IOTA/IOTA-ES occultation update for
          (0) 1999 TR11 / UCAC2 41841566 event on 2009 Feb 04, 17:26 UT
                                  Visible from 


Summary
-------
On 2009 Feb 04 UT, the 69 km diameter asteroid (0) 1999 TR11 will occult a 12.2
mag star in the constellation Taurus for observers along a path across .

In the case of an occultation, the combined light of the asteroid and the star
will drop by 11.3 mag to 23.5 mag (the magnitude of the asteroid) for at most
7.7 seconds.

This update is based on historical astrometry from the MPC files (via AstDys),
and the following catalogs for the star position: UCAC.

The event at a glimpse
----------------------
    * Rank: 0
    * date and approx. time of event: 2009 Feb 04, 17:26  - 2009 Feb 04, 17:26  UT
    * magnitude of target star: 12.2
    * magnitude drop [mag]: 11.3
    * estimated maximum duration [s]: 7.7
    * Moon: 70 % sunlit, 5° distance
    * Sun: 118° distance
    * rough path description: 

The occultation path
--------------------
    * approximate projected width [km]: 69
    * 1 sigma uncertainty interval [path widths]: +/- 123.74
    * 1 sigma uncertainty interval [seconds]: +/- 4076.0
    * 1 sigma uncertainty interval approx RA,DE ["]: (+/- 1.729 +/- .806)
    * 1 sigma uncertainty ellipse (major, minor, PA): ( 1.908", .090", 65° )
    * approx speed of asteroid's shadow [km/s]: 8.9425
    * website for maps:
          http://www.asteroidoccultation.com

Path Coordinates:
   Path does not land on Earth.
 

Data for the target star
------------------------
 * name: UCAC2 41841566
 * constellation : Taurus
 * J2000 position with proper motion  to date of event [h,m,s ; °,',"]
        RA: 04 47 46.9777  DE: +28 52 37.403
 * position source: mpos:UCAC2 pm:UCAC2
 * standard error: RA,DE ["]: ( .062, .056 )
 * V mag [mag]: 12.2
 * B mag [mag]: 0.0
 * remarks:

Data for the minor planet
-------------------------
 * general information:
     (number) name: (0) 1999 TR11
     approx. diameter [km]: 69
     approx. diameter ["]: .003
     distance from Earth [AU]: 30.35800

 * orbital information:
      orbit source: Preston
      date of fit: 2008 Mar 19
      source of used astrometry: MPC (via Astdys)
      number of used observations: 25
      number of rejected observations: 0
      time covered by the observations: 1999 Oct 07 - 2000 Dec 28
      1 sigma uncertainty ellipse (major, minor, PA): 1.907, 0.072, 65°
      remarks: 

 * orbital elements for (0) 1999 TR11 :
      Mean anomaly       =  21.36430467 deg
      Arg. of pericenter = 346.54281727 deg
      Long. of node      =  54.71890358 deg
      Inclination        =  17.14700372 deg
      Eccentricity       =   0.24458947
      Semimajor axis     =  39.33454139 AU
      Perihelion dist    =  29.71372681 AU
      Mag:             H = 8.42,  G = 0.15
      Epoch of elements  : MJD   54866.72700000 TDT
                           (2009 Feb 04.727)

------ occelmnt file for Occult  BEGIN -----------------------------------
 2009 Feb  4
     0 1999 TR11      
18h 18.4m UT
  12.2    4 47 46.978 28 52 37.40UCAC2 41841566         0.0
23.5     69    7.7  30.358    -0.107     -0.40
  22.3035  28.877   -91.10  -16.02
 18.3066  1.34519 -4.78825 -4.85909 -1.36591  0.00546  0.00035
2000     21.3374292009 129.00000346.542817 54.718904 17.1470040.2445894739.334541429.7137268 8.4 5.00.15
RATE 0.0399520 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000
Meas  1.908 0.090    65124.74 0.388 0                                      54776.5020090204_841566
------ occelmnt file for Occult  END   -----------------------------------

============================================
Calculator (s): Steve Preston
Date of update: 2008 Nov 06, 05:04 UT

Steve Preston
7640 NE 32nd St
Medina, WA 98039
425-688-9965

mailto: stevepr@acm.org