GJ 1061

GJ 1061 is a red dwarf star located 12 ly from Earth in the southern constellation of Horologium. Even though it is a relatively nearby star, it has an apparent visual magnitude of about 13, so it can only be seen with at least a moderately-sized telescope.

The proper motion of GJ 1061 has been known since 1974, but it was estimated to be further away: approximately 25 ly distant based upon an estimated parallax of 0.130″. The RECONS accurately determined its distance in 1997. At that time, it was the 20th-nearest star system to the Sun. The discovery team noted that many more stars like this are likely to be discovered nearby.

This star is a tiny, dim, red dwarf, close to the lower mass limit. It has an estimated mass of about 12.5% that of the Sun and is only about 0.2% as luminous. The star displays no significant infrared excess due to circumstellar dust.

Planetary system
On August 13, 2019, a planetary system was announced orbiting the star GJ 1061 by the Red Dots project for detecting terrestrial planets around nearby red dwarf stars. The planet GJ 1061 d orbits in the conservative circumstellar habitable zone of its star and the planet GJ 1061 c orbits in the inner edge of the habitable zone. GJ 1061 is a non-variable star that does not suffer flares, so there is a greater probability that the exoplanets still conserve their atmosphere if they had one.

GJ 1061 c
GJ 1061 c is a potentially habitable exoplanet orbiting within the limits of the optimistically defined habitable zone of its red dwarf parent star.

GJ 1061 c is at least 74% more massive than the Earth. The planet receives 35% more stellar flux than Earth and has an equilibrium temperature of 275 K. The average temperature on the surface would be warmer, 34 C, provided the atmosphere is of similar composition to the Earth's.

GJ 1061 c orbits its parent star very closely, every 6.7 days at a distance of just 0.035 au, so it is probably gravitationally locked and in synchronous rotation with its star.

GJ 1061 d
GJ 1061 d is a potentially habitable exoplanet largely orbiting within the limits of the conservatively defined habitable zone of its parent red dwarf star.

The exoplanet is at least 64% more massive than the Earth. The planet receives about 40% less stellar flux than Earth and has an estimated equilibrium temperature of 218 K. The average temperature on the surface would be colder than Earth's and at around 250 K, provided the atmosphere is similar to that of Earth.

GJ 1061 d orbits its star every 13 days, and due to its close-in semi-major axis, it is likely that the exoplanet is tidally locked. However, if the planet's orbit is confirmed to be highly eccentric then this eccentricity could be desynchronising it, enabling the existence of non-synchronised states of equilibrium in its rotation, relative to which side of the planet is facing the star, and thereby it will experience a day/night cycle.

Another solution for this planet gives it a slightly shorter period of 12.4 days and a slightly smaller minimum mass of.