Update for (256) Walpurga - July 5/6, 2002
Update computed by Jan Manek; issued 30 Jun 2002 21:25:00 +0200 (CEST)
Jan Manek's update
IOTA/IOTA-ES occultation update for
(256) Walpurga / TYC 0581-00210-1 on July 5/6, 2002
visible from NW Africa and Turkey
Summary
In the night of July 5/6, 2002 a faint 11.3 mag star TYC 0581-00210-1
will be occulted by a 66 km asteroid (256) Walpurga. This update is based on
USNO/Flagstaff astrometry for the asteroid and recent UCAC star position.
The updated path shows ~3 path width south shift with time ~1.9 minutes earlier compared to
Edwin Goffin's nominal prediction.
Updated path runs over NW Africa from 0:27 UT to 0:35 UT, followed by Turkey around 0:40 UT.
Please check the path chart for details.
No recent opposition astrometry. Uncertainty may be larger than expected.Clear sky and good luck !!!
The event at one glimpse:
* date and approx. UT time of event: July 6, 2002 @ 00:40 UT
* magnitude of target star: 11.3
* magnitude drop [mag]: 3.9
* estimated maximum duration [s]: 12.5
* path description: given above
* Goffin's original chart reference: A02_0722
The occultation path:
* approximate ground width [km]: 85
* uncertainty [path widths]: 3.2
* uncertainty in time [s]: 35
* map: below
* remarks: Path uncertainties are given according to nominal star
position errors and expected asteroid positional accuracy.
Data for the target star:
* name: TYC 0581-00210-1
* constellation: Pisces
* J2000 position [h,m,s; o,',"]: 23h 24m 49.2084s; +04o 28' 07.516"
* position source: UCAC combined with Tycho-2 proper motion
* estimated accuracy ["]: 0.01" (0.008", 0.012")
* V mag [mag]: 11.32
* B-V [mag]: +0.39
* remarks:
Recent UCAC position was provided by Marion and Norbert Zacharias.
Target star is in west Pisces, about 2.2 degrees NE of 3.7 mag star gamma Piscii = SAO 128085.
Purple stars in identification chart are so called 'non-star' objects in GSC; in dense fields
the 'non-stars' are often real stars or blends of close pairs. Be careful about this.
Close finding chart (prepared in GUIDE7):
* occulted star is in center - labeled with cross
* field is 4.5x4.5 degrees
* limiting magnitude is 13.0
* labeled stars have indicated SAO numbers
* remarks:
Data for the minor planet:
* general information:
number, name: (256) Walpurga
approx. diameter [km]: 66
* orbital information
orbit source: calculation Manek
source of used astrometry: USNO/Flagstaff (Ron Stone)
number of used observations: 62 USNO
number of rejected observations: 12 USNO
time covered by the observations: 1998 09 25 - 2001 07 20
rms residuals ["] (RA,DE): 0.09", 0.11"
estimated positional accuracy at epoch of event ["]: 0.09", 0.10"
remarks: No recent opposition astrometry.
Uncertainty may be larger than expected.
Data for the event:
* UT date and time of least geocentric approach: 00:42.1 UT
* approx. V mag of minor planet at event [mag]: 15.2
* geocentric parallax of minor planet ["]: 3.484
* magnitude drop [mag]: 3.9
* estimated maximum duration [s]: 12.5
* apparent motion of minor planet ["/h]: 10.35
* angular distance to moon, phase of moon [deg,%]: 58, 20%
* remarks:
Elements for WinOccult:
============ cut here ===========================================
2002 Jul 06
256 Walpurga
0h 42.1m UT
81-00210-1 11.3 23 24 49.208 4 28 7.52TYC 0581-00210-1
15.2 66 12.5 2.524 0.659 3.11
56.852 4.468 -189.35 22.72
0.7012 -.18162 .57958 2.83411 0.89318 -0.00476 -0.00233
2000 92.81731672002 7 5.0000050.397542 183.11689613.318523 0.070460122.999040702.787727949.805 0.15
RATE 1.8977130 .0000000 .0000000 .0000000 .00000000 .00000000 .00000000
============ cut here ===========================================
Calculator(s): Jan Manek
Path coordinates:
Latitude Latitude
Center Altitude Path Limits
E. Longitude Latitude U.T. star sun Limit 1 Limit 2
........................... shortened .............................
