IOTA/IOTA-ES occultation update for (343) Ostara / HIP 28238 event on 2012 Sep 19, 06:09 UT Visible from N Brazil Summary ------- On 2012 Sep 19 UT, the 22 km diameter asteroid (343) Ostara will occult a 7.9 mag star in the constellation Taurus for observers along a path across N Brazil. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.4 mag to 15.3 mag (the magnitude of the asteroid) for at most 1.1 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Hugh Harris, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: . The event at a glimpse ---------------------- * Rank: 52 * date and approx. time of event: 2012 Sep 19, 06:04 - 2012 Sep 19, 06:09 UT * geocentric midpoint of event [JD]: 2456189.75675 * magnitude of target star: 7.9 * magnitude drop [mag]: 7.4 * estimated maximum duration [s]: 1.1 * Moon: 13 % sunlit, 129° distance * Sun: 87° distance * rough path description: N Brazil Additional comments ------------------- close double star The occultation path -------------------- * approximate projected width [km]: 23 * 1 sigma uncertainty interval [path widths]: +/- 1.24 * 1 sigma uncertainty interval [seconds]: +/- 1.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .036 +/- .024) * 1 sigma uncertainty ellipse (major, minor, PA): ( .036", .023", 88° ) * approx speed of asteroid's shadow [km/s]: 21.1270 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 28238 by 343 Ostara on 2012 Sep 19 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 - 81 0 0 -17 2 10 6 4 51 1 64 -70 -17 9 0 -16 55 20 -17 25 58 -16 38 25 - 80 0 0 -16 34 5 6 4 51 2 64 -70 -16 40 55 -16 27 15 -16 57 53 -16 10 19 - 79 0 0 -16 5 54 6 4 51 3 63 -70 -16 12 44 -15 59 4 -16 29 43 -15 42 8 - 78 0 0 -15 37 38 6 4 52 4 63 -70 -15 44 28 -15 30 48 -16 1 27 -15 13 52 - 77 0 0 -15 9 18 6 4 52 5 63 -69 -15 16 9 -15 2 28 -15 33 7 -14 45 32 - 76 0 0 -14 40 55 6 4 53 6 63 -69 -14 47 45 -14 34 5 -15 4 44 -14 17 9 - 75 0 0 -14 12 29 6 4 53 7 62 -68 -14 19 20 -14 5 39 -14 36 18 -13 48 43 - 74 0 0 -13 44 2 6 4 54 8 62 -68 -13 50 52 -13 37 12 -14 7 50 -13 20 16 - 73 0 0 -13 15 33 6 4 55 10 62 -67 -13 22 23 -13 8 43 -13 39 21 -12 51 48 - 72 0 0 -12 47 4 6 4 56 11 62 -66 -12 53 54 -12 40 14 -13 10 51 -12 23 19 - 71 0 0 -12 18 35 6 4 57 12 61 -66 -12 25 25 -12 11 46 -12 42 22 -11 54 51 - 70 0 0 -11 50 8 6 4 59 13 61 -65 -11 56 58 -11 43 19 -12 13 54 -11 26 25 - 69 0 0 -11 21 43 6 5 0 14 61 -64 -11 28 32 -11 14 54 -11 45 28 -10 58 0 - 68 0 0 -10 53 20 6 5 1 15 61 -64 -11 0 9 -10 46 32 -11 17 5 -10 29 39 - 67 0 0 -10 25 2 6 5 3 16 60 -63 -10 31 50 -10 18 13 -10 48 45 -10 1 21 - 66 0 0 - 9 56 47 6 5 5 17 60 -62 -10 3 36 - 9 49 59 -10 20 30 - 9 33 7 - 65 0 0 - 9 28 38 6 5 7 18 60 -61 - 9 35 26 - 9 21 50 - 9 52 19 - 9 4 59 - 64 0 0 - 9 0 35 6 5 8 19 60 -60 - 9 7 22 - 8 53 47 - 9 24 14 - 8 36 57 - 63 0 0 - 8 32 38 6 5 11 20 60 -59 - 8 39 25 - 8 25 51 - 8 56 17 - 8 9 2 - 62 0 0 - 8 4 49 6 5 13 22 59 -59 - 8 11 36 - 7 58 2 - 8 28 26 - 7 41 14 - 61 0 0 - 7 37 8 6 5 15 23 59 -58 - 7 43 54 - 7 30 22 - 8 0 44 - 7 13 35 - 60 0 0 - 7 9 36 6 5 17 24 59 -57 - 7 16 22 - 7 2 50 - 7 33 10 - 6 46 5 - 59 0 0 - 6 42 14 6 5 20 25 59 -56 - 6 48 59 - 6 35 28 - 7 5 46 - 6 18 44 - 58 0 0 - 6 15 2 6 5 22 26 59 -55 - 6 21 47 - 6 8 17 - 6 38 33 - 5 51 34 - 57 0 0 - 5 48 1 6 5 25 27 59 -54 - 5 54 46 - 5 41 17 - 6 11 30 - 5 24 35 - 56 0 0 - 5 21 13 6 5 28 28 58 -53 - 5 27 57 - 5 14 29 - 5 44 40 - 4 57 49 - 55 0 0 - 4 54 37 6 5 31 29 58 -52 - 5 1 20 - 4 47 53 - 5 18 1 - 4 31 14 - 54 0 0 - 4 28 14 6 5 34 30 58 -51 - 4 34 56 - 4 21 31 - 4 51 36 - 4 4 53 - 53 0 0 - 4 2 5 6 5 37 31 58 -50 - 4 8 47 - 3 55 23 - 4 25 25 - 3 38 47 - 52 0 0 - 3 36 10 6 5 40 32 58 -49 - 3 42 52 - 3 29 29 - 3 59 29 - 3 12 54 - 51 0 0 - 3 10 31 6 5 43 33 58 -48 - 3 17 12 - 3 3 50 - 3 33 47 - 2 47 17 - 50 0 0 - 2 45 8 6 5 46 35 57 -47 - 2 51 48 - 2 38 28 - 3 8 22 - 2 21 56 - 49 0 0 - 2 20 1 6 5 50 36 57 -46 - 2 26 40 - 2 13 21 - 2 43 13 - 1 56 52 - 48 0 0 - 1 55 11 6 5 53 37 57 -45 - 2 1 50 - 1 48 32 - 2 18 20 - 1 32 4 - 47 0 0 - 1 30 39 6 5 57 38 57 -44 - 1 37 17 - 1 24 0 - 1 53 46 - 1 7 34 - 46 0 0 - 1 6 24 6 6 1 39 57 -43 - 1 13 2 - 0 59 47 - 1 29 29 - 0 43 22 - 45 0 0 - 0 42 29 6 6 4 40 56 -42 - 0 49 6 - 0 35 52 - 1 5 31 - 0 19 29 - 44 0 0 - 0 18 53 6 6 8 41 56 -41 - 0 25 29 - 0 12 17 - 0 41 52 0 4 4 - 43 0 0 0 4 24 6 6 12 42 56 -40 - 0 2 12 0 10 59 - 0 18 33 0 27 18 - 42 0 0 0 27 20 6 6 16 43 56 -39 0 20 45 0 33 55 0 4 25 0 50 12 - 41 0 0 0 49 56 6 6 20 44 55 -38 0 43 22 0 56 29 0 27 4 1 12 45 - 40 0 0 1 12 10 6 6 24 45 55 -37 1 5 37 1 18 43 0 49 21 1 34 57 - 39 0 0 1 34 3 6 6 28 46 55 -36 1 27 30 1 40 35 1 11 16 1 56 47 - 38 0 0 1 55 34 6 6 33 47 55 -35 1 49 2 2 2 6 1 32 50 2 18 16 - 37 0 0 2 16 42 6 6 37 48 54 -34 2 10 11 2 23 13 1 54 1 2 39 22 - 36 0 0 2 37 28 6 6 41 49 54 -33 2 30 58 2 43 58 2 14 49 3 0 5 - 35 0 0 2 57 51 6 6 46 50 54 -32 2 51 21 3 4 20 2 35 14 3 20 25 - 34 0 0 3 17 50 6 6 50 51 53 -31 3 11 21 3 24 19 2 55 16 3 40 22 - 33 0 0 3 37 26 6 6 55 52 53 -30 3 30 57 3 43 53 3 14 54 3 59 55 - 32 0 0 3 56 37 6 7 0 53 53 -29 3 50 9 4 3 4 3 34 8 4 19 3 - 31 0 0 4 15 24 6 7 4 54 52 -27 4 8 57 4 21 50 3 52 57 4 37 48 - 30 0 0 4 33 46 6 7 9 55 52 -26 4 27 20 4 40 12 4 11 22 4 56 7 - 29 0 0 4 51 43 6 7 14 56 51 -25 4 45 18 4 58 8 4 29 21 5 14 2 - 28 0 0 5 9 15 6 7 19 57 51 -24 5 2 50 5 15 39 4 46 56 5 31 32 - 27 0 0 5 26 21 6 7 23 58 50 -23 5 19 58 5 32 45 5 4 5 5 48 36 - 26 0 0 5 43 2 6 7 28 59 49 -22 5 36 39 5 49 25 5 20 48 6 5 14 - 25 0 0 5 59 17 6 7 33 60 49 -21 5 52 55 6 5 39 5 37 5 6 21 27 - 24 0 0 6 15 6 6 7 38 61 48 -20 6 8 44 6 21 27 5 52 56 6 37 13 - 23 0 0 6 30 28 6 7 43 62 47 -19 6 24 7 6 36 49 6 8 21 6 52 33 - 22 0 0 6 45 24 6 7 48 63 46 -18 6 39 4 6 51 45 6 23 19 7 7 27 - 21 0 0 6 59 54 6 7 53 64 45 -17 6 53 34 7 6 13 6 37 