Coordinates: 14h 29m 42.9487s, −62° 40′ 46.141″
Epoch J2000.0 Equinox J2000.0 (ICRS)
||14h 29m 42.94853s
||−62° 40′ 46.1631″
|Apparent magnitude (V)
||10.43 – 11.11
||Main sequence red dwarf
|Apparent magnitude (U)
|Apparent magnitude (B)
|Apparent magnitude (V)
|Apparent magnitude (R)
|Apparent magnitude (I)
|Apparent magnitude (J)
|Apparent magnitude (H)
|Apparent magnitude (K)
|U−B color index
|B−V color index
|V−R color index
|R−I color index
|J−H color index
|J−K color index
||UV Ceti ("flare star")
|Radial velocity (Rv)||−22.204±0.032 km/s|
|Proper motion (μ)|| RA: −3781.741 mas/yr |
Dec.: 769.465 mas/yr
|Parallax (π)||768.0665 ± 0.0499 mas|
|Distance||4.2465 ± 0.0003 ly |
(1.30197 ± 0 pc)
|Absolute magnitude (MV)||15.60|
|Primary||Alpha Centauri AB|
|Semi-major axis (a)||8700+700|
|Longitude of the node (Ω)||126±5°|
|Periastron epoch (T)||+283+59|
|Argument of periastron (ω)|
|Luminosity (bolometric)||0.0017 L☉|
|Luminosity (visual, LV)||0.00005[nb 1] L☉|
|Surface gravity (log g)||5.20±0.23 cgs|
|Metallicity [Fe/H]||0.21[nb 2] dex|
|Rotational velocity (v sin i)||< 0.1 km/s|
Alf Cen C, Alpha Centauri C
, V645 Centauri
70890, CCDM J14396-6050C
The location of Proxima Centauri (circled in red)
Proxima Centauri is a small, low-mass star located 4.2465 light-years (1.3020 pc) away from the Sun in the southern constellation of Centaurus. Its Latin name means the "nearest [star] of Centaurus". This object was discovered in 1915 by Robert Innes and is the nearest-known star to the Sun. With a quiescent apparent magnitude 11.13, it is too faint to be seen with the unaided eye. Proxima Centauri is a member of the Alpha Centauri system, being identified as component Alpha Centauri C, and is 2.18° to the southwest of the Alpha Centauri AB pair. It is currently 12,950 AU (0.2 ly) from AB, which it orbits with a period of about 550,000 years.
Proxima Centauri is a red dwarf star with a mass about an eighth (12.5%) of the Sun's mass (M☉), and average density about 33 times that of the Sun. Because of Proxima Centauri's proximity to Earth, its angular diameter can be measured directly. Its actual diameter is about one-seventh (14%) the diameter of the Sun. Although it has a very low average luminosity, Proxima Centauri is a flare star that randomly undergoes dramatic increases in brightness because of magnetic activity. The star's magnetic field is created by convection throughout the stellar body, and the resulting flare activity generates a total X-ray emission similar to that produced by the Sun. The thorough internal mixing of its fuel by convection through its core, and Proxima's relatively low energy-production rate, mean that it will be a main-sequence star for another four trillion years.
Proxima Centauri has two confirmed exoplanets: Proxima Centauri b and Proxima Centauri c. Proxima Centauri b orbits the star at a distance of roughly 0.05 AU (7.5 million km) with an orbital period of approximately 11.2 Earth days. Its estimated mass is at least 1.17 times that of Earth. Proxima b is orbiting within Proxima Centauri's habitable zone—the range where temperatures are right for liquid water to exist on its surface—but because Proxima Centauri is a red dwarf and a flare star, its habitability is disputed. A super-Earth, Proxima Centauri c, orbits roughly 1.5 AU (220 million km) away every 1,900 d (5.2 yr). A faint additional signal was detected in a 2019 exoplanet search using radial velocity data, with a period of 5.15 days. Possible explanations for the signal include undiscovered exoplanets or statistical noise.[nb 3]
An anomalous radio signal apparently originating from Proxima or its vicinity was detected in mid-2019 by Breakthrough Listen using the Parkes radio telescope.
