Update for (492) Gismonda - May 16, 1999
Update computed by Jan Manek; issued 11 May 1999 15:37:10 +0200 (CEST)
Update computed by Martin Federspiel; issued 11 May 1999 13:20:29 +0200 (CEST)
Jan Manek's update
IOTA/IOTA-ES occultation update for
(492) Gismonda / SAO 119021 event on 1999, May 16
visible from Caucasus, Romania, Hungary and east Austria
Summary
On the evening May 16, 1999 will be occulted 9.5 mag star by a small 55km
asteroid (492) Gismonda. This update is based on USNO/Flagstaff astrometry
for asteroid and ACT star position.
This update gives significant southward path shift and time about 2.3
minutes earlier compared to the
Goffin's nominal prediction.
This updated path is about 1 path width south of Martin Federspiel's update with
0.7 minute difference in time. But the expected errors are quite large due
to very small body and very slow asteroid motion so all within 4 path
widths of cetral line have a chance in about 10 minute observing window
centered on the closest approach to particular location (please consult the
map). However due to the slow motion the occultation will be rather long
~16 seconds so there is a good chance to have accurate profile of this
asteroid.
The event at one glimpse:
* date and approx. UT time of event: May 16, 1999 @ 19:55 UT
* magnitude of target star: 9.5
* magnitude drop [mag]: 6.1
* estimated maximum duration [s]: 15.9
* path description: Path runs over Caucasus and Black Sea, Romania ~19:52 UT,
Hungary ~19:55 UT and western Austria ~19:56. Eastern Austria, south
Germany and north France will probably have problem with strong twilight.
The occultation path:
* approximate width [km]: 80
* uncertainty [path widths]: 4
* uncertainty in time [s]: 65
* 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 119201 = PPM 158480 = TYC 0280 00522 1
* constellation: Virgo
* J2000 position [h,m,s; o,',"]: 12h 04m 29.265s; +00o 41' 52.38"
* position source: ACT
* estimated accuracy ["]: 0.03" (0.02", 0.02")
* Johnson V mag [mag]: 9.47
* B-V [mag]: +0.50
* remarks: 4.5' NE of target star is 9.4 mag star SAO 119205. These are
approximately midway between 3.6 mag star beta Vir and 3.9 mag star
eta Vir in the western part of Virgo.
Be sure to have enough time for finding the correct star.
Data for the minor planet:
* general information:
mumber, name: (492) Gismonda
approx. diameter [km]: 55
* orbital information
orbit source: calculation Manek
source of used astrometry: USNO/Flagstaff (Ron Stone)
number of used observations: 31 USNO
number of rejected observations: 0
time covered by the observations: 1998 01 29 - 1999 05 10
rms residuals ["] (RA,DE): 0.11", 0.11"
estimated positional accuracy at epoch of event ["]: 0.09"
remarks:
Data for the event:
* UT date and time of least geocentric approach: 19:53:53 UT
* approx. V mag of minor planet at event [mag]: 15.6
* geocentric parallax of minor planet ["]: 3.105
* magnitude drop [mag]: 6.1
* estimated maximum duration [s]: 15.9
* apparent motion of minor planet ["/h]: 6.05
* angular distance to moon, phase of moon [deg,%]: 108, 2%
* remarks:
Calculator(s): Jan Manek
Path coordinates:
Altitude
E. Longitude Latitude U.T. star sun
......... shortened .........................
