Update for (337) Devosa - November 23/24, 1999
Update computed by Jan Manek; issued 17 Nov 1999 16:18:43 +0100 (CET)
Jan Manek's update
IOTA/IOTA-ES occultation update for
(337) Devosa / TYC 2366 01236 1 event on November 23/24, 1999
visible from Russia, N Belarus, Lithuania,
S Sweden, Denmark and Scotland in Europe
and Florida in USA
Summary
In the night November 23/24, 1999 a 10.1 mag star TYC 2366 01236 1 will be
occulted by a small 63 km asteroid (337) Devosa. This update is based on
USNO/Flagstaff astrometry and TMO for the asteroid and ACT/TRC star
position.
The updated path shows ~4 path width north shift with time ~2.3 minutes
later compared to
Edwin Goffin's nominal prediction.
The path now runs over Russia ~23:21 -> 23:23 UT, N Belarus few seconds
later, Lithuania ~23:24, very south Sweden and north Denmark at ~23:25.5 UT,
Scotland at St.Andrew ~23:27.5 UT and after crossing Atlantic Ocean also
middle Florida ~23:37 UT.
Drift scan observation may be tried with benefit for this event if you can
make about 1 minute long (time calibrated) unguided exposure; read a local
time of closest approach from the chart for this purpose and center the
exposition on this time. As the time accuracy is ~10 seconds, the
occultation should be recorded if you will have the chance being truly in
the path.
HOWEVER using TRC1.0 star position gives path almost 1 full path width to
north compared to ACT based path, so observers from ~1.3 path width south
up to ~2.2 path widths north of depicted path should try to observe this
event.
The event at one glimpse:
* date and approx. UT time of event: November 23, 1999 @ 23:26 UT (Euro)
23:37 UT (USA)
* magnitude of target star: 10.1
* magnitude drop [mag]: 1.4
* estimated maximum duration [s]: 7.5
* path description: given above
The occultation path:
* approximate ground width [km]: 70
* uncertainty [path widths]: 1.2
* uncertainty in time [s]: 10
* map: attached
* remarks: Path uncertainities are given according to ACT 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: TYC 2366 01236 1
* constellation: Perseus
* J2000 position [h,m,s; o,',"]: 04h 07m 49.975s; +34o 56' 33.20"
* position source: ACT
* estimated accuracy ["]: 0.05" (0.03", 0.03")
* V mag [mag]: 10.10
* B-V [mag]: +0.47
* remarks: TYCHO gives quality flag 4 (=high) with 'no duplicity' flag.
TRC1.0 gives end figures as 49.972s(0.03") and 33.14" (0.03") which
means the ACT and TRC positions differ by more than their nominal
errors. Using TRC star position gives path almost full 1 path width
more north with time ~4 seconds later.
Target star is in SE Perseus, 2 degrees east of 4.1 mag star ksi Per
or 4.2 degrees NE of 2.9 mag star dzeta Persei. There is only 1.6' NW
of target a 10.8 mag star GSC 2366.1158 and 4.3' SE of target 10.7 mag
star GSC 2366.1548 both can serve as good reference star for better
visual observation of the 1.4 magnitude drop.
Data for the minor planet:
* general information:
number, name: (337) Devosa
approx. diameter [km]: 63
* orbital information
orbit source: calculation Manek
source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
number of used observations: 34 USNO, 9 TMO
number of rejected observations: 2 USNO
time covered by the observations: 1998 06 19 - 1999 11 12
rms residuals ["] (RA,DE): 0.11", 0.13"
estimated positional accuracy at epoch of event ["]: 0.07"
remarks: Total RMS's are quite large due to scatter in 1998 data (low
declination and faint object). On the other hand the scatter in
1999 data is very small, so I have estimated the current positional
accuracy as 0.07" only.
Data for the event:
* UT date and time of least geocentric approach: 23:26:05 UT
* approx. V mag of minor planet at event [mag]: 11.1
* geocentric parallax of minor planet ["]: 7.873
* magnitude drop [mag]: 1.4
* estimated maximum duration [s]: 7.5
* apparent motion of minor planet ["/h]: 37.16
* angular distance to moon, phase of moon [deg,%]: 18, 99%
* remarks:
Calculator(s): Jan Manek
Path coordinates:
Altitude
E. Longitude Latitude U.T. star sun
........ shortened ..........................
