IOTA/IOTA-ES occultation update for (977) Philippa / TYC 1935-00619-1 event on 2008 Oct 12, 00:44 UT Visible from Africa Summary ------- On 2008 Oct 12 UT, the 66 km diameter asteroid (977) Philippa will occult a 9.5 mag star in the constellation Cancer 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 6.0 mag to 15.5 mag (the magnitude of the asteroid) for at most 3.1 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: 66 * date and approx. time of event: 2008 Oct 12, 00:39 - 2008 Oct 12, 00:43 UT * midpoint of event [JD]: 2454751.53055417 * magnitude of target star: 9.5 * magnitude drop [mag]: 6.0 * estimated maximum duration [s]: 3.1 * Moon: 90 % sunlit, 135° distance * Sun: 81° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 66 * 1 sigma uncertainty interval [path widths]: +/- 0.91 * 1 sigma uncertainty interval [seconds]: +/- 2.7 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .029 +/- .027) * 1 sigma uncertainty ellipse (major, minor, PA): ( .029", .027", 90° ) * approx speed of asteroid's shadow [km/s]: 21.3935 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 1935-00619-1 by 977 Philippa on 2008 Oct 12 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 5 0 0 - 5 31 12 0 39 2 1 63 -68 - 5 51 16 - 5 11 9 - 6 27 46 - 4 34 38 6 0 0 - 5 0 46 0 39 2 2 63 -67 - 5 20 51 - 4 40 42 - 5 57 23 - 4 4 10 7 0 0 - 4 30 12 0 39 2 3 63 -67 - 4 50 17 - 4 10 7 - 5 26 51 - 3 33 33 8 0 0 - 3 59 30 0 39 2 4 63 -66 - 4 19 36 - 3 39 24 - 4 56 12 - 3 2 48 9 0 0 - 3 28 41 0 39 3 6 63 -65 - 3 48 48 - 3 8 34 - 4 25 25 - 2 31 57 10 0 0 - 2 57 46 0 39 3 7 63 -65 - 3 17 54 - 2 37 39 - 3 54 32 - 2 1 1 11 0 0 - 2 26 46 0 39 4 8 63 -64 - 2 46 54 - 2 6 38 - 3 23 33 - 1 29 59 12 0 0 - 1 55 42 0 39 5 9 63 -63 - 2 15 51 - 1 35 34 - 2 52 30 - 0 58 54 13 0 0 - 1 24 35 0 39 6 10 63 -62 - 1 44 43 - 1 4 26 - 2 21 24 - 0 27 45 14 0 0 - 0 53 24 0 39 7 11 63 -62 - 1 13 34 - 0 33 15 - 1 50 14 0 3 26 15 0 0 - 0 22 13 0 39 8 12 63 -61 - 0 42 22 - 0 2 3 - 1 19 3 0 34 38 16 0 0 0 9 0 0 39 10 13 63 -60 - 0 11 10 0 29 9 - 0 47 51 1 5 50 17 0 0 0 40 12 0 39 11 15 63 -59 0 20 3 1 0 21 - 0 16 38 1 37 2 18 0 0 1 11 23 0 39 13 16 63 -58 0 51 14 1 31 32 0 14 34 2 8 13 19 0 0 1 42 33 0 39 14 17 63 -57 1 22 24 2 2 42 0 45 44 2 39 22 20 0 0 2 13 39 0 39 16 18 63 -57 1 53 31 2 33 48 1 16 51 3 10 27 21 0 0 2 44 42 0 39 18 19 63 -56 2 24 34 3 4 50 1 47 55 3 41 29 22 0 0 3 15 40 0 39 20 20 63 -55 2 55 33 3 35 48 2 18 55 4 12 25 23 0 0 3 46 33 0 39 22 21 63 -54 3 26 26 4 6 40 2 49 50 4 43 16 24 0 0 4 17 20 0 39 24 22 63 -53 3 57 14 4 37 26 3 20 39 5 14 0 25 0 0 4 47 59 0 39 26 24 63 -52 4 27 54 5 8 4 3 51 20 5 44 37 26 0 0 5 18 30 0 39 29 25 63 -51 4 58 26 5 38 34 4 21 54 6 15 6 27 0 0 5 48 52 0 39 