IOTA/IOTA-ES occultation update for (16943) 1998 HP42 / TYC 6957-01214-1 event on 2012 Dec 06, 19:09 UT Visible from Africa Summary ------- On 2012 Dec 06 UT, the 19 km diameter asteroid (16943) 1998 HP42 will occult a 9.7 mag star in the constellation Piscis Austrinus for observers along a path across Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 7.9 mag to 17.6 mag (the magnitude of the asteroid) for at most 0.7 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: 19 * date and approx. time of event: 2012 Dec 06, 19:11 - 2012 Dec 06, 19:13 UT * geocentric midpoint of event [JD]: 2456268.29860833 * magnitude of target star: 9.7 * magnitude drop [mag]: 7.9 * estimated maximum duration [s]: 0.7 * Moon: 49 % sunlit, 152° distance * Sun: 70° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 20 * 1 sigma uncertainty interval [path widths]: +/- 3.50 * 1 sigma uncertainty interval [seconds]: +/- 3.1 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .054 +/- .038) * 1 sigma uncertainty ellipse (major, minor, PA): ( .055", .037", 77° ) * approx speed of asteroid's shadow [km/s]: 28.8222 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6957-01214-1 by 16943 1998 HP42 on 2012 Dec 6 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 50 22 31 14 0 0 19 13 32 0 243 -70 ... .. .. 50 10 15 ... .. .. ... .. .. 48 23 11 13 0 0 19 13 32 2 243 -68 48 34 59 48 11 25 49 58 50 46 50 15 46 29 39 12 0 0 19 13 31 4 243 -66 46 41 1 46 18 19 48 1 38 45 0 1 44 41 9 11 0 0 19 13 31 6 242 -64 44 52 8 44 30 12 46 9 59 43 14 24 42 57 6 10 0 0 19 13 30 8 242 -62 43 7 45 42 46 28 44 23 9 41 32 52 41 16 57 9 0 0 19 13 28 10 242 -60 41 27 19 41 6 37 42 40 35 39 54 57 39 40 18 8 0 0 19 13 27 12 241 -58 39 50 24 39 30 13 41 1 47 38 20 17 38 6 46 7 0 0 19 13 25 14 241 -56 38 16 38 37 56 55 39 26 21 36 48 31 36 36 3 6 0 0 19 13 23 16 241 -54 36 45 43 36 26 24 37 53 56 35 19 22 35 7 52 5 0 0 19 13 21 18 241 -52 35 17 21 34 58 24 36 24 14 33 52 36 33 41 58 4 0 0 19 13 19 19 241 -51 33 51 17 33 32 40 34 56 58 32 27 58 32 18 9 3 0 0 19 13 17 21 241 -49 32 27 19 32 9 0 33 31 56 31 5 18 30 56 13 2 0 0 19 13 14 23 241 -47 31 5 16 30 47 12 32 8 54 29 44 23 29 36 0 1 0 0 19 13 11 24 241 -46 29 44 56 29 27 6 30 47 42 28 25 6 28 17 21 0 0 0 19 13 8 26 241 -44 28 26 10 28 8 33 29 28 10 27 7 15 27 0 6 - 1 0 0 19 13 5 28 241 -42 27 8 49 26 51 24 28 10 8 25 50 45 Latitude Latitude Latitude Latitude 26 0 0 - 1 47 24 19 13 3 29 241 -41 - 1 54 16 - 1 40 33 - 2 42 27 - 0 52 42 25 0 0 - 2 35 18 19 13 0 30 242 -40 - 2 42 12 - 2 28 25 - 3 30 37 - 1 40 20 24 0 0 - 3 23 47 19 12 58 31 242 -38 - 3 30 43 - 3 16 52 - 4 19 22 - 2 28 33 23 0 0 - 4 12 48 19 12 55 33 242 -37 - 4 19 45 - 4 5 51 - 5 8 38 - 3 17 18 22 0 0 - 5 2 19 19 12 52 34 242 -36 - 5 9 19 - 4 55 20 - 5 58 25 - 4 6 35 21 0 0 - 5 52 20 19 12 49 35 242 -35 - 5 59 21 - 5 45 19 - 6 48 40 - 4 56 21 20 0 0 - 6 42 47 19 12 46 37 243 -33 - 6 49 50 - 6 35 44 - 7 39 21 - 5 46 34 19 0 0 - 7 33 39 19 12 43 38 243 -32 - 7 40 44 - 7 26 35 - 8 30 27 - 6 37 13 18 0 0 - 8 24 54 19 12 40 39 244 -31 - 8 32 0 - 8 17 48 - 9 21 55 - 7 28 15 17 0 0 - 9 16 29 19 12 36 40 244 -29 - 9 23 37 - 9 9 21 -10 13 43 - 8 19 38 16 0 0 -10 8 22 19 12 33 42 244 -28 -10 15 32 -10 1 13 -11 5 48 - 9 11 20 15 0 0 -11 0 32 19 12 29 43 245 -27 -11 7 42 -10 53 21 -11 58 8 -10 3 18 14 0 0 -11 52 54 19 12 25 44 245 -25 -12 0 6 -11 45 43 -12 50 41 -10 55 30 13 0 0 -12 45 28 19 12 22 45 246 -24 -12 52 41 -12 38 15 -13 43 24 -11 47 54 12 0 0 -13 38 10 19 12 18 47 247 -23 -13 45 24 -13 30 56 -14 36 15 -12 40 28 11 0 0 -14 30 57 19 12 14 48 247 -22 -14 38 13 -14 23 42 -15 29 11 -13 33 7 10 0 0 -15 23 48 19 12 10 49 248 -20 -15 31 4 -15 16 32 -16 22 8 -14 25 51 9 0 0 -16 16 39 19 12 6 50 249 -19 -16 23 56 -16 9 23 -17 15 6 -15 18 36 8 0 0 -17 9 28 19 12 2 52 250 -18 -17 16 46 -17 2 11 -18 8 0 -16 11 20 7 0 0 -18 2 13 19 11 58 53 251 -16 -18 9 31 -17 54 55 -19 0 49 -17 4 0 6 0 0 -18 54 49 19 11 53 54 252 -15 -19 2 8 -18 47 31 -19 53 29 -17 56 33 5 0 0 -19 47 16 19 11 49 55 253 -14 -19 54 35 -19 39 57 -20 45 58 -18 48 58 4 0 0 -20 39 30 19 11 45 56 254 -13 -20 46 49 -20 32 11 -21 38 13 -19 41 10 3 0 0 -21 31 28 19 11 41 58 255 -11 -21 38 48 -21 24 10 -22 30 12 -20 33 8 2 0 0 -22 23 9 19 11 36 59 257 -10 -22 30 28 -22 15 51 -23 21 52 -21 24 50 1 0 0 -23 14 30 19 11 32 60 258 -9 -23 21 49 -23 7 11 -24 13 12 -22 16 12 0 0 0 -24 5 28 19 11 27 61 260 -8 -24 12 47 -23 58 10 -25 4 7 -23 7 12 - 1 0 0 -24 56 1 19 11 23 62 261 -6 -25 3 19 -24 48 43 -25 54 37 -23 57 49 - 2 0 0 -25 46 7 19 11 19 63 263 -5 -25 53 25 -25 38 50 -26 44 38 -24 47 59 - 3 0 0 -26 35 44 19 11 14 64 265 -4 -26 43 1 -26 28 28 -27 34 10 -25 37 42 - 4 0 0 -27 24 50 19 11 10 65 267 -3 -27 32 6 -27 17 34 -28 23 9 -26 26 53 - 5 0 0 -28 13 23 19 11 5 66 269 -2 -28 20 38 -28 6 8 -29 11 35 -27 15 33 - 6 0 0 -29 1 20 19 11 1 67 272 -1 -29 8 35 -28 54 6 -29 59 24 -28 3 39 Uncertainty in time = +/- 3 secs Prediction of 2012 Dec 3.0 Data for the target star ------------------------ * name: TYC 6957-01214-1 * constellation : Piscis Austrinus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 22 06 14.8795 DE: -25 47 28.713 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .028, .025 ) * V mag [mag]: 9.7 * B mag [mag]: 11.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (16943) 1998 HP42 approx. diameter [km]: 19 approx. diameter ["]: .011 distance from Earth [AU]: 2.45300 * orbital information: orbit source: Preston date of fit: 2012 Oct 25 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 759 number of rejected observations: 4 time covered by the observations: 1958 Oct 13 - 2012 Oct 20 1 sigma uncertainty ellipse (major, minor, PA): 0.047, 0.027, 72° remarks: * orbital elements for (16943) 1998 HP42 : Mean anomaly = 316.05623962 deg Arg. of pericenter = 339.31099578 deg Long. of node = 69.66089824 deg Inclination = 14.21547453 deg Eccentricity = 0.17787746 Semimajor axis = 2.59616632 AU Perihelion dist = 2.13436684 AU Mag: H = 12.39, G = 0.15 Epoch of elements : MJD 56267.79900000 TDT (2012 Dec 06.799) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Dec 6 16943 1998 HP42 19h 10.0m UT 9.7 22 6 14.880-25 47 28.71TYC 6957-01214-1 11.3 17.6 19 0.7 2.453 3.666 30.81 -31.9072 -25.800 -109.66 -22.60 19.1666 0.14897 -0.23885 13.81112 8.59665 0.00518 0.00151 2000 314.21866920121129.00000339.310996 69.660898 14.2154750.17787746 2.5961663 2.134366812.7 5.00.15 RATE 2.3561620 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.055 0.037 77 4.50 0.037 0 0-5-3 056264.0020121206_1214-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 25, 22:53 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org