IOTA/IOTA-ES occultation update for (895) Helio / TYC 0753-02343-1 event on 2012 Dec 23, 14:12 UT Visible from New Zealand Summary ------- On 2012 Dec 23 UT, the 128 km diameter asteroid (895) Helio will occult a 12.1 mag star in the constellation Gemini for observers along a path across New Zealand. In the case of an occultation, the combined light of the asteroid and the star will drop by 0.9 mag to 12.3 mag (the magnitude of the asteroid) for at most 8.5 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: 97 * date and approx. time of event: 2012 Dec 23, 14:08 - 2012 Dec 23, 14:16 UT * geocentric midpoint of event [JD]: 2456285.09199167 * magnitude of target star: 12.1 * magnitude drop [mag]: 0.9 * estimated maximum duration [s]: 8.5 * Moon: 80 % sunlit, 68° distance * Sun: 161° distance * rough path description: New Zealand The occultation path -------------------- * approximate projected width [km]: 209 * 1 sigma uncertainty interval [path widths]: +/- 0.38 * 1 sigma uncertainty interval [seconds]: +/- 3.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .038 +/- .036) * 1 sigma uncertainty ellipse (major, minor, PA): ( .038", .036", 106° ) * approx speed of asteroid's shadow [km/s]: 15.1663 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 0753-02343-1 by 895 Helio on 2012 Dec 23 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 Latitude Latitude Latitude Latitude 148 0 0 -66 29 1 14 16 27 13 12 0 -64 35 52 -68 33 22 -63 15 41 -70 17 59 149 0 0 -65 45 2 14 16 24 13 11 -1 -63 52 32 -67 48 33 -62 32 45 -69 32 17 150 0 0 -65 0 11 14 16 22 14 10 -2 -63 8 24 -67 2 43 -61 49 5 -68 45 29 151 0 0 -64 14 30 14 16 19 15 9 -2 -62 23 33 -66 15 58 -61 4 44 -67 57 39 152 0 0 -63 28 3 14 16 16 16 8 -3 -61 38 0 -65 28 22 -60 19 45 -67 8 53 153 0 0 -62 40 55 14 16 13 17 7 -4 -60 51 50 -64 39 59 -59 34 11 -66 19 14 154 0 0 -61 53 9 14 16 10 18 6 -5 -60 5 5 -63 50 53 -58 48 5 -65 28 49 155 0 0 -61 4 48 14 16 7 18 5 -5 -59 17 50 -63 1 9 -58 1 30 -64 37 42 156 0 0 -60 15 58 14 16 3 19 4 -6 -58 30 7 -62 10 52 -57 14 30 -63 46 0 157 0 0 -59 26 41 14 15 59 20 3 -7 -57 42 0 -61 20 6 -56 27 8 -62 53 47 158 0 0 -58 37 3 14 15 55 21 2 -7 -56 53 34 -60 28 56 -55 39 27 -62 1 8 159 0 0 -57 47 6 14 15 51 22 1 -8 -56 4 50 -59 37 26 -54 51 31 -61 8 9 160 0 0 -56 56 54 14 15 46 23 360 -9 -55 15 54 -58 45 41 -54 3 22 -60 14 54 161 0 0 -56 6 32 14 15 41 24 359 -10 -54 26 48 -57 53 44 -53 15 5 -59 21 28 162 0 0 -55 16 3 14 15 36 24 358 -10 -53 37 35 -57 1 41 -52 26 41 -58 27 56 163 0 0 -54 25 31 14 15 31 25 357 -11 -52 48 19 -56 9 34 -51 38 15 -57 34 21 164 0 0 -53 34 59 14 15 26 26 355 -12 -51 59 3 -55 17 29 -50 49 49 -56 40 48 165 0 0 -52 44 30 14 15 21 27 354 -12 -51 9 51 -54 25 27 -50 1 26 -55 47 20 166 0 0 -51 54 7 14 15 15 28 353 -13 -50 20 44 -53 33 33 -49 13 9 -54 54 2 167 0 0 -51 3 55 14 15 9 28 352 -13 -49 31 46 -52 41 50 -48 25 1 -54 0 56 168 0 0 -50 13 54 14 15 3 29 351 -14 -48 43 0 -51 50 21 -47 37 3 -53 8 6 169 0 0 -49 24 9 14 14 57 30 350 -15 -47 54 28 -50 59 8 -46 49 20 -52 15 34 170 0 0 -48 34 42 14 14 51 30 349 -15 -47 6 13 -50 8 15 -46 1 53 -51 