IOTA/IOTA-ES occultation update for (306) Unitas / TYC 5767-02388-1 event on 2008 Mar 27, 09:37 UT Visible from Argentina, Chile Summary ------- On 2008 Mar 27 UT, the 47 km diameter asteroid (306) Unitas will occult a 11.5 mag star in the constellation Capricornus for observers along a path across Argentina, Chile. In the case of an occultation, the combined light of the asteroid and the star will drop by 2.2 mag to 13.5 mag (the magnitude of the asteroid) for at most 1.3 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: 71 * date and approx. time of event: 2008 Mar 27, 09:34 - 2008 Mar 27, 09:35 UT * midpoint of event [JD]: 2454552.90080417 * magnitude of target star: 11.5 * magnitude drop [mag]: 2.2 * estimated maximum duration [s]: 1.3 * Moon: 73 % sunlit, 60° distance * Sun: 59° distance * rough path description: Argentina, Chile The occultation path -------------------- * approximate projected width [km]: 50 * 1 sigma uncertainty interval [path widths]: +/- 0.81 * 1 sigma uncertainty interval [seconds]: +/- 1.6 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .036 +/- .022) * 1 sigma uncertainty ellipse (major, minor, PA): ( .036", .022", 89° ) * approx speed of asteroid's shadow [km/s]: 36.2900 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 5767-02388-1 by 306 Unitas on 2008 Mar 27 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 -118 0 0 -32 40 19 9 34 25 1 107 -53 -32 54 34 -32 26 6 -33 17 41 -32 3 6 -117 0 0 -32 55 42 9 34 25 2 106 -52 -33 9 56 -32 41 30 -33 33 2 -32 18 32 -116 0 0 -33 10 51 9 34 25 3 106 -51 -33 25 3 -32 56 39 -33 48 8 -32 33 43 -115 0 0 -33 25 44 9 34 25 3 105 -50 -33 39 56 -33 11 34 -34 2 59 -32 48 39 -114 0 0 -33 40 23 9 34 25 4 104 -49 -33 54 34 -33 26 13 -34 17 35 -33 3 20 -113 0 0 -33 54 46 9 34 26 5 104 -49 -34 8 56 -33 40 38 -34 31 56 -33 17 46 -112 0 0 -34 8 54 9 34 26 6 103 -48 -34 23 3 -33 54 47 -34 46 1 -33 31 57 -111 0 0 -34 22 47 9 34 26 7 103 -47 -34 36 55 -34 8 40 -34 59 51 -33 45 52 -110 0 0 -34 36 24 9 34 27 8 102 -46 -34 50 31 -34 22 18 -35 13 25 -33 59 32 -109 0 0 -34 49 45 9 34 27 9 102 -46 -35 3 51 -34 35 41 -35 26 44 -34 12 55 -108 0 0 -35 2 50 9 34 27 9 101 -45 -35 16 55 -34 48 47 -35 39 46 -34 26 3 -107 0 0 -35 15 40 9 34 28 10 100 -44 -35 29 43 -35 1 37 -35 52 33 -34 38 55 -106 0 0 -35 28 13 9 34 28 11 100 -43 -35 42 16 -35 14 12 -36 5 4 -34 51 31 -105 0 0 -35 40 30 9 34 29 12 99 -42 -35 54 32 -35 26 30 -36 17 18 -35 3 51 -104 0 0 -35 52 31 9 34 30 13 99 -42 -36 6 32 -35 38 32 -36 29 16 -35 15 55 -103 0 0 -36 4 15 9 34 30 14 98 -41 -36 18 15 -35 50 17 -36 40 58 -35 27 42 -102 0 0 -36 15 43 9 34 31 14 98 -40 -36 29 42 -36 1 46 -36 52 24 -35 39 12 -101 0 0 -36 26 55 9 34 32 15 97 -39 -36 40 53 -36 12 59 -37 3 32 -35 50 26 -100 0 0 -36 37 50 9 34 32 16 96 -39 -36 51 47 -36 23 