Both updates agree well, the path is shift south of Europen continent. Manek's path is slightly north of Federspiel's.
For details see the individual reports.
Dear observers of minor planet occultations,
during the night of Aug 14/15 around midnight UT the minor planet (645) Agrippina (diameter about 30 km, V=14.9 mag) will occult the star TAC -5 13715 in Aqr (V=12.4 mag) for a maximum duration of 3.6 s. Due to the faintness of the target star the event will be rather difficult to observe. The central line of this event was predicted to cross the northern Black Sea, northern Greece, southern Italy, and Gibraltar by Ewin Goffin.
New and accurate data for both the asteroid and the target star were provided recently by Ron Stone (USNO/Flagstaff). There are 4 recent position measurements for Agrippina which allow to derive a differential correction to the MPC 18085 orbit; the mean (O-C) in declination is +0.18" with an uncertainty of about 0.10" (the offset isn't very homogeneous and no trend is obvious). The USNO/ACT position of the star is about 0.7" north of its TAC position which leads to a considerable south shift of the central line of the occultation. Applying the differential correction with negative sign to the USNO/ACT position of the star yields the following path:
Central line for an occultation by (645) Agrippina
(645) Agrippina occults TAC -5 13715 (RA 23 40 2.734 DE -5 17 41.36)
orbit MPC 18085, USNO diff. corr. applied to USNO position of star
Minimum geocentric distance:
date: 1998 8 15 time: 0 3 9.UT; d=2.08", PW=345.00 deg, pi=3.84", mu=19.09"/h
substellar point on earth (lat., long.), PA of least distance:
-5.30 31.01 345.00
Lat. Long. hh:mm:ss UT StarAlt° StarAzi° SunAlt° SunAzi°
39.00 69.02 23:55:41. ! 34.5 225.5 -8.2 64.2
38.14 65.59 23:56: 5. ! 37.0 222.5 -10.9 62.0
37.30 62.37 23:56:29. ! 39.2 219.5 -13.5 60.0
36.50 59.32 23:56:53. ! 41.3 216.6 -15.9 58.1
35.72 56.43 23:57:17. ! 43.2 213.7 -18.2 56.3
34.97 53.65 23:57:41. ! 45.0 210.7 -20.5 54.5
34.24 50.98 23:58: 5. ! 46.7 207.7 -22.6 52.8
33.52 48.40 23:58:29. ! 48.3 204.7 -24.7 51.1
32.83 45.89 23:58:53. ! 49.7 201.6 -26.7 49.5
32.15 43.45 23:59:18. ! 51.0 198.4 -28.6 47.8
31.48 41.07 23:59:42. ! 52.2 195.0 -30.5 46.1
30.83 38.74 0: 0: 6. ! 53.3 191.6 -32.3 44.4
30.20 36.44 0: 0:30. ! 54.2 188.1 -34.0 42.7
29.58 34.19 0: 0:54. ! 55.0 184.5 -35.7 40.9
28.97 31.96 0: 1:18. ! 55.7 180.9 -37.4 39.1
28.37 29.76 0: 1:42. ! 56.3 177.1 -39.0 37.3
27.78 27.58 0: 2: 6. ! 56.7 173.3 -40.6 35.3
27.21 25.41 0: 2:30. ! 57.0 169.4 -42.1 33.4
26.64 23.26 0: 2:55. ! 57.2 165.6 -43.5 31.3
26.09 21.12 0: 3:19. ! 57.2 161.7 -44.9 29.1
25.54 18.98 0: 3:43. ! 57.1 157.8 -46.3 26.8
25.01 16.85 0: 4: 7. ! 56.8 154.1 -47.6 24.4
24.49 14.71 0: 4:31. ! 56.4 150.3 -48.8 21.9
23.97 12.56 0: 4:55. ! 55.9 146.7 -49.9 19.2
23.47 10.40 0: 5:19. ! 55.2 143.2 -51.0 16.4
22.98 8.23 0: 5:43. ! 54.4 139.9 -51.9 13.4
22.49 6.04 0: 6: 7. ! 53.5 136.7 -52.8 10.3
22.02 3.83 0: 6:32. ! 52.4 133.6 -53.6 7.0
21.56 1.58 0: 6:56. ! 51.3 130.6 -54.2 3.6
21.11 -.70 0: 7:20. ! 50.0 127.9 -54.7 360.0
20.67 -3.02 0: 7:44. ! 48.6 125.2 -55.1 356.2
20.24 -5.39 0: 8: 8. ! 47.1 122.7 -55.3 352.3
19.82 -7.82 0: 8:32. ! 45.4 120.4 -55.3 348.3
19.42 -10.31 0: 8:56. ! 43.7 118.1 -55.2 344.2
19.03 -12.89 0: 9:20. ! 41.7 116.0 -54.8 340.0
18.66 -15.56 0: 9:44. ! 39.7 114.0 -54.3 335.8
18.31 -18.35 0:10: 9. ! 37.5 112.1 -53.5 331.6
17.97 -21.29 0:10:33. ! 35.1 110.3 -52.4 327.4
17.66 -24.41 0:10:57. ! 32.5 108.5 -51.0 323.3
17.38 -27.77 0:11:21. ! 29.6 106.8 -49.3 319.2
17.14 -31.44 0:11:45. ! 26.4 105.1 -47.1 315.1
16.94 -35.59 0:12: 9. ! 22.7 103.4 -44.4 311.1
16.83 -40.49 0:12:33. ! 18.3 101.6 -40.9 306.9
16.87 -47.00 0:12:57. ! 12.3 99.5 -35.9 302.4
The updated path crosses Iran, Iraq, northernmost Saudi-Arabia, southern
Jordania, the Sinai peninsula, Egypt, Lybia, southern Algeria etc. (see
attached map).
