Much work has been accomplished at CFHT on VASAO over these past
months, though the earthquake aftermath has made us busy lately.
Simulations and error-budget calculations were carefully looked at,
with more work to be done (it is really complex!). Challenges are
humongous, but also very exciting! The corresponding documents
are available on the "More
In parallel, we are building a prototype of a seismometer à la
issues we could have using it on our telescope. We are also studying
the design of an experiment making use of our AO (Pueo) to check the
performances of a laser polychromatic guide star coupled to a
seismometer at the level needed for science, i.e. a few
milli-arcseconds in differential position of the components of a
two-color star as well as in vibration monitoring, and how well the sum
of a seismometer information and a
differential tip-tilt measurement are actually tracking the overall
tip-tilt. The good thing about this is that there is no need for a
laser... Bright stars, chosen dimmer and dimmer to see how much
flux is really needed for the level of performance to be reached, are
On the French side. much time has been spent within the ELP-OA project
trying to solve a divergence of opinion about the use of a
single-photon excitation from a laser at 330nm
for making a
polychromatic laser guide star instead of the two-photon excitation
initially proposed. ELP-OA will go through more review process in the
coming months. It is a good thing that lasers are not needed very soon
VASAO is presented at the SPIE. Here
the corresponding paper (pdf), which presents the project and gives the
status of the feasibility study as on early May 2006.
30 - February 3, 2006
J.P. Pique (mode-less laser developer) and A. Le Van Suu (ELP-OA
project manager) visit CFHT.
Early January 2006
The VASAO mailing list is created and an announcement
sent to the C, F and H communities.
The VASAO web pages are created and the VASAO
VASAO has been presented to the Scientific Advisory Council at its
November meeting and to the Board of Directors of the CFHT Corporation
at its December meeting. The VASAO concept is seen as a challenging and
scientifically potentially interesting development, worth the
feasibility study proposed by CFHT for 2006.