In 1915, the Scottish astronomer Robert Innes, Director of the Union Observatory in Johannesburg, South Africa, discovered a star that had the same proper motion as Alpha Centauri. He suggested that it be named Proxima Centauri (actually Proxima Centaurus). In 1917, at the Royal Observatory at the Cape of Good Hope, the Dutch astronomer Joan Voûte measured the star's trigonometric parallax at 0.755″±0.028″ and determined that Proxima Centauri was approximately the same distance from the Sun as Alpha Centauri. It was also found to be the lowest-luminosity star known at the time. An equally accurate parallax determination of Proxima Centauri was made by American astronomer Harold L. Alden in 1928, who confirmed Innes's view that it is closer, with a parallax of 0.783″±0.005″.
Stars closest to the Sun
, including Proxima Centauri
In 1951, American astronomer Harlow Shapley announced that Proxima Centauri is a flare star. Examination of past photographic records showed that the star displayed a measurable increase in magnitude on about 8% of the images, making it the most active flare star then known.
The proximity of the star allows for detailed observation of its flare activity. In 1980, the Einstein Observatory produced a detailed X-ray energy curve of a stellar flare on Proxima Centauri. Further observations of flare activity were made with the EXOSAT and ROSAT satellites, and the X-ray emissions of smaller, solar-like flares were observed by the Japanese ASCA satellite in 1995. Proxima Centauri has since been the subject of study by most X-ray observatories, including XMM-Newton and Chandra.
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name Proxima Centauri for this star on August 21, 2016 and it is now so included in the List of IAU approved Star Names.
Because of Proxima Centauri's southern declination, it can only be viewed south of latitude 27° N.[nb 4] Red dwarfs such as Proxima Centauri are too faint to be seen with the naked eye. Even from Alpha Centauri A or B, Proxima would only be seen as a fifth magnitude star. It has apparent visual magnitude 11, so a telescope with an aperture of at least 8 cm (3.1 in) is needed to observe it, even under ideal viewing conditions—under clear, dark skies with Proxima Centauri well above the horizon.
In 2018, a superflare was observed from Proxima Centauri, the strongest flare ever seen. The optical brightness increased by a factor of 68× to approximately magnitude 6.8. It is estimated that similar flares occur around five times every year but are of such short duration, just a few minutes, that they have never been observed before.
On 2020 April 22 and 23, the New Horizons spacecraft took images of two of the nearest stars, Proxima Centauri and Wolf 359. When compared with Earth-based images, a very large parallax effect was easily visible. However, this was mostly useful for illustrative purposes and did not improve on previous distance measurements.
Proxima Centauri is a red dwarf, because it belongs to the main sequence on the Hertzsprung–Russell diagram and is of spectral class M5.5. M5.5 means that it falls in the low-mass end of M-type dwarf stars. Its absolute visual magnitude, or its visual magnitude as viewed from a distance of 10 parsecs (33 ly), is 15.5. Its total luminosity over all wavelengths is 0.17% that of the Sun, although when observed in the wavelengths of visible light the eye is most sensitive to, it is only 0.0056% as luminous as the Sun. More than 85% of its radiated power is at infrared wavelengths.
The two bright points are the Alpha Centauri
system (left) and Beta Centauri
(right). The faint red star in the centre of the red circle is Proxima Centauri.