31 26 63 -50 5 28 49 6 8 55 4 52 19 6 45 25 28 0 0 6 19 5 0 39 34 27 63 -49 5 59 3 6 39 7 5 22 35 7 15 34 29 0 0 6 49 7 0 39 37 28 63 -48 6 29 6 7 9 7 5 52 40 7 45 33 30 0 0 7 18 57 0 39 39 29 64 -47 6 58 58 7 38 56 6 22 35 8 15 19 31 0 0 7 48 36 0 39 42 30 64 -46 7 28 38 8 8 33 6 52 17 8 44 54 32 0 0 8 18 1 0 39 45 31 64 -45 7 58 5 8 37 58 7 21 47 9 14 15 33 0 0 8 47 13 0 39 48 33 64 -44 8 27 18 9 7 8 7 51 3 9 43 22 34 0 0 9 16 10 0 39 51 34 64 -43 8 56 17 9 36 4 8 20 5 10 12 15 35 0 0 9 44 53 0 39 55 35 64 -42 9 25 1 10 4 44 8 48 53 10 40 53 36 0 0 10 13 19 0 39 58 36 64 -41 9 53 30 10 33 9 9 17 24 11 9 14 37 0 0 10 41 29 0 40 1 37 65 -40 10 21 41 11 1 17 9 45 39 11 37 19 38 0 0 11 9 22 0 40 5 38 65 -39 10 49 36 11 29 8 10 13 38 12 5 6 39 0 0 11 36 57 0 40 8 39 65 -38 11 17 13 11 56 41 10 41 19 12 32 36 40 0 0 12 4 14 0 40 12 40 65 -37 11 44 32 12 23 56 11 8 41 12 59 47 41 0 0 12 31 12 0 40 16 41 65 -36 12 11 32 12 50 52 11 35 45 13 26 38 42 0 0 12 57 50 0 40 20 42 66 -35 12 38 13 13 17 28 12 2 29 13 53 11 43 0 0 13 24 8 0 40 23 43 66 -34 13 4 33 13 43 44 12 28 54 14 19 23 44 0 0 13 50 6 0 40 27 45 66 -33 13 30 33 14 9 39 12 54 58 14 45 14 45 0 0 14 15 43 0 40 31 46 66 -32 13 56 12 14 35 13 13 20 41 15 10 44 46 0 0 14 40 58 0 40 35 47 67 -31 14 21 29 15 0 26 13 46 2 15 35 52 47 0 0 15 5 51 0 40 39 48 67 -30 14 46 24 15 25 17 14 11 2 16 0 39 48 0 0 15 30 21 0 40 43 49 67 -29 15 10 57 15 49 45 14 35 39 16 25 3 49 0 0 15 54 29 0 40 48 50 67 -28 15 35 8 16 13 50 14 59 54 16 49 4 50 0 0 16 18 14 0 40 52 51 68 -27 15 58 55 16 37 32 15 23 45 17 12 41 51 0 0 16 41 35 0 40 56 52 68 -26 16 22 18 17 0 51 15 47 13 17 35 55 52 0 0 17 4 32 0 41 0 53 68 -25 16 45 18 17 23 46 16 10 17 17 58 45 53 0 0 17 27 5 0 41 5 54 68 -24 17 7 53 17 46 16 16 32 57 18 21 11 54 0 0 17 49 13 0 41 9 55 69 -23 17 30 4 18 8 22 16 55 13 18 43 13 55 0 0 18 10 57 0 41 14 56 69 -23 17 51 50 18 30 3 17 17 3 19 4 49 56 0 0 18 32 15 0 41 18 57 69 -22 18 13 11 18 51 19 17 38 29 19 26 1 57 0 0 18 53 8 0 41 23 58 70 -21 18 34 7 19 12 10 17 59 29 19 46 47 58 0 0 19 13 36 0 41 27 59 70 -20 18 54 37 19 32 35 18 20 4 20 7 8 59 0 0 19 33 38 0 41 32 60 70 -19 19 14 42 19 52 34 18 40 13 20 27 3 60 0 0 19 53 14 0 41 36 61 71 -18 19 34 20 20 12 8 18 59 56 20 46 32 61 0 0 20 12 24 0 41 41 62 71 -17 19 53 33 20 31 16 19 19 13 21 5 35 62 0 0 20 31 8 0 41 46 63 71 -16 20 12 19 20 49 57 19 38 3 21 24 12 63 0 0 20 49 25 0 41 50 64 72 -15 20 30 39 21 8 12 19 56 28 21 42 23 64 0 0 21 7 16 0 41 55 65 72 -14 20 48 32 21 26 1 20 14 25 22 0 7 65 0 0 21 24 41 0 42 0 66 72 -13 21 5 58 21 43 23 20 31 56 22 17 24 66 0 0 21 41 38 0 42 4 67 73 -12 21 22 58 22 0 18 20 49 0 22 34 15 67 0 0 21 58 9 0 42 9 68 73 -11 21 39 31 22 16 46 