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 |
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 MEarth. [7]
Lalande 21185 is a star in the south of Ursa Major. It is the apparent brightest red dwarf in the northern hemisphere. Despite this, and being relatively close by, it is very dim, being only magnitude 7.5 in visible light and thus too faint to be seen with the unaided eye. The star is visible through a small telescope or binoculars.
Luyten's Star (GJ 273) is a red dwarf in the constellation Canis Minor located at a distance of 12.35 light-years from the Sun. It has a visual magnitude of 9.9, making it too faint to be viewed with the unaided eye. It is named after Willem Jacob Luyten, who, in collaboration with Edwin G. Ebbighausen, first determined its high proper motion in 1935. The star has two confirmed planets and two candidate planets, of which Luyten b is in the circumstellar habitable zone.
Gliese 229 is a binary system composed of a red dwarf and the first brown dwarf seen by astronomers, 18.8 light years away in the constellation Lepus. The primary component has 58% of the mass of the Sun, 69% of the Sun's radius, and a very low projected rotation velocity of 1 km/s at the stellar equator.
Wolf 1061 is an M-class red dwarf star located about 14.1 light-years away in the constellation Ophiuchus. It is the 36th-closest-known star system to the Sun and has a relatively high proper motion of 1.2 seconds of arc per year. Wolf 1061 does not have any unusual spectroscopic features.
Gliese 581 is a red dwarf star of spectral type M3V at the center of the Gliese 581 planetary system, about 20.5 light years away from Earth in the Libra constellation. Its estimated mass is about a third of that of the Sun, and it is the 101st closest known star system to the Sun. Gliese 581 is one of the oldest, least active M dwarfs known. Its low stellar activity improves the likelihood of its planets retaining significant atmospheres, and lessens the sterilizing impact of stellar flares.
Gliese 667 is a triple-star system in the constellation Scorpius lying at a distance of about 7.2 parsecs from Earth. All three of the stars have masses smaller than the Sun. There is a 12th-magnitude star close to the other three, but it is not gravitationally bound to the system. To the naked eye, the system appears to be a single faint star of magnitude 5.89.
Gliese 832 is a red dwarf of spectral type M2V in the southern constellation Grus. The apparent visual magnitude of 8.66 means that it is too faint to be seen with the naked eye. It is located relatively close to the Sun, at a distance of 16.2 light years and has a high proper motion of 818.16 milliarcseconds per year. Gliese 832 has just under half the mass and radius of the Sun. Its estimated rotation period is a relatively leisurely 46 days. The star is roughly 6 billion years old.
HD 40307 is an orange (K-type) main-sequence star located approximately 42 light-years away in the constellation of Pictor, taking its primary name from its Henry Draper Catalogue designation. It is calculated to be slightly less massive than the Sun. The star has six known planets, three discovered in 2008 and three more in 2012. One of them, HD 40307 g, is a potential super-Earth in the habitable zone, with an orbital period of about 200 days. This object might be capable of supporting liquid water on its surface, although much more information must be acquired before its habitability can be assessed.
Gliese 433 is a dim red dwarf star with multiple exoplanetary companions, located in the equatorial constellation of Hydra. The system is located at a distance of 29.6 light-years from the Sun based on parallax measurements, and it is receding with a radial velocity of +18 km/s. Based on its motion through space, this is an old disk star. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 9.81 and an absolute magnitude of 10.07.
Gliese 180, is a small red dwarf star in the equatorial constellation of Eridanus. It is invisible to the naked eye with an apparent visual magnitude of 10.9. The star is located at a distance of 39 light years from the Sun based on parallax, and is drifting closer with a radial velocity of −14.6 km/s. It has a high proper motion, traversing the sky at the rate of 0.765 arcseconds per year.
GJ 3323 is a nearby single star located in the equatorial constellation Eridanus, about 0.4° to the northwest of the naked eye star Psi Eridani. It is invisible to the naked eye with an apparent visual magnitude 12.20. Parallax measurements give a distance estimate of 17.5 light-years from the Sun. It is drifting further away with a radial velocity of +42.3 km/s. Roughly 104,000 years ago, the star is believed to have come to within 7.34 ± 0.16 light-years of the Solar System.
GJ 625 is a small red dwarf star with an exoplanetary companion in the northern constellation of Draco. The system is located at a distance of 21.1 light-years from the Sun based on parallax, but is drifting closer with a radial velocity of −13 km/s. It is too faint to be visible to the naked eye, having an apparent visual magnitude of 10.13 and an absolute magnitude of 11.06.
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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.