In 2002, optical interferometry with the Very Large Telescope (VLTI) found that the angular diameter of Proxima Centauri is 1.02±0.08 mas. Because its distance is known, the actual diameter of Proxima Centauri can be calculated to be about 1/7 that of the Sun, or 1.5 times that of Jupiter. The star's mass, estimated from stellar theory, is 12.2% M☉, or 129 Jupiter masses (MJ). The mass has been calculated directly, although with less precision, from observations of microlensing events to be 0.150+0.062
Lower mass main-sequence stars have higher mean density than higher mass ones, and Proxima Centauri is no exception: it has a mean density of 47.1×103 kg/m3 (47.1 g/cm3), compared with the Sun's mean density of 1.411×103 kg/m3 (1.411 g/cm3).[nb 5]
A 1998 study of photometric variations indicates that Proxima Centauri rotates once every 83.5 days. A subsequent time series analysis of chromospheric indicators in 2002 suggests a longer rotation period of 116.6±0.7 days. This was subsequently ruled out in favor of a rotation period of 82.6±0.1 days.
Because of its low mass, the interior of the star is completely convective, causing energy to be transferred to the exterior by the physical movement of plasma rather than through radiative processes. This convection means that the helium ash left over from the thermonuclear fusion of hydrogen does not accumulate at the core, but is instead circulated throughout the star. Unlike the Sun, which will only burn through about 10% of its total hydrogen supply before leaving the main sequence, Proxima Centauri will consume nearly all of its fuel before the fusion of hydrogen comes to an end after about 4 trillion years.
Convection is associated with the generation and persistence of a magnetic field. The magnetic energy from this field is released at the surface through stellar flares that briefly increase the overall luminosity of the star. These flares can grow as large as the star and reach temperatures measured as high as 27 million K—hot enough to radiate X-rays. Proxima Centauri's quiescent X-ray luminosity, approximately (4–16) × 1026 erg/s ((4–16) × 1019 W), is roughly equal to that of the much larger Sun. The peak X-ray luminosity of the largest flares can reach 1028 erg/s (1021 W).
Proxima Centauri's chromosphere is active, and its spectrum displays a strong emission line of singly ionized magnesium at a wavelength of 280 nm. About 88% of the surface of Proxima Centauri may be active, a percentage that is much higher than that of the Sun even at the peak of the solar cycle. Even during quiescent periods with few or no flares, this activity increases the corona temperature of Proxima Centauri to 3.5 million K, compared to the 2 million K of the Sun's corona, and its total X-ray emission is comparable to the sun's. Proxima Centauri's overall activity level is considered low compared to other red dwarfs, which is consistent with the star's estimated age of 4.85 × 109 years, since the activity level of a red dwarf is expected to steadily wane over billions of years as its stellar rotation rate decreases. The activity level also appears to vary with a period of roughly 442 days, which is shorter than the solar cycle of 11 years.
Proxima Centauri has a relatively weak stellar wind, no more than 20% of the mass loss rate of the solar wind. Because the star is much smaller than the Sun, the mass loss per unit surface area from Proxima Centauri may be eight times that from the solar surface.
A red dwarf with the mass of Proxima Centauri will remain on the main sequence for about four trillion years. As the proportion of helium increases because of hydrogen fusion, the star will become smaller and hotter, gradually transforming into a so-called "blue dwarf". Near the end of this period it will become significantly more luminous, reaching 2.5% of the Sun's luminosity (L☉) and warming up any orbiting bodies for a period of several billion years. When the hydrogen fuel is exhausted, Proxima Centauri will then evolve into a white dwarf (without passing through the red giant phase) and steadily lose any remaining heat energy.
Distance and motion
Based on a parallax of 768.0665±0.0499 mas, published in 2020 in Gaia Data Release 3, Proxima Centauri is 4.2465 light-years (1.3020 pc; 268,550 AU) from the Sun. Previously published parallaxes include: 768.5±0.2 mas in 2018 by Gaia DR2, 768.13±1.04 mas, in 2014 by the Research Consortium On Nearby Stars; 772.33±2.42 mas, in the original Hipparcos Catalogue, in 1997; 771.64±2.60 mas in the Hipparcos New Reduction, in 2007; and 768.77±0.37 mas using the Hubble Space Telescope's Fine Guidance Sensors, in 1999. From Earth's vantage point, Proxima Centauri is separated from Alpha Centauri by 2.18 degrees, or four times the angular diameter of the full Moon. Proxima Centauri also has a relatively large proper motion—moving 3.85 arcseconds per year across the sky. It has a radial velocity toward the Sun of 22.2 km/s.
