IOTA/IOTA-ES occultation update for (409) Aspasia / TYC 6104-00779-1 event on 2012 Dec 15, 03:27 UT Visible from Russia Summary ------- On 2012 Dec 15 UT, the 183 km diameter asteroid (409) Aspasia will occult a 10.7 mag star in the constellation Corvus for observers along a path across Russia. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.1 mag to 12.6 mag (the magnitude of the asteroid) for at most 6.2 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: 98 * date and approx. time of event: 2012 Dec 15, 03:25 - 2012 Dec 15, 03:26 UT * geocentric midpoint of event [JD]: 2456276.6442 * magnitude of target star: 10.7 * magnitude drop [mag]: 2.1 * estimated maximum duration [s]: 6.2 * Moon: 5 % sunlit, 94° distance * Sun: 68° distance * rough path description: Russia The occultation path -------------------- * approximate projected width [km]: 349 * 1 sigma uncertainty interval [path widths]: +/- 0.36 * 1 sigma uncertainty interval [seconds]: +/- 1.8 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .026 +/- .036) * 1 sigma uncertainty ellipse (major, minor, PA): ( .036", .026", 0° ) * approx speed of asteroid's shadow [km/s]: 29.5377 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 6104-00779-1 by 409 Aspasia on 2012 Dec 15 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 41 9 46 74 0 0 3 25 47 0 167 -21 35 20 39 47 7 7 ... .. .. 51 32 14 42 4 8 73 0 0 3 25 47 1 167 -21 36 33 58 47 42 13 ... .. .. 51 52 53 42 58 32 72 0 0 3 25 48 3 168 -20 37 45 4 48 19 38 ... .. .. 52 17 36 43 53 3 71 0 0 3 25 48 4 169 -20 38 54 25 48 59 6 ... .. .. 52 45 50 44 47 45 70 0 0 3 25 49 5 170 -19 40 2 19 49 40 22 ... .. .. 53 17 6 45 42 40 69 0 0 3 25 49 6 171 -19 41 9 4 50 23 16 37 55 10 53 51 5 46 37 51 68 0 0 3 25 50 7 172 -18 42 14 53 51 7 40 39 8 39 54 27 29 47 33 21 67 0 0 3 25 51 8 173 -17 43 19 58 51 53 27 40 20 39 55 6 5 48 29 13 66 0 0 3 25 52 9 174 -17 44 24 30 52 40 32 41 31 25 55 46 42 49 25 30 65 0 0 3 25 53 10 174 -16 45 28 37 53 28 52 42 41 12 56 29 10 50 22 14 64 0 0 3 25 55 11 175 -15 46 32 28 54 18 24 43 50 11 57 13 25 51 19 27 63 0 0 3 25 56 12 176 -14 47 36 10 55 9 6 44 58 33 57 59 20 52 17 13 62 0 0 3 25 58 13 177 -14 48 39 49 56 0 57 46 6 26 58 46 51 53 15 34 61 0 0 3 26 0 14 178 -13 49 43 31 56 53 56 47 14 0 59 35 56 54 14 34 60 0 0 3 26 2 15 179 -12 50 47 21 57 48 4 48 21 22 60 26 33 55 14 15 59 0 0 3 26 4 16 180 -11 51 51 26 58 43 22 49 28 38 61 18 40 56 14 40 58 0 0 3 26 6 17 181 -10 52 55 50 59 39 50 50 35 57 62 12 18 57 15 53 57 0 0 3 26 9 18 182 -9 54 0 39 60 37 31 51 43 23 63 7 27 58 17 58 56 0 0 3 26 11 19 183 -8 55 5 57 61 36 26 52 51 3 64 4 8 59 20 58 55 0 0 3 26 14 20 184 -7 56 11 50 62 36 39 53 59 3 65 2 24 60 24 58 54 0 0 3 26 17 21 186 -6 57 18 22 63 38 13 55 7 29 66 2 18 61 30 1 53 0 0 3 26 20 22 187 -5 58 25 39 64 41 11 56 16 26 67 3 52 62 36 14 52 0 0 3 26 23 23 188 -4 59 33 46 65 45 39 57 26 1 68 7 11 63 43 41 51 0 0 3 26 27 23 189 -3 60 42 49 66 51 41 58 36 19 69 12 20 64 52 28 50 0 0 3 26 31 24 191 -2 61 52 54 67 59 23 59 47 27 70 19 25 66 2 42 49 0 0 3 26 34 25 192 0 63 4 8 69 8 53 60 59 31 71 28 35 Uncertainty in time = +/- 2 secs Prediction of 2012 Dec 3.0 Data for the target star ------------------------ * name: TYC 6104-00779-1 * constellation : Corvus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 12 42 18.2335 DE: -15 07 29.387 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .025, .035 ) * V mag [mag]: 10.7 * B mag [mag]: 11.3 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (409) Aspasia approx. diameter [km]: 183 approx. diameter ["]: .094 distance from Earth [AU]: 2.67400 * orbital information: orbit source: Preston date of fit: 2012 Jul 10 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1505 number of rejected observations: 140 time covered by the observations: 1902 Jul 07 - 2012 Mar 04 1 sigma uncertainty ellipse (major, minor, PA): 0.009, 0.006, 104° remarks: * orbital elements for (409) Aspasia : Mean anomaly = 304.21746923 deg Arg. of pericenter = 354.17993184 deg Long. of node = 242.20794098 deg Inclination = 11.26160767 deg Eccentricity = 0.07261336 Semimajor axis = 2.57525318 AU Perihelion dist = 2.38825540 AU Mag: H = 7.66, G = 0.29 Epoch of elements : MJD 56276.14400000 TDT (2012 Dec 15.144) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Dec 15 409 Aspasia 3h 27.6m UT 10.7 12 42 18.233-15 7 29.39TYC 6104-00779-1 11.3 12.6 183 6.2 2.674 3.358 -25.32 54.4673 -15.117 126.89 -23.28 3.4608 0.39204 0.75588 14.78818 -7.69822 -0.00514 0.00181 2000 302.752173201212 9.00000354.179932242.207941 11.2616080.07261336 2.5752532 2.3882554 7.6 5.00.29 RATE 2.3849220 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.036 0.026 0 1.36 0.034 0 0 5 3 056264.0020121215_0779-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Jul 10, 05:26 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org