23 25 171 0 0 -47 45 35 14 14 44 31 347 -16 -46 18 17 -49 17 45 -45 14 44 -50 31 39 172 0 0 -46 56 50 14 14 38 32 346 -16 -45 30 42 -48 27 39 -44 27 55 -49 40 20 173 0 0 -46 8 31 14 14 31 32 345 -16 -44 43 31 -47 37 59 -43 41 29 -48 49 30 174 0 0 -45 20 38 14 14 24 33 344 -17 -43 56 44 -46 48 49 -42 55 28 -47 59 11 175 0 0 -44 33 14 14 14 17 33 342 -17 -43 10 26 -46 0 9 -42 9 53 -47 9 25 176 0 0 -43 46 20 14 14 10 34 341 -18 -42 24 36 -45 12 2 -41 24 46 -46 20 13 177 0 0 -42 59 59 14 14 3 35 340 -18 -41 39 16 -44 24 29 -40 40 9 -45 31 38 178 0 0 -42 14 11 14 13 56 35 338 -18 -40 54 29 -43 37 32 -39 56 3 -44 43 41 179 0 0 -41 28 59 14 13 49 35 337 -19 -40 10 16 -42 51 12 -39 12 30 -43 56 23 180 0 0 -40 44 23 14 13 42 36 336 -19 -39 26 38 -42 5 31 -38 29 31 -43 9 45 -179 0 0 -40 0 26 14 13 34 36 335 -19 -38 43 36 -41 20 30 -37 47 7 -42 23 50 -178 0 0 -39 17 7 14 13 27 36 333 -19 -38 1 11 -40 36 10 -37 5 20 -41 38 37 -177 0 0 -38 34 28 14 13 20 37 332 -19 -37 19 25 -39 52 32 -36 24 10 -40 54 9 -176 0 0 -37 52 31 14 13 12 37 330 -19 -36 38 19 -39 9 37 -35 43 39 -40 10 25 -175 0 0 -37 11 16 14 13 5 37 329 -20 -35 57 53 -38 27 26 -35 3 48 -39 27 27 -174 0 0 -36 30 43 14 12 57 37 328 -20 -35 18 9 -37 46 0 -34 24 36 -38 45 15 -173 0 0 -35 50 54 14 12 50 37 326 -20 -34 39 6 -37 5 19 -33 46 7 -38 3 50 -172 0 0 -35 11 50 14 12 42 38 325 -20 -34 0 47 -36 25 25 -33 8 19 -37 23 13 -171 0 0 -34 33 31 14 12 35 38 324 -20 -33 23 11 -35 46 17 -32 31 13 -36 43 25 -170 0 0 -33 55 57 14 12 27 38 322 -20 -32 46 20 -35 7 56 -31 54 51 -36 4 25 -169 0 0 -33 19 9 14 12 20 38 321 -19 -32 10 13 -34 30 23 -31 19 13 -35 26 14 -168 0 0 -32 43 9 14 12 12 38 320 -19 -31 34 52 -33 53 39 -30 44 20 -34 48 53 -167 0 0 -32 7 55 14 12 5 37 318 -19 -31 0 16 -33 17 43 -30 10 11 -34 12 23 -166 0 0 -31 33 29 14 11 58 37 317 -19 -30 26 27 -32 42 36 -29 36 48 -33 36 42 -165 0 0 -30 59 50 14 11 51 37 316 -19 -29 53 24 -32 8 19 -29 4 10 -33 1 52 -164 0 0 -30 27 0 14 11 43 37 315 -19 -29 21 9 -31 34 51 -28 32 18 -32 27 53 -163 0 0 -29 54 59 14 11 36 37 314 -18 -28 49 40 -31 2 13 -28 1 13 -31 54 45 -162 0 0 -29 23 46 14 11 29 37 312 -18 -28 18 59 -30 30 26 -27 30 55 -31 22 29 -161 0 0 -28 53 22 14 11 22 36 311 -18 -27 49 6 -29 59 28 -27 1 24 -30 51 4 -160 0 0 -28 23 47 14 11 15 36 310 -17 -27 20 1 -29 29 21 -26 32 40 -30 20 30 -159 0 0 -27 55 2 14 11 8 36 309 -17 -26 51 45 -29 0 5 -26 4 43 -29 50 48 -158 0 0 -27 27 6 14 11 1 35 308 -17 -26 24 16 -28 31 39 -25 37 34 -29 21 58 -157 0 0 -27 0 0 14 10 55 35 307 -16 -25 57 37 -28 4 5 -25 11 13 -28 54 0 -156 0 0 -26 33 44 14 10 48 34 306 -16 -25 31 46 -27 37 21 -24 45 40 -28 26 54 -155 0 0 -26 8 18 14 10 42 34 305 -15 -25 6 43 -27 11 28 -24 20 56 -28 0 39 -154 0 0 -25 43 41 14 10 35 33 304 -15 -24 42 30 -26 46 27 -23 56 59 -27 35 17 -153 0 0 -25 19 55 14 10 29 33 303 -14 -24 19 6 -26 22 16 -23 33 51 -27 10 47 -152 0 0 -24 56 58 14 10 23 32 302 -14 -23 56 31 -25 58 57 -23 11 31 -26 47 9 -151 0 0 -24 34 52 14 10 16 32 301 -13 -23 34 45 -25 36 28 -22 49 59 -26 24 23 -150 0 0 -24 13 36 14 10 11 31 300 -13 -23 13 49 -25 14 52 -22 29 17 -26 2 29 -149 0 0 -23 