54 -37 14 25 -36 1 24 - 99 0 0 -36 48 28 9 34 33 17 96 -38 -37 2 24 -36 34 34 -37 25 1 -36 12 5 - 98 0 0 -36 58 50 9 34 34 18 95 -37 -37 12 45 -36 44 56 -37 35 20 -36 22 29 - 97 0 0 -37 8 55 9 34 35 19 94 -36 -37 22 48 -36 55 2 -37 45 22 -36 32 36 - 96 0 0 -37 18 43 9 34 36 19 94 -35 -37 32 36 -37 4 51 -37 55 8 -36 42 26 - 95 0 0 -37 28 14 9 34 37 20 93 -35 -37 42 6 -37 14 23 -38 4 36 -36 52 0 - 94 0 0 -37 37 28 9 34 37 21 92 -34 -37 51 19 -37 23 38 -38 13 48 -37 1 16 - 93 0 0 -37 46 25 9 34 38 22 92 -33 -38 0 16 -37 32 36 -38 22 43 -37 10 16 - 92 0 0 -37 55 6 9 34 39 23 91 -32 -38 8 55 -37 41 18 -38 31 21 -37 18 59 - 91 0 0 -38 3 29 9 34 40 23 90 -31 -38 17 18 -37 49 42 -38 39 43 -37 27 24 - 90 0 0 -38 11 35 9 34 42 24 90 -31 -38 25 23 -37 57 49 -38 47 47 -37 35 32 - 89 0 0 -38 19 25 9 34 43 25 89 -30 -38 33 12 -38 5 39 -38 55 34 -37 43 24 - 88 0 0 -38 26 57 9 34 44 26 88 -29 -38 40 43 -38 13 12 -39 3 4 -37 50 58 - 87 0 0 -38 34 12 9 34 45 26 88 -28 -38 47 57 -38 20 28 -39 10 17 -37 58 15 - 86 0 0 -38 41 10 9 34 46 27 87 -28 -38 54 55 -38 27 26 -39 17 13 -38 5 15 - 85 0 0 -38 47 51 9 34 47 28 86 -27 -39 1 35 -38 34 8 -39 23 52 -38 11 57 - 84 0 0 -38 54 14 9 34 49 29 86 -26 -39 7 58 -38 40 32 -39 30 14 -38 18 23 - 83 0 0 -39 0 21 9 34 50 30 85 -25 -39 14 3 -38 46 39 -39 36 19 -38 24 31 - 82 0 0 -39 6 10 9 34 51 30 84 -24 -39 19 52 -38 52 29 -39 42 6 -38 30 22 - 81 0 0 -39 11 42 9 34 52 31 83 -24 -39 25 24 -38 58 2 -39 47 37 -38 35 56 - 80 0 0 -39 16 57 9 34 54 32 83 -23 -39 30 38 -39 3 17 -39 52 50 -38 41 12 - 79 0 0 -39 21 55 9 34 55 33 82 -22 -39 35 35 -39 8 16 -39 57 47 -38 46 11 - 78 0 0 -39 26 35 9 34 57 33 81 -21 -39 40 15 -39 12 57 -40 2 26 -38 50 53 - 77 0 0 -39 30 59 9 34 58 34 80 -21 -39 44 38 -39 17 20 -40 6 48 -38 55 18 - 76 0 0 -39 35 5 9 34 59 35 80 -20 -39 48 43 -39 21 27 -40 10 53 -38 59 25 - 75 0 0 -39 38 53 9 35 1 36 79 -19 -39 52 32 -39 25 16 -40 14 40 -39 3 15 - 74 0 0 -39 42 25 9 35 2 36 78 -18 -39 56 3 -39 28 48 -40 18 11 -39 6 48 - 73 0 0 -39 45 39 9 35 4 37 77 -18 -39 59 17 -39 32 3 -40 21 24 -39 10 3 - 72 0 0 -39 48 37 9 35 5 38 76 -17 -40 2 14 -39 35 0 -40 24 20 -39 13 1 - 71 0 0 -39 51 16 9 35 7 39 76 -16 -40 4 53 -39 37 41 -40 26 59 -39 15 42 - 70 0 0 -39 53 39 9 35 9 39 75 -15 -40 7 16 -39 40 4 -40 29 21 -39 18 5 - 69 0 0 -39 55 44 9 35 10 40 74 -14 -40 9 21 -39 42 9 -40 31 26 -39 20 11 - 68 0 0 -39 57 33 9 35 12 41 73 -14 -40 11 9 -39 43 57 -40 33 14 -39 22 0 - 67 0 0 -39 59 3 9 35 14 42 72 -13 -40 12 39 -39 45 28 -40 34 44 -39 23 31 - 66 0 0 -40 0 17 9 35 15 42 71 -12 -40 13 53 -39 46 42 -40 35 57 -39 24 45 - 65 0 0 -40 1 13 9 35 17 43 70 -11 -40 14 49 -39 47 39 -40 36 53 -39 25 42 - 64 0 0 -40 1 52 9 35 19 44 70 -11 -40 15 28 -39 48 18 -40 37 32 -39 26 21 - 63 0 0 -40 2 14 9 35 21 44 69 -10 -40 15 50 -39 48 40 -40 37 