Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cygnus [1] |
Right ascension | 20h 49m 27.44052s [2] |
Declination | +33° 36′ 50.9686″ [2] |
Apparent magnitude (V) | 17.8 (estimate) [3] |
Characteristics | |
Evolutionary stage | Red dwarf |
Spectral type | M6.5±0.5 [4] |
Apparent magnitude (B) | 19 [5] |
Apparent magnitude (R) | 16.4 [5] |
Apparent magnitude (G) | 15.379 [2] |
Apparent magnitude (J) | 11.5 [6] |
Apparent magnitude (H) | 10.867±0.021 [5] |
Apparent magnitude (K) | 10.54 [6] |
Astrometry | |
Proper motion (μ) |
RA: –207.809
mas/
yr
[2] Dec.: –412.215 mas/ yr [2] |
Parallax (π) | 59.7005 ± 0.0434 mas [2] |
Distance | 54.63 ± 0.04
ly (16.75 ± 0.01 pc) [2] |
Details [4] | |
Mass | 0.1009±0.0024 M☉ |
Radius | 0.123±0.0022 R☉ |
Luminosity | 0.000835±0.000019 L☉ |
Surface gravity (log g) | 5.265±0.014 cgs |
Temperature | 2800±29 K |
Metallicity [Fe/H] | 0.07±0.1 dex |
Rotation | 1.34±0.14 d |
Rotational velocity (v sin i) | 4.8±0.5 km/s |
Age | 6.6+1.8 −2.4 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
SPECULOOS-3, also known as LSPM J2049+3336, is a red dwarf star ( spectral type M6.5) located 54.6 light-years from Earth [4] in the constellation Cygnus. It is one of the smallest known stars, and is much cooler, dimmer and smaller than the Sun, having 0.1 times the mass, 0.08% the Sun's luminosity, and an effective temperature of 2,800 K (2,530 °C), which is less than half of the Sun's temperature (5,772 K). [4] It is orbited by one known exoplanet, and is the second ultra-cool dwarf discovered to have a planetary system, after TRAPPIST-1. [7] [8]
The age of SPECULOOS-3 is constrained at 6.6 billion years, 44% older than the Solar System, with significant margins of error. A bayesian analysis of the star derived a mass of 0.101 M☉, an effective temperature of 2,800 K (2,530 °C; 4,580 °F) and a luminosity of 8.35×10−6 L☉. These characteristics classify SPECULOOS-3 as an ultracool dwarf, which are stars at the end of the main sequence, with low temperatures, low luminosites and sizes similar to Jupiter. It is spinning at a rotational velocity of 4.8 km/s and has a projected rotational period of 1.34 days. [4]
The stellar radius, computed using the Stefan–Boltzmann law, is 0.134 R☉ (93,000 kilometres). [4] This makes SPECULOOS-3 the second-smallest star known to host a transiting planet, just marginally larger than TRAPPIST-1, [4] and its size is similar to that of Jupiter. [9] Its apparent magnitude is estimated at 17.8, [3] which is too faint to be seen by the naked eye.
It was first discovered in 2005 as part of the LSPM-North catalog, whose objective was to map stars in the northern celestial hemisphere with proper motions larger than 0.15" per year and apparent magnitudes smaller than 21m. [3] Its trignometric parallax was first measured in 2014 at 67.5±1.7 mas, translating into a distance of 14.8 parsecs (48.27 ly). [6] Gaia Data Release 3 (2023) published a parallax of 59.7 milliarcseconds, translating into a distance of 16.75 parsecs (54.6 ly). [2] This make this star relatively close to Earth. [10]
Red dwarf stars such as SPECULOOS-3 are the most numerous type of stars, making up 70% of all stars in the Milky Way galaxy. They are expected to live 10 times more than the Sun, with lifespans longer than 100 billion years. [10]
In 2024, an exoplanet was found around the star using the transit method. [11] Named SPECULOOS-3 b, it is an Earth-sized exoplanet that has a radius similar to that of Earth, equivalent to 0.98 Earth radii. [4] It takes only about 17 hours to complete an orbit around SPECULOOS-3, and, because of that proximity, it receives very high levels of radiation and is likely tidally locked, meaning that one side of the planet always faces its host star. [9] Its discovery was made using the SPECULOOS project, and was announced on 15 May 2024 in the academic journal Nature Astronomy. [12]
The mass of SPECULOOS-3 b has been not measured, [4] but it has been estimated by NASA's Eyes on Exoplanets at 0.894 ME. [13] Its equilibrium temperature is about 553 K (280 °C; 536 °F), meaning that its dayside is likely formed by solid rock. [4] The planet is an optimal target for characterization with the James Webb Space Telescope, giving more information about the planet's mineralogy [12] and the possibility of hosting an atmosphere. [14]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | — | 0.007330(55) | 0.71912603(57) | — | 89.44±0.39 ° | 0.977±0.022 R🜨 |
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cite journal}}
