description GJ 357 b Overview
GJ 357 b is a transiting exoplanet with a radius about 1.2 times Earth's, discovered through NASA's TESS observations of the nearby M dwarf GJ 357. It is the innermost of three known planets in the system and completes an orbit in about 3.9 days. Its estimated equilibrium temperature is roughly 525 K, or about 250 degrees Celsius, so it receives too much irradiation to be considered a temperate or habitable-zone planet.
help GJ 357 b FAQ
How was GJ 357 b discovered?
NASA's TESS mission detected the planet as it crossed, or transited, its M dwarf star, and radial-velocity observations helped confirm the system. The discovery was announced in 2019. [NASA Exoplanet Archive](https://exoplanetarchive.ipac.caltech.edu/overview/GJ%20357)
How large and hot is GJ 357 b?
GJ 357 b has a radius of about 1.2 Earth radii and an estimated equilibrium temperature around 525 kelvins. Equilibrium temperature is a model value, not a direct measurement of the planet's surface temperature. [NASA Science](https://science.nasa.gov/exoplanet-catalog/gj-357-b/)
How long is a year on GJ 357 b?
One orbit takes about 3.93 Earth days, at a distance of roughly 0.036 astronomical units from its star. That makes it the innermost known planet in the GJ 357 system. [NASA Exoplanet Archive](https://exoplanetarchive.ipac.caltech.edu/overview/GJ%20357)
What other planets orbit GJ 357?
The system also includes GJ 357 c, with an orbit of about 9.12 days, and GJ 357 d, with an orbit of about 55.66 days. Unlike b, those two planets were identified through radial-velocity signals rather than a confirmed transit. [NASA Exoplanet Archive](https://exoplanetarchive.ipac.caltech.edu/overview/GJ%20357)
explore Explore More
Reviews & Comments
Write a Review
Be the first to review
Share your thoughts with the community and help others make better decisions.
