IOTA/IOTA-ES occultation update for (1070) Tunica / TYC 5730-01183-1 event on 2012 Oct 28, 00:58 UT Visible from Brazil, Bolivia, Peru Summary ------- On 2012 Oct 28 UT, the 39 km diameter asteroid (1070) Tunica will occult a 10.1 mag star in the constellation Sagittarius for observers along a path across Brazil, Bolivia, Peru. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.4 mag to 16.5 mag (the magnitude of the asteroid) for at most 1.6 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, TMO astrometry for the asteroid kindly provided by Bill Owen, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 41 * date and approx. time of event: 2012 Oct 28, 00:59 - 2012 Oct 28, 01:02 UT * geocentric midpoint of event [JD]: 2456228.540675 * magnitude of target star: 10.1 * magnitude drop [mag]: 6.4 * estimated maximum duration [s]: 1.6 * Moon: 97 % sunlit, 84° distance * Sun: 76° distance * rough path description: Brazil, Bolivia, Peru The occultation path -------------------- * approximate projected width [km]: 39 * 1 sigma uncertainty interval [path widths]: +/- 1.62 * 1 sigma uncertainty interval [seconds]: +/- 2.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .031 +/- .027) * 1 sigma uncertainty ellipse (major, minor, PA): ( .031", .027", 92° ) * approx speed of asteroid's shadow [km/s]: 25.0939 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5730-01183-1 by 1070 Tunica on 2012 Oct 28 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 -104 0 0 -16 50 13 0 59 44 73 284 -1 -17 0 53 -16 39 34 -17 35 26 -16 5 2 -103 0 0 -16 57 9 0 59 48 73 284 -2 -17 7 48 -16 46 30 -17 42 20 -16 11 59 -102 0 0 -17 3 48 0 59 53 72 283 -3 -17 14 27 -16 53 9 -17 48 57 -16 18 40 -101 0 0 -17 10 11 0 59 57 71 282 -4 -17 20 49 -16 59 32 -17 55 19 -16 25 4 -100 0 0 -17 16 17 1 0 1 70 282 -5 -17 26 55 -17 5 39 -18 1 24 -16 31 12 - 99 0 0 -17 22 7 1 0 5 69 281 -5 -17 32 45 -17 11 29 -18 7 12 -16 37 3 - 98 0 0 -17 27 40 1 0 9 68 281 -6 -17 38 18 -17 17 3 -18 12 44 -16 42 37 - 97 0 0 -17 32 57 1 0 13 67 280 -7 -17 43 34 -17 22 19 -18 17 59 -16 47 55 - 96 0 0 -17 37 56 1 0 17 66 280 -8 -17 48 33 -17 27 19 -18 22 58 -16 52 56 - 95 0 0 -17 42 39 1 0 21 65 279 -9 -17 53 16 -17 32 3 -18 27 40 -16 57 40 - 94 0 0 -17 47 6 1 0 25 64 279 -10 -17 57 42 -17 36 29 -18 32 5 -17 2 7 - 93 0 0 -17 51 15 1 0 28 63 278 -11 -18 1 52 -17 40 39 -18 36 14 -17 6 18 - 92 0 0 -17 55 8 1 0 32 62 278 -12 -18 5 44 -17 44 32 -18 40 6 -17 10 11 - 91 0 0 -17 58 43 1 0 36 61 277 -13 -18 9 19 -17 48 8 -18 43 40 -17 13 48 - 90 0 0 -18 2 2 1 0 40 60 277 -14 -18 12 38 -17 51 26 -18 46 58 -17 17 7 - 89 0 0 -18 5 4 1 0 43 59 276 -14 -18 15 40 -17 54 28 -18 49 59 -17 20 10 - 88 0 0 -18 7 49 1 0 47 58 276 -15 -18 18 24 -17 57 13 -18 52 44 -17 22 55 - 87 0 0 -18 10 17 1 0 51 57 276 -16 -18 20 52 -17 59 41 -18 55 11 -17 25 24 - 86 0 0 -18 12 27 1 0 54 56 275 -17 -18 23 3 -18 1 52 -18 57 21 -17 27 35 - 85 0 0 -18 14 21 1 0 58 55 275 -18 -18 24 56 -18 3 46 -18 59 14 -17 29 29 - 84 0 0 -18 15 58 1 1 1 54 274 -19 -18 26 33 -18 5 23 -19 0 51 -17 31 6 - 83 0 0 -18 17 18 1 1 5 53 274 -20 -18 27 52 -18 6 43 -19 2 10 -17 32 26 - 82 0 0 -18 18 20 1 1 8 52 274 -21 -18 28 55 -18 7 45 -19 3 13 -17 33 29 - 81 0 0 -18 19 6 1 1 12 51 273 -22 -18 29 41 -18 8 31 -19 3 58 -17 34 15 - 80 0 0 -18 19 34 1 1 15 50 273 -22 -18 30 9 -18 9 0 -19 4 26 -17 34 43 - 79 0 0 -18 19 46 1 1 18 49 273 -23 -18 30 21 -18 9 11 -19 4 38 -17 34 55 - 78 0 0 -18 19 40 1 1 21 48 272 -24 -18 30 15 -18 9 6 -19 4 32 -17 34 49 - 77 0 0 -18 19 18 1 1 25 47 272 -25 -18 29 53 -18 8 43 -19 4 10 -17 34 27 - 76 0 0 -18 18 38 1 1 28 46 272 -26 -18 29 13 -18 8 3 -19 3 31 -17 33 47 - 75 0 0 -18 17 42 1 1 31 46 271 -27 -18 28 17 -18 7 7 -19 2 34 -17 32 50 - 74 0 0 -18 16 28 1 1 34 45 271 -28 -18 27 3 -18 5 53 -19 1 21 -17 31 37 - 73 0 0 -18 14 58 1 1 37 44 270 -29 -18 25 33 -18 4 23 -18 59 51 -17 30 6 - 72 0 0 -18 13 10 1 1 40 43 270 -29 -18 23 45 -18 2 35 -18 58 4 -17 28 18 - 71 0 0 -18 11 6 1 1 43 42 270 -30 -18 21 41 -18 0 31 -18 56 0 -17 26 13 - 70 0 0 -18 8 45 1 1 45 41 269 -31 -18 19 20 -17 58 10 -18 53 40 -17 23 51 - 69 0 0 -18 6 7 1 1 48 40 269 -32 -18 16 43 -17 55 31 -18 51 2 -17 21 13 - 68 0 0 -18 3 12 1 1 51 39 269 -33 -18 13 48 -17 52 37 -18 48 8 -17 18 17 - 67 0 0 -18 0 1 1 1 53 38 268 -34 -18 10 37 -17 49 25 -18 44 57 -17 15 5 - 66 0 0 -17 56 32 1 1 56 37 268 -35 -18 7 9 -17 45 56 -18 41 30 -17 11 36 - 65 0 0 -17 52 48 1 1 59 36 268 -35 -18 3 24 -17 42 11 -18 37 46 -17 7 50 - 64 0 0 -17 48 46 1 2 1 35 267 -36 -17 59 23 -17 38 10 -18 33 45 -17 3 48 - 63 0 0 -17 44 28 1 2 4 34 267 -37 -17 55 5 -17 33 51 -18 29 28 -16 59 29 - 62 0 0 -17 39 54 1 2 6 33 267 -38 -17 50 31 -17 29 17 -18 24 55 -16 54 53 - 61 0 0 -17 35 3 1 2 8 32 266 -39 -17 45 40 -17 24 25 -18 20 5 -16 50 1 - 60 0 0 -17 29 55 1 2 10 31 266 -40 -17 40 33 -17 19 18 -18 14 59 -16 44 53 - 59 0 0 -17 24 32 1 2 13 30 266 -41 -17 35 9 -17 13 54 -18 9 36 -16 39 28 - 58 0 0 -17 18 52 1 2 15 29 266 -41 -17 29 30 -17 8 14 -18 3 58 -16 33 47 - 57 0 0 -17 12 56 1 2 17 28 265 -42 -17 23 34 -17 2 17 -17 58 3 -16 27 49 - 56 0 0 -17 6 43 1 2 19 27 265 -43 -17 17 22 -16 56 5 -17 51 52 -16 21 36 - 55 0 0 -17 0 15 1 2 21 26 265 -44 -17 10 54 -16 49 36 -17 45 25 -16 15 6 - 54 0 0 -16 53 31 1 2 23 25 264 -45 -17 4 10 -16 42 52 -17 38 43 -16 8 21 - 53 0 0 -16 46 31 1 2 24 24 264 -46 -16 57 11 -16 35 51 -17 31 44 -16 1 19 - 52 0 0 -16 39 15 1 2 26 23 264 -46 -16 49 56 -16 28 35 -17 24 30 -15 54 2 - 51 0 0 -16 31 44 1 2 28 22 263 -47 -16 42 25 -16 21 4 -17 17 0 -15 46 29 - 50 0 0 -16 23 57 1 2 29 21 263 -48 -16 34 38 -16 13 17 -17 9 15 -15 38 41 - 49 0 0 -16 15 55 1 2 31 20 263 -49 -16 26 36 -16 5 14 -17 1 15 -15 30 37 - 48 0 0 -16 7 37 1 2 32 19 263 -50 -16 18 19 -15 56 56 -16 52 59 -15 22 18 - 47 0 0 -15 59 5 1 2 34 18 262 -50 -16 9 47 -15 48 23 -16 44 27 -15 13 43 - 46 0 0 -15 50 17 1 2 35 17 262 -51 -16 0 59 -15 39 34 -16 35 41 -15 4 53 - 45 0 0 -15 41 14 1 2 36 16 262 -52 -15 51 57 -15 30 31 -16 26 40 -14 55 49 - 44 0 0 -15 31 56 1 2 38 15 261 -53 -15 42 39 -15 21 13 -16 17 24 -14 46 29 - 43 0 0 -15 22 24 1 2 39 15 261 -53 -15 33 7 -15 11 40 -16 7 54 -14 36 55 - 42 0 0 -15 12 37 1 2 40 14 261 -54 -15 23 21 -15 1 53 -15 58 8 -14 27 6 - 41 0 0 -15 2 35 1 2 41 13 261 -55 -15 13 20 -14 51 51 -15 48 9 -14 17 3 - 40 0 0 -14 52 19 1 2 42 12 260 -56 -15 3 5 -14 41 35 -15 37 55 -14 6 45 - 39 0 0 -14 41 50 1 2 43 11 260 -56 -14 52 35 -14 31 4 -15 27 27 -13 56 14 - 38 0 0 -14 31 6 1 2 43 10 260 -57 -14 41 52 -14 20 20 -15 16 45 -13 45 28 - 37 0 0 -14 20 8 1 2 44 9 260 -58 -14 30 55 -14 9 22 -15 5 50 -13 34 28 - 36 0 0 -14 8 57 1 2 45 8 259 -58 -14 19 44 -13 58 10 -14 54 40 -13 23 15 - 35 0 0 -13 57 32 1 2 45 7 259 -59 -14 8 20 -13 46 45 -14 43 17 -13 11 49 - 34 0 0 -13 45 54 1 2 46 6 259 -60 -13 56 42 -13 35 7 -14 31 41 -13 0 9 - 33 0 0 -13 34 3 1 2 46 5 259 -60 -13 44 51 -13 23 15 -14 19 52 -12 48 16 - 32 0 0 -13 21 59 1 2 46 4 258 -61 -13 32 48 -13 11 11 -14 7 50 -12 36 10 - 31 0 0 -13 9 42 1 2 47 3 258 -61 -13 20 31 -12 58 53 -13 55 35 -12 23 51 - 30 0 0 -12 57 13 1 2 47 2 258 -62 -13 8 3 -12 46 24 -13 43 8 -12 11 20 - 29 0 0 -12 44 32 1 2 47 1 258 -63 -12 55 22 -12 33 42 -13 30 28 -11 58 36 Uncertainty in time = +/- 3 secs Prediction of 2012 Oct 8.0 Data for the target star ------------------------ * name: TYC 5730-01183-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 19 24 57.1791 DE: -12 06 02.575 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .024, .024 ) * V mag [mag]: 10.1 * B mag [mag]: 11.2 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1070) Tunica approx. diameter [km]: 39 approx. diameter ["]: .017 distance from Earth [AU]: 3.10600 * orbital information: orbit source: Preston date of fit: 2012 Oct 07 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 972 number of rejected observations: 37 time covered by the observations: 1903 Sep 29 - 2012 Sep 30 1 sigma uncertainty ellipse (major, minor, PA): 0.020, 0.014, 95° remarks: * orbital elements for (1070) Tunica : Mean anomaly = 323.83638632 deg Arg. of pericenter = 185.30839624 deg Long. of node = 165.42098965 deg Inclination = 16.96447034 deg Eccentricity = 0.07968786 Semimajor axis = 3.23112671 AU Perihelion dist = 2.97364514 AU Mag: H = 10.66, G = 0.15 Epoch of elements : MJD 56228.04100000 TDT (2012 Oct 28.041) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Oct 28 1070 Tunica 0h 58.6m UT 10.1 19 24 57.179-12 6 2.57TYC 5730-01183-1 11.2 16.5 39 1.6 3.106 2.688 -7.38 -120.1884 -12.099 161.31 -13.19 0.9762 -0.00199 -0.03849 13.92114 -2.60987 0.00559 0.00107 2000 322.47185620121020.00000185.308396165.420990 16.9644700.07968786 3.2311267 2.973645110.7 5.00.15 RATE 1.6969660 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.031 0.027 92 2.62 0.028 0 0 1-5 056208.0020121028_1183-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 07, 19:32 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org