IOTA/IOTA-ES occultation update for (244) Sita / TYC 5790-00369-1 event on 2012 Sep 18, 16:09 UT Visible from Russia, SW Asia, Arabia Summary ------- On 2012 Sep 18 UT, the 12 km diameter asteroid (244) Sita will occult a 10.2 mag star in the constellation Capricornus for observers along a path across Russia, SW Asia, Arabia. In the case of an occultation, the combined light of the asteroid and the star will drop by 4.3 mag to 14.5 mag (the magnitude of the asteroid) for at most 3.3 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: 29 * date and approx. time of event: 2012 Sep 18, 15:52 - 2012 Sep 18, 16:18 UT * geocentric midpoint of event [JD]: 2456189.17313333 * magnitude of target star: 10.2 * magnitude drop [mag]: 4.3 * estimated maximum duration [s]: 3.3 * Moon: 9 % sunlit, 111° distance * Sun: 146° distance * rough path description: Russia, SW Asia, Arabia The occultation path -------------------- * approximate projected width [km]: 21 * 1 sigma uncertainty interval [path widths]: +/- 2.30 * 1 sigma uncertainty interval [seconds]: +/- 8.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .044 +/- .035) * 1 sigma uncertainty ellipse (major, minor, PA): ( .044", .034", 77° ) * approx speed of asteroid's shadow [km/s]: 3.4825 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5790-00369-1 by 244 Sita on 2012 Sep 18 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 47 41 13 76 0 0 15 52 26 1 141 -3 47 10 7 48 11 59 44 42 30 ... .. .. 50 30 51 75 0 0 15 52 28 2 144 -4 50 3 22 50 58 7 47 53 45 53 0 44 52 45 37 74 0 0 15 52 31 3 146 -5 52 20 49 53 10 14 50 24 24 55 1 24 54 34 14 73 0 0 15 52 35 4 148 -5 54 11 32 54 56 47 52 25 19 56 38 52 56 2 30 72 0 0 15 52 40 5 149 -6 55 41 31 56 23 23 54 3 29 57 58 4 57 14 31 71 0 0 15 52 47 6 150 -7 56 54 56 57 34 0 55 23 38 59 2 31 58 13 14 70 0 0 15 52 54 8 151 -8 57 54 50 58 31 32 56 29 12 59 54 49 59 0 53 69 0 0 15 53 2 9 152 -9 58 43 30 59 18 11 57 22 42 60 36 57 59 39 11 68 0 0 15 53 11 10 153 -9 59 22 41 59 55 37 58 6 3 61 10 27 60 9 29 67 0 0 15 53 22 11 153 -10 59 53 46 60 25 8 58 40 47 61 36 32 60 32 51 66 0 0 15 53 33 12 153 -11 60 17 49 60 47 50 59 8 2 61 56 10 60 50 9 65 0 0 15 53 45 12 154 -11 60 35 43 61 4 32 59 28 48 62 10 9 61 2 6 64 0 0 15 53 57 13 154 -12 60 48 13 61 15 56 59 43 51 62 19 7 61 9 17 63 0 0 15 54 11 14 154 -12 60 55 53 61 22 38 59 53 48 62 23 38 61 12 11 62 0 0 15 54 26 15 154 -13 60 59 14 61 25 6 59 59 13 62 24 6 61 11 13 61 0 0 15 54 41 16 154 -13 60 58 40 61 23 44 60 0 31 62 20 57 61 6 44 60 0 0 15 54 58 17 154 -14 60 54 33 61 18 53 59 58 5 62 14 27 60 59 1 59 0 0 15 55 15 18 153 -14 60 47 9 61 10 51 59 52 14 62 4 55 60 48 19 58 0 0 15 55 33 19 153 -15 60 36 45 60 59 51 59 43 15 61 52 33 60 34 51 57 0 0 15 55 52 20 153 -15 60 23 34 60 46 6 59 31 20 61 37 34 60 18 48 56 0 0 15 56 12 21 153 -15 60 7 46 60 29 48 59 16 43 61 20 7 60 0 20 55 0 0 15 56 32 21 152 -16 59 49 32 60 11 6 58 59 33 61 0 22 59 39 34 54 0 0 15 56 54 22 152 -16 59 28 59 59 50 8 58 40 0 60 38 26 59 16 38 53 0 0 15 57 16 23 151 -16 59 6 15 59 27 0 58 18 9 60 14 25 58 51 38 52 0 0 15 57 39 24 151 -17 58 41 25 59 1 49 57 54 9 59 48 26 58 24 38 51 0 0 15 58 3 25 150 -17 58 14 35 58 34 39 57 28 3 59 20 32 57 55 43 50 0 0 15 58 28 25 149 -17 57 45 48 58 5 36 56 59 58 58 50 48 57 24 56 49 0 0 15 58 54 26 149 -17 57 15 10 57 34 41 56 29 57 58 19 16 56 52 21 48 0 0 15 59 20 27 148 -17 56 42 42 57 1 58 55 58 3 57 46 0 56 17 59 47 0 0 15 59 47 27 147 -17 56 8 27 56 27 30 55 24 18 57 11 2 55 41 53 46 0 0 16 0 15 28 147 -17 55 32 26 55 51 18 54 48 45 56 34 24 55 4 4 45 0 0 16 0 44 