Astronomy professor Jonathan Gagné will be part of the Landolt space mission, which involves solving problems caused by errors in astronomical calibrations.
A major scientific breakthrough is about to take place thanks to NASA’s Landolt space mission. The $19.5 million mission aims to create artificial stars that will help calibrate ground-based telescopes and measure the brightness of stars more accurately.
Jonathan Gagné , scientific advisor at the Montreal Planetarium, associate professor at the University of Montreal and member of the Trottier Institute for Research on Exoplanets, is part of the team made up of specialists from 12 organizations or establishments, mainly American.
“Participating in this space mission alongside seasoned scientists by contributing to target selection and data analysis is a stimulating experience,” said Jonathan Gagné.
The Landolt mission , scheduled for 2029, is named in honor of the astronomer Arlo Landolt, who established widely used stellar brightness catalogs between the 1970s and 1990s. It is based on the activation of calibrated lasers on board a small CubeSat satellite that will be launched to an altitude of nearly 36,000 km. These harmless lasers will be directed towards the Earth and will produce “artificial stars”, whose brightness is precisely known. These stars, invisible to the naked eye, will be able to be observed by ground-based telescopes, which will make it possible to calibrate their observation and possibly to evaluate much more precisely the brightness of the billions of stars that are found in several large astronomical catalogs.
Knowing the brightness of stars precisely is the key to solving many mysteries in astronomy. “The benefits that the Landolt mission will have in various fields of astrophysics, particularly in the characterization of exoplanets and measurements of the acceleration of the expansion of the Universe, will be particularly interesting to follow,” said Jonathan Gagné.
Old calibrations had indeed become the main source of measurement errors in determining the brightness of most stars. These calibrations had been made in 1995 by scientists at the Space Telescope Science Institute: they were based on a comparison of the observed brightness of three white dwarfs with physical models of their atmospheres.
The Landolt mission is a crucial step in the quest for precision in astronomy. By improving old calibrations, it opens the way to discoveries and a better understanding of the Universe.
