 52 ... .. .. - 44 59 17 57 0 0 5 43 53 5 201 -6 - 45 24 57 - 44 33 48 - 51 53 27 ... .. .. - 46 12 17 56 0 0 5 43 56 6 200 -8 - 46 37 49 - 45 46 56 - 53 5 17 ... .. .. - 47 28 27 55 0 0 5 44 0 8 199 -9 - 47 53 56 - 47 3 10 - 54 21 36 ... .. .. - 48 47 58 54 0 0 5 44 4 9 198 -10 - 49 13 27 - 48 22 40 - 55 42 41 ... .. .. - 50 11 3 53 0 0 5 44 9 10 197 -11 - 50 36 39 - 49 45 40 - 57 8 56 ... .. .. - 51 38 1 52 0 0 5 44 15 11 195 -13 - 52 3 48 - 51 12 27 - 58 40 50 - 45 29 26 - 53 9 13 51 0 0 5 44 22 12 194 -14 - 53 35 18 - 52 43 23 - 60 19 5 - 46 57 57 - 54 45 7 50 0 0 5 44 30 14 193 -16 - 55 11 36 - 54 18 54 - 62 4 34 - 48 29 46 - 56 26 16 49 0 0 5 44 39 15 191 -17 - 56 53 18 - 55 59 32 - 63 58 28 - 50 5 16 - 58 13 24 48 0 0 5 44 49 16 190 -18 - 58 41 9 - 57 45 59 - 66 2 30 - 51 44 52 - 60 7 26 47 0 0 5 45 0 17 188 -20 - 60 36 8 - 59 39 8 - 68 19 6 - 53 29 5 - 62 9 39 46 0 0 5 45 13 18 186 -21 - 62 39 33 - 61 40 10 - 70 52 5 - 55 18 33 Latitude Latitude Latitude Latitude - 64 0 0 45 9 31 5 45 25 19 185 -23 45 23 17 44 55 55 48 59 14 41 55 44 - 65 0 0 44 43 32 5 45 32 20 184 -23 44 57 7 44 30 6 48 29 33 41 31 57 - 66 0 0 44 18 32 5 45 39 20 183 -24 44 31 57 44 5 16 48 1 9 41 9 2 - 67 0 0 43 54 32 5 45 46 21 182 -25 44 7 47 43 41 25 47 33 59 40 47 0 - 68 0 0 43 31 31 5 45 53 21 181 -25 43 44 37 43 18 33 47 8 1 40 25 49 - 69 0 0 43 9 29 5 46 0 21 180 -26 43 22 26 42 56 39 46 43 14 40 5 31 - 70 0 0 42 48 24 5 46 7 22 179 -26 43 1 14 42 35 42 46 19 36 39 46 4 - 71 0 0 42 28 17 5 46 14 22 178 -27 42 41 0 42 15 42 45 57 6 39 27 29 - 72 0 0 42 9 7 5 46 22 22 177 -27 42 21 43 41 56 39 45 35 43 39 9 45 - 73 0 0 41 50 54 5 46 29 23 176 -28 42 3 23 41 38 32 45 15 26 38 52 52 - 74 0 0 41 33 37 5 46 37 23 175 -28 41 46 0 41 21 20 44 56 14 38 36 51 - 75 0 0 41 17 16 5 46 44 23 174 -29 41 29 33 41 5 5 44 38 7 38 21 40 - 76 0 0 41 1 50 5 46 52 23 173 -29 41 14 2 40 49 44 44 21 3 38 7 20 - 77 0 0 40 47 19 5 46 59 23 172 -30 40 59 27 40 35 18 44 5 1 37 53 50 - 78 0 0 40 33 44 5 47 7 23 171 -30 40 45 47 40 21 47 43 50 2 37 41 11 - 79 0 0 40 21 3 5 47 15 24 170 -30 40 33 2 40 9 11 43 36 5 37 29 22 - 80 0 0 40 9 17 5 47 22 24 169 -31 40 21 12 39 57 28 43 23 9 37 18 24 - 81 0 0 39 58 25 5 47 30 24 168 -31 40 10 17 39 46 40 43 11 13 37 8 16 - 82 0 0 39 48 28 5 47 38 24 167 -31 40 0 16 39 36 45 43 0 18 36 58 58 - 83 0 0 39 39 24 5 47 45 24 167 -31 39 51 10 39 27 44 42 50 22 36 50 29 - 84 