IOTA/IOTA-ES occultation update for (4484) Sif / TYC 2944-01670-1 event on 2008 Jan 01, 00:58 UT Visible from Brazil Summary ------- On 2008 Jan 01 UT, the 21 km diameter asteroid (4484) Sif will occult a 11.2 mag star in the constellation Auriga for observers along a path across Brazil. In the case of an occultation, the combined light of the asteroid and the star will drop by 4.1 mag to 15.3 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: 10 * date and approx. time of event: 2008 Jan 01, 00:56 - 2008 Jan 01, 01:00 UT * midpoint of event [JD]: 2454466.54059167 * magnitude of target star: 11.2 * magnitude drop [mag]: 4.1 * estimated maximum duration [s]: 1.3 * Moon: 43 % sunlit, 94° distance * Sun: 163° distance * rough path description: Brazil The occultation path -------------------- * approximate projected width [km]: 60 * 1 sigma uncertainty interval [path widths]: +/- 6.84 * 1 sigma uncertainty interval [seconds]: +/- 6.4 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .147 +/- .098) * 1 sigma uncertainty ellipse (major, minor, PA): ( .152", .090", 72° ) * approx speed of asteroid's shadow [km/s]: 15.8800 * website for maps: http://lunar-occultations.com/iota/asteroids/astrndx.htm http://www.asteroidoccultation.com Path Coordinates: Occultation of TYC 2944-01670-1 by 4484 Sif on 2008 Jan 01 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 - 43 32 7 -44 0 0 0 56 9 0 29 -18 - 43 5 58 ... .. .. ... .. .. ... .. .. - 42 49 53 -43 0 0 0 56 9 1 28 -19 - 42 24 56 - 43 15 16 ... .. .. ... .. .. - 42 14 25 -42 0 0 0 56 10 2 28 -20 - 41 50 28 - 42 38 46 ... .. .. ... .. .. - 41 44 58 -41 0 0 0 56 11 3 28 -21 - 41 21 51 - 42 8 27 ... .. .. - 48 21 13 - 41 20 54 -40 0 0 0 56 12 4 27 -22 - 40 58 29 - 41 43 39 ... .. .. - 47 41 20 - 41 1 44 -39 0 0 0 56 14 5 27 -23 - 40 39 55 - 41 23 52 ... .. .. - 47 9 14 - 40 47 5 -38 0 0 0 56 16 6 27 -24 - 40 25 47 - 41 8 41 ... .. .. - 46 43 57 - 40 36 38 -37 0 0 0 56 18 7 27 -25 - 40 15 45 - 40 57 48 ... .. .. - 46 24 46 - 40 30 8 -36 0 0 0 56 21 8 27 -26 - 40 9 36 - 40 50 56 ... .. .. - 46 11 9 - 40 27 22 -35 0 0 0 56 24 9 27 -27 - 40 7 8 - 40 47 52 ... .. .. - 46 2 40 - 40 28 12 -34 0 0 0 56 27 10 27 -27 - 40 8 12 - 40 48 27 ... .. .. - 45 59 2 - 40 32 28 -33 0 0 0 56 31 11 27 -28 - 40 12 39 - 40 52 33 - 36 2 41 - 46 0 1 - 40 40 7 -32 0 0 0 56 35 12 27 -29 - 40 20 25 - 41 0 4 - 36 12 2 - 46 5 28 - 40 51 4 -31 0 0 0 56 39 13 27 -30 - 40 31 27 - 41 10 56 - 36 24 6 - 46 15 17 - 41 5 17 -30 0 0 0 56 44 13 28 -31 - 40 45 41 - 41 25 7 - 36 38 51 - 46 29 27 - 41 22 46 -29 0 0 0 56 49 14 28 -32 - 41 3 9 - 41 42 38 - 36 56 16 - 46 47 59 - 41 43 32 -28 0 0 0 56 54 15 28 -32 - 41 23 51 - 42 3 30 - 37 16 22 - 47 10 59 - 42 7 40 -27 0 0 0 56 59 16 29 -33 - 41 47 51 - 42 27 46 - 37 39 9 - 47 38 36 - 42 35 16 -26 0 0 0 57 5 16 29 -34 - 42 15 15 - 42 55 33 - 38 4 42 - 48 11 6 - 43 6 26 -25 0 0 0 57 12 17 30 -34 - 42 46 9 - 43 27 0 - 38 33 5 - 48 48 52 - 43 41 21 -24 0 0 0 57 18 18 30 -35 - 43 20 44 - 44 2 18 - 39 4 22 - 49 32 23 - 44 20 18 -23 0 0 0 57 25 18 31 -35 - 43 59 15 - 44 41 41 - 39 38 42 - 50 22 23 - 45 3 33 -22 0 0 0 57 33 19 31 -36 - 44 41 58 - 45 25 31 - 40 16 13 - 51 19 55 - 45 51 33 -21 0 0 0 57 41 19 32 -36 - 45 29 17 - 46 14 13 - 40 57 8 - 52 26 33 - 46 44 48 -20 0 0 0 57 49 20 33 -36 - 46 21 42 - 47 8 23 - 41 41 41 - 53 44 45 - 47 44 4 -19 0 0 0 57 58 20 34 -36 - 47 19 54 - 48 8 47 - 42 30 10 - 55 18 53 - 48 50 21 -18 0 0 0 58 8 20 34 -37 - 48 24 49 - 49 16 32 - 43 23 0 - 57 17 56 - 50 5 4 -17 0 0 0 58 19 20 35 -37 - 49 37 45 - 50 33 13 - 44 20 39 - 60 8 54 - 51 30 27 -16 0 0 0 58 30 20 36 -36 - 51 0 40 - 52 1 20 - 45 23 49 ... .. .. - 53 10 6 -15 0 0 0 58 43 20 37 -36 - 52 36 42 - 53 45 5 - 46 33 20 ... .. .. - 55 10 49 -14 0 