TESS, Gaia Discover 40,000-Light-Year Super-Jupiter via Microlensing, Marking Telescope's First Such Planet
Updated
Updated · EarthSky · Jul 9
TESS, Gaia Discover 40,000-Light-Year Super-Jupiter via Microlensing, Marking Telescope's First Such Planet
3 articles · Updated · EarthSky · Jul 9
Summary
Gaia23bra b — a super-Jupiter about 40,000 light-years away orbiting an orange dwarf — was confirmed after TESS captured dense light-curve data from a 2023 microlensing event.
TESS became the first to discover a new exoplanet through gravitational microlensing, a method that detects a planet when its gravity bends and magnifies a more distant star’s light.
Less than 5% of known exoplanets have been found this way, but microlensing is especially useful for planets farther from their stars, including Earth-mass worlds at Earth-like distances.
Gaia’s sparser observations flagged the event, while TESS recorded the same region every 200 seconds for nearly 60 days, revealing the planetary signal Gaia alone could not resolve.
The find offers a test case for NASA’s Nancy Grace Roman Space Telescope, scheduled to launch as early as Aug. 30, 2026, with expectations of up to 1,000 microlensing planets.
TESS wasn't designed to find planets this way. How many more alien worlds are hiding in its archived data?
This discovery is a test for the Roman telescope. What does it reveal about the thousands of new worlds Roman is expected to find?
Microlensing events are fleeting and unique. How can we be certain this faint flicker of light was truly a distant planet?
Gaia23bra b: TESS’s First Microlensing Exoplanet Discovery Expands the Hunt for Distant Super-Jupiters
Overview
The discovery of Gaia23bra b, a super-Jupiter exoplanet, marks a historic breakthrough for NASA's TESS mission and the field of exoplanet research. As the first definitive microlensing planet found using TESS data, Gaia23bra b demonstrates a profound expansion of TESS's scientific reach, showing its ability to detect distant worlds far beyond its original design. This pivotal moment not only highlights TESS's unexpected capabilities but also serves as a preview of the exciting discoveries expected from future missions, ushering in a new era for exoplanet exploration.