0 0 39 31 14 5 47 53 24 166 -32 39 42 57 39 19 37 42 41 27 36 42 51 - 85 0 0 39 23 58 5 48 0 24 165 -32 39 35 39 39 12 23 42 33 30 36 36 3 - 86 0 0 39 17 36 5 48 8 23 164 -32 39 29 15 39 6 2 42 26 33 36 30 5 - 87 0 0 39 12 7 5 48 15 23 163 -32 39 23 45 39 0 35 42 20 35 36 24 56 - 88 0 0 39 7 32 5 48 23 23 162 -32 39 19 8 38 56 1 42 15 35 36 20 38 - 89 0 0 39 3 50 5 48 30 23 161 -32 39 15 25 38 52 20 42 11 35 36 17 9 - 90 0 0 39 1 2 5 48 37 23 160 -32 39 12 36 38 49 32 42 8 33 36 14 30 - 91 0 0 38 59 7 5 48 45 22 159 -32 39 10 41 38 47 38 42 6 29 36 12 41 - 92 0 0 38 58 5 5 48 52 22 158 -32 39 9 39 38 46 37 42 5 25 36 11 42 - 93 0 0 38 57 57 5 48 59 22 157 -32 39 9 31 38 46 29 42 5 18 36 11 32 - 94 0 0 38 58 43 5 49 6 22 156 -32 39 10 17 38 47 14 42 6 11 36 12 13 - 95 0 0 39 0 22 5 49 13 21 156 -32 39 11 57 38 48 53 42 8 2 36 13 44 - 96 0 0 39 2 55 5 49 20 21 155 -32 39 14 31 38 51 25 42 10 53 36 16 5 - 97 0 0 39 6 22 5 49 26 21 154 -31 39 17 59 38 54 51 42 14 42 36 19 16 - 98 0 0 39 10 43 5 49 33 20 153 -31 39 22 22 38 59 10 42 19 31 36 23 18 - 99 0 0 39 15 58 5 49 39 20 152 -31 39 27 39 39 4 23 42 25 19 36 28 10 -100 0 0 39 22 8 5 49 46 19 151 -31 39 33 50 39 10 31 42 32 7 36 33 52 -101 0 0 39 29 11 5 49 52 19 150 -31 39 40 56 39 17 32 42 39 55 36 40 25 -102 0 0 39 37 10 5 49 58 18 150 -30 39 48 58 39 25 28 42 48 43 36 47 49 -103 0 0 39 46 3 5 50 4 18 149 -30 39 57 54 39 34 18 42 58 33 36 56 4 -104 0 0 39 55 52 5 50 9 17 148 -29 40 7 46 39 44 4 43 9 24 37 5 10 -105 0 0 40 6 36 5 50 15 17 147 -29 40 18 34 39 54 44 43 21 16 37 15 7 -106 0 0 40 18 16 5 50 21 16 146 -29 40 30 18 40 6 20 43 34 11 37 25 55 -107 0 0 40 30 52 5 50 26 16 146 -28 40 42 58 40 18 52 43 48 9 37 37 36 -108 0 0 40 44 25 5 50 31 15 145 -28 40 56 35 40 32 20 44 3 11 37 50 8 -109 0 0 40 58 54 5 50 36 14 144 -27 41 11 10 40 46 44 44 19 17 38 3 32 -110 0 0 41 14 20 5 50 40 14 143 -27 41 26 42 41 2 5 44 36 28 38 17 49 -111 0 0 41 30 44 5 50 45 13 143 -26 41 43 12 41 18 23 44 54 45 38 32 58 -112 0 0 41 48 6 5 50 49 12 142 -26 42 0 40 41 35 39 45 14 8 38 49 0 -113 0 0 42 6 27 5 50 53 12 141 -25 42 19 7 41 53 53 45 34 40 39 5 55 -114 0 0 42 25 46 5 50 57 11 140 -24 42 38 34 42 13 5 45 56 21 39 23 43 -115 0 0 42 46 5 5 51 1 10 140 -24 42 59 1 42 33 17 46 19 11 39 42 25 -116 0 0 43 7 25 5 51 4 9 139 -23 43 20 29 42 54 28 46 43 13 40 2 0 -117 0 0 43 29 45 5 51 7 9 138 -22 43 42 58 43 16 39 47 8 28 40 22 