IOTA/IOTA-ES occultation update for
(773) Irmintraud / UCAC2 45650405 = GSC 2930-01590 on September 24/25, 2005
visible from Africa, Turkey, S Russia and N Khazachstan
Summary
In the night of September 24/25, 2005 a faint 12.3 mag star UCAC2 45650405 = GSC 2930-01590 will be occulted by a 146 km asteroid (773) Irmintraud. This update is based on USNO/Flagstaff, TMO, Ondrejov, LaSilla nad Geneva astrometry for the asteroid and UCAC2 star position.
The updated path shows ~1.5 path width south shift with time ~1.0 minutes later compared to Edwin Goffin's nominal prediction.
Updated path runs over Africa ~00:58-01:00 UT, Turkey ~01:00.8 UT, S Russia ~1:02 UT and N Khazachstan ~1:03.2 UT in strong twilight. Please check the path chart for details.
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Moon in last quarter is only 12 degrees south of target star.
Target star is the C component of triple star STF 883. The B component will be occulted for Europe about 1 hour later. However as there is no accurate position for B component, there will be no update computed for the second event. Anyone in Europe should try this second event.
Clear sky and good luck !!!
The event at one glimpse:
* date and approx. UT time of event: September 25, 2005 @ 01:00 UT (Europe)
* magnitude of target star: 10.9
* magnitude drop [mag]: 4.0
* estimated maximum duration [s]: 6.1
* approx. V mag of minor planet at event [mag]: 14.9
* geocentric parallax of minor planet ["]: 3.059
* apparent motion of minor planet ["/h]: 28.17
* angular distance to moon, phase of moon [deg,%]: 12, 52%
* Goffin's original chart reference: A05_0950
The occultation path with path maps:
* approximate ground width [km]: 100
* uncertainty [path widths]: 1.3
* uncertainty in time [s]: 12
* map: Overview
European part
* remarks: Path uncertainties [2 sigmas] are given according to nominal star
position errors and expected asteroid positional accuracy.
Elements for WinOccult - use 'Save as ...' to download and save these elements.
Finding charts (prepared in GUIDE8):
* occulted star is in center - labeled with cross
* labeled stars have indicated SAO numbers
* (smaller) square box shows 30' field in all wider field charts
* (larger) square box shows 3° field in wide field charts
* remarks:
Target star is in middle Auriga, about 4.6 degrees ENE of 2.6 mag star theta Aurigae = SAO 58636.
Target is the C component of triple star STF 883. The B component will be occulted for Europe
about 1 hour later. However as there is no accurate position for B component, there will be no update
computed for the second event. Anyone in Europe should try this second event.
!!! IMPORTANT !!!
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.
40-degree chart
3-degree chart
0.5-degree chart
Data for the target star:
* name: UCAC2 45650405 = GSC 2930-01590
* constellation: Auriga
* J2000 position [h,m,s; o,',"]: 06h 19m 05.6355s; +39d 46' 22.084"
* position source: UCAC2
* estimated 1-sigma accuracy ["]: 0.044" (0.031", 0.031")
* V mag [mag]: 10.85 (GSC magnitude)
* B-V [mag]: +?.?
* remarks:
Data for the minor planet:
* general information:
number, name: (773) Irmintraud
approx. diameter [km]: 99
* orbital information
orbit source: calculation Manek
source of used astrometry: USNO/Flagstaff (Ron Stone), TMO (Bill Owen)
number of used observations: 140 USNO, 8 TMO
number of rejected observations: 0
time covered by the observations: 1998 03 10 - 2004 11 26
estimated positional 2-sigma accuracy at epoch of event ["]: 0.080", 0.042", 100 deg
remarks:
* orbital elements
Semimajor axis = 2.85758784097108
Eccentricity = 0.081507369167376
Inclination = 16.6789405120955 deg
Long. of node = 322.4751529987766 deg
Arg. of pericenter = 334.3283631776477 deg
Mean anomaly = 129.2352818671336 deg
Epoch of elements : MJD 53638.04000000 TDT (Sep 25, 2005, 0.960000 h)
Path coordinates: click here
Calculator(s): Jan Manek
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Jan Manek
Werichova 950
152 00 Praha 5 - Barrandov |_|_|
Czech Republic / \
Internet : jan.manek AT worldonline.cz |-O-O-|
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