IOTA/IOTA-ES occultation update for (590) Tomyris / TYC 6389-00407-1 event on 2012 Dec 17, 00:22 UT Visible from Caribbean, Central America Summary ------- On 2012 Dec 17 UT, the 37 km diameter asteroid (590) Tomyris will occult a 9.7 mag star in the constellation Aquarius for observers along a path across Caribbean, Central America. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.0 mag to 15.7 mag (the magnitude of the asteroid) for at most 1.4 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: 33 * date and approx. time of event: 2012 Dec 17, 00:23 - 2012 Dec 17, 00:25 UT * geocentric midpoint of event [JD]: 2456278.515325 * magnitude of target star: 9.7 * magnitude drop [mag]: 6.0 * estimated maximum duration [s]: 1.4 * Moon: 18 % sunlit, 24° distance * Sun: 69° distance * rough path description: Caribbean, Central America The occultation path -------------------- * approximate projected width [km]: 38 * 1 sigma uncertainty interval [path widths]: +/- 2.03 * 1 sigma uncertainty interval [seconds]: +/- 2.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .031 +/- .033) * 1 sigma uncertainty ellipse (major, minor, PA): ( .033", .031", 358° ) * approx speed of asteroid's shadow [km/s]: 26.9316 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6389-00407-1 by 590 Tomyris on 2012 Dec 17 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 - 97 0 0 3 13 11 0 23 38 63 213 -1 3 1 2 3 25 21 2 11 47 4 14 51 - 96 0 0 3 51 53 0 23 43 62 214 -2 3 39 43 4 4 5 2 50 22 4 53 41 - 95 0 0 4 30 49 0 23 47 61 215 -4 4 18 37 4 43 2 3 29 11 5 32 44 - 94 0 0 5 9 58 0 23 52 60 216 -5 4 57 45 5 22 12 4 8 13 6 11 59 - 93 0 0 5 49 19 0 23 56 59 217 -6 5 37 4 6 1 34 4 47 28 6 51 26 - 92 0 0 6 28 49 0 24 0 58 218 -7 6 16 33 6 41 5 5 26 52 7 31 2 - 91 0 0 7 8 28 0 24 5 57 219 -8 6 56 11 7 20 45 6 6 26 8 10 46 - 90 0 0 7 48 14 0 24 9 56 219 -9 7 35 56 8 0 33 6 46 8 8 50 37 - 89 0 0 8 28 6 0 24 13 54 220 -11 8 15 48 8 40 25 7 25 55 9 30 33 - 88 0 0 9 8 3 0 24 17 53 221 -12 8 55 43 9 20 23 8 5 48 10 10 33 - 87 0 0 9 48 2 0 24 21 52 221 -13 9 35 42 10 0 22 8 45 44 10 50 36 - 86 0 0 10 28 3 0 24 25 51 222 -14 10 15 42 10 40 24 9 25 43 11 30 39 - 85 0 0 11 8 3 0 24 29 50 222 -15 10 55 43 11 20 25 10 5 41 12 10 42 - 84 0 0 11 48 3 0 24 33 49 223 -17 11 35 42 12 0 24 10 45 39 12 50 43 - 83 0 0 12 27 59 0 24 37 47 223 -18 12 15 38 12 40 21 11 25 34 13 30 40 - 82 0 0 13 7 51 0 24 40 46 224 -19 12 55 30 13 20 13 12 5 26 14 10 32 - 81 0 0 13 47 37 0 24 44 45 224 -20 13 35 16 13 59 59 12 45 12 14 50 18 - 80 0 0 14 27 16 0 24 47 44 225 -21 14 14 55 14 39 38 13 24 52 15 29 57 - 79 0 0 15 6 47 0 24 51 43 225 -22 14 54 26 15 19 8 14 4 24 16 9 26 - 78 0 0 15 46 7 0 24 54 42 226 -23 15 33 47 15 58 29 14 43 46 16 48 45 - 77 0 0 16 25 17 0 24 57 41 226 -25 16 12 57 16 37 38 15 22 58 17 27 52 - 76 0 0 17 4 13 0 25 0 39 227 -26 16 51 54 17 16 34 16 1 57 18 6 46 - 75 0 0 17 42 56 0 25 4 38 227 -27 17 30 37 17 55 16 16 40 43 18 45 25 - 74 0 0 18 21 24 0 25 7 37 228 -28 18 9 6 18 33 43 17 19 15 19 23 49 - 73 0 0 18 59 36 0 25 9 36 228 -29 18 47 18 19 11 54 17 57 31 20 1 56 - 72 0 0 19 37 30 0 25 12 35 228 -30 19 25 13 19 49 47 18 35 30 20 39 45 - 71 0 0 20 15 5 0 25 15 34 229 -31 20 2 50 20 27 21 19 13 11 21 17 15 - 70 0 0 20 52 21 0 25 17 33 229 -32 20 40 7 21 4 36 19 50 32 21 54 25 - 69 0 0 21 29 16 0 25 20 31 230 -33 21 17 3 21 41 30 20 27 34 22 31 14 - 68 0 0 22 5 50 0 25 22 30 230 -34 21 53 38 22 18 2 21 4 14 23 7 41 - 67 0 0 22 42 0 0 25 25 29 231 -35 22 29 50 22 54 11 21 40 32 23 43 45 - 66 0 0 23 17 48 0 25 27 28 231 -36 23 5 39 23 29 57 22 16 26 24 19 25 - 65 0 0 23 53 11 0 25 29 27 232 -38 23 41 4 24 5 19 22 51 57 