IOTA/IOTA-ES occultation update for (1958) Chandra / TYC 7445-01373-1 event on 2008 May 19, 04:51 UT Visible from Africa Summary ------- On 2008 May 19 UT, the 34 km diameter asteroid (1958) Chandra will occult a 9.8 mag star in the constellation Sagittarius 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 5.4 mag to 15.2 mag (the magnitude of the asteroid) for at most 7.0 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: 35 * date and approx. time of event: 2008 May 19, 04:31 - 2008 May 19, 05:00 UT * midpoint of event [JD]: 2454605.70274583 * magnitude of target star: 9.8 * magnitude drop [mag]: 5.4 * estimated maximum duration [s]: 7.0 * Moon: 99 % sunlit, 68° distance * Sun: 120° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 36 * 1 sigma uncertainty interval [path widths]: +/- 1.88 * 1 sigma uncertainty interval [seconds]: +/- 11.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .049 +/- .042) * 1 sigma uncertainty ellipse (major, minor, PA): ( .050", .041", 70° ) * approx speed of asteroid's shadow [km/s]: 4.8741 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 7445-01373-1 by 1958 Chandra on 2008 May 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 - 66 0 0 33 52 33 4 31 11 0 132 -36 33 39 47 34 5 20 32 51 57 .. .. .. - 65 0 0 33 7 17 4 31 11 1 132 -37 32 54 28 33 20 7 32 6 27 34 8 30 - 64 0 0 32 21 12 4 31 12 3 133 -38 32 8 21 32 34 5 31 20 8 33 22 40 - 63 0 0 31 34 20 4 31 14 4 134 -38 31 21 26 31 47 16 30 33 3 32 36 2 - 62 0 0 30 46 42 4 31 16 5 134 -39 30 33 45 30 59 40 29 45 11 31 48 36 - 61 0 0 29 58 18 4 31 18 6 135 -40 29 45 18 30 11 18 28 56 35 31 0 24 - 60 0 0 29 9 9 4 31 21 7 135 -40 28 56 6 29 22 12 28 7 14 30 11 27 - 59 0 0 28 19 16 4 31 25 8 136 -41 28 6 12 28 32 22 27 17 11 29 21 46 - 58 0 0 27 28 42 4 31 30 10 136 -42 27 15 35 27 41 49 26 26 26 28 31 21 - 57 0 0 26 37 27 4 31 35 11 137 -42 26 24 18 26 50 36 25 35 2 27 40 16 - 56 0 0 25 45 33 4 31 41 12 137 -43 25 32 22 25 58 44 24 42 59 26 48 30 - 55 0 0 24 53 2 4 31 48 13 137 -43 24 39 49 25 6 15 23 50 20 25 56 7 - 54 0 0 23 59 55 4 31 56 15 138 -44 23 46 42 24 13 10 22 57 7 25 3 8 - 53 0 0 23 6 16 4 32 4 16 138 -44 22 53 1 23 19 32 22 3 22 24 9 34 - 52 0 0 22 12 6 4 32 13 17 139 -45 21 58 50 22 25 23 21 9 7 23 15 29 - 51 0 0 21 17 27 4 32 22 19 139 -45 21 4 10 21 30 45 20 14 24 22 20 54 - 50 0 0 20 22 22 4 32 33 20 140 -46 20 9 5 20 35 41 19 19 17 21 25 52 - 49 0 0 19 26 54 4 32 44 21 140 -46 19 13 37 19 40 13 18 23 47 20 30 26 - 48 0 0 18 31 6 4 32 57 23 140 -46 18 17 48 18 44 25 17 27 58 19 34 38 - 47 0 0 17 35 0 4 33 9 24 141 -47 17 21 43 17 48 19 16 31 53 18 38 32 - 46 0 0 16 38 40 4 33 23 25 141 -47 16 25 22 16 51 58 15 35 34 17 42 10 - 45 0 0 15 42 8 4 33 38 27 142 -47 15 28 51 15 55 26 14 39 5 16 45 35 - 44 0 0 14 45 28 4 33 53 28 142 -47 14 32 12 14 58 45 13 42 29 15 48 51 - 43 0 0 13 48 43 4 34 9 30 142 -48 13 35 28 14 1 59 12 45 49 14 52 1 - 42 0 0 12 51 56 4 34 26 31 143 -48 12 38 43 13 5 11 11 49 8 13 55 8 - 41 0 0 11 55 11 4 34 44 32 143 -48 11 41 59 12 8 24 10 52 31 12 58 15 - 40 0 0 10 58 31 4 35 2 34 144 -48 10 45 21 11 11 42 9 56 0 12 1 27 - 39 0 0 10 2 0 4 35 21 35 144 -48 9 48 52 10 15 9 8 59 38 11 4 