Unfortunately it is shifted away from European observers and no longer of interest for them, even if the remaining uncertainty of about 0.15" or about 250 km around the above path is considered.
Good luck to all observers in the Arabic world!
Martin Federspiel
------------------------------------------------------------------------- Martin Federspiel ******** E-mail: martin@astro.unibas.ch Astronomisches Institut ******** oder: federspi@astro.unibas.ch der Universitaet Basel **** oder: federspielm@ubaclu.unibas.ch Venusstr. 7 Telefon: (CH)-61/2055413 CH-4102 Binningen (Schweiz) Fax: (CH)-61/2055455 -------------------------------------------------------------------------
Hi all,
I have finished calculation of update based on Ron Stone's (U.S.N.O.) 4 positions of minor planet and 9 positions of target star. The occultation takes place in the night August 14/15 with following results:
Unfortunately I must confirm earlier finding of Martin Federspiel, the path shifts again off the European continent, this time to south.
The path now crosses Iran (23:58 UT), Iraq (23:59 UT), north tip of Saudi Arabia (24:00 UT), Jordania, south Israel and Sinai peninsula (00:01 UT)
and moves to Egypt (00:02 UT), Lybia and more to west. Hopefully in the area of middle east there are some observers to watch this event.
I must emphasize the target star TAC -5 13715 = GSC 5258.0841 is extremely faint (12.4 mag V) and event duration is only less than 4 seconds (asteroid diameter 32km). I think this event has only very small chance to be successfully observed. However I wish the potential observers good luck.
Jan Manek
Path location computed with OCCULT 4.07:
Occultation of TAC -5 13715 by 645 Agrippina on 1998 Aug 15 E. Longitude Latitude U.T. star sun - 47 00 00 + 16 55 14 0 13 03 12 -36 - 45 00 00 + 16 53 00 0 12 57 14 -38 - 43 00 00 + 16 52 03 0 12 50 16 -39 - 41 00 00 + 16 52 23 0 12 41 18 -41 - 39 00 00 + 16 53 59 0 12 32 20 -42 - 37 00 00 + 16 56 51 0 12 23 21 -43 - 35 00 00 + 17 00 58 0 12 12 23 -45 - 33 00 00 + 17 06 19 0 12 00 25 -46 - 31 00 00 + 17 12 55 0 11 48 27 -47 - 29 00 00 + 17 20 43 0 11 35 29 -49 - 27 00 00 + 17 29 44 0 11 22 30 -50 - 25 00 00 + 17 39 56 0 11 07 32 -51 - 23 00 00 + 17 51 18 0 10 52 34 -52 - 21 00 00 + 18 03 49 0 10 36 35 -53 - 19 00 00 + 18 17 29 0 10 20 37 -53 - 17 00 00 + 18 32 15 0 10 03 39 -54 - 15 00 00 + 18 48 07 0 09 45 40 -54 - 13 00 00 + 19 05 04 0 09 27 42 -55 - 11 00 00 + 19 23 03 0 09 09 43 -55 - 9 00 00 + 19 42 04 0 08 50 45 -55 - 7 00 00 + 20 02 05 0 08 30 46 -55 - 5 00 00 + 20 23 04 0 08 10 47 -55 - 3 00 00 + 20 45 00 0 07 50 49 -55 - 1 00 00 + 21 07 50 0 07 29 50 -55 + 1 00 00 + 21 31 34 0 07 08 51 -54 + 3 00 00 + 21 56 09 0 06 46 52 -54 + 5 00 00 + 22 21 33 0 06 25 53 -53 + 7 00 00 + 22 47 45 0 06 03 54 -52 + 9 00 00 + 23 14 42 0 05 41 55 -52 + 11 00 00 + 23 42 22 0 05 19 55 -51 + 13 00 00 + 24 10 43 0 04 56 56 -50 + 15 00 00 + 24 39 43 0 04 34 56 -49 + 17 00 00 + 25 09 19 0 04 11 57 -47 + 19 00 00 + 25 39 28 0 03 49 57 -46 + 21 00 00 + 26 10 10 0 03 26 57 -45 + 23 00 00 + 26 41 20 0 03 04 57 -44 + 25 00 00 + 27 12 57 0 02 41 57 -42 + 27 00 00 + 27 44 57 0 02 19 57 -41 + 29 00 00 + 28 17 19 0 01 57 56 -40 + 31 00 00 + 28 50 00 0 01 35 56 -38 + 33 00 00 + 29 22 56 0 01 13 55 -37 + 35 00 00 + 29 56 06 0 00 52 55 -35 + 37 00 00 + 30 29 26 0 00 30 54 -34 + 39 00 00 + 31 02 54 0 00 09 53 -32 + 41 00 00 + 31 36 27 0 00 11 52 -31 + 43 00 00 + 32 10 02 0 00 32 51 -29 + 45 00 00 + 32 43 37 0 00 51 50 -27 + 47 00 00 + 33 17 09 0 01 11 49 -26 + 49 00 00 + 33 50 35 0 01 30 48 -24 + 51 00 00 + 34 23 52 0 01 48 47 -23 + 53 00 00 + 34 56 59 0 02 07 45 -21 + 55 00 00 + 35 29 52 0 02 24 44 -19 + 57 00 00 + 36 02 29 0 02 41 43 -18 + 59 00 00 + 36 34 48 0 02 58 41 -16 + 61 00 00 + 37 06 45 0 03 14 40 -15 + 63 00 00 + 37 38 20 0 03 29 39 -13 + 65 00 00 + 38 09 29 0 03 44 37 -11 + 67 00 00 + 38 40 11 0 03 59 36 -10 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---