21 5 37 22 50 40 68 0 0 22 14 13 0 42 14 69 73 -10 21 55 38 22 32 48 21 21 48 23 6 37 69 0 0 22 29 50 0 42 19 70 74 -9 22 11 17 22 48 23 21 37 31 23 22 8 70 0 0 22 45 0 0 42 24 71 74 -8 22 26 29 23 3 30 21 52 47 23 37 12 71 0 0 22 59 42 0 42 28 72 74 -7 22 41 14 23 18 11 22 7 36 23 51 49 72 0 0 23 13 58 0 42 33 73 74 -7 22 55 31 23 32 25 22 21 57 24 5 58 73 0 0 23 27 47 0 42 38 74 75 -6 23 9 22 23 46 11 22 35 51 24 19 41 74 0 0 23 41 8 0 42 43 75 75 -5 23 22 45 23 59 31 22 49 18 24 32 57 75 0 0 23 54 2 0 42 48 76 75 -4 23 35 42 24 12 23 23 2 18 24 45 46 76 0 0 24 6 29 0 42 52 77 76 -3 23 48 11 24 24 48 23 14 51 24 58 7 77 0 0 24 18 29 0 42 57 78 76 -2 24 0 12 24 36 46 23 26 56 25 10 2 78 0 0 24 30 2 0 43 2 79 76 -1 24 11 47 24 48 17 23 38 33 25 21 30 79 0 0 24 41 7 0 43 7 80 76 0 24 22 54 24 59 21 23 49 43 25 32 30 Uncertainty in time = +/- 3 secs [Prediction of 2008 Sep 5.0] Data for the target star ------------------------ * name: TYC 1935-00619-1 * constellation : Cancer * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 08 06 41.7918 DE: +26 34 03.715 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .016, .024 ) * V mag [mag]: 9.5 * B mag [mag]: 10.4 * Apparent position with proper motion RA(deg): 121.8101800721 DE(deg): 26.5426006265 * Equation of equinoxes (radians) : 0.000048838584667 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (977) Philippa approx. diameter [km]: 66 approx. diameter ["]: .030 distance from Earth [AU]: 3.06600 * orbital information: orbit source: Preston date of fit: 2008 Sep 04 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 649 number of rejected observations: 51 time covered by the observations: 1914 Dec 19 - 2008 Mar 10 1 sigma uncertainty ellipse (major, minor, PA): 0.024, 0.013, 90° remarks: * orbital elements for (977) Philippa : Mean anomaly = 304.53214515 deg Arg. of pericenter = 82.44981712 deg Long. of node = 75.90609240 deg Inclination = 15.19817401 deg Eccentricity = 0.02887051 Semimajor axis = 3.11738545 AU Perihelion dist = 3.02738496 AU Mag: H = 9.76, G = 0.15 Epoch of elements : MJD 54751.03100000 TDT (2008 Oct 12.031) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Oct 12 977 Philippa 0h 44.0m UT 9.5 8 6 41.792 26 34 3.72TYC 1935-00619-1 10.4 15.5 66 3.1 3.066 2.567 3.73 89.7031 26.567 165.63 -7.47 0.7333 0.00192 -0.00833 12.00518 1.29742 -0.00559 0.00130 2000 304.34752620081011.00000 82.449817 75.906092 15.1981740.02887051 3.1173855 3.0273849 9.7 5.00.15 RATE 1.7906810 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.029 0.027 90 1.91 0.027 0 54714.5020081012_0619-1 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 Sep 11, 16:28 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org