Distances of the nearest stars
from 20,000 years ago through 80,000 years in the future. Proxima Centauri is in yellow.
Among the known stars, Proxima Centauri has been the closest star to the Sun for about 32,000 years and will be so for about another 25,000 years, after which Alpha Centauri A and Alpha Centauri B will alternate approximately every 79.91 years as the closest star to the Sun. In 2001, J. García-Sánchez et al. predicted that Proxima Centauri will make its closest approach to the Sun in approximately 26,700 years, coming within 3.11 ly (0.95 pc). A 2010 study by V. V. Bobylev predicted a closest approach distance of 2.90 ly (0.89 pc) in about 27,400 years, followed by a 2014 study by C. A. L. Bailer-Jones predicting a perihelion approach of 3.07 ly (0.94 pc) in roughly 26,710 years. Proxima Centauri is orbiting through the Milky Way at a distance from the Galactic Centre that varies from 27 to 31 kly (8.3 to 9.5 kpc), with an orbital eccentricity of 0.07.
of Proxima Centauri as presently seen from Earth
Ever since the discovery of Proxima Centauri, it has been suspected to be a true companion of the Alpha Centauri binary star system. Data from the Hipparcos satellite, combined with ground-based observations, were consistent with the hypothesis that the three stars are a bound system. For this reason, Proxima Centauri is sometimes referred to as Alpha Centauri C. Kervella et al. (2017) used high-precision radial velocity measurements to determine with a high degree of confidence that Proxima and Alpha Centauri are gravitationally bound. Proxima Centauri's orbital period around the Alpha Centauri AB barycenter is 547000+6600
−4000 years with an eccentricity of 0.5±0.08; it approaches Alpha Centauri to 4300+1100
−900 AU at periastron and retreats to 13000+300
−100 AU at apastron. At present, Proxima Centauri is 12,947 ± 260 AU (1.94 ± 0.04 trillion km) from the Alpha Centauri AB barycenter, nearly to the farthest point in its orbit.
Such a triple system can form naturally through a low-mass star being dynamically captured by a more massive binary of 1.5–2 M☉ within their embedded star cluster before the cluster disperses. However, more accurate measurements of the radial velocity are needed to confirm this hypothesis. If Proxima Centauri was bound to the Alpha Centauri system during its formation, the stars are likely to share the same elemental composition. The gravitational influence of Proxima might also have stirred up the Alpha Centauri protoplanetary disks. This would have increased the delivery of volatiles such as water to the dry inner regions, so possibly enriching any terrestrial planets in the system with this material. Alternatively, Proxima Centauri may have been captured at a later date during an encounter, resulting in a highly eccentric orbit that was then stabilized by the galactic tide and additional stellar encounters. Such a scenario may mean that Proxima Centauri's planetary companions have had a much lower chance for orbital disruption by Alpha Centauri.
Six single stars, two binary star systems, and a triple star share a common motion through space with Proxima Centauri and the Alpha Centauri system. The space velocities of these stars are all within 10 km/s of Alpha Centauri's peculiar motion. Thus, they may form a moving group of stars, which would indicate a common point of origin, such as in a star cluster.
Ever since the first exoplanets were discovered, there has been a hunt for exoplanets in the Alpha Centauri system. Multiple measurements of the star's radial velocity constrained the maximum mass that a detectable companion to Proxima Centauri could possess. The activity level of the star adds noise to the radial velocity measurements, complicating detection of a companion using this method. In 1998, an examination of Proxima Centauri using the Faint Object Spectrograph on board the Hubble Space Telescope appeared to show evidence of a companion orbiting at a distance of about 0.5 AU. A subsequent search using the Wide Field Planetary Camera 2 failed to locate any companions. Astrometric measurements at the Cerro Tololo Inter-American Observatory appear to rule out a Jupiter-sized planet with an orbital period of 2−12 years.
