WASP-96 b

WASP-96 b is a hot Jupiter exoplanet orbiting the G-type star WASP-96 in the constellation Phoenix. It was discovered in 2013 by the Wide Angle Search for Planets (WASP) consortium using the transit method and has since become a significant target for atmospheric characterization. The planet is notable for its cloud-free atmosphere, which has allowed for the clear detection of sodium and other chemical species, providing a pristine window into the composition of gas giant worlds beyond our Solar System.

Discovery and observation

WASP-96 b was identified in 2013 by the Wide Angle Search for Planets survey team using data from the La Silla Observatory in Chile. The initial detection was made via the transit method, which measures the periodic dimming of a star's light as a planet passes in front of it. Follow-up radial velocity measurements with instruments like the High Accuracy Radial Velocity Planet Searcher (HARPS) confirmed the planet's mass and orbital characteristics. Subsequent observations by space-based telescopes, most notably the Hubble Space Telescope and later the James Webb Space Telescope, have been pivotal in advancing the study of its atmosphere. These facilities, operated by NASA and the European Space Agency, have provided the high-precision spectroscopic data necessary for detailed atmospheric analysis.

Physical characteristics

Classified as a hot Jupiter, WASP-96 b is a gas giant with a mass approximately 0.48 times that of Jupiter but a radius about 1.20 times larger, resulting in a low bulk density. This inflated radius is typical for highly irradiated planets orbiting close to their host stars. The planet's equilibrium temperature is estimated to be around 1,285 K (1,012 °C; 1,854 °F), a consequence of its extremely tight orbit. Its physical parameters make it an ideal benchmark for studying the atmospheric physics and thermal structure of highly irradiated gas giants, contributing to models developed by institutions like the University of Exeter and the University of Geneva.

Atmospheric composition

The atmosphere of WASP-96 b is remarkably cloud-free, a conclusion drawn from the full, unobscured detection of its sodium doublet signature in transmission spectroscopy data from the Hubble Space Telescope. This clear atmosphere has allowed astronomers to detect a range of chemical species, including water vapor, potassium, and lithium. Observations from the James Webb Space Telescope's Near-Infrared Spectrograph (NIRSpec) have further revealed the presence of carbon dioxide and carbon monoxide, providing insights into the planet's carbon-to-oxygen ratio and atmospheric chemistry. These findings are critical for testing theories of planetary formation and atmospheric evolution developed by researchers at the California Institute of Technology and the Massachusetts Institute of Technology.

Orbit and host star

WASP-96 b orbits its host star, WASP-96, every 3.4 Earth days at a distance of only 0.0453 AU, over ten times closer than Mercury is to the Sun. The host star, WASP-96, is a G8-type star slightly older and more massive than the Sun, located roughly 1,120 light-years from Earth in the Phoenix constellation. The star's properties, such as its metallicity and effective temperature, are well-characterized by surveys like the Gaia mission, providing essential context for understanding the planet's formation environment. This close-in orbit places the planet within the category of highly irradiated hot Jupiters studied by projects like the Exoplanet Characterisation Observatory (EChO) concept.

Significance and study

WASP-96 b holds significant importance in the field of exoplanetology as a benchmark "clear-sky" hot Jupiter. Its pristine atmosphere serves as a natural laboratory for testing atmospheric models and spectroscopic techniques, with data from the James Webb Space Telescope setting new standards for precision. The planet was among the first targets of Webb's early release science programs, led by teams from the Space Telescope Science Institute and international collaborators. Findings from WASP-96 b directly inform the study of other exoplanetary atmospheres and guide the design of future missions, such as the Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) by the European Space Agency. Its continued observation contributes to overarching goals in the search for biosignatures and the understanding of planetary system diversity.

Category:Exoplanets Category:Hot Jupiters Category:Transiting exoplanets Category:Exoplanets discovered in 2013 Category:Exoplanets discovered by WASP