51 7 21 54 - 20 0 0 7 13 56 6 7 58 65 44 -16 7 7 37 7 20 15 6 51 55 7 35 55 - 19 0 0 7 27 32 6 8 4 66 43 -15 7 21 13 7 33 50 7 5 33 7 49 28 - 18 0 0 7 40 40 6 8 9 66 42 -14 7 34 22 7 46 58 7 18 44 8 2 35 - 17 0 0 7 53 22 6 8 14 67 41 -13 7 47 4 7 59 39 7 31 27 8 15 14 - 16 0 0 8 5 36 6 8 19 68 39 -12 7 59 19 8 11 52 7 43 43 8 27 26 - 15 0 0 8 17 22 6 8 24 69 38 -11 8 11 6 8 23 38 7 55 31 8 39 11 - 14 0 0 8 28 41 6 8 30 70 36 -10 8 22 25 8 34 57 8 6 52 8 50 28 - 13 0 0 8 39 33 6 8 35 70 34 -9 8 33 17 8 45 48 8 17 45 9 1 18 - 12 0 0 8 49 56 6 8 40 71 32 -8 8 43 41 8 56 11 8 28 11 9 11 40 - 11 0 0 8 59 52 6 8 45 72 30 -7 8 53 38 9 6 7 8 38 8 9 21 34 - 10 0 0 9 9 20 6 8 51 72 28 -6 9 3 6 9 15 34 8 47 38 9 31 1 - 9 0 0 9 18 20 6 8 56 73 25 -5 9 12 7 9 24 34 8 56 40 9 39 59 - 8 0 0 9 26 53 6 9 1 73 22 -4 9 20 39 9 33 6 9 5 13 9 48 30 - 7 0 0 9 34 57 6 9 7 74 20 -3 9 28 44 9 41 10 9 13 19 9 56 33 - 6 0 0 9 42 33 6 9 12 74 17 -2 9 36 21 9 48 45 9 20 56 10 4 8 - 5 0 0 9 49 41 6 9 17 75 13 -1 9 43 29 9 55 53 9 28 5 10 11 15 Uncertainty in time = +/- 2 secs Prediction of 2012 Jul 21.0 Data for the target star ------------------------ * name: HIP 28238 * constellation : Taurus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 05 58 00.2948 DE: +24 37 01.640 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .022, .012 ) * V mag [mag]: 7.9 * B mag [mag]: 8.0 * Apparent position with proper motion RA(deg): 89.7008745592 DE(deg): 24.6163664252 * Equation of equinoxes (radians) : 0.000065430265969 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (343) Ostara approx. diameter [km]: 22 approx. diameter ["]: .019 distance from Earth [AU]: 1.62200 * orbital information: orbit source: Preston date of fit: 2012 Jul 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1024 number of rejected observations: 56 time covered by the observations: 1903 Sep 30 - 2011 Sep 19 1 sigma uncertainty ellipse (major, minor, PA): 0.028, 0.020, 86° remarks: * orbital elements for (343) Ostara : Mean anomaly = 5.23104442 deg Arg. of pericenter = 9.75259481 deg Long. of node = 38.65667256 deg Inclination = 3.26638246 deg Eccentricity = 0.22969556 Semimajor axis = 2.41231999 AU Perihelion dist = 1.85822079 AU Mag: H = 11.54, G = 0.15 Epoch of elements : MJD 56189.25700000 TDT (2012 Sep 19.257) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 19 343 Ostara 6h 9.7m UT 7.9 5 58 0.295 24 37 1.64HIP 28238 8.0 15.3 22 1.1 1.622 4.726 5.28 -1.4857 24.615 86.00 1.30 6.1620 0.02020 -0.24836 11.88480 0.97395 -0.00506 -0.00001 2000 2.7959152012 910.00000 9.752595 38.656673 3.2663820.22969556 2.4123200 1.858220811.6 5.00.15 RATE 2.6305810 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.036 0.023 88 2.24 0.023 0 0-2 0 056129.0020120919__28238 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 22, 04:06 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org