54 -39 26 43 - 62 0 0 -40 2 19 9 35 22 45 68 -9 -40 15 54 -39 48 44 -40 37 58 -39 26 47 - 61 0 0 -40 2 6 9 35 24 46 67 -8 -40 15 42 -39 48 31 -40 37 45 -39 26 34 - 60 0 0 -40 1 36 9 35 26 47 66 -8 -40 15 12 -39 48 1 -40 37 15 -39 26 4 - 59 0 0 -40 0 48 9 35 28 47 65 -7 -40 14 24 -39 47 14 -40 36 28 -39 25 17 - 58 0 0 -39 59 44 9 35 30 48 64 -6 -40 13 20 -39 46 9 -40 35 24 -39 24 12 - 57 0 0 -39 58 22 9 35 32 49 63 -5 -40 11 58 -39 44 47 -40 34 2 -39 22 49 - 56 0 0 -39 56 43 9 35 33 49 62 -4 -40 10 19 -39 43 8 -40 32 24 -39 21 10 - 55 0 0 -39 54 46 9 35 35 50 61 -4 -40 8 22 -39 41 11 -40 30 28 -39 19 13 - 54 0 0 -39 52 32 9 35 37 51 60 -3 -40 6 9 -39 38 57 -40 28 14 -39 16 58 - 53 0 0 -39 50 1 9 35 39 51 58 -2 -40 3 38 -39 36 25 -40 25 44 -39 14 26 - 52 0 0 -39 47 12 9 35 41 52 57 -1 -40 0 49 -39 33 36 -40 22 56 -39 11 37 - 51 0 0 -39 44 6 9 35 43 53 56 -1 -39 57 44 -39 30 30 -40 19 51 -39 8 30 Uncertainty in time = +/- 2 secs [Prediction of 2008 Feb 14.0] Data for the target star ------------------------ * name: TYC 5767-02388-1 * constellation : Capricornus * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 20 36 36.8373 DE: -14 27 54.836 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .033, .020 ) * V mag [mag]: 11.5 * B mag [mag]: 12.2 * Apparent position with proper motion RA(deg): 309.2681414787 DE(deg): -14.4384224637 * Equation of equinoxes (radians) : 0.000040698654924 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (306) Unitas approx. diameter [km]: 47 approx. diameter ["]: .028 distance from Earth [AU]: 2.35300 * orbital information: orbit source: Preston date of fit: 2008 Feb 13 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 710 number of rejected observations: 135 time covered by the observations: 1902 Mar 13 - 2007 Jul 25 1 sigma uncertainty ellipse (major, minor, PA): 0.015, 0.008, 83° remarks: * orbital elements for (306) Unitas : Mean anomaly = 340.17219603 deg Arg. of pericenter = 167.43785406 deg Long. of node = 142.01571587 deg Inclination = 7.26883463 deg Eccentricity = 0.15063093 Semimajor axis = 2.35868896 AU Perihelion dist = 2.00339746 AU Mag: H = 8.69, G = 0.15 Epoch of elements : MJD 54552.40100000 TDT (2008 Mar 27.401) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Mar 27 306 Unitas 9h 37.2m UT 11.5 20 36 36.837-14 27 54.84TYC 5767-02388-1 12.3 13.5 47 1.3 2.353 5.140 17.04 -20.3286 -14.470 37.04 2.82 9.6193 0.07924 -0.34241 19.96940 4.55851 -0.00446 -0.00096 2000 339.5189302008 325.00000167.437854142.015716 7.2688350.15063093 2.3586890 2.0033974 9.0 5.00.15 RATE 2.7208090 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.036 0.022 89 1.81 0.022 0 54510.5020080327_2388-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Feb 14, 19:56 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org