IOTA/IOTA-ES occultation update for (410) Chloris / HIP 34218 event on 2012 Sep 24, 09:47 UT Visible from Peru Summary ------- On 2012 Sep 24 UT, the 107 km diameter asteroid (410) Chloris will occult a 7.9 mag star in the constellation Gemini for observers along a path across Peru. In the case of an occultation, the combined light of the asteroid and the star will drop by 6.6 mag to 14.5 mag (the magnitude of the asteroid) for at most 5.4 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: . The event at a glimpse ---------------------- * Rank: 99 * date and approx. time of event: 2012 Sep 24, 09:42 - 2012 Sep 24, 09:46 UT * geocentric midpoint of event [JD]: 2456194.9081875 * magnitude of target star: 7.9 * magnitude drop [mag]: 6.6 * estimated maximum duration [s]: 5.4 * Moon: 68 % sunlit, 172° distance * Sun: 76° distance * rough path description: Peru Additional comments ------------------- 1.8" double star The occultation path -------------------- * approximate projected width [km]: 116 * 1 sigma uncertainty interval [path widths]: +/- 0.34 * 1 sigma uncertainty interval [seconds]: +/- 2.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .022 +/- .014) * 1 sigma uncertainty ellipse (major, minor, PA): ( .022", .014", 89° ) * approx speed of asteroid's shadow [km/s]: 19.8962 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of HIP 34218 by 410 Chloris on 2012 Sep 24 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 -124 0 0 -20 3 48 9 42 52 1 67 -59 -20 37 44 -19 30 1 -21 0 53 -19 7 8 -123 0 0 -19 40 27 9 42 53 2 67 -58 -20 14 22 -19 6 41 -20 37 31 -18 43 49 -122 0 0 -19 17 8 9 42 53 3 67 -58 -19 51 2 -18 43 24 -20 14 10 -18 20 31 -121 0 0 -18 53 52 9 42 53 4 66 -57 -19 27 44 -18 20 8 -19 50 52 -17 57 17 -120 0 0 -18 30 39 9 42 54 5 66 -57 -19 4 30 -17 56 56 -19 27 36 -17 34 6 -119 0 0 -18 7 29 9 42 54 6 66 -56 -18 41 19 -17 33 48 -19 4 24 -17 10 59 -118 0 0 -17 44 24 9 42 55 7 65 -55 -18 18 12 -17 10 44 -18 41 16 -16 47 56 -117 0 0 -17 21 24 9 42 56 8 65 -55 -17 55 10 -16 47 46 -18 18 13 -16 24 58 -116 0 0 -16 58 29 9 42 57 9 65 -54 -17 32 14 -16 24 53 -17 55 16 -16 2 6 -115 0 0 -16 35 40 9 42 58 10 65 -53 -17 9 23 -16 2 5 -17 32 24 -15 39 20 -114 0 0 -16 12 58 9 42 59 11 64 -53 -16 46 39 -15 39 25 -17 9 39 -15 16 41 -113 0 0 -15 50 23 9 43 0 12 64 -52 -16 24 3 -15 16 52 -16 47 1 -14 54 9 -112 0 0 -15 27 56 9 43 1 13 64 -51 -16 1 34 -14 54 27 -16 24 31 -14 31 46 -111 0 0 -15 5 38 9 43 3 14 63 -50 -15 39 13 -14 32 10 -16 2 8 -14 9 30 -110 0 0 -14 43 28 9 43 4 15 63 -50 -15 17 1 -14 10 3 -15 39 55 -13 47 24 -109 0 0 -14 21 28 9 43 6 16 63 -49 -14 54 59 -13 48 5 -15 17 51 -13 25 28 -108 0 0 -13 59 37 9 43 8 17 62 -48 -14 33 6 -13 26 17 -14 55 57 -13 3 41 -107 0 0 -13 37 