24 54 40 - 64 0 0 24 28 9 0 25 31 26 232 -39 24 16 3 24 40 15 23 27 3 25 29 29 - 63 0 0 25 2 41 0 25 33 25 233 -40 24 50 37 25 14 45 24 1 44 26 3 53 - 62 0 0 25 36 46 0 25 35 24 233 -41 25 24 44 25 48 49 24 35 58 26 37 49 - 61 0 0 26 10 24 0 25 37 23 234 -42 25 58 24 26 22 25 25 9 45 27 11 18 - 60 0 0 26 43 34 0 25 38 22 234 -42 26 31 36 26 55 33 25 43 5 27 44 19 - 59 0 0 27 16 16 0 25 40 21 235 -43 27 4 20 27 28 13 26 15 56 28 16 51 - 58 0 0 27 48 29 0 25 42 20 235 -44 27 36 35 28 0 24 26 48 19 28 48 53 - 57 0 0 28 20 13 0 25 43 19 236 -45 28 8 20 28 32 6 27 20 13 29 20 27 - 56 0 0 28 51 26 0 25 44 18 236 -46 28 39 36 29 3 17 27 51 37 29 51 30 - 55 0 0 29 22 10 0 25 46 17 237 -47 29 10 22 29 33 59 28 22 31 30 22 3 - 54 0 0 29 52 23 0 25 47 16 237 -48 29 40 37 30 4 10 28 52 55 30 52 5 - 53 0 0 30 22 5 0 25 48 15 238 -49 30 10 21 30 33 50 29 22 48 31 21 36 - 52 0 0 30 51 16 0 25 49 14 238 -50 30 39 35 31 2 59 29 52 10 31 50 36 - 51 0 0 31 19 56 0 25 50 13 239 -51 31 8 17 31 31 36 30 21 1 32 19 5 - 50 0 0 31 48 5 0 25 51 12 239 -52 31 36 27 31 59 42 30 49 21 32 47 2 - 49 0 0 32 15 41 0 25 51 11 240 -52 32 4 6 32 27 17 31 17 9 33 14 27 - 48 0 0 32 42 46 0 25 52 10 240 -53 32 31 13 32 54 19 31 44 25 33 41 20 - 47 0 0 33 9 19 0 25 53 9 241 -54 32 57 48 33 20 50 32 11 9 34 7 42 - 46 0 0 33 35 20 0 25 53 8 241 -55 33 23 52 33 46 49 32 37 22 34 33 31 - 45 0 0 34 0 49 0 25 54 7 242 -56 33 49 23 34 12 16 33 3 3 34 58 49 - 44 0 0 34 25 46 0 25 54 6 242 -56 34 14 23 34 37 11 33 28 11 35 23 34 - 43 0 0 34 50 12 0 25 55 5 243 -57 34 38 50 35 1 34 33 52 48 35 47 48 - 42 0 0 35 14 5 0 25 55 4 244 -58 35 2 45 35 25 25 34 16 52 36 11 30 - 41 0 0 35 37 26 0 25 55 3 244 -58 35 26 9 35 48 44 34 40 25 36 34 39 - 40 0 0 36 0 16 0 25 55 2 245 -59 35 49 1 36 11 31 35 3 26 36 57 18 - 39 0 0 36 22 34 0 25 55 1 245 -60 36 11 21 36 33 47 35 25 55 37 19 24 - 38 0 0 36 44 20 0 25 55 1 246 -60 36 33 10 36 55 31 35 47 53 37 40 59 Uncertainty in time = +/- 3 secs Prediction of 2012 Dec 3.0 Data for the target star ------------------------ * name: TYC 6389-00407-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 22 38 46.0972 DE: -18 53 10.893 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .025, .030 ) * V mag [mag]: 9.7 * B mag [mag]: 10.6 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (590) Tomyris approx. diameter [km]: 37 approx. diameter ["]: .016 distance from Earth [AU]: 3.20500 * orbital information: orbit source: Preston date of fit: 2012 Oct 26 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 839 number of rejected observations: 44 time covered by the observations: 1906 Mar 05 - 2012 Oct 09 1 sigma uncertainty ellipse (major, minor, PA): 0.019, 0.012, 76° remarks: * orbital elements for (590) Tomyris : Mean anomaly = 274.14535022 deg Arg. of pericenter = 341.37628104 deg Long. of node = 106.20205487 deg Inclination = 11.18055601 deg Eccentricity = 0.07900019 Semimajor axis = 2.99789968 AU Perihelion dist = 2.76106503 AU Mag: H = 9.93, G = 0.15 Epoch of elements : MJD 56278.01500000 TDT (2012 Dec 17.015) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Dec 17 590 Tomyris 0h 22.1m UT 9.7 22 38 46.097-18 53 10.89TYC 6389-00407-1 10.6 15.7 37 1.4 3.205 2.607 19.28 -111.8656 -18.892 173.51 -23.36 0.3678 -0.09279 0.18005 13.48064 7.02430 0.00533 0.00178 2000 272.623465201212 9.00000341.376281106.202055 11.1805560.07900019 2.9978997 2.7610650 9.9 5.00.15 RATE 1.8987960 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.033 0.031 358 3.03 0.032 0 0 2-3 056264.0020121217_0407-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 25, 23:41 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org