Location of GJ 1061 in the constellation Horologium | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Horologium |
Right ascension | 03h 35m 59.69916s [1] |
Declination | −44° 30′ 45.7308″ [1] |
Apparent magnitude (V) | 13.03 [2] |
Characteristics | |
Spectral type | M5.5 V [2] |
Apparent magnitude (J) | 7.52 ± 0.02 [3] |
U−B color index | 1.52 [3] |
B−V color index | 1.90 [3] |
Astrometry | |
Radial velocity (Rv) | 1.49±0.23 [1] km/s |
Proper motion (μ) | RA: 745.654 mas/yr [1] Dec.: −373.323 mas/yr [1] |
Parallax (π) | 272.1615±0.0316 mas [1] |
Distance | 11.984 ± 0.001 ly (3.6743 ± 0.0004 pc) |
Absolute magnitude (MV) | 15.26 [4] |
Details | |
Mass | 0.125±0.003 [5] M☉ |
Radius | 0.152±0.007 [5] R☉ |
Luminosity (bolometric) | 0.001641±0.000037 [5] L☉ |
Luminosity (visual, LV) | 0.00007 [nb 1] L☉ |
Temperature | 2,977+72 −69 [5] K |
Metallicity [Fe/H] | −0.03±0.09 [5] dex |
Rotational velocity (v sin i) | ≤ 5 [6] km/s |
Age | >7.0±0.5 [7] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
GJ 1061 is a red dwarf star located 12 light-years (3.7 parsecs ) 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, [2] 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 light-years (7.7 parsecs) 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. [2]
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. [5] The star displays no significant infrared excess due to circumstellar dust. [8]
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. [7] 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. [7] 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. [9]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥1.37+0.16 −0.15 M🜨 | 0.021±0.001 | 3.204±0.001 | <0.31 | — | — |
c | ≥1.74±0.23 M🜨 | 0.035±0.001 | 6.689±0.005 | <0.29 | — | — |
d | ≥1.64+0.24 −0.23 M🜨 | 0.054±0.001 | 13.031+0.025 −0.032 | <0.53 | — | — |
GJ 1061 c is a potentially habitable exoplanet orbiting within the limits of the optimistically defined habitable zone of its red dwarf parent star. [10] [11] [7]
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 (2 °C; 35 °F). [12] The average temperature on the surface would be warmer, 34 °C (307 K; 93 °F), 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 is a potentially habitable exoplanet largely orbiting within the limits of the conservatively defined habitable zone of its parent red dwarf star. [10] [13] [7]
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 (−55 °C; −67 °F). [10] [7] The average temperature on the surface would be colder than Earth's and at around 250 K (−23 °C; −10 °F), 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. [14] 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. [15]
Another solution for this planet gives it a slightly shorter period of 12.4 days and a slightly smaller minimum mass of 1.53 ME. [7]
While the semidiurnal tide drives the body towards the spin-orbit synchronous rotation, eccentricity tides tend to desynchronise it, and thereby enable the existence of non-synchronised states of equilibrium.