+ 97 00 00 + 29 12 22 23 15 00 19 -10
+ 95 00 00 + 30 31 48 23 15 11 21 -12
+ 93 00 00 + 31 49 35 23 15 22 23 -14
+ 91 00 00 + 33 05 36 23 15 34 25 -16
+ 89 00 00 + 34 19 44 23 15 47 27 -18
+ 87 00 00 + 35 31 54 23 16 01 29 -20
+ 85 00 00 + 36 42 00 23 16 15 31 -22
+ 83 00 00 + 37 50 01 23 16 29 33 -23
+ 81 00 00 + 38 55 51 23 16 44 35 -25
+ 79 00 00 + 39 59 29 23 17 00 36 -27
+ 77 00 00 + 41 00 53 23 17 15 38 -28
+ 75 00 00 + 42 00 03 23 17 31 40 -30
+ 73 00 00 + 42 56 58 23 17 47 41 -31
+ 71 00 00 + 43 51 39 23 18 03 43 -33
+ 69 00 00 + 44 44 06 23 18 19 44 -34
+ 67 00 00 + 45 34 19 23 18 36 46 -35
+ 65 00 00 + 46 22 22 23 18 52 47 -36
+ 63 00 00 + 47 08 15 23 19 08 49 -38
+ 61 00 00 + 47 52 01 23 19 25 50 -39
+ 59 00 00 + 48 33 41 23 19 41 51 -40
+ 57 00 00 + 49 13 19 23 19 57 53 -41
+ 55 00 00 + 49 50 56 23 20 13 54 -42
+ 53 00 00 + 50 26 35 23 20 29 55 -43
+ 51 00 00 + 51 00 19 23 20 45 56 -44
+ 49 00 00 + 51 32 11 23 21 01 57 -45
+ 47 00 00 + 52 02 12 23 21 17 58 -45
+ 45 00 00 + 52 30 26 23 21 32 59 -46
+ 43 00 00 + 52 56 54 23 21 48 60 -47
+ 41 00 00 + 53 21 40 23 22 03 61 -48
+ 39 00 00 + 53 44 46 23 22 18 62 -48
+ 37 00 00 + 54 06 14 23 22 33 62 -49
+ 35 00 00 + 54 26 06 23 22 49 63 -49
+ 33 00 00 + 54 44 24 23 23 03 64 -50
+ 31 00 00 + 55 01 10 23 23 18 65 -51
+ 29 00 00 + 55 16 25 23 23 33 65 -51
+ 27 00 00 + 55 30 12 23 23 48 66 -51
+ 25 00 00 + 55 42 32 23 24 02 66 -52
+ 23 00 00 + 55 53 25 23 24 17 67 -52
+ 21 00 00 + 56 02 54 23 24 31 67 -53
+ 19 00 00 + 56 11 00 23 24 46 67 -53
+ 17 00 00 + 56 17 42 23 25 00 68 -53
+ 15 00 00 + 56 23 03 23 25 15 68 -53
+ 13 00 00 + 56 27 02 23 25 29 68 -53
+ 11 00 00 + 56 29 40 23 25 43 68 -54
+ 9 00 00 + 56 30 57 23 25 57 68 -54
+ 7 00 00 + 56 30 54 23 26 12 68 -54
+ 5 00 00 + 56 29 30 23 26 26 68 -54
+ 3 00 00 + 56 26 45 23 26 40 68 -54
+ 1 00 00 + 56 22 40 23 26 55 68 -54
- 1 00 00 + 56 17 13 23 27 09 68 -54
- 3 00 00 + 56 10 23 23 27 23 67 -54
- 5 00 00 + 56 02 11 23 27 38 67 -54
- 7 00 00 + 55 52 36 23 27 52 67 -53
- 9 00 00 + 55 41 35 23 28 07 66 -53
- 11 00 00 + 55 29 08 23 28 21 66 -53
- 13 00 00 + 55 15 14 23 28 36 65 -53
- 15 00 00 + 54 59 52 23 28 51 65 -52
- 17 00 00 + 54 42 58 23 29 06 64 -52
........ shortened ..........................
- 73 00 00 + 34 14 00 23 36 23 27 -23
- 75 00 00 + 32 59 43 23 36 36 25 -21
- 77 00 00 + 31 43 35 23 36 48 23 -19
- 79 00 00 + 30 25 41 23 37 00 21 -17
- 81 00 00 + 29 06 09 23 37 10 19 -15
- 83 00 00 + 27 45 07 23 37 20 17 -13
- 85 00 00 + 26 22 45 23 37 28 15 -11
- 87 00 00 + 24 59 13 23 37 36 12 -9
........ 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-|
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