Update for (162) Laurentia - September 7/8, 1999
Update computed by Jan Manek; issued 2 Sep 1999 12:33:05 +0200 (CEST)
Update computed by Martin Federspiel; issued 2 Sep 1999 11:52:05 +0200 (CEST)
Martin Federspiel's update
IOTA/IOTA-ES occultation update for
(162) Laurentia/TYC 4673 00353 event on 1999 Sep 8
visible from Norway, Scottland
Summary
On the early morning of 1999 September 08 the 105 km large asteroid
(162) Laurentia will occult a 10.3 mag star in Cetus for observers
in a 200 km wide path from Norway to Scottland. Northern Ireland
may also have a chance.
According to this update the path is shifted significantly
northwestwards compared to the
nominal prediction of E. Goffin, who predicted the path to cross
central Europe.
The event at one glimpse:
The event at one glimpse:
* date and approx. UT time of event: 1999 Sep 08 @ 1h 10m UT
* magnitude of target star: 10.3
* magnitude drop [mag]: 3.8
* estimated maximum duration [s]: 9
* rough path description: Norway, Scottland
The occultation path:
* approximate widths [km]: 200
* more detailed path description: Norway, Scottland - see map
* uncertainty [path widths]: 2
* map: attached
* remarks: path about 0.4" or 6.5 pathwidths northwest of E. Goffin's
nominal prediction; event now predicted to occur 1.7 minutes later
in Goffin's prediction
Data for the target star:
* name: TYC 4673 00353
* constellation: northern Cetus, near 20 Ceti
* J2000 position [h,m,s; °,',"]: RA 0 46 15.138 DE -0 2 19.20
* position source: ACT
* estimated accuracy ["]: 0.05
* V mag [mag]: 10.3
* remarks: medium quality flag (4) in Tycho, no doublicity found
Data for the minor planet:
* general information:
mumber, name: (162) Laurentia
approx. diameter [km]: 105
* orbital information
orbit source: calculation Federspiel
source of used astrometry: USNO, TMO
number of used observations: 20
number of rejected observations: 2 USNO
time covered by the observations: 1998 Jun - 1999 Aug 25
rms residuals ["] (RA,DE): 0.10",0.09"
estimated positional accuracy at epoch of event ["]: 0.12
remarks: TMO positions averaged to one position per night
Data for the event:
* UT date and time of least geocentric approach: 1999 Sep 08 @ 1h 13m 10s UT
* least geocentric distance ["]: 2.92
* uncertainty in time [s]: 18
* approx. V mag of minor planet at event [mag]: 14.1
* geocentric parallax of minor planet ["]: 3.52
* magnitude drop [mag]: 3.8
* estimated maximum duration [s]: 9
* apparent motion of minor planet ["/h]: 23.76
* angular distance to moon, phase of moon [°,%]: 131°,4%-
* remarks:
Calculator(s): Martin Federspiel
Path coordinates:
Lat. Long. hh:mm:ss UT StarAlt° StarAzi° SunAlt° SunAzi°
71.71 40.05 1: 8:45. ! 15.4 213.7 -3.9 57.5
69.65 30.78 1: 9: 3. ! 18.7 204.5 -7.6 48.8
67.76 23.76 1: 9:21. ! 21.3 197.4 -10.7 42.2
66.02 18.03 1: 9:39. ! 23.5 191.5 -13.5 36.9
64.39 13.15 1: 9:56. ! 25.5 186.4 -16.0 32.3
62.86 8.85 1:10:14. ! 27.1 181.7 -18.2 28.3
61.40 4.98 1:10:32. ! 28.6 177.4 -20.3 24.6
60.00 1.42 1:10:50. ! 29.8 173.4 -22.3 21.2
58.66 -1.89 1:11: 8. ! 30.9 169.5 -24.1 17.9
57.37 -5.01 1:11:25. ! 31.8 165.8 -25.8 14.8
56.13 -7.98 1:11:43. ! 32.6 162.2 -27.4 11.7
54.92 -10.82 1:12: 1. ! 33.2 158.7 -28.8 8.7
53.75 -13.57 1:12:19. ! 33.6 155.3 -30.2 5.8
52.62 -16.25 1:12:37. ! 34.0 151.9 -31.4 2.8
51.51 -18.87 1:12:54. ! 34.2 148.6 -32.6 359.8
50.42 -21.45 1:13:12. ! 34.2 145.4 -33.6 356.8
49.37 -23.99 1:13:30. ! 34.1 142.2 -34.5 353.8
48.33 -26.52 1:13:48. ! 33.9 139.1 -35.3 350.8
47.31 -29.05 1:14: 6. ! 33.5 136.0 -36.0 347.6
46.32 -31.59 1:14:23. ! 33.0 132.9 -36.6 344.5
45.34 -34.15 1:14:41. ! 32.4 129.9 -37.0 341.2
44.38 -36.74 1:14:59. ! 31.6 127.0 -37.3 337.9
43.43 -39.39 1:15:17. ! 30.6 124.1 -37.4 334.6
42.50 -42.10 1:15:35. ! 29.5 121.3 -37.4 331.1
41.58 -44.91 1:15:52. ! 28.2 118.4 -37.1 327.6
40.68 -47.83 1:16:10. ! 26.7 115.6 -36.7 324.0
39.79 -50.92 1:16:28. ! 25.0 112.8 -36.0 320.3
38.91 -54.22 1:16:46. ! 23.0 110.0 -35.0 316.5
38.04 -57.82 1:17: 4. ! 20.6 107.1 -33.6 312.6
37.18 -61.87 1:17:21. ! 17.8 104.1 -31.8 308.4
36.33 -66.68 1:17:39. ! 14.3 100.8 -29.2 303.9
35.49 -73.16 1:17:57. ! 9.4 96.7 -25.2 298.4
-------------------------------------------------------------------------
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
-------------------------------------------------------------------------
Jan Manek's update
IOTA/IOTA-ES occultation update for
(162) Laurentia / PPM 701090 event on September 7/8, 1999
visible from N Finland, N Sweden, Norway, Scotland and N Ireland
Summary
In the night September 7/8, 1999 a 10.2 mag star PPM 701090 will be
occulted by a 105 km asteroid (162) Laurentia. This update is based on
USNO/Flagstaff and TMO astrometry for the asteroid (kindly provided by
Ron Stone and Bill Owen) and TRC1.0 star position.