58 9 43 10 18 62 -47 -14 11 25 -13 4 40 -14 34 14 -12 42 5 -106 0 0 -13 16 29 9 43 12 19 62 -46 -13 49 54 -12 43 13 -14 12 42 -12 20 41 -105 0 0 -12 55 13 9 43 14 20 62 -45 -13 28 35 -12 21 59 -13 51 21 -11 59 28 -104 0 0 -12 34 8 9 43 16 21 61 -45 -13 7 28 -12 0 57 -13 30 12 -11 38 27 -103 0 0 -12 13 16 9 43 18 22 61 -44 -12 46 33 -11 40 7 -13 9 16 -11 17 40 -102 0 0 -11 52 38 9 43 21 23 61 -43 -12 25 52 -11 19 31 -12 48 33 -10 57 5 -101 0 0 -11 32 13 9 43 23 24 60 -42 -12 5 24 -10 59 9 -12 28 4 -10 36 45 -100 0 0 -11 12 2 9 43 26 25 60 -41 -11 45 11 -10 39 1 -12 7 48 -10 16 38 - 99 0 0 -10 52 6 9 43 29 26 60 -40 -11 25 12 -10 19 7 -11 47 48 - 9 56 46 - 98 0 0 -10 32 25 9 43 32 27 60 -39 -11 5 29 - 9 59 29 -11 28 2 - 9 37 10 - 97 0 0 -10 12 59 9 43 35 28 59 -38 -10 46 0 - 9 40 6 -11 8 32 - 9 17 49 - 96 0 0 - 9 53 50 9 43 38 29 59 -37 -10 26 48 - 9 20 59 -10 49 19 - 8 58 44 - 95 0 0 - 9 34 57 9 43 41 30 59 -36 -10 7 53 - 9 2 9 -10 30 21 - 8 39 55 - 94 0 0 - 9 16 21 9 43 44 31 58 -35 - 9 49 14 - 8 43 36 -10 11 40 - 8 21 24 - 93 0 0 - 8 58 2 9 43 48 32 58 -34 - 9 30 52 - 8 25 20 - 9 53 17 - 8 3 10 - 92 0 0 - 8 40 1 9 43 51 33 58 -33 - 9 12 49 - 8 7 21 - 9 35 11 - 7 45 13 - 91 0 0 - 8 22 18 9 43 54 34 57 -32 - 8 55 3 - 7 49 41 - 9 17 24 - 7 27 35 - 90 0 0 - 8 4 53 9 43 58 35 57 -32 - 8 37 36 - 7 32 19 - 8 59 54 - 7 10 15 - 89 0 0 - 7 47 48 9 44 2 36 57 -31 - 8 20 27 - 7 15 16 - 8 42 44 - 6 53 13 - 88 0 0 - 7 31 1 9 44 6 37 56 -30 - 8 3 38 - 6 58 32 - 8 25 53 - 6 36 31 - 87 0 0 - 7 14 34 9 44 10 38 56 -29 - 7 47 8 - 6 42 8 - 8 9 22 - 6 20 9 - 86 0 0 - 6 58 27 9 44 14 39 55 -28 - 7 30 58 - 6 26 4 - 7 53 10 - 6 4 6 - 85 0 0 - 6 42 40 9 44 18 40 55 -27 - 7 15 9 - 6 10 19 - 7 37 18 - 5 48 24 - 84 0 0 - 6 27 14 9 44 22 41 55 -26 - 6 59 40 - 5 54 56 - 7 21 48 - 5 33 2 - 83 0 0 - 6 12 8 9 44 26 42 54 -25 - 6 44 32 - 5 39 53 - 7 6 37 - 5 18 1 - 82 0 0 - 5 57 24 9 44 30 43 54 -24 - 6 29 44 - 5 25 11 - 6 51 49 - 5 3 20 - 81 0 0 - 5 43 0 9 44 35 44 53 -23 - 6 15 19 - 5 10 50 - 6 37 21 - 4 49 1 - 80 0 0 - 5 28 59 9 44 39 45 53 -22 - 6 1 15 - 4 56 51 - 6 23 15 - 4 35 4 - 79 0 0 - 5 15 19 9 44 43 46 52 -21 - 5 47 32 - 4 43 14 - 6 9 31 - 4 21 28 - 78 0 0 - 5 2 2 9 44 48 47 52 -20 - 5 34 12 - 4 29 59 - 5 56 10 - 4 8 15 - 77 0 0 - 4 49 7 9 44 53 48 51 -19 - 5 21 15 - 4 17 6 - 5 43 11 - 3 55 24 - 76 0 0 - 4 36 34 9 44 57 49 50 -18 - 5 8 40 - 4 4 36 - 5 30 34 - 3 42 55 - 75 0 0 - 4 24 24 9 45 2 50 50 -17 - 4 56 28 - 3 52 28 - 5 18 21 - 3 30 49 - 74 0 0 - 4 12 38 9 45 7 51 49 -16 - 4 44 39 - 3 40 44 - 5 6 30 - 3 19 6 - 73 0 0 - 4 1 14 9 45 12 52 48 -15 - 4 33 13 - 3 29 22 - 4 55 3 - 3 7 46 - 72 0 0 - 3 50 14 9 45 17 53 47 -14 - 4 22 11 - 3 18 24 - 4 43 59 - 2 56 50 - 71 0 0 - 3 39 38 9 45 22 53 47 -13 - 4 