Its other properties are only poorly understood as of 2025[update], but it is a potentially Earth-like planet with a minimum mass of 1.07 M🜨 and a slightly larger radius than that of Earth.

Proxima Centauri is a flare star with intense emission of electromagnetic radiation that could strip an atmosphere off the planet.

Announced on 24 August 2016 by the European Southern Observatory (ESO), Proxima Centauri b was confirmed via several years of Doppler spectroscopy measurements of its parent star.

[11] Based on observations with instruments[b] at the European Southern Observatory in Chile prior to 2016, motion anomalies were identified in Proxima Centauri[12] that could not be satisfactorily explained by flares[c] or chromospheric[d] activity of the star.

In January 2016, a team of astronomers launched the Pale Red Dot project to confirm this hypothetical exoplanet's existence.

[15] An exoplanet candidate named Proxima Centauri c was reported in 2020,[16] but its existence has since been disputed due to potential artifacts in the data.

[30] Little is known about Proxima Centauri b as of 2021[update]—mainly its distance from the star and its orbital period[31]—but a number of simulations of its physical properties have been done.

[18] A number of simulations and models have been created that assume Earth-like compositions[32] and include predictions of the galactic environment, internal heat generation from radioactive decay and magnetic induction heating,[f] planetary rotation, the effects of stellar radiation, the amount of volatile species the planet consists of and the changes of these parameters over time.

Instead, the planet, or protoplanetary fragments, likely formed at larger distances and then migrated to the current orbit of Proxima Centauri b.

[3] A number of different formation scenarios are possible, many of which depend on the existence of other planets around Proxima Centauri and which would result in different compositions.

[41] A non-locked orbit, however, would result in tidal heating of the planet's mantle, increasing volcanic activity and potentially shutting down a magnetic field-generating dynamo.

[42] The exact dynamics are strongly dependent on the internal structure of the planet and its evolution in response to tidal heating.

[46] With an effective temperature[i] of 3,050±100 Kelvin, it has a spectral type[j] of M5.5V, making it an M-type main-sequence star that is fusing hydrogen at its core to generate energy.

The magnetic field of Proxima Centauri is considerably stronger than that of the Sun, with an intensity of 600±150 G;[49] it varies in a seven-year-long cycle.

However, it is also possible that Proxima Centauri b had a primordial hydrogen atmosphere or formed farther away from its star, which would have reduced the escape of water.

Depending on its properties such as whether it is tidally locked, the amount of water and carbon dioxide a number of scenarios are possible: A planet partially or wholly covered with ice, planet-wide or small oceans or only dry land, combinations between these,[65] scenarios with one or two "eyeballs"[m][67] or lobster-shaped areas with liquid water (meaning near the equator, with two nearly identical areas on each hemisphere, sprouting from the equator like lobster claws),[68] or a subsurface ocean[69] with a thin (less than a kilometre) ice cover that may be slushy in some places.

[42] In the context of exoplanet research, "habitability" is usually defined as the possibility that liquid water exists on the surface of a planet.

[31] Even the fastest spacecraft built by humans would take a long time to travel interstellar distances; Voyager 2 would take about 75,000 years to reach Proxima Centauri.