30 -118 0 0 43 53 6 5 51 10 8 138 -22 44 6 29 43 39 52 47 34 58 40 43 54 -119 0 0 44 17 30 5 51 13 7 137 -21 44 31 2 44 4 5 48 2 44 .. .. .. -120 0 0 44 42 56 5 51 15 6 136 -20 44 56 40 44 29 21 48 31 48 .. .. .. -121 0 0 45 9 26 5 51 18 6 135 -20 45 23 21 44 55 40 49 2 13 .. .. .. -122 0 0 45 37 0 5 51 19 5 135 -19 45 51 8 45 23 2 49 34 1 .. .. .. -123 0 0 46 5 40 5 51 21 4 134 -18 46 20 1 45 51 29 50 7 15 .. .. .. -124 0 0 46 35 26 5 51 22 3 133 -17 46 50 1 46 21 1 50 41 57 .. .. .. -125 0 0 47 6 19 5 51 23 2 132 -16 47 21 10 46 51 40 .. .. .. .. .. .. -126 0 0 47 38 21 5 51 24 1 132 -16 47 53 28 47 23 26 .. .. .. .. .. .. -127 0 0 48 11 33 5 51 24 1 131 -15 48 26 57 47 56 21 .. .. .. .. .. .. Uncertainty in time = +/- 19 secs [Prediction of 2008 May 8.0] Data for the target star ------------------------ * name: TYC 6800-01653-1 * constellation : Scorpius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 16 43 19.2471 DE: -25 36 22.477 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .026, .024 ) * V mag [mag]: 10.2 * B mag [mag]: 11.8 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (2355) Nei Monggol approx. diameter [km]: 17 approx. diameter ["]: .012 distance from Earth [AU]: 1.97600 * orbital information: orbit source: Preston date of fit: 2008 May 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 635 number of rejected observations: 8 time covered by the observations: 1973 Dec 21 - 2008 Apr 16 1 sigma uncertainty ellipse (major, minor, PA): 0.145, 0.058, 107° remarks: * orbital elements for (2355) Nei Monggol : Mean anomaly = 287.31126005 deg Arg. of pericenter = 279.03750441 deg Long. of node = 53.99680653 deg Inclination = 10.00793023 deg Eccentricity = 0.11918073 Semimajor axis = 3.01863667 AU Perihelion dist = 2.65887335 AU Mag: H = 11.48, G = 0.15 Epoch of elements : MJD 54601.24100000 TDT (2008 May 15.241) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 15 2355 Nei Monggol 5h 47.6m UT 10.2 16 43 19.247-25 36 22.48TYC 6800-01653-1 11.8 15.7 17 1.5 1.976 -2.036 -5.06 -69.3988 -25.604 92.20 18.96 5.7931 -0.16532 0.89944 -6.18460 -1.13791 -0.00167 0.00053 2000 287.0780432008 514.00000279.037504 53.996807 10.0079300.11918073 3.0186367 2.658873311.4 5.00.15 RATE 1.8792640 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.147 0.063 106 8.12 0.084 0 54594.5020080515_1653-1 ------ 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