45 - 38 0 0 9 5 40 4 35 41 36 144 -47 8 52 35 9 18 47 8 3 30 10 8 15 - 37 0 0 8 9 36 4 36 1 38 145 -47 7 56 33 8 22 40 7 7 37 9 11 59 - 36 0 0 7 13 51 4 36 23 39 145 -47 7 0 50 7 26 52 6 12 5 8 16 0 - 35 0 0 6 18 27 4 36 44 41 146 -47 6 5 29 6 31 25 5 16 55 7 20 22 - 34 0 0 5 23 28 4 37 7 42 146 -46 5 10 34 5 36 24 4 22 12 6 25 8 - 33 0 0 4 28 58 4 37 30 43 147 -46 4 16 7 4 41 50 3 27 57 5 30 22 - 32 0 0 3 34 58 4 37 53 45 147 -46 3 22 11 3 47 47 2 34 14 4 36 5 - 31 0 0 2 41 33 4 38 17 46 148 -45 2 28 49 2 54 18 1 41 7 3 42 22 - 30 0 0 1 48 44 4 38 42 47 148 -45 1 36 5 2 1 25 0 48 37 2 49 15 - 29 0 0 0 56 35 4 39 7 49 149 -44 0 43 59 1 9 12 - 0 3 14 1 56 47 - 28 0 0 0 5 8 4 39 32 50 149 -44 - 0 7 24 0 17 40 - 0 54 21 1 4 59 - 27 0 0 - 0 45 35 4 39 58 51 150 -43 - 0 58 3 - 0 33 7 - 1 44 44 0 13 56 - 26 0 0 - 1 35 32 4 40 24 52 151 -42 - 1 47 55 - 1 23 8 - 2 34 20 - 0 36 22 - 25 0 0 - 2 24 41 4 40 50 54 151 -42 - 2 36 59 - 2 12 21 - 3 23 7 - 1 25 52 - 24 0 0 - 3 12 59 4 41 16 55 152 -41 - 3 25 13 - 3 0 44 - 4 11 4 - 2 14 33 - 23 0 0 - 4 0 26 4 41 43 56 153 -40 - 4 12 35 - 3 48 16 - 4 58 9 - 3 2 21 - 22 0 0 - 4 46 59 4 42 10 57 154 -40 - 4 59 3 - 4 34 53 - 5 44 20 - 3 49 17 - 21 0 0 - 5 32 37 4 42 38 58 155 -39 - 5 44 37 - 5 20 37 - 6 29 36 - 4 35 18 - 20 0 0 - 6 17 20 4 43 5 60 156 -38 - 6 29 15 - 6 5 24 - 7 13 56 - 5 20 23 - 19 0 0 - 7 1 5 4 43 32 61 157 -37 - 7 12 56 - 6 49 14 - 7 57 18 - 6 4 31 - 18 0 0 - 7 43 53 4 44 0 62 158 -37 - 7 55 38 - 7 32 6 - 8 39 43 - 6 47 42 - 17 0 0 - 8 25 42 4 44 28 63 160 -36 - 8 37 22 - 8 14 0 - 9 21 10 - 7 29 53 - 16 0 0 - 9 6 31 4 44 55 64 161 -35 - 9 18 7 - 8 54 54 -10 1 37 - 8 11 6 - 15 0 0 - 9 46 21 4 45 23 65 163 -34 - 9 57 52 - 9 34 48 -10 41 4 - 8 51 18 - 14 0 0 -10 25 10 4 45 51 66 164 -33 -10 36 37 -10 13 43 -11 19 31 - 9 30 30 - 13 0 0 -11 2 59 4 46 18 67 166 -32 -11 14 21 -10 51 36 -11 56 58 -10 8 41 - 12 0 0 -11 39 47 4 46 46 67 168 -31 -11 51 4 -11 28 29 -12 33 25 -10 45 51 - 11 0 0 -12 15 34 4 47 14 68 170 -31 -12 26 47 -12 4 20 -13 8 50 -11 22 0 - 10 0 0 -12 50 21 4 47 41 69 173 -30 -13 1 29 -12 39 11 -13 43 16 -11 57 7 - 9 0 0 -13 24 6 4 48 8 70 175 -29 -13 35 10 -13 13 1 -14 16 41 -12 31 14 - 8 0 0 -13 56 51 4 48 36 70 178 -28 -14 7 51 -13 45 51 -14 49 5 -13 4 20 - 7 0 0 -14 28 36 4 49 3 71 181 -27 -14 39 31 -14 17 39 -15 20 30 -13 36 24 - 6 0 0 -14 59 20 4 49 30 71 183 -26 -15 10 12 -14 48 28 -15 50 55 -14 7 28 - 5 0 0 -15 29 5 4 49 56 72 186 -25 -15 39 52 -15 18 16 -16 20 20 -14 37 32 - 4 0 0 -15 57 50 4 50 23 72 190 -24 -16 8 33 -15 47 5 -16 48 47 -15 6 36 - 3 0 0 -16 25 35 4 50 50 72 193 -23 -16 36 15 -16 14 55 -17 16 15 -15 34 40 - 2 0 0 -16 52 23 4 51 16 72 196 -22 -17 2 59 -16 41 46 -17 42 44 -16 1 45 - 1 0 0 -17 18 11 4 51 42 72 199 -21 -17 28 44 -17 7 38 -18 8 16 -16 27 51 0 0 0 -17 43 3 4 52 8 72 203 -21 -17 53 32 -17 32 33 -18 32 51 -16 52 59 1 0 0 -18 6 56 4 52 34 72 206 -20 -18 17 22 -17 56 30 -18 56 29 -17 17 9 2 0 0 -18 29 54 4 52 59 72 209 -19 -18 40 16 -18 19 30 -19 19 10 -17 40 21 3 0 0 -18 51 54 4 53 24 72 212 -18 -19 2 14 -18 41 34 -19 40 56 -18 2 37 4 0 0 -19 12 59 4 53 49 72 215 -17 -19 23 16 -19 2 43 -20 1 47 -18 23 57 5 0 0 -19 33 9 4 54 14 71 218 -16 -19 43 23 -19 22 55 -20 21 43 -18 44 21 6 0 0 -19 52 25 4 54 39 71 220 -15 -20 2 35 -19 42 13 -20 40 45 -19 3 49 7 0 0 -20 10 46 4 55 3 71 223 -14 -20 20 53 -20 0 37 -20 58 54 -19 22 23 8 0 0 -20 28 13 4 55 28 70 225 -13 -20 38 18 -20 18 7 -21 16 9 -19 40 3 9 0 0 -20 44 47 4 55 52 69 227 -12 -20 54 50 -20 34 44 -21 32 32 -19 56 49 10 0 0 -21 0 29 4 56 15 69 229 -11 -21 10 29 -20 50 27 -21 48 2 -20 12 41 11 0 0 -21 15 18 4 56 39 68 231 -11 -21 25 17 -21 5 19 -22 2 41 -20 27 41 12 0 0 -21 29 16 4 57 2 68 232 -10 -21 39 12 -21 19 19 -22 16 29 -20 41 49 13 0 0 -21 42 22 4 57 25 67 234 -9 -21 52 17 -21 32 27 -22 29 27 -20 55 5 14 0 0 -21 54 38 4 57 48 66 235 -8 -22 4 31 -21 44 45 -22 41 34 -21 7 30 15 0 0 -22 6 4 4 58 10 65 236 -7 -22 15 54 -21 56 12 -22 52 51 -21 19 3 16 0 0 -22 16 39 4 58 33 65 238 -6 -22 26 28 -22 6 49 -23 3 19 -21 29 47 17 0 0 -22 26 25 4 58 55 64 239 -5 -22 36 13 -22 16 37 -23 12 58 -21 39 40 18 0 0 -22 35 22 4 59 17 63 239 -4 -22 45 8 -22 25 35 -23 21 48 -21 48 43 19 0 0 -22 43 30 4 59 38 62 240 -3 -22 53 15 -22 33 44 -23 29 50 -21 56 57 20 0 0 -22 50 49 5 0 0 62 241 -2 -23 0 33 -22 41 5 -23 37 4 -22 4 22 21 0 0 -22 57 21 5 0 21 61 242 -2 -23 7 4 -22 47 37 -23 43 31 -22 10 58 22 0 0 -23 3 4 5 0 42 60 242 -1 -23 12 46 -22 53 22 -23 49 10 -22 16 46 Uncertainty in time = +/- 15 secs [Prediction of 2008 Apr 9.0] Data for the target star ------------------------ * name: TYC 7445-01373-1 * constellation : Sagittarius * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 20 08 35.0780 DE: -33 36 15.324 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .020, .025 ) * V mag [mag]: 9.8 * B mag [mag]: 11.2 * Apparent position with proper motion RA(deg): 302.2863325299 DE(deg): -33.5788181039 * Equation of equinoxes (radians) : 0.000039556916990 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (1958) Chandra approx. diameter [km]: 34 approx. diameter ["]: .024 distance from Earth [AU]: 1.95700 * orbital information: orbit source: Preston date of fit: 2008 Apr 08 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 844 number of rejected observations: 18 time covered by the observations: 1954 Oct 06 - 2007 Aug 09 1 sigma uncertainty ellipse (major, minor, PA): 0.046, 0.033, 66° remarks: * orbital elements for (1958) Chandra : Mean anomaly = 340.41632891 deg Arg. of pericenter = 319.80708387 deg Long. of node = 345.07899951 deg Inclination = 10.55810422 deg Eccentricity = 0.16998537 Semimajor axis = 3.10366120 AU Perihelion dist = 2.57608419 AU Mag: H = 11.17, G = 0.15 Epoch of elements : MJD 54605.20300000 TDT (2008 May 19.203) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 19 1958 Chandra 4h 52.0m UT 9.8 20 8 35.078-33 36 15.32TYC 7445-01373-1 11.2 15.2 34 7.0 1.957 0.899 -5.13 -8.0782 -33.602 106.14 19.85 4.8659 0.12491 0.27337 2.50311 -1.14142 -0.00474 -0.00038 2000 339.4784512008 514.00000319.807084345.079000 10.5581040.16998537 3.1036612 2.576084210.7 5.00.15 RATE 1.8025720 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.050 0.041 70 2.88 0.045 0 54565.5020080519_1373-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Apr 13, 03:16 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org