Landolt space mission: artificial stars for more precise measurements of star brightnesses

The deep field of the James Webb Telescope. Credit: NASA, ESA, CSA, and STScI
The deep field of the James Webb Telescope. Credit: NASA, ESA, CSA, and STScI

The new NASA Landolt space mission, planned for 2029, promises major scientific breakthroughs. The mission, at a cost of $19.5 million, aims to create artificial stars that will enable better calibration of ground-based telescope observations, thus allowing for more precise measurement of star brightnesses.

Jonathan Gagné. (Crdit : Courtesy image.)

Jonathan Gagné, scientific advisor at the Montreal Planétarium, adjunct professor at the Université de Montréal and member of the Trottier Institute for Research on Exoplanets (iREx), is part of the Landolt scientific team made of experts from 12 institutions, mostly in the United States.

“Being a part of this space mission along with brilliant experts by contributing to target selection and data analysis is an exciting prospect ! ” said Jonathan Gagné.

The Landolt mission is named in honor of astronomer Arlo Landolt, who created widely-used catalogues of stellar luminosities in the 1970s, 1980s, and 1990s. The mission concept is built on the deployment of lasers calibrated on board a “CubeSat”-type small satellite, at an altitude of 36 000 kilometers. These harmless lasers will be directed towards the Earth and will produce “artificial stars” whose brightness is known with precision. These artificial stars, invisible to the naked eye, will allow telescopes on the ground to calibrate their observations and refine our measurements of stellar brightnesses for billions of other stars in several major astronomical catalogues.

Knowing the brightness of stars with precision is the key to solving many mysteries in astronomy. “The impact the Landolt mission will have in different areas of astrophysics, notably in exoplanet characterisation and in measuring the accelerating expansion of the Universe, will be particularly interesting,” added Jonathan Gagné.

With technological progress, the old calibrations have become the principal source of uncertainty in measuring the luminosity for the majority of stars. These calibrations were made in 1995 by scientists at the Space Telescope Science Institute and were based on a comparison of the observed brightness of three white dwarfs with the expected brightness from models of their atmospheres based on fundamental physics.

The Landolt mission represents a crucial step in the quest for precision in astronomy. In solving the problems caused by the older calibrations, it paves the way to new discoveries and a better understanding of the Universe that surrounds us.

Media Contact

Isabel Matte
Space for Life
514 250-7753

Marie-Eve Naud
Trottier Institute for Research on Exoplanets, iREx
marie-eve.naud@umontreal.ca, 514-279-3222

Contact scientifique
Jonathan Gagné
Planétarium de Montréal, Université de Montréal, Trottier Institute for Research on Exoplanets, iREx