  GJ 1061 Location of GJ 1061 in the constellationHorologium | |
| 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−Bcolor index | 1.52[3] |
| B−Vcolor index | 1.90[3] |
| Astrometry | |
| Radial velocity (Rv) | 1.49±0.23[1] km/s |
| Proper motion (μ) | RA: 745.654mas/yr[1] Dec.: −373.323mas/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 | |
| GJ 1061,LHS 1565,LFT 295,LTT 1702, LP 995-46, L 372-58[3] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
GJ 1061 is ared dwarfstar located 12light-years (3.7parsecs) fromEarth in the southernconstellation ofHorologium. Even though it is a relatively nearby star, it has anapparent visual magnitude of about 13,[2] so it can only be seen with at least a moderately-sizedtelescope.
Theproper 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″. TheRECONS accurately determined its distance in 1997. At that time, it was the20th-nearest star system to theSun. 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% asluminous.[5] The star displays no significantinfrared 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 conservativecircumstellar 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 habitableexoplanet orbiting within the limits of the optimistically defined habitable zone of itsred dwarf parent star.[10][11][7]
GJ 1061 c isat 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 0.035au, so it is probablygravitationally locked and in synchronous rotation with its star.
GJ 1061 d is a potentially habitableexoplanet 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 istidally 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 smallerminimum 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.
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