Artist's conception of Proxima Centauri b as a rocky-like exoplanet, with Proxima Centauri and the Alpha Centauri
binary system in the background. The actual appearance of the planet is unknown.
Proxima Centauri b, or Alpha Centauri Cb, orbits the star at a distance of roughly 0.05 AU (7.5 million km) with an orbital period of approximately 11.2 Earth days. Its estimated mass is at least 1.17 times that of the Earth. Moreover, the equilibrium temperature of Proxima Centauri b is estimated to be within the range where water could exist as liquid on its surface; thus, placing it within the habitable zone of Proxima Centauri.
The first indications of the exoplanet Proxima Centauri b were found in 2013 by Mikko Tuomi of the University of Hertfordshire from archival observation data. To confirm the possible discovery, a team of astronomers launched the Pale Red Dot[nb 7] project in January 2016. On August 24, 2016, the team of 31 scientists from all around the world, led by Guillem Anglada-Escudé of Queen Mary University of London, confirmed the existence of Proxima Centauri b through a peer-reviewed article published in Nature. The measurements were performed using two spectrographs: HARPS on the ESO 3.6 m Telescope at La Silla Observatory and UVES on the 8 m Very Large Telescope at Paranal Observatory. Several attempts to detect a transit of this planet across the face of Proxima Centauri have been made. A transit-like signal appearing on September 8, 2016 was tentatively identified, using the Bright Star Survey Telescope at the Zhongshan Station in Antarctica.
Proxima Centauri c is a super-Earth or gas dwarf about 7 Earth masses orbiting at roughly 1.5 astronomical units (220,000,000 km) every 1,900 days (5.2 yr). If Proxima Centauri b were the star's Earth, Proxima Centauri c would be equivalent to Neptune. Due to its large distance from Proxima Centauri, it is unlikely to be habitable, with a low equilibrium temperature of around 39 K. The planet was first reported by Italian astrophysicist Mario Damasso and his colleagues in April 2019. Damasso's team had noticed minor movements of Proxima Centauri in the radial velocity data from the ESO's HARPS instrument, indicating a possible additional planet orbiting Proxima Centauri. In 2020, the planet's existence was confirmed by Hubble astrometry data from c. 1995. A possible direct imaging counterpart was detected in the infrared with the SPHERE, but the authors admit that they "did not obtain a clear detection." If their candidate source is in fact Proxima Centauri c, it is too bright for a planet of its mass and age, implying that the planet may have a ring system with a radius of around 5 RJ. If this direct imaging detection is confirmed, Proxima Centauri c will be the closest exoplanet ever directly imaged.
In 2016, in a paper that helped to confirm Proxima Centauri b's existence, a second signal in the range of 60 to 500 days was also detected. However, its nature is still unclear due to stellar activity and inadequate sampling.
In 2017, a team of astronomers using the Atacama Large Millimeter/submillimeter Array reported detecting a belt of cold dust orbiting Proxima Centauri at a range of 1−4 AU from the star. This dust has a temperature of around 40 K and has a total estimated mass of 1% of the planet Earth. They also tentatively detected two additional features: a cold belt with a temperature of 10 K orbiting around 30 AU and a compact emission source about 1.2 arcseconds from the star. There was also a hint at an additional warm dust belt at a distance of 0.4 AU from the star. However, upon further analysis, these emissions were determined to be most likely the result of a large flare emitted by the star in March 2017. The presence of dust is not needed to model the observations.
In 2019, a team of astronomers revisited the data from ESPRESSO about Proxima Centauri b to refine its mass. While doing so, the team found another radial velocity spike with a periodicity of 5.15 days. They estimated that if it were a planetary companion, it would be no less than 0.29 Earth masses. The discovery was released in 2020.