11 33 - 3 7 50 - 4 33 19 - 2 46 17 - 70 0 0 - 3 29 25 9 45 27 54 46 -12 - 4 1 18 - 2 57 39 - 4 23 3 - 2 36 7 - 69 0 0 - 3 19 36 9 45 32 55 45 -11 - 3 51 27 - 2 47 52 - 4 13 11 - 2 26 22 - 68 0 0 - 3 10 12 9 45 37 56 44 -10 - 3 42 1 - 2 38 30 - 4 3 43 - 2 17 0 - 67 0 0 - 3 1 11 9 45 42 57 43 -9 - 3 32 59 - 2 29 31 - 3 54 40 - 2 8 3 - 66 0 0 - 2 52 35 9 45 48 58 42 -7 - 3 24 21 - 2 20 57 - 3 46 1 - 1 59 30 - 65 0 0 - 2 44 23 9 45 53 58 41 -6 - 3 16 8 - 2 12 47 - 3 37 47 - 1 51 21 - 64 0 0 - 2 36 36 9 45 58 59 39 -5 - 3 8 19 - 2 5 1 - 3 29 57 - 1 43 36 - 63 0 0 - 2 29 14 9 46 4 60 38 -4 - 3 0 55 - 1 57 40 - 3 22 32 - 1 36 17 - 62 0 0 - 2 22 17 9 46 9 60 37 -3 - 2 53 56 - 1 50 44 - 3 15 32 - 1 29 22 - 61 0 0 - 2 15 44 9 46 14 61 35 -2 - 2 47 23 - 1 44 13 - 3 8 58 - 1 22 51 - 60 0 0 - 2 9 37 9 46 20 62 34 -1 - 2 41 14 - 1 38 7 - 3 2 48 - 1 16 46 - 59 0 0 - 2 3 55 9 46 25 62 32 0 - 2 35 30 - 1 32 26 - 2 57 4 - 1 11 6 Uncertainty in time = +/- 3 secs Prediction of 2012 Aug 7.0 Data for the target star ------------------------ * name: HIP 34218 * constellation : Gemini * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 05 41.1183 DE: +20 59 44.876 * position source: mpos:HIP2 pm:HIP2 plx:HIP2 * standard error: RA,DE ["]: ( .020, .012 ) * V mag [mag]: 7.9 * B mag [mag]: 8.1 * Diameter [mas]: 0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (410) Chloris approx. diameter [km]: 107 approx. diameter ["]: .042 distance from Earth [AU]: 3.47600 * orbital information: orbit source: Preston date of fit: 2012 Aug 06 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 1111 number of rejected observations: 83 time covered by the observations: 1910 Mar 08 - 2012 Mar 15 1 sigma uncertainty ellipse (major, minor, PA): 0.010, 0.007, 86° remarks: * orbital elements for (410) Chloris : Mean anomaly = 177.89537873 deg Arg. of pericenter = 172.78159566 deg Long. of node = 96.95024817 deg Inclination = 10.95620748 deg Eccentricity = 0.23946119 Semimajor axis = 2.72793889 AU Perihelion dist = 2.07470340 AU Mag: H = 8.17, G = 0.15 Epoch of elements : MJD 56194.40800000 TDT (2012 Sep 24.408) ------ occelmnt file for Occult BEGIN ----------------------------------- 2012 Sep 24 410 Chloris 9h 47.8m UT 7.9 7 5 41.118 20 59 44.88HIP 34218 8.1 14.5 107 5.4 3.476 2.028 -0.38 -44.1608 20.996 31.03 -0.70 9.7965 -0.00885 -0.38179 11.22897 -0.15119 -0.00563 0.00060 2000 176.9311202012 920.00000172.781596 96.950248 10.9562070.23946119 2.7279389 2.0747034 8.3 5.00.15 RATE 2.1875200 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.022 0.014 89 1.34 0.014 0 0 3-4 056146.0020120924__34218 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2012 Aug 06, 20:55 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org