IOTA/IOTA-ES occultation update for (894) Erda / TYC 5761-01722-1 event on 2012 Nov 22, 01:22 UT Visible from Argentina, Chile Summary ------- On 2012 Nov 22 UT, the 38 km diameter asteroid (894) Erda will occult a 10.3 mag star in the constellation Aquarius for observers along a path across Argentina, Chile. In the case of an occultation, the combined light of the asteroid and the star will drop by 4.7 mag to 15.0 mag (the magnitude of the asteroid) for at most 1.3 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: 36 * date and approx. time of event: 2012 Nov 22, 01:24 - 2012 Nov 22, 01:25 UT * geocentric midpoint of event [JD]: 2456253.5574875 * magnitude of target star: 10.3 * magnitude drop [mag]: 4.7 * estimated maximum duration [s]: 1.3 * Moon: 65 % sunlit, 35° distance * Sun: 72° distance * rough path description: Argentina, Chile The occultation path -------------------- * approximate projected width [km]: 51 * 1 sigma uncertainty interval [path widths]: +/- 1.86 * 1 sigma uncertainty interval [seconds]: +/- 3.0 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .040 +/- .033) * 1 sigma uncertainty ellipse (major, minor, PA): ( .040", .033", 89° ) * approx speed of asteroid's shadow [km/s]: 28.0823 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5761-01722-1 by 894 Erda on 2012 Nov 22 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 - 90 0 0 -48 5 15 1 24 17 39 305 0 -48 19 21 -47 51 11 -49 12 19 -46 59 20 - 89 0 0 -47 56 54 1 24 19 39 304 -1 -48 11 1 -47 42 50 -49 4 1 -46 50 57 - 88 0 0 -47 48 26 1 24 21 38 303 -2 -48 2 33 -47 34 21 -48 55 35 -46 42 27 - 87 0 0 -47 39 51 1 24 23 38 302 -2 -47 53 59 -47 25 46 -48 47 2 -46 33 50 - 86 0 0 -47 31 9 1 24 26 37 301 -3 -47 45 17 -47 17 4 -48 38 22 -46 25 6 - 85 0 0 -47 22 20 1 24 28 37 300 -4 -47 36 29 -47 8 15 -48 29 35 -46 16 16 - 84 0 0 -47 13 25 1 24 30 36 298 -4 -47 27 34 -46 59 19 -48 20 42 -46 7 19 - 83 0 0 -47 4 24 1 24 32 36 297 -5 -47 18 33 -46 50 17 -48 11 43 -45 58 15 - 82 0 0 -46 55 16 1 24 35 35 296 -5 -47 9 26 -46 41 9 -48 2 36 -45 49 5 - 81 0 0 -46 46 1 1 24 37 34 295 -6 -47 0 12 -46 31 54 -47 53 24 -45 39 49 - 80 0 0 -46 36 41 1 24 39 34 294 -7 -46 50 52 -46 22 33 -47 44 6 -45 30 27 - 79 0 0 -46 27 15 1 24 41 33 293 -7 -46 41 26 -46 13 7 -47 34 41 -45 21 0 - 78 0 0 -46 17 43 1 24 43 33 292 -8 -46 31 54 -46 3 35 -47 25 11 -45 11 26 - 77 0 0 -46 8 5 1 24 45 32 291 -9 -46 22 17 -45 53 57 -47 15 35 -45 1 47 - 76 0 0 -45 58 22 1 24 47 32 290 -9 -46 12 34 -45 44 13 -47 5 53 -44 52 2 - 75 0 0 -45 48 34 1 24 49 31 289 -10 -46 2 46 -45 34 24 -46 56 6 -44 42 12 - 74 0 0 -45 38 40 1 24 51 30 288 -11 -45 52 53 -45 24 30 -46 46 14 -44 32 17 - 73 0 0 -45 28 41 1 24 53 30 287 -11 -45 42 54 -45 14 32 -46 36 17 -44 22 18 - 72 0 0 -45 18 38 1 24 55 29 287 -12 -45 32 51 -45 4 28 -46 26 15 -44 12 13 - 71 0 0 -45 8 30 1 24 57 28 286 -12 -45 22 43 -44 54 20 -46 16 8 -44 2 4 - 70 0 0 -44 58 17 1 24 59 28 285 -13 -45 12 31 -44 44 7 -46 5 56 -43 51 50 - 69 0 0 -44 48 0 1 25 0 27 284 -14 -45 2 14 -44 33 50 -45 55 40 -43 41 32 - 68 0 0 -44 37 39 1 25 2 27 283 -14 -44 51 54 -44 23 28 -45 45 20 -43 31 10 - 67 0 0 -44 27 14 1 25 4 26 282 -15 -44 41 29 -44 13 3 -45 34 56 -43 20 44 - 66 0 0 -44 16 46 1 25 6 25 281 -15 -44 31 0 -44 2 34 -45 24 29 -43 10 15 - 65 0 0 -44 6 13 1 25 7 24 280 -16 -44 20 28 -43 52 2 -45 13 57 -42 59 42 - 64 0 0 -43 55 38 1 25 9 24 280 -17 -44 9 53 -43 41 26 -45 3 22 -42 49 5 - 63 0 0 -43 44 59 1 25 11 23 279 -17 -43 59 14 -43 30 47 -44 52 44 -42 38 26 - 62 0 0 -43 34 17 1 25 12 22 278 -18 -43 48 32 -43 20 5 -44 42 3 -42 27 44 - 61 0 0 -43 23 33 1 25 14 22 277 -18 -43 37 48 -43 9 21 -44 31 19 -42 16 59 - 60 0 0 -43 12 46 1 25 15 21 276 -19 -43 27 1 -42 58 34 -44 20 32 -42 6 11 - 59 0 0 -43 1 56 1 25 