0 0 58 58 20 39 -35 - 54 31 30 - 55 52 46 - 47 50 26 ... .. .. Latitude Latitude Latitude Latitude - 57 0 0 -13 16 25 0 59 11 19 40 -34 -12 59 7 -13 33 58 - 9 23 8 -18 8 1 - 58 0 0 -12 56 28 0 59 17 19 40 -34 -12 39 25 -13 13 46 - 9 6 1 -17 42 33 - 59 0 0 -12 39 14 0 59 24 19 41 -33 -12 22 23 -12 56 19 - 8 51 8 -17 20 45 - 60 0 0 -12 24 36 0 59 30 18 41 -33 -12 7 55 -12 41 30 - 8 38 27 -17 2 26 - 61 0 0 -12 12 31 0 59 36 18 42 -32 -11 55 59 -12 29 18 - 8 27 57 -16 47 26 - 62 0 0 -12 2 57 0 59 42 17 42 -32 -11 46 30 -12 19 36 - 8 19 34 -16 35 39 - 63 0 0 -11 55 50 0 59 47 17 43 -31 -11 39 27 -12 12 25 - 8 13 18 -16 26 58 - 64 0 0 -11 51 9 0 59 53 16 43 -30 -11 34 49 -12 7 41 - 8 9 7 -16 21 21 - 65 0 0 -11 48 53 0 59 58 15 43 -29 -11 32 34 -12 5 24 - 8 7 2 -16 18 46 - 66 0 0 -11 49 2 1 0 3 15 44 -29 -11 32 42 -12 5 34 - 8 7 1 -16 19 13 - 67 0 0 -11 51 36 1 0 8 14 44 -28 -11 35 14 -12 8 11 - 8 9 6 -16 22 41 - 68 0 0 -11 56 36 1 0 12 13 45 -27 -11 40 10 -12 13 16 - 8 13 16 -16 29 13 - 69 0 0 -12 4 5 1 0 17 12 45 -26 -11 47 33 -12 20 51 - 8 19 34 -16 38 53 - 70 0 0 -12 14 5 1 0 21 12 45 -25 -11 57 24 -12 30 59 - 8 28 0 -16 51 47 - 71 0 0 -12 26 39 1 0 25 11 46 -24 -12 9 48 -12 43 43 - 8 38 37 -17 8 0 - 72 0 0 -12 41 51 1 0 28 10 46 -23 -12 24 48 -12 59 8 - 8 51 28 -17 27 44 - 73 0 0 -12 59 47 1 0 32 9 46 -22 -12 42 29 -13 17 19 .. .. .. -17 51 11 - 74 0 0 -13 20 33 1 0 35 8 46 -21 -13 2 58 -13 38 24 .. .. .. -18 18 35 - 75 0 0 -13 44 17 1 0 37 7 47 -20 -13 26 21 -14 2 29 .. .. .. -18 50 18 - 76 0 0 -14 11 9 1 0 40 6 47 -19 -13 52 49 -14 29 46 .. .. .. -19 26 46 - 77 0 0 -14 41 19 1 0 42 5 47 -18 -14 22 32 -15 0 27 .. .. .. -20 8 36 - 78 0 0 -15 15 4 1 0 44 4 48 -17 -14 55 43 -15 34 46 .. .. .. -20 56 36 - 79 0 0 -15 52 39 1 0 45 3 48 -16 -15 32 39 -16 13 2 .. .. .. .. .. .. - 80 0 0 -16 34 27 1 0 46 2 48 -15 -16 13 41 -16 55 39 .. .. .. .. .. .. - 81 0 0 -17 20 55 1 0 47 1 48 -13 .. .. .. -17 43 8 .. .. .. .. .. .. Data for the target star ------------------------ * name: TYC 2944-01670-1 * constellation : Auriga * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 07 14 56.8568 DE: +39 11 20.069 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .017, .016 ) * V mag [mag]: 11.2 * B mag [mag]: 12.4 * Apparent position with proper motion RA(deg): 108.8845953152 DE(deg): 39.1752871281 * Equation of equinoxes (radians) : 0.000038680704310 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (4484) Sif approx. diameter [km]: 21 approx. diameter ["]: .020 distance from Earth [AU]: 1.42300 * orbital information: orbit source: Preston date of fit: 2007 Nov 21 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 378 number of rejected observations: 5 time covered by the observations: 1964 Nov 11 - 2007 Oct 20 1 sigma uncertainty ellipse (major, minor, PA): 0.151, 0.089, 72° remarks: * orbital elements for (4484) Sif : Mean anomaly = 16.45493343 deg Arg. of pericenter = 0.05876423 deg Long. of node = 85.10852882 deg Inclination = 29.78028526 deg Eccentricity = 0.10191384 Semimajor axis = 2.63435557 AU Perihelion dist = 2.36587829 AU Mag: H = 12.13, G = 0.15 Epoch of elements : MJD 54466.04100000 TDT (2008 Jan 01.041) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 Jan 01 4484 Sif 0h 58.5m UT 11.2 7 14 56.857 39 11 20.07TYC 2944-01670-1 12.4 15.3 21 1.3 1.423 -3.267 40.31 -5.945 39.177 166.17 -23.06 0.9742 -.68251 -.64247 -6.14482 6.52525 -0.00077 -0.00157 2000 15.062413420071226.00000 0.058764 85.108529 29.7802850.101913842.634355572.3658782912.15 0.15 RATE 2.3051143 .0000000 .0000000 .0000000 .00000000 .00000000 .00000000 Meas 0.152 0.090 72.2 7.840 0.137 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2007 Nov 24, 16:43 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org