Pale Red Dot
is an international search for an Earth-like exoplanet around the closest star Proxima Centauri.
Prior to the discovery of Proxima Centauri b, the TV documentary Alien Worlds hypothesized that a life-sustaining planet could exist in orbit around Proxima Centauri or other red dwarfs. Such a planet would lie within the habitable zone of Proxima Centauri, about 0.023–0.054 AU (3.4–8.1 million km) from the star, and would have an orbital period of 3.6–14 days. A planet orbiting within this zone may experience tidal locking to the star. If the orbital eccentricity of this hypothetical planet is low, Proxima Centauri would move little in the planet's sky, and most of the surface would experience either day or night perpetually. The presence of an atmosphere could serve to redistribute the energy from the star-lit side to the far side of the planet.
Proxima Centauri's flare outbursts could erode the atmosphere of any planet in its habitable zone, but the documentary's scientists thought that this obstacle could be overcome. Gibor Basri of the University of California, Berkeley, mentioned that "no one [has] found any showstoppers to habitability". For example, one concern was that the torrents of charged particles from the star's flares could strip the atmosphere off any nearby planet. If the planet had a strong magnetic field, the field would deflect the particles from the atmosphere; even the slow rotation of a tidally locked planet that spins once for every time it orbits its star would be enough to generate a magnetic field, as long as part of the planet's interior remained molten.
Other scientists, especially proponents of the rare-Earth hypothesis, disagree that red dwarfs can sustain life. Any exoplanet in this star's habitable zone would likely be tidally locked, resulting in a relatively weak planetary magnetic moment, leading to strong atmospheric erosion by coronal mass ejections from Proxima Centauri.
The Sun as seen from the Alpha Centauri system, using Celestia
Because of the star's proximity to Earth, Proxima Centauri has been proposed as a flyby destination for interstellar travel.
Proxima Centauri currently moves toward Earth at a rate of 22.2 km/s. ( Barycenter of system moving closer, while rotation around AB is away from Sun, i.e. prograde). After 26,700 years, when it will come within 3.11 light-years, it will begin to move farther away.
If non-nuclear, conventional propulsion technologies are used, the flight of a spacecraft to Proxima Centauri and its planets would probably require thousands of years. For example, Voyager 1, which is now travelling 17 km/s (38,000 mph) relative to the Sun, would reach Proxima Centauri in 73,775 years, were the spacecraft travelling in the direction of that star. A slow-moving probe would have only several tens of thousands of years to catch Proxima Centauri near its closest approach, and could end up watching it recede into the distance.
Nuclear pulse propulsion might enable such interstellar travel with a trip timescale of a century, inspiring several studies such as Project Orion, Project Daedalus, and Project Longshot.
Project Breakthrough Starshot aims to reach the Alpha Centauri system within the first half of the 21st century, with microprobes travelling at 20% of the speed of light propelled by around 100 gigawatts of Earth-based lasers. The probes would perform a fly-by of Proxima Centauri to take photos and collect data of its planets' atmospheric compositions. It would take 4.25 years for the information collected to be sent back to Earth.
From Proxima Centauri, the Sun would appear as a bright 0.4-magnitude star in the constellation Cassiopeia, similar to that of Achernar from Earth.[nb 8]
In December 2020, a candidate SETI radio signal BLC-1 was announced as potentially coming from the star.
- ^ From knowing the absolute visual magnitude of Proxima Centauri, , and the absolute visual magnitude of the Sun, , the visual luminosity of Proxima Centauri can therefore be calculated:
- ^ If Proxima Centauri was a later capture into the Alpha Centauri star system then its metallicity and age could be quite different to that of Alpha Centauri A and B. Through comparing Proxima Centauri to other similar stars it was estimated that it had a lower metallicity, ranging from less than a third, to about the same, of our Sun's.
- ^ If a planet is confirmed to be the cause of this signal, as of August 2020 it would be designated as Proxima Centauri d in accordance with IAU exoplanet naming policies.