The updated path runs ~5 path width north with time ~1.4 minutes later compared to
Goffin's nominal prediction. Unfortunately the path moved off the
central Europe where many observers are.
The path now runs over N Finland and N Sweden ~1:09 UT, S Norway ~1:10 UT,
Scotland at ~1:11 UT and north of Ireland ~1:11.5 UT. Within possible errors
is also almost whole England and maybe very north Denmark.
The event at one glimpse:
* date and approx. UT time of event: September 8, 1999 @ 01:11 UT (Scotland)
* magnitude of target star: 10.2
* magnitude drop [mag]: 3.8
* estimated maximum duration [s]: 8.8
* path description: Path runs over Scandinavia, Scotland and Ireland.
The occultation path:
* approximate ground width [km]: 185
* uncertainty [path widths]: 2
* uncertainty in time [s]: 20
* 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: PPM 701090 = TYC 4673 00353 1
* constellation: Cetus
* J2000 position [h,m,s; o,',"]: 00h 46m 15.136s; -00o 02' 19.19"
* position source: TRC1.0
* estimated accuracy ["]: 0.04" (0.03", 0.03")
* V mag [mag]: 10.20
* B-V [mag]: +0.47
* remarks: TYCHO gives quality flag 4 (high) together with 'no duplicity' flag.
Target star is in NW Cetus, in a poor region quite far from bright stars.
2.0 mag bright star beta Cet is full 18 degrees south of target. 'Only'
2 degrees SE of target is 4.8 mag star 20 Ceti and 23.5' NW of target is
7.0 mag star SAO 128932.
Be sure to have enough time for finding the correct star in this poor area.
Data for the minor planet:
* general information:
number, name: (162) Laurentia
approx. diameter [km]: 105
* orbital information
orbit source: calculation Manek
source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
number of used observations: 19 USNO, 5 TMO
number of rejected observations: 1 USNO (1998 07 05.408029)
time covered by the observations: 1998 06 16 - 1999 08 25
rms residuals ["] (RA,DE): 0.09", 0.10"
estimated positional accuracy at epoch of event ["]: 0.09"
remarks:
Data for the event:
* UT date and time of least geocentric approach: 01:12:52 UT
* approx. V mag of minor planet at event [mag]: 14.0
* geocentric parallax of minor planet ["]: 3.523
* magnitude drop [mag]: 3.8
* estimated maximum duration [s]: 8.8
* apparent motion of minor planet ["/h]: 23.77
* angular distance to moon, phase of moon [deg,%]: 131, 4%
* remarks:
Calculator(s): Jan Manek
Path coordinates:
Altitude
E. Longitude Latitude U.T. star sun
........ shortened ..........................
+ 36 00 00 + 69 51 39 1 08 32 18 -6
+ 34 00 00 + 69 24 07 1 08 36 18 -7
+ 32 00 00 + 68 55 17 1 08 41 19 -8
+ 30 00 00 + 68 25 09 1 08 45 20 -9
+ 28 00 00 + 67 53 40 1 08 50 21 -10
+ 26 00 00 + 67 20 52 1 08 56 21 -11
+ 24 00 00 + 66 46 43 1 09 02 22 -11
+ 22 00 00 + 66 11 14 1 09 08 23 -12
+ 20 00 00 + 65 34 25 1 09 14 24 -13
+ 18 00 00 + 64 56 17 1 09 21 25 -14
+ 16 00 00 + 64 16 51 1 09 29 25 -15
+ 14 00 00 + 63 36 10 1 09 36 26 -17
+ 12 00 00 + 62 54 16 1 09 45 27 -18
+ 10 00 00 + 62 11 11 1 09 53 28 -19
+ 8 00 00 + 61 27 00 1 10 02 29 -20
+ 6 00 00 + 60 41 45 1 10 12 29 -21
+ 4 00 00 + 59 55 32 1 10 22 30 -22
+ 2 00 00 + 59 08 24 1 10 32 31 -23
+ 0 00 00 + 58 20 29 1 10 43 31 -24
- 2 00 00 + 57 31 50 1 10 54 32 -25
- 4 00 00 + 56 42 33 1 11 06 33 -26
- 6 00 00 + 55 52 46 1 11 18 33 -27
- 8 00 00 + 55 02 35 1 11 30 34 -29
- 10 00 00 + 54 12 06 1 11 43 34 -30
- 12 00 00 + 53 21 25 1 11 56 34 -31
- 14 00 00 + 52 30 41 1 12 09 35 -32
- 16 00 00 + 51 39 58 1 12 23 35 -32
- 18 00 00 + 50 49 26 1 12 37 35 -33
........ 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---
Be sure to use the RELOAD button of your browser,
so you will surely use the latest version of predictions page!