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link)
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cygnus [1] |
Right ascension | 20h 49m 27.44052s [2] |
Declination | +33° 36′ 50.9686″ [2] |
Apparent magnitude (V) | 17.8 (estimate) [3] |
Characteristics | |
Evolutionary stage | Red dwarf |
Spectral type | M6.5±0.5 [4] |
Apparent magnitude (B) | 19 [5] |
Apparent magnitude (R) | 16.4 [5] |
Apparent magnitude (G) | 15.379 [2] |
Apparent magnitude (J) | 11.5 [6] |
Apparent magnitude (H) | 10.867±0.021 [5] |
Apparent magnitude (K) | 10.54 [6] |
Astrometry | |
Proper motion (μ) |
RA: –207.809
mas/
yr
[2] Dec.: –412.215 mas/ yr [2] |
Parallax (π) | 59.7005 ± 0.0434 mas [2] |
Distance | 54.63 ± 0.04
ly (16.75 ± 0.01 pc) [2] |
Details [4] | |
Mass | 0.1009±0.0024 M☉ |
Radius | 0.123±0.0022 R☉ |
Luminosity | 0.000835±0.000019 L☉ |
Surface gravity (log g) | 5.265±0.014 cgs |
Temperature | 2800±29 K |
Metallicity [Fe/H] | 0.07±0.1 dex |
Rotation | 1.34±0.14 d |
Rotational velocity (v sin i) | 4.8±0.5 km/s |
Age | 6.6+1.8 −2.4 Gyr |
Other designations | |
Database references | |
SIMBAD | data |
SPECULOOS-3, also known as LSPM J2049+3336, is a red dwarf star ( spectral type M6.5) located 54.6 light-years from Earth [4] in the constellation Cygnus. It is one of the smallest known stars, and is much cooler, dimmer and smaller than the Sun, having 0.1 times the mass, 0.08% the Sun's luminosity, and an effective temperature of 2,800 K (2,530 °C), which is less than half of the Sun's temperature (5,772 K). [4] It is orbited by one known exoplanet, and is the second ultra-cool dwarf discovered to have a planetary system, after TRAPPIST-1. [7] [8]
The age of SPECULOOS-3 is constrained at 6.6 billion years, 44% older than the Solar System, with significant margins of error. A bayesian analysis of the star derived a mass of 0.101 M☉, an effective temperature of 2,800 K (2,530 °C; 4,580 °F) and a luminosity of 8.35×10−6 L☉. These characteristics classify SPECULOOS-3 as an ultracool dwarf, which are stars at the end of the main sequence, with low temperatures, low luminosites and sizes similar to Jupiter. It is spinning at a rotational velocity of 4.8 km/s and has a projected rotational period of 1.34 days. [4]
The stellar radius, computed using the Stefan–Boltzmann law, is 0.134 R☉ (93,000 kilometres). [4] This makes SPECULOOS-3 the second-smallest star known to host a transiting planet, just marginally larger than TRAPPIST-1, [4] and its size is similar to that of Jupiter. [9] Its apparent magnitude is estimated at 17.8, [3] which is too faint to be seen by the naked eye.
It was first discovered in 2005 as part of the LSPM-North catalog, whose objective was to map stars in the northern celestial hemisphere with proper motions larger than 0.15" per year and apparent magnitudes smaller than 21m. [3] Its trignometric parallax was first measured in 2014 at 67.5±1.7 mas, translating into a distance of 14.8 parsecs (48.27 ly). [6] Gaia Data Release 3 (2023) published a parallax of 59.7 milliarcseconds, translating into a distance of 16.75 parsecs (54.6 ly). [2] This make this star relatively close to Earth. [10]
Red dwarf stars such as SPECULOOS-3 are the most numerous type of stars, making up 70% of all stars in the Milky Way galaxy. They are expected to live 10 times more than the Sun, with lifespans longer than 100 billion years. [10]
In 2024, an exoplanet was found around the star using the transit method. [11] Named SPECULOOS-3 b, it is an Earth-sized exoplanet that has a radius similar to that of Earth, equivalent to 0.98 Earth radii. [4] It takes only about 17 hours to complete an orbit around SPECULOOS-3, and, because of that proximity, it receives very high levels of radiation and is likely tidally locked, meaning that one side of the planet always faces its host star. [9] Its discovery was made using the SPECULOOS project, and was announced on 15 May 2024 in the academic journal Nature Astronomy. [12]
The mass of SPECULOOS-3 b has been not measured, [4] but it has been estimated by NASA's Eyes on Exoplanets at 0.894 ME. [13] Its equilibrium temperature is about 553 K (280 °C; 536 °F), meaning that its dayside is likely formed by solid rock. [4] The planet is an optimal target for characterization with the James Webb Space Telescope, giving more information about the planet's mineralogy [12] and the possibility of hosting an atmosphere. [14]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | — | 0.007330(55) | 0.71912603(57) | — | 89.44±0.39 ° | 0.977±0.022 R🜨 |
{{
cite journal}}
: CS1 maint: bibcode (
link)