IOTA/IOTA-ES occultation update for (705) Erminia / 2UCAC 27302218 event on 2012 Nov 23, 11:08 UT Visible from S USA Summary ------- On 2012 Nov 23 UT, the 150 km diameter asteroid (705) Erminia will occult a 13.0 mag star in the constellation Virgo for observers along a path across S USA. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.5 mag to 14.2 mag (the magnitude of the asteroid) for at most 3.7 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: UCAC. The event at a glimpse ---------------------- * Rank: 80 * date and approx. time of event: 2012 Nov 23, 11:06 - 2012 Nov 23, 11:06 UT * geocentric midpoint of event [JD]: 2456254.96444167 * magnitude of target star: 13.0 * magnitude drop [mag]: 1.5 * estimated maximum duration [s]: 3.7 * Moon: 77 % sunlit, 160° distance * Sun: 37° distance * rough path description: S USA Additional comments ------------------- possible double star The occultation path -------------------- * approximate projected width [km]: 150 * 1 sigma uncertainty interval [path widths]: +/- 0.67 * 1 sigma uncertainty interval [seconds]: +/- 2.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .034 +/- .041) * 1 sigma uncertainty ellipse (major, minor, PA): ( .041", .034", 174° ) * approx speed of asteroid's shadow [km/s]: 40.1083 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 27302218 by 705 Erminia on 2012 Nov 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 -106 11 47 34 0 0 11 6 9 3 107 -33 -109 5 20 -103 32 13 ... .. .. -100 14 55 -102 31 59 33 0 0 11 6 10 6 109 -29 -105 5 7 -100 8 28 -108 50 9 - 97 8 9 Latitude Latitude Latitude Latitude -102 0 0 32 50 38 11 6 10 6 109 -29 32 7 38 33 33 39 31 10 1 34 31 20 -101 0 0 32 32 38 11 6 10 7 110 -28 31 49 30 33 15 48 30 51 42 34 13 39 -100 0 0 32 14 4 11 6 11 8 111 -27 31 30 47 32 57 22 30 32 47 33 55 25 - 99 0 0 31 54 55 11 6 11 9 111 -26 31 11 29 32 38 21 30 13 18 33 36 36 - 98 0 0 31 35 11 11 6 11 10 112 -25 30 51 36 32 18 46 29 53 13 33 17 13 - 97 0 0 31 14 52 11 6 12 11 112 -25 30 31 8 31 58 36 29 32 33 32 57 15 - 96 0 0 30 53 57 11 6 12 12 113 -24 30 10 5 31 37 51 29 11 17 32 36 42 - 95 0 0 30 32 28 11 6 13 13 113 -23 29 48 25 31 16 31 28 49 25 32 15 34 - 94 0 0 30 10 22 11 6 13 14 114 -22 29 26 10 30 54 35 28 26 58 31 53 51 - 93 0 0 29 47 41 11 6 14 15 114 -21 29 3 19 30 32 3 28 3 53 31 31 32 - 92 0 0 29 24 23 11 6 15 16 115 -20 28 39 52 30 8 55 27 40 13 31 8 38 - 91 0 0 29 0 29 11 6 16 16 115 -19 28 15 48 29 45 11 27 15 56 30 45 7 - 90 0 0 28 35 59 11 6 16 17 116 -18 27 51 8 29 20 51 26 51 3 30 21 1 - 89 0 0 28 10 53 11 6 17 18 116 -17 27 25 52 28 55 55 26 25 33 29 56 18 - 88 0 0 27 45 10 11 6 18 19 117 -16 26 59 58 28 30 22 25 59 26 29 30 59 - 87 0 0 27 18 50 11 6 19 20 117 -15 26 33 29 28 4 13 25 32 42 29 5 4 - 86 0 0 26 51 54 11 6 20 21 117 -14 26 6 22 27 37 27 25 5 21 28 38 32 - 85 0 0 26 24 21 11 6 21 22 118 -13 25 38 38 27 10 5 24 37 24 28 11 23 - 84 0 0 25 56 11 11 6 22 23 118 -12 25 10 18 26 42 6 24 8 50 27 43 38 - 83 0 0 25 27 25 11 6 23 24 119 -11 24 41 21 26 13 30 23 39 39 27 15 17 - 82 0 0 24 58 2 11 6 24 26 119 -10 24 11 48 25 44 17 23 9 51 26 46 19 - 81 0 0 24 28 3 11 6 26 27 120 -9 23 41 38 25 14 29 22 39 27 26 16 44 - 80 0 0 23 57 27 11 6 27 28 120 -8 23 10 52 24 44 3 22 8 27 25 46 33 - 79 0 0 23 26 15 11 6 28 29 121 -7 22 39 29 24 13 2 21 36 50 25 15 45 - 78 0 0 22 54 27 11 6 30 30 121 -6 22 7 31 23 41 24 21 4 37 24 44 22 - 77 0 0 22 22 3 11 6 31 31 121 -5 21 34 56 23 9 11 20 31 49 24 12 23 - 76 0 0 21 49 4 11 6 33 32 122 -4 21 1 47 22 36 22 19 58 26 23 39 48 - 75 0 0 21 15 30 11 6 35 33 122 -3 20 28 2 22 2 58 19 24 28 23 6 37 - 74 0 0 20 41 20 11 6 36 34 122 -2 19 53 43 21 28 59 18 49 55 22 32 52 - 73 0 0 20 6 37 11 6 38 35 123 -1 19 18 50 20 54 26 18 14 48 21 58 32 Uncertainty in time = +/- 3 secs Prediction of 2012 Oct 25.0 Data for the target star ------------------------ * name: 2UCAC 27302218 * constellation : Virgo * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 13 24 13.9159 DE: -12 36 52.566 * position source: mpos:UCAC4 pm:UCAC4 * standard error: RA,DE ["]: ( .033, .039 ) * V mag [mag]: 13.0 * B mag [mag]: 0.0 * Apparent position with proper motion RA(deg): 201.2285582204 DE(deg): -12.6804828717 * Equation of equinoxes (radians) : 0.000058553939644 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (705) Erminia approx. diameter [km]: 150 approx. diameter ["]: .057 distance from Earth [AU]: 3.63900 * orbital information: orbit source: Preston date of fit: 2012 Oct 24 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 915 number of rejected observations: 50 time covered by the observations: 1910 Oct 06 - 2012 May 18 1 sigma uncertainty ellipse (major, minor, PA): 0.016, 0.007, 136° remarks: * orbital elements for (705) Erminia : Mean anomaly = 84.51448052 deg Arg. of pericenter = 100.25486040 deg Long. of node = 2.92056345 deg Inclination = 25.04520210 deg Eccentricity = 0.04867396 Semimajor axis = 2.92274025 AU Perihelion dist = 2.78047890 AU Mag: H = 8.41, G = 0.15 Epoch of elements : MJD 56254.46500000 TDT (2012 Nov 23.465) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Nov 23 705 Erminia 11h 8.8m UT 13.0 13 24 13.916-12 36 52.572UCAC 27302218 0.0 14.2 150 3.7 3.639 3.111 -30.33 -28.9685 -12.606 9.44 -20.47 11.1466 0.01804 0.02726 18.84067-12.55067 -0.00345 0.00107 2000 83.63375620121119.00000100.254860 2.920563 25.0452020.04867396 2.9227403 2.7804789 8.4 5.00.15 RATE 1.9725080 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.041 0.034 174 1.67 0.038 0 0-1 4 056225.0020121123_302218 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Oct 25, 05:41 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org