A major scientific breakthrough is about to take place thanks to NASA's Landolt space mission.
The objective of this mission is to create artificial stars that will allow for better calibration of ground-based telescopes, thus enabling more precise measurement of stellar brightness.
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Landolt mission, scheduled for 2029, is named in honor of astronomer Arlo Landolt, who established widely used stellar brightness catalogs between the 1970s and 1990s. It involves deploying calibrated lasers aboard a small CubeSat satellite, which will be launched approximately 22,000 miles (36,000 km) above the Earth.
These harmless lasers will be directed towards Earth and will produce "artificial stars," whose brightness is known with precision. Although invisible to the naked eye, these stars can be observed by ground-based telescopes, facilitating the calibration of observations and allowing much more precise evaluation of the brightness of billions of stars listed in several major astronomical catalogs.
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 consisting of specialists from 12 organizations or institutions, primarily in the United States.
Accurately knowing the brightness of stars is key to solving many mysteries in astronomy. "The impact of the Landolt mission in various fields of astrophysics, notably in the characterization of exoplanets and the measurement of the universe's accelerating expansion, will be particularly interesting to follow," said Jonathan Gagné.
Indeed, outdated calibrations had become the main source of measurement errors in determining the brightness of most stars. These calibrations were performed in 1995 by scientists at the Space Telescope Science Institute, based on a comparison of the observed brightness of three white dwarfs with physical models of their atmospheres.
The Landolt mission represents a crucial step in the pursuit of precision in astronomy. By improving outdated calibrations, it paves the way for discoveries and a better understanding of the universe.