- ^ For a star south of the zenith, the angle to the zenith is equal to the Latitude minus the Declination. The star is hidden from sight when the zenith angle is 90° or more, i.e. below the horizon. Thus, for Proxima Centauri:
See: Campbell, William Wallace (1899). The elements of practical astronomy. London: Macmillan. pp. 109–110. Retrieved 12 August 2008.
- Highest latitude = 90° + (−62.68°) = 27.32°.
- ^ The density (ρ) is given by the mass divided by the volume. Relative to the Sun, therefore, the density is:
||= 0.122 · 0.154−3 · (1.41 × 103 kg/m3)
||= 33.4 · (1.41 × 103 kg/m3)
||= 4.71 × 104 kg/m3
where is the average solar density.
- Munsell, Kirk; Smith, Harman; Davis, Phil; Harvey, Samantha (11 June 2008). "Sun: facts & figures". Solar system exploration. NASA. Archived from the original on 2 January 2008. Retrieved 12 July 2008.
- Bergman, Marcel W.; Clark, T. Alan; Wilson, William J. F. (2007). Observing projects using Starry Night Enthusiast (8th ed.). Macmillan. pp. 220–221. ISBN 978-1-4292-0074-5.
- ^ This is actually an upper limit on the quantity m sin i, where i is the angle between the orbit normal and the line of sight, in a circular orbit. If the planetary orbits are close to face-on as observed from Earth, or in an eccentric orbit, more massive planets could have evaded detection by the radial velocity method.
- ^ Pale Red Dot is a reference to Pale Blue Dot, a distant photo of Earth taken by Voyager 1.
- ^ The coordinates of the Sun would be diametrically opposite Proxima Centauri, at α=02h 29m 42.9487s, δ=+62° 40′ 46.141″. The absolute magnitude Mv of the Sun is 4.83, so at a parallax π of 0.77199 the apparent magnitude m is given by 4.83 − 5(log10(0.77199) + 1) = 0.40.
See: Tayler, Roger John (1994). The Stars: Their Structure and Evolution. Cambridge University Press. p. 16. ISBN 978-0-521-45885-6.
- ^ "Collins English Dictionary". HarperCollins Publishers. Retrieved 30 September 2020.
- ^ a b c Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR online data catalog: General catalogue of variable stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ Bessell, M. S. (1991). "The late-M dwarfs". The Astronomical Journal. 101: 662. Bibcode:1991AJ....101..662B. doi:10.1086/115714.
- ^ a b c d e Jao, Wei-Chun; Henry, Todd J.; Subasavage, John P.; Winters, Jennifer G.; Gies, Douglas R.; Riedel, Adric R.; Ianna, Philip A. (2014). "The Solar neighborhood. XXXI. Discovery of an unusual red+white dwarf binary at ~25 pc via astrometry and UV imaging". The Astronomical Journal. 147 (1): 21. arXiv:1310.4746. Bibcode:2014AJ....147...21J. doi:10.1088/0004-6256/147/1/21. ISSN 0004-6256. S2CID 17528018.
- ^ a b c Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; Beichman, C. A.; Carpenter, J. M.; Chester, T.; Cambresy, L.; Evans, T.; Fowler, J.; Gizis, J.; Howard, E.; Huchra, J.; Jarrett, T.; Kopan, E. L.; Kirkpatrick, J. D.; Light, R. M.; Marsh, K. A.; McCallon, H.; Schneider, S.; Stiening, R.; Sykes, M.; Weinberg, M.; Wheaton, W. A.; Wheelock, S.; Zacarias, N. (2003). "VizieR online data catalog: 2MASS all-sky catalog of point sources (Cutri+ 2003)". VizieR On-line Data Catalog: II/246. Originally Published in: 2003yCat.2246....0C. 2246: 0. Bibcode:2003yCat.2246....0C.
