Вярно, че звездата е доста слаба и ще е предизвикателство за по-малки инструменти (10" и по-малки) още повече, че времето за експониране трябва да е около секунда-две. Но интересното в случая е вероятността да се открие атмосфера около това тяло. Ще копирам имейла, там е обяснено малко по-добре какви са целите на наблюдението.
" Dear all,
I am contacting you because there will be an interesting occultation
by the large Transneptunian Object named Quaoar, on May 28th at ~23:40
UT, favorable for a large part of Europe. You participated in the very
successful Haumea event in 2017 and we need a large effort for the
Quaoar event, with similar equipment if we want to succeed.
The prediction is very accurate, with an uncertainty of only a few
milliarcseconds. The main scientific goal in this case is to try to
find an atmosphere. Quaoar is one of the few TNOs with the potential
to host a tenuous atmosphere, either global or local. Detecting an
atmosphere in a TNO other than Pluto would be a very important
scientific breakthrough with the potential for a high impact
publication. Also, we will be able to determine an accurate size and
shape, and a good geometric albedo to improve our knowledge of this
TNO. Quaoar has a satellite named Weywot and we might detect it in the
occultation as well, but currently its position is not well known. The
probability to detect the satellite occultation is low, but one never
knows. We do not expect to find rings in this case, but again, we
might find surprises...
The event will be somewhat challenging because the occultation star is
not bright (it is 16.9 mag) and it will be low in the sky for most
locations. The good thing compared to the occultation by Haumea in
2017 is the fact that the occultation drop will be more than 2
magnitudes, so even with a low signal to noise ratio, the event can be
An important issue here is that in order to try to detect an
atmosphere, we need to sample the ingress and egress with enough time
resolution in order to record a gradual occultation (which is what an
atmosphere would cause). Therefore, integration times should be in the
order of 1s. Usually, for atmosphereless bodies we request
observations with integration times such that they are around 2 to 4
times the readout time, but in this case our main driver is to try to
find an atmosphere so we are particularly interested in short
integration times. The event will take place at around 23:40 UT, and
this is accurately determined to withing a couple of minutes, but
observing at least ~15 minutes prior and after the nominal time is
recommended for several reasons.
We are preparing a large campaign and several ~1m class telescopes in
France, Germany, Austria, etc will be participating but weather and
technical problems can ruin all our plans... Your participation will
thus be very important, and the more chords we can detect, the better.
Attached are two zoomed maps with the two most extreme shadow paths
that we are expecting. Probably, the final path will be in between
those two paths. The maps also contain the star coordinates, its
magnitude, the occultation time and the basic info that you need to
arrange the observations. But you can find further information and
star maps on this link
http://lesia.obspm.fr/lucky-star/campai ... uaoar.html
Please let us know who will be participating. But please do not do
"reply to all" in order to not generate too much email exchange (note
that we are more than 80 people in this list). Just reply to me with
cc to ххх@iaa.es and ххх@gmail.com Also, if you have
questions, please do not hesitate to contact us. You may have
received this through the planoccult list as well. If that was the
case, my apologies for the duplication, but I think it is important to
emphasize the good potential of this event.
Like in previous occultations by TNOs, note that we are carrying out
this campaing within the "Lucky Star" umbrella. Lucky Star is an
EU-funded research activity that agglomerates the efforts of the
Paris, Granada and Rio teams. So you may be contacted by different
people of these three teams, but we are working together.
Jose Luis "