IOTA/IOTA-ES occultation update for (257) Silesia / PPM 96143 event on December 21/22, 1999 visible from Sardegna and SW France Summary
In the night December 21/22, 1999 (in fact morning of December 22) a bright 7.9 mag star PP 96143 will be occulted by a 74 km asteroid (257) Silesia. This update is based on USNO/Flagstaff astrometry for the asteroid and ACT star position.
The updated path shows ~4 path widths northern shift with time ~1.4 minutes earlier compared to Edwin Goffin's nominal prediction.
The path now runs over Sicilia in morning twilight at ~5:31.5 UT, Sardegna few seconds later and then over France. Marseille is on the northern limit at ~5:32 UT and path runs to NW with Bordeaux south of the path at ~5:32.5 UT. Centerline then runs along northen coast of Biskai Bay in France up to ~5:33 UT. SW tips of England and Ireland are just off the path.
Full Moon is only 17 degrees away from target star so this may make the location of star harder, however as the star is bright, occultation should be easily visible.
The event at one glimpse: * date and approx. UT time of event: December 22, 1999 @ 05:32 UT * magnitude of target star: 7.9 * magnitude drop [mag]: 5.4 * estimated maximum duration [s]: 6.5 * path description: given above The occultation path: * approximate ground width [km]: 100 * uncertainty [path widths]: 1.7 * uncertainty in time [s]: 15 * map: attached * remarks: Path uncertainities are given according to nominal star position errors and expected asteroid positional accuracy. !!!!!!! Circles along the path are OCCULT exactly calculated centerline points. !!!!!!! Data for the target star: * name: SAO 78483 = PPM 93143 = TYC 1887 00862 1 * constellation: Auriga * J2000 position [h,m,s; o,',"]: 06h 33m 04.906s; +28o 04' 54.57" * position source: ACT * estimated accuracy ["]: 0.04" (0.01", 0.04") * V mag [mag]: 7.90 * B-V [mag]: +0.18 * remarks: TYCHO gives quality flag 2(=very high) with 'no duplicity' flag. Target star is in SE Auriga, close to Gemini border. There is 8.4 mag star SAO 78488 only 3.2' east of target with declination difference only 13" which may be a problem for drift scan observations with such a bright stars. There is also 7.5 mag star SAO 78496 about 10' SE of target and a bright 5.3 mag star 49 Aurigae = SAO 78524 about 28' east of target. Data for the minor planet: * general information: number, name: (257) Silesia approx. diameter [km]: 73.5 * orbital information orbit source: calculation Manek source of used astrometry: USNO/Flagstaff (Ron Stone) number of used observations: 34 USNO number of rejected observations: 7 USNO time covered by the observations: 1998 08 02 - 1999 12 14 rms residuals ["] (RA,DE): 0.10", 0.07" estimated positional accuracy at epoch of event ["]: 0.08" remarks: Data for the event: * UT date and time of least geocentric approach: 05:38:01 UT * approx. V mag of minor planet at event [mag]: 13.3 * geocentric parallax of minor planet ["]: 4.837 * magnitude drop [mag]: 5.4 * estimated maximum duration [s]: 6.5 * apparent motion of minor planet ["/h]: 31.29 * angular distance to moon, phase of moon [deg,%]: 17, 99% * remarks: Calculator(s): Jan ManekPath coordinates: Altitude E. Longitude Latitude U.T. star sun ........ shortened .......................... + 17 00 00 + 35 52 50 5 31 11 15 -6 + 15 00 00 + 37 04 06 5 31 17 16 -8 + 13 00 00 + 38 15 12 5 31 25 18 -10 + 11 00 00 + 39 25 56 5 31 33 20 -11 + 9 00 00 + 40 36 10 5 31 41 22 -13 + 7 00 00 + 41 45 43 5 31 51 24 -15 + 5 00 00 + 42 54 27 5 32 00 25 -17 + 3 00 00 + 44 02 13 5 32 10 27 -18 + 1 00 00 + 45 08 53 5 32 21 29 -20 - 1 00 00 + 46 14 18 5 32 32 30 -22 - 3 00 00 + 47 18 24 5 32 43 32 -23 - 5 00 00 + 48 21 02 5 32 54 33 -25 - 7 00 00 + 49 22 08 5 33 06 35 -26 - 9 00 00 + 50 21 36 5 33 17 36 -27 - 11 00 00 + 51 19 24 5 33 29 37 -29 - 13 00 00 + 52 15 26 5 33 40 38 -30 - 15 00 00 + 53 09 41 5 33 52 39 -31 - 17 00 00 + 54 02 07 5 34 04 41 -32 - 19 00 00 + 54 52 42 5 34 16 42 -33 - 21 00 00 + 55 41 25 5 34 27 42 -34 - 23 00 00 + 56 28 17 5 34 39 43 -35 - 25 00 00 + 57 13 16 5 34 50 44 -36 ........ shortened .......................... ---------------------------------------------------------------------------- Jan Manek Stefanik Observatory Private : Petrin 205 Werichova 950 118 46 Praha 1 152 00 Praha 5 - Barrandov |_|_| Czech Republic Czech Republic / \ Internet : jmanek@mbox.vol.cz |-O-O-| --------------------------------------------------------------------U---U---