16 20 276 -20 -43 16 12 -42 47 44 -44 9 43 -41 55 22 - 58 0 0 -42 51 5 1 25 18 20 275 -20 -43 5 20 -42 36 53 -43 58 52 -41 44 30 - 57 0 0 -42 40 11 1 25 19 19 274 -21 -42 54 27 -42 25 59 -43 47 58 -41 33 36 - 56 0 0 -42 29 16 1 25 20 18 273 -21 -42 43 32 -42 15 4 -43 37 3 -41 22 41 - 55 0 0 -42 18 20 1 25 22 17 273 -22 -42 32 35 -42 4 7 -43 26 6 -41 11 45 - 54 0 0 -42 7 22 1 25 23 17 272 -22 -42 21 37 -41 53 9 -43 15 9 -41 0 47 - 53 0 0 -41 56 23 1 25 24 16 271 -23 -42 10 38 -41 42 11 -43 4 9 -40 49 48 - 52 0 0 -41 45 23 1 25 25 15 270 -23 -41 59 38 -41 31 11 -42 53 9 -40 38 49 - 51 0 0 -41 34 23 1 25 26 14 270 -24 -41 48 38 -41 20 11 -42 42 9 -40 27 49 - 50 0 0 -41 23 22 1 25 27 14 269 -24 -41 37 37 -41 9 10 -42 31 8 -40 16 49 - 49 0 0 -41 12 21 1 25 28 13 268 -25 -41 26 36 -40 58 10 -42 20 6 -40 5 48 - 48 0 0 -41 1 21 1 25 29 12 268 -25 -41 15 36 -40 47 9 -42 9 5 -39 54 48 - 47 0 0 -40 50 20 1 25 30 11 267 -26 -41 4 35 -40 36 9 -41 58 4 -39 43 49 - 46 0 0 -40 39 21 1 25 31 11 266 -26 -40 53 35 -40 25 9 -41 47 4 -39 32 50 - 45 0 0 -40 28 22 1 25 31 10 266 -27 -40 42 36 -40 14 11 -41 36 4 -39 21 52 - 44 0 0 -40 17 24 1 25 32 9 265 -27 -40 31 38 -40 3 13 -41 25 5 -39 10 55 - 43 0 0 -40 6 28 1 25 33 8 264 -28 -40 20 42 -39 52 17 -41 14 8 -38 59 59 - 42 0 0 -39 55 33 1 25 33 7 264 -28 -40 9 46 -39 41 22 -41 3 12 -38 49 5 - 41 0 0 -39 44 39 1 25 34 7 263 -28 -39 58 53 -39 30 29 -40 52 18 -38 38 13 - 40 0 0 -39 33 48 1 25 34 6 262 -29 -39 48 2 -39 19 38 -40 41 25 -38 27 23 - 39 0 0 -39 22 59 1 25 35 5 262 -29 -39 37 12 -39 8 49 -40 30 35 .. .. .. - 38 0 0 -39 12 13 1 25 35 4 261 -29 -39 26 26 -38 58 3 -40 19 47 .. .. .. - 37 0 0 -39 1 29 1 25 35 4 260 -30 -39 15 42 -38 47 20 -40 9 2 .. .. .. - 36 0 0 -38 50 48 1 25 36 3 260 -30 -39 5 0 -38 36 39 -39 58 20 .. .. .. - 35 0 0 -38 40 11 1 25 36 2 259 -31 -38 54 23 -38 26 2 -39 47 41 .. .. .. - 34 0 0 -38 29 36 1 25 36 1 258 -31 -38 43 48 -38 15 28 -39 37 5 .. .. .. - 33 0 0 -38 19 6 1 25 36 0 258 -31 -38 33 17 -38 4 58 -39 26 33 .. .. .. Uncertainty in time = +/- 3 secs Prediction of 2012 Nov 16.0 Data for the target star ------------------------ * name: TYC 5761-01722-1 * constellation : Aquarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 20 49 22.8894 DE: -09 47 54.930 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .037, .032 ) * V mag [mag]: 10.3 * B mag [mag]: 11.4 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (894) Erda approx. diameter [km]: 38 approx. diameter ["]: .018 distance from Earth [AU]: 2.92800 * orbital information: orbit source: Preston date of fit: 2012 Nov 16 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 932 number of rejected observations: 60 time covered by the observations: 1907 May 14 - 2012 Oct 29 1 sigma uncertainty ellipse (major, minor, PA): 0.016, 0.010, 83° remarks: * orbital elements for (894) Erda : Mean anomaly = 21.15847264 deg Arg. of pericenter = 113.80462513 deg Long. of node = 190.84902476 deg Inclination = 12.69818682 deg Eccentricity = 0.11411208 Semimajor axis = 3.11567231 AU Perihelion dist = 2.76013648 AU Mag: H = 9.54, G = 0.15 Epoch of elements : MJD 56253.05800000 TDT (2012 Nov 22.058) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 22 894 Erda 1h 22.8m UT 10.3 20 49 22.889- 9 47 54.93TYC 5761-01722-1 11.4 15.0 38 1.3 2.928 3.216 2.50 -129.7918 -9.800 155.84 -20.18 1.3797 0.03569 -0.66376 15.82862 0.83102 0.00532 0.00175 2000 20.61043120121119.00000113.804625190.849025 12.6981870.11411208 3.1156723 2.7601365 9.4 5.00.15 RATE 1.7921580 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.040 0.033 89 2.86 0.033 0 0 4 0 056247.0020121122_1722-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Nov 16, 08:35 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org