Lison Malo

Observatoire du Mont-Mégantic Resident Astronomer and iREx Researcher

Since 2017, Lison is the resident astronomer of Observatoire du Mont-Mégantic. She is also an iREx researcher, involved in the NIRPS project.

Between 2014 and 2017, Lison was a Resident Astronomer for Canada-France-Hawaii Telescope (CFHT), which is located on the Big Island of Hawaii, in the United States. As a Resident Astronomer, she prepared observations made with the various instruments of the telescope (the infrared and optical cameras WIRCam and MegaCam and the spectrograph-polarimeter ESPaDOnS), she established a contact between the user and the observatory, and she optimized the observations to reach the user’s scientific goals. She was also the scientific lead for the project GRACES at CFHT. This ambitious project that allowed in 2015 to analyse with ESPaDOnS photons collected by CFHT’s neighbour telescope Gemini North, using a 270 meters optical fiber. This projects required the development of a new reduction pipeline, OPERA, on which Lison actively worked.

Lison also continues to work on diverse research projects. Interested by the identification of young stars of the solar neighborhood, she is working on the selection and characterization of the star sample that will be observed with SPIRou, an instrument that will be installed on CFHT in 2018. She is also interested by the characterization of stars that host brown dwarf of exoplanetary companions, and of binary star systems.

 

For her PhD thesis (2010-2014) and her master thesis (2007-2009), under the supervision of René Doyon and in collaboration with David Lafrenière and Étienne Artigau, Lison searched for young, low-mass stars in the solar neighbourhood. Nearly 70% of stars in the galaxy have a mass of less than 0.8 solar-mass. However, because these stars are faint and difficult to observe, this statistic does not reflect the current survey of the population of young or old low-mass stars in the solar neighbourhood. Low-mass stars are excellent targets to search for exoplanets with various techniques (direct imaging, radial velocity, transit). In addition, the characterization of exoplanets depends on our knowledge of their basic parameters, i.e. their bolometric luminosity, effective temperature, radius and age.

The main objective of my doctoral research is searching for and characterizing young, low-mass stars. The first part is devoted to developing the statistical method combining Bayesian inference and empirical models of several observable parameters for confirmed members of 7 groups of stars (8-120 million years old). This part of the research led to the development of a tool called BANYAN. Using this tool we can predict the probability of association, the radial velocity and trigonometric distance of a star as a member of a given association.

The second part consists of measuring the radial velocity of stars with a high probability of association, and studying the behaviour of X-ray luminosity, as an indicator of youth for low-mass stars.

The last part consists of determining a star’s fundamental parameters in order to deduce its exact age. This step calls for comparison between the fundamental properties and the latest theoretical evolutionary models, including processing the magnetic field. The scope of this work is discussed in connection with current astronomical projects, including the Gaia Space Telescope and SPIRou, an instrument to be deployed on the Canada-France-Hawaii Telescope in 2017.

Students
Contact

Email: malo@cfht.hawaii.edu

Links