2UCAC 26029329 by
(50000) Quaoar on 2011 Feb 2 for Europe
Results of the
have reported, that they were clouded out. In the graphics you see
the area, where stations have observed no occultation (but not
have been clouded out) marked in light blue. The most northern
station as known for the moment, which was not totally clouded
out, is the one marked with an asterik (Sudelfeld, by B.
Gaehrken). He reported no occultation for longer than about 30
seconds. He observed with a 6 inch telescope and a video camera!
So we know, that
either the true path was about south of the blue area, or north.
Astronometry has to solve this in the future perhaps.
A big "Thank
You" to all observers, who either traveled to an
observing site, or observed from their own observatories! In any
case it has been learned, that a star, such faint as 13m3, can
observed easily in the beginning dusk! (sun higher than about 7.5
degrees below the horizon). This can largely extend the range of
observability of such events for the future.
the old report about the announcement of the event can be found:
Based on astrometry
from the RIO group for Europe an occultation of the 13m3 star
3UCAC 26029329 can be observed in the morning of the 2nd
of February 2011.
The occultation is
very well in reach of many video and digital camera systems
attached to telescopes as small as 8 inch. We urgently ask
everybody, to take part in the international campaign for
The goal is to
determine the diameter of Quaoar and find out, if the TNO has an
atmosphere. Therefore, not only the determination of the exact
time point of dis- and reappearance is necessary, but also the
exact determination of the lightcurve during dis- and reappearance
of the star behind the disk of Quaoar.
this site, more infos will be posted, to give you informations
about how to observe. For the moment, there are two predictions
from the same astrometry available, one, from Bruno Sicardy from
Paris/Meudon observatory and one generated using Occult V
220.127.116.11. The RIO astrometry group, leaded by Marcelo Assafin, has
made astrometric observations with large telescopes, to define the
position of the star as well as possible in the mas range. The
table of the astrometry you can find on Bruno
The occultation track
The prediction based
on the Rio group astrometry has been gernerated by Occult V
18.104.22.168 as follows:
track prediction by B. Sicardy puts the occultation line about one
Quaoar radius farer south, the difference can not be explained at
the moment. However, according to the relative large errors in the
orbit and positions, this is not relevant for planning and
information about the event will come up soon, for the moment you
will only get the local circumstances for European sites. More
infos will come soon!