Short answers, pulled from the story.
Proxima Centauri b was announced on the 24th of August 2016 by the European Southern Observatory. The discovery was made by a team led by Anglada-Escudé using Doppler spectroscopy data collected at the observatory's facilities in Chile.
Proxima Centauri b is approximately 4.2 light-years from Earth, making it the closest known exoplanet to the Solar System. Its host star, Proxima Centauri, is the nearest star to the Sun.
Proxima Centauri b orbits within its star's habitable zone, but several factors complicate habitability. It likely faces intense stellar radiation 10-60 times stronger than Earth receives in ultraviolet and X-rays, probable tidal locking, and uncertainty about whether it retains any atmosphere at all.
Proxima Centauri b completes one orbit around Proxima Centauri approximately every 11.2 Earth days. It orbits at a distance of about 0.04848 AU, more than 20 times closer to its star than Earth is to the Sun.
Proxima Centauri b is likely tidally locked to its star, meaning one hemisphere would permanently face Proxima Centauri. However, if the planet's orbital eccentricity exceeds about 0.06-0.1, it could instead enter a Mercury-like 3:2 spin-orbit resonance rather than a full tidal lock.
Proxima Centauri b has not been directly imaged and is unlikely to transit its star as seen from Earth. In April-May 2019, the Breakthrough Listen project detected a radio signal called BLC1 near Proxima Centauri, but later investigation indicated it is probably of human origin.