+ 66 00 00 + 38 16 23 19 38 28 28 -33
+ 64 00 00 + 38 32 55 19 39 01 30 -32
+ 62 00 00 + 38 49 59 19 39 36 31 -32
+ 60 00 00 + 39 07 33 19 40 11 32 -32
+ 58 00 00 + 39 25 36 19 40 48 33 -31
+ 56 00 00 + 39 44 06 19 41 25 34 -31
+ 54 00 00 + 40 03 01 19 42 04 35 -30
+ 52 00 00 + 40 22 20 19 42 43 36 -30
+ 50 00 00 + 40 42 01 19 43 22 37 -29
+ 48 00 00 + 41 02 04 19 44 03 38 -28
+ 46 00 00 + 41 22 25 19 44 43 38 -28
+ 44 00 00 + 41 43 05 19 45 25 39 -27
+ 42 00 00 + 42 04 01 19 46 07 40 -26
+ 40 00 00 + 42 25 11 19 46 49 41 -25
+ 38 00 00 + 42 46 35 19 47 31 41 -24
+ 36 00 00 + 43 08 10 19 48 14 42 -23
+ 34 00 00 + 43 29 56 19 48 57 42 -22
+ 32 00 00 + 43 51 50 19 49 40 43 -22
+ 30 00 00 + 44 13 51 19 50 23 43 -21
+ 28 00 00 + 44 35 58 19 51 06 43 -20
+ 26 00 00 + 44 58 09 19 51 49 43 -18
+ 24 00 00 + 45 20 22 19 52 32 44 -17
+ 22 00 00 + 45 42 37 19 53 14 44 -16
+ 20 00 00 + 46 04 51 19 53 57 44 -15
+ 18 00 00 + 46 27 04 19 54 39 44 -14
+ 16 00 00 + 46 49 13 19 55 21 43 -13
+ 14 00 00 + 47 11 18 19 56 03 43 -12
+ 12 00 00 + 47 33 16 19 56 44 43 -11
+ 10 00 00 + 47 55 07 19 57 25 43 -10
+ 8 00 00 + 48 16 50 19 58 05 43 -9
+ 6 00 00 + 48 38 22 19 58 45 42 -7
+ 4 00 00 + 48 59 43 19 59 25 42 -6
+ 2 00 00 + 49 20 52 20 00 03 41 -5
+ 0 00 00 + 49 41 46 20 00 42 41 -4
- 2 00 00 + 50 02 26 20 01 19 40 -3
- 4 00 00 + 50 22 49 20 01 56 40 -2
- 6 00 00 + 50 42 55 20 02 32 39 -0
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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-|
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Martin Federspiel's update
IOTA/IOTA-ES occultation update for
(492) Gismonda/TYC 0280 00522 event on 1999 May 16
visible from Black Sea, Romania, Hungary, (Austria, Germany)
Summary
On the evening of May 16 (UT) the 55 km small and very slowly moving
asteroid (492) Gismonda occults a 9.5 mag star in Virgo along a rather
narrow path for observers on Crimean peninsula, Romania, and
Hungary. For more western observers in Austria, southern Germany,
northern France/southern Belgium twilight is strongly interfering.
The updated path is about 0.4" south of
Edwin Goffin's nominal prediction.
Times are 3 minutes earlier than predicted by Goffin.
This update is exclusively based on accurate USNO positions of the
asteroid and the ACT position of the star.
The event at one glimpse:
* date and approx. UT time of event: 1999 May 16 @ 19h 45m UT
* magnitude of target star: 9.5
* magnitude drop [mag]: 6.1
* estimated maximum duration [s]: 16
* rough path description: Black Sea, Romania, Hungary, (in twilight
Austria, Germany, northern France/southern Belgium)
The occultation path:
* approximate widths [km]: 60
* more detailed path description: Black Sea, Romania, Hungary, (in twilight
Austria, Germany, northern France/southern Belgium)
* uncertainty [path widths]: +/-3 pathwidths or about +/-180 km
* map: attached
* remarks: path 0.4" south of Goffin's path, 3 minutes earlier than
predicted by Goffin
Data for the target star:
* name: TYC 0280 00522
* constellation: Virgo (west of eta Vir)
* J2000 position [h,m,s; °,',"]: RA 12 4 29.265 DE +0 41 52.38
* position source: ACT
* estimated accuracy ["]: 0.04
* V mag [mag]: 9.5
* remarks: quality flag 3 in TYCHO (very good), no duplicity found