- ^ a b c d e f g h i Kervella, P.; Thévenin, F.; Lovis, C. (2017). "Proxima's orbit around α Centauri". Astronomy & Astrophysics. 598: L7. arXiv:1611.03495. Bibcode:2017A&A...598L...7K. doi:10.1051/0004-6361/201629930. ISSN 0004-6361. S2CID 50867264. Separation: 3.1, left column of page 3; Orbital period and epoch of periastron: Table 3, right column of page 3.
- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics (in press). arXiv:2012.01533. doi:10.1051/0004-6361/202039657. S2CID 227254300. Gaia EDR3 record for this source at VizieR.
- ^ a b c Benedict, G. Fritz, Chappell DW, Nelan E, Jefferys WH, Van Altena W, Lee J, Cornell D, Shelus PJ (1999). "Interferometric astrometry of Proxima Centauri and Barnard's Star using Hubble Space Telescope fine guidance sensor 3: detection limits for substellar companions". The Astronomical Journal. 118 (2): 1086–1100. arXiv:astro-ph/9905318. Bibcode:1999AJ....118.1086B. doi:10.1086/300975. S2CID 18099356.
- ^ a b See Table 1, Doyle, J. G.; Butler, C. J. (1990). "Optical and infrared photometry of dwarf M and K stars". Astronomy and Astrophysics. 235: 335–339. Bibcode:1990A&A...235..335D. and p. 57, Peebles, P. J. E. (1993). Principles of physical cosmology. Princeton, New Jersey: Princeton University Press. ISBN 978-0-691-01933-8.
- ^ a b Ségransan, D.; Kervella, P.; Forveille, T.; Queloz, D. (2003). "First radius measurements of very low mass stars with the VLTI". Astronomy and Astrophysics. 397 (3): L5–L8. arXiv:astro-ph/0211647. Bibcode:2003A&A...397L...5S. doi:10.1051/0004-6361:20021714. S2CID 10748478.
- ^ Schlaufman, K. C.; Laughlin, G. (September 2010). "A physically-motivated photometric calibration of M dwarf metallicity". Astronomy and Astrophysics. 519: A105. arXiv:1006.2850. Bibcode:2010A&A...519A.105S. doi:10.1051/0004-6361/201015016. S2CID 119260592.
- ^ Passegger, V. M.; Wende-von Berg, S.; Reiners, A. (March 2016). "Fundamental M-dwarf parameters from high-resolution spectra using PHOENIX ACES models. I. Parameter accuracy and benchmark stars". Astronomy & Astrophysics. 587. A19. arXiv:1709.03560. Bibcode:2016A&A...587A..19P. doi:10.1051/0004-6361/201322261. ISSN 0004-6361. S2CID 10458151.
- ^ a b Feng, F.; Jones, H. R. A. (January 2018). "Was Proxima captured by Alpha Centauri A and B?". Monthly Notices of the Royal Astronomical Society. 473 (3): 3185−3189. arXiv:1709.03560. Bibcode:2018MNRAS.473.3185F. doi:10.1093/mnras/stx2576. S2CID 55711316.
- ^ a b c Collins, John M.; Jones, Hugh R. A.; Barnes, John R. (June 2017). "Calculations of periodicity from Hα profiles of Proxima Centauri". Astronomy & Astrophysics. 602. A48. arXiv:1608.07834. Bibcode:2017A&A...602A..48C. doi:10.1051/0004-6361/201628827. S2CID 18949162. See section 4: "the vsini is probably less than 0.1 km/s for Proxima Centauri".
- ^ a b c Kervella, Pierre; Thevenin, Frederic (15 March 2003). "A family portrait of the Alpha Centauri system: VLT interferometer studies the nearest stars". European Southern Observatory. Retrieved 10 May 2016.
- ^ "SIMBAD query result: V* V645 Cen – Flare Star". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 11 August 2008.—some of the data is located under "Measurements".
- ^ a b c d Suárez Mascareño, A.; Faria, J. P.; et al. (2020). "