o ' " o ' " h m s o o o ' " o ' "
- 18 0 0 21 30 27 0 26 36 12 -44 21 7 26 21 53 35
- 16 0 0 21 50 34 0 26 47 14 -44 21 27 28 22 13 46
- 14 0 0 22 12 11 0 27 1 16 -44 21 49 2 22 35 28
- 12 0 0 22 35 20 0 27 16 18 -44 22 12 6 22 58 41
- 10 0 0 22 59 57 0 27 32 20 -44 22 36 39 23 23 23
- 8 0 0 23 26 3 0 27 51 22 -44 23 2 40 23 49 33
- 6 0 0 23 53 34 0 28 11 23 -43 23 30 7 24 17 10
- 4 0 0 24 22 31 0 28 32 25 -43 23 58 58 24 46 11
- 2 0 0 24 52 49 0 28 56 27 -42 24 29 11 25 16 34
0 0 0 25 24 27 0 29 20 29 -42 25 0 44 25 48 17
2 0 0 25 57 22 0 29 46 31 -41 25 33 34 26 21 17
4 0 0 26 31 31 0 30 14 32 -40 26 7 38 26 55 32
6 0 0 27 6 50 0 30 43 34 -39 26 42 52 27 30 56
8 0 0 27 43 17 0 31 13 36 -38 27 19 14 28 7 28
10 0 0 28 20 47 0 31 45 37 -37 27 56 39 28 45 2
12 0 0 28 59 15 0 32 18 39 -35 28 35 3 29 23 36
14 0 0 29 38 39 0 32 51 41 -34 29 14 22 30 3 4
16 0 0 30 18 52 0 33 26 42 -33 29 54 31 30 43 21
18 0 0 30 59 50 0 34 2 43 -31 30 35 25 31 24 23
20 0 0 31 41 28 0 34 38 45 -30 31 16 60 32 6 5
22 0 0 32 23 40 0 35 15 46 -28 31 59 8 32 48 20
24 0 0 33 6 21 0 35 53 47 -27 32 41 46 33 31 4
26 0 0 33 49 25 0 36 31 48 -25 33 24 48 34 14 11
28 0 0 34 32 47 0 37 10 49 -23 34 8 8 34 57 35
30 0 0 35 16 21 0 37 48 50 -22 34 51 40 35 41 11
32 0 0 36 0 1 0 38 27 51 -20 35 35 18 36 24 52
34 0 0 36 43 41 0 39 7 51 -18 36 18 58 37 8 33
36 0 0 37 27 16 0 39 46 52 -17 37 2 32 37 52 9
38 0 0 38 10 40 0 40 25 52 -15 37 45 56 38 35 33
40 0 0 38 53 49 0 41 3 52 -13 38 29 5 39 18 41
42 0 0 39 36 36 0 41 42 52 -12 39 11 53 40 1 27
44 0 0 40 18 57 0 42 20 52 -10 39 54 15 40 43 47
46 0 0 41 0 47 0 42 57 52 -8 40 36 7 41 25 35
48 0 0 41 42 2 0 43 35 52 -6 41 17 25 42 6 48
50 0 0 42 22 37 0 44 11 52 -5 41 58 3 42 47 21
........................... shortened .............................
----------------------------------------------------------------------------
Jan Manek
Stefanik Observatory Private :
Petrin 205 Werichova 950
118 46 Praha 1 152 00 Praha 5 - Barrandov |_|_|
Czech Republic Czech Republic / \
Internet : jan.manek@worldonline.cz |-O-O-|
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