53 10 14 10 5 31 299 -12 -22 53 41 -24 54 6 -22 9 23 -25 41 27 -148 0 0 -23 33 35 14 9 59 30 299 -12 -22 34 23 -24 34 11 -21 50 17 -25 21 17 -147 0 0 -23 14 49 14 9 53 29 298 -11 -22 15 55 -24 15 8 -21 32 1 -25 1 59 -146 0 0 -22 56 54 14 9 48 29 297 -10 -21 58 15 -23 56 56 -21 14 33 -24 43 33 -145 0 0 -22 39 49 14 9 42 28 296 -10 -21 41 26 -23 39 35 -20 57 54 -24 25 59 -144 0 0 -22 23 35 14 9 37 27 296 -9 -21 25 25 -23 23 6 -20 42 3 -24 9 18 -143 0 0 -22 8 11 14 9 32 27 295 -9 -21 10 15 -23 7 27 -20 27 2 -23 53 28 -142 0 0 -21 53 37 14 9 27 26 294 -8 -20 55 53 -22 52 40 -20 12 50 -23 38 30 -141 0 0 -21 39 54 14 9 22 25 294 -7 -20 42 21 -22 38 44 -19 59 26 -23 24 24 -140 0 0 -21 27 1 14 9 18 24 293 -6 -20 29 39 -22 25 40 -19 46 52 -23 11 10 -139 0 0 -21 14 58 14 9 13 24 292 -6 -20 17 46 -22 13 26 -19 35 6 -22 58 48 -138 0 0 -21 3 46 14 9 9 23 292 -5 -20 6 43 -22 2 4 -19 24 10 -22 47 18 -137 0 0 -20 53 24 14 9 4 22 291 -4 -19 56 30 -21 51 34 -19 14 2 -22 36 40 -136 0 0 -20 43 53 14 9 0 21 291 -4 -19 47 6 -21 41 54 -19 4 44 -22 26 54 -135 0 0 -20 35 12 14 8 56 20 290 -3 -19 38 32 -21 33 6 -18 56 15 -22 18 0 -134 0 0 -20 27 21 14 8 52 20 290 -2 -19 30 48 -21 25 9 -18 48 35 -22 9 58 -133 0 0 -20 20 21 14 8 49 19 289 -1 -19 23 53 -21 18 4 -18 41 44 -22 2 48 -132 0 0 -20 14 12 14 8 45 18 289 0 -19 17 48 -21 11 50 -18 35 43 -21 56 30 Uncertainty in time = +/- 3 secs Prediction of 2012 Dec 3.0 Data for the target star ------------------------ * name: TYC 0753-02343-1 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 04 15.8704 DE: +10 28 58.525 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .026, .033 ) * V mag [mag]: 12.1 * B mag [mag]: 12.5 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (895) Helio approx. diameter [km]: 128 approx. diameter ["]: .098 distance from Earth [AU]: 1.80300 * orbital information: orbit source: Preston date of fit: 2012 Nov 30 source of used astrometry: FASTT TMO MPC (via Astdys) number of used observations: 1034 number of rejected observations: 56 time covered by the observations: 1906 Jun 21 - 2012 Nov 28 1 sigma uncertainty ellipse (major, minor, PA): 0.028, 0.015, 120° remarks: * orbital elements for (895) Helio : Mean anomaly = 14.74949849 deg Arg. of pericenter = 178.18241060 deg Long. of node = 264.70477535 deg Inclination = 26.08574849 deg Eccentricity = 0.14702469 Semimajor axis = 3.20247610 AU Perihelion dist = 2.73163304 AU Mag: H = 8.31, G = 0.15 Epoch of elements : MJD 56284.59200000 TDT (2012 Dec 23.592) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Dec 23 895 Helio 14h 12.5m UT 12.1 7 4 15.870 10 28 58.52TYC 0753-02343-1 12.5 12.3 128 8.5 1.803 -2.430 -21.45 160.4256 10.488 -33.28 -23.42 14.2078 0.40597 -0.67815 -7.34510 -4.39634 -0.00128 0.00135 2000 13.95977120121219.00000178.182411264.704775 26.0857480.14702469 3.2024761 2.7316330 8.3 5.00.15 RATE 1.7197890 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.038 0.036 106 1.38 0.037 0 0 4 5 056264.0020121223_2343-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Nov 30, 00:08 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org