The First Unveiling: Pulsar Planets
Astronomers Aleksander Wolszczan and Dale Frail announce the discovery of planets PSR B1257+12 b and c orbiting a pulsar (a rapidly rotating neutron star). These were the first confirmed exoplanets, challenging previous assumptions about where planets could form.
A Sun-Like Star's Companion: 51 Pegasi b
Michel Mayor and Didier Queloz discover 51 Pegasi b, the first exoplanet found orbiting a Sun-like star. This gas giant, dubbed a "hot Jupiter," revolutionized exoplanet research and earned them the Nobel Prize in Physics in 2019.
The Radial Velocity Method
The discovery of 51 Pegasi b was made using the radial velocity (or Doppler spectroscopy) method. This technique detects tiny wobbles in a star caused by the gravitational tug of an orbiting planet, revealing the planet's presence and mass.
Accelerating Discoveries & New Methods
The early 2000s saw a rapid increase in exoplanet discoveries, primarily through radial velocity. The transit method, detecting dips in a star's brightness as a planet passes in front of it, also began to gain prominence.
Kepler's Revolution: A Planet Hunter's Legacy
NASA launches the Kepler Space Telescope, dedicated to finding exoplanets using the transit method. Kepler identified thousands of planet candidates, including many Earth-sized planets in habitable zones, vastly expanding our understanding of planetary diversity.
TESS Takes the Baton: Surveying the Nearest Stars
The Transiting Exoplanet Survey Satellite (TESS) is launched as Kepler's successor. TESS focuses on surveying the brightest and nearest stars for transiting exoplanets, providing excellent targets for follow-up studies and atmospheric characterization.
The Search Continues: From Biosignatures to New Worlds
With missions like the James Webb Space Telescope, astronomers are not only discovering new exoplanets but also characterizing their atmospheres, searching for potential biosignatures. The ultimate goal remains finding life beyond Earth.