Data for the minor planet:
* general information:
mumber, name: (492) Gismonda
approx. diameter [km]: 55
* orbital information
orbit source: calculation Federspiel
source of used astrometry: USNO
number of used observations: 24
number of rejected observations: 7
time covered by the observations: 1998 Jan - 1999 May 10
rms residuals ["] (RA,DE): 0.08",0.08"
estimated positional accuracy at epoch of event ["]: 0.09
remarks: asteroid moves *very* slowly at epoch of event
probably due to the faintness of the asteroid the USNO positions
show a slightly larger scatter than for brighter targets
Data for the event:
* UT date and time of least geocentric approach: 1999 5 16 @ 19 53 35.UT
* least geocentric distance ["]: 2.29
* uncertainty in time [s]: 59
* approx. V mag of minor planet at event [mag]: 15.6
* geocentric parallax of minor planet ["]: 3.11
* magnitude drop [mag]: 6.1
* estimated maximum duration [s]: 16
* apparent motion of minor planet ["/h]: 6.07
* angular distance to moon, phase of moon [°,%]: 103°, 3%-
* remarks: path 0.4" south of Goffin's path, 3 minutes earlier than
predicted by Goffin
Calculator(s): Martin Federspiel
Path coordinates:
Lat. Long. hh:mm:ss UT StarAlt° StarAzi° SunAlt° SunAzi°
36.95 90.09 19:33:43. ! 11.3 262.3 -29.4 26.6
37.49 83.10 19:34:45. ! 16.4 257.9 -31.0 19.6
38.01 77.70 19:35:46. ! 20.3 254.3 -31.6 14.0
38.53 73.08 19:36:47. ! 23.4 251.0 -31.8 9.1
39.05 68.92 19:37:49. ! 26.0 247.8 -31.7 4.8
39.56 65.08 19:38:50. ! 28.4 244.7 -31.3 .8
40.07 61.48 19:39:52. ! 30.4 241.7 -30.7 357.1
40.58 58.05 19:40:53. ! 32.3 238.6 -30.0 353.6
41.09 54.75 19:41:54. ! 33.9 235.5 -29.2 350.4
41.60 51.56 19:42:56. ! 35.4 232.4 -28.3 347.3
42.12 48.45 19:43:57. ! 36.7 229.2 -27.3 344.4
42.63 45.40 19:44:58. ! 37.9 226.0 -26.2 341.6
43.15 42.41 19:45:60. ! 38.9 222.7 -25.0 338.9
43.67 39.46 19:47: 1. ! 39.8 219.4 -23.8 336.3
44.20 36.53 19:48: 3. ! 40.6 216.0 -22.5 333.8
44.72 33.62 19:49: 4. ! 41.2 212.5 -21.2 331.4
45.25 30.72 19:50: 5. ! 41.7 209.0 -19.8 329.0
45.78 27.82 19:51: 7. ! 42.1 205.4 -18.3 326.7
46.32 24.92 19:52: 8. ! 42.3 201.8 -16.8 324.4
46.86 22.00 19:53:10. ! 42.4 198.1 -15.3 322.1
47.40 19.06 19:54:11. ! 42.4 194.4 -13.7 319.9
47.95 16.09 19:55:12. ! 42.3 190.7 -12.1 317.6
48.50 13.08 19:56:14. ! 42.0 186.9 -10.5 315.4
49.05 10.02 19:57:15. ! 41.6 183.1 -8.8 313.1
49.61 6.91 19:58:16. ! 41.1 179.3 -7.0 310.9
50.18 3.73 19:59:18. ! 40.5 175.4 -5.2 308.5
50.74 .47 20: 0:19. ! 39.7 171.6 -3.3 306.2
51.32 -2.89 20: 1:21. ! 38.8 167.7 -1.4 303.7
51.90 -6.36 20: 2:22. ! 37.7 163.8 .6 301.2
52.48 -9.95 20: 3:23. ! 36.5 159.8 2.7 298.6
53.07 -13.70 20: 4:25. ! 35.2 155.8 4.8 295.8
53.66 -17.63 20: 5:26. ! 33.7 151.6 7.0 292.9
54.25 -21.78 20: 6:28. ! 32.0 147.4 9.4 289.8
54.86 -26.21 20: 7:29. ! 30.1 143.0 11.9 286.5
55.46 -30.96 20: 8:30. ! 28.0 138.4 14.5 282.8
56.07 -36.16 20: 9:32. ! 25.7 133.6 17.4 278.7
56.68 -41.94 20:10:33. ! 23.0 128.3 20.5 274.0
57.29 -48.57 20:11:34. ! 19.8 122.3 24.0 268.4
57.89 -56.59 20:12:36. ! 15.9 115.3 28.0 261.4
58.47 -67.55 20:13:37. ! 10.4 105.9 33.4 251.1
-------------------------------------------------------------------------
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
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