Asteroid occultation event in the early morning of Sept. 20

[PTS]

Hi,
Here are details and finder charts for the September 20 event.
See also:
http://forum.hkas.org.hk/redirect.php?t ... t#lastpost

PTS
-------------------------------------------------

IOTA/IOTA-ES occultation update for
(23) Thalia / TYC 1898-00334-1 event on 2010 Sep 19, 19:35 UT
Visible from Japan, S China


Summary
-------
On 2010 Sep 19 UT, the 106 km diameter asteroid (23) Thalia will occult a 10.8
mag star in the constellation Gemini for observers along a path across Japan, S
China.

In the case of an occultation, the combined light of the asteroid and the star
will drop by 1.2 mag to 11.6 mag (the magnitude of the asteroid) for at most 3.6
seconds.

This update is based on UNSO/Flagstaff astrometry for the asteroid kindly
provided by Alice Monet, historical astrometry from the MPC files (via AstDys),
and the following catalogs for the star position: UCAC.

The event at a glimpse
----------------------
* Rank: 99
* date and approx. time of event: 2010 Sep 19, 19:32 - 2010 Sep 19, 19:34 UT
* magnitude of target star: 10.8
* magnitude drop [mag]: 1.2
* estimated maximum duration [s]: 3.6
* Moon: 89 % sunlit, 145?distance
* Sun: 73?distance
* rough path description: Japan, S China

The occultation path
--------------------
* approximate projected width [km]: 108
* 1 sigma uncertainty interval [path widths]: +/- 0.31
* 1 sigma uncertainty interval [seconds]: +/- 1.4
* 1 sigma uncertainty interval approx RA,DE ["]: (+/- .027 +/- .020)
* 1 sigma uncertainty ellipse (major, minor, PA): ( .027", .020", 88?)
* approx speed of asteroid's shadow [km/s]: 29.0949
* website for maps:
http://www.asteroidoccultation.com