29 146 -17 54 54 42 55 13 24 54 11 24 55 56 5 54 24 32 44 0 0 16 1 14 29 145 -17 54 15 15 54 33 48 53 32 18 55 16 8 53 43 18 43 0 0 16 1 44 30 144 -17 53 34 5 53 52 30 52 51 26 54 34 33 53 0 22 42 0 0 16 2 16 30 143 -17 52 51 13 53 9 31 52 8 48 53 51 19 52 15 44 41 0 0 16 2 48 31 142 -17 52 6 37 52 24 50 51 24 24 53 6 25 51 29 22 40 0 0 16 3 21 31 141 -17 51 20 17 51 38 25 50 38 13 52 19 51 50 41 14 39 0 0 16 3 54 32 140 -17 50 32 10 50 50 16 49 50 13 51 31 36 49 51 19 38 0 0 16 4 29 32 139 -17 49 42 16 50 0 21 49 0 22 50 41 36 48 59 35 37 0 0 16 5 4 33 138 -16 48 50 32 49 8 36 48 8 37 49 49 51 48 5 57 36 0 0 16 5 40 33 137 -16 47 56 54 48 14 59 47 14 56 48 56 16 47 10 23 35 0 0 16 6 17 33 135 -16 47 1 18 47 19 27 46 19 14 48 0 49 46 12 48 34 0 0 16 6 55 33 134 -15 46 3 41 46 21 54 45 21 26 47 3 25 45 13 7 33 0 0 16 7 33 34 133 -15 45 3 58 45 22 16 44 21 29 46 3 59 44 11 14 32 0 0 16 8 13 34 132 -14 44 2 1 44 20 26 43 19 14 45 2 26 43 7 2 31 0 0 16 8 53 34 130 -14 42 57 44 43 16 19 42 14 34 43 58 38 42 0 23 30 0 0 16 9 34 34 129 -13 41 50 59 42 9 45 41 7 22 42 52 30 40 51 7 29 0 0 16 10 16 34 128 -12 40 41 36 41 0 36 39 57 26 41 43 51 39 39 4 28 0 0 16 10 58 34 126 -12 39 29 24 39 48 41 38 44 34 40 32 31 38 23 59 27 0 0 16 11 42 34 125 -11 38 14 10 38 33 45 37 28 33 39 18 18 37 5 37 26 0 0 16 12 27 33 123 -10 36 55 37 37 15 35 36 9 4 38 0 57 35 43 40 25 0 0 16 13 12 33 122 -9 35 33 26 35 53 51 34 45 48 36 40 12 34 17 45 24 0 0 16 13 59 32 121 -8 34 7 15 34 28 12 33 18 20 35 15 42 32 47 23 23 0 0 16 14 46 32 119 -7 32 36 34 32 58 9 31 46 7 33 47 1 31 12 1 22 0 0 16 15 35 31 118 -6 31 0 49 31 23 9 30 8 31 32 13 39 29 30 53 21 0 0 16 16 25 30 116 -4 29 19 13 29 42 28 28 24 41 30 34 56 27 43 2 20 0 0 16 17 16 30 115 -3 27 30 48 27 55 10 26 33 29 28 50 3 25 47 10 19 0 0 16 18 9 29 113 -1 25 34 14 26 0 0 24 33 24 26 57 52 Uncertainty in time = +/- 9 secs Prediction of 2012 Aug 26.0 Data for the target star ------------------------ * name: TYC 5790-00369-1 * constellation : Capricornus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 21 32 23.4071 DE: -10 11 48.036 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .024, .024 ) * V mag [mag]: 10.2 * B mag [mag]: 11.6 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (244) Sita approx. diameter [km]: 12 approx. diameter ["]: .016 distance from Earth [AU]: 1.00500 * orbital information: orbit source: Preston date of fit: 2012 Aug 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1311 number of rejected observations: 62 time covered by the observations: 1900 Sep 29 - 2012 Aug 06 1 sigma uncertainty ellipse (major, minor, PA): 0.037, 0.025, 71° remarks: * orbital elements for (244) Sita : Mean anomaly = 332.27910923 deg Arg. of pericenter = 166.27208959 deg Long. of node = 209.03227825 deg Inclination = 2.84440241 deg Eccentricity = 0.13696891 Semimajor axis = 2.17429263 AU Perihelion dist = 1.87648215 AU Mag: H = 12.00, G = 0.15 Epoch of elements : MJD 56188.67300000 TDT (2012 Sep 18.673) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 18 244 Sita 16h 9.3m UT 10.2 21 32 23.407-10 11 48.04TYC 5790-00369-1 11.6 14.5 12 3.3 1.005 -0.855 -11.64 82.7878 -10.192 -63.84 1.53 16.1552 -0.56143 0.61017 -1.44616 -1.33130 0.00283 0.00063 2000 329.6128862012 910.00000166.272090209.032278 2.8444020.13696891 2.1742926 1.876482112.2 5.00.15 RATE 3.0741650 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.044 0.034 77 3.30 0.038 0 0 1 4 056165.0020120918_0369-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 25, 22:58 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org