NASA's TESS Finds 1.6-Jupiter-Mass Exoplanet 40,000 Light-Years Away Using Microlensing
Updated
Updated · Space.com · Jul 6
NASA's TESS Finds 1.6-Jupiter-Mass Exoplanet 40,000 Light-Years Away Using Microlensing
3 articles · Updated · Space.com · Jul 6
Summary
Gaia23bra b became TESS's first microlensing planet after researchers confirmed a world 1.6 times Jupiter's mass orbiting an orange dwarf about 40,000 light-years away.
TESS usually detects transits around stars within roughly 150 light-years, so microlensing let it verify a planet too distant and too Jupiter-like in orbit for its standard method.
Gaia first flagged the event in 2023 when the planet briefly brightened a background star, and the team said similar one-off signals may still be hidden in TESS archives.
About 5% of roughly 6,000 known exoplanets have been found by microlensing versus about 75% by transits, making the method a way to catch wider-orbit worlds that transits miss.
NASA cast the result as a preview of the Nancy Grace Roman Space Telescope, which is expected to find about 1,000 microlensing planets alongside an estimated 100,000 transiting worlds.
A satellite built for nearby planets found one 40,000 light-years away. What other cosmic secrets are we missing?
How many more distant worlds lie hidden in eight years of archived NASA satellite data?
This accidental find precedes the Roman telescope's launch. How has it changed the hunt for Earth-like solar systems?
Unveiling Gaia23bra b: How TESS and Gaia Redefined Exoplanet Discovery via Microlensing
Overview
On July 1, 2026, astronomers announced the discovery of Gaia23bra b, a distant gas giant exoplanet. This breakthrough marks the first time a planet was definitively found using gravitational microlensing data from NASA’s TESS mission, which was not originally designed for this purpose. The discovery was made possible by an unexpected synergy between TESS and ESA’s Gaia mission, demonstrating the power of combining different space telescopes. This event highlights how microlensing can reveal planets that other methods might miss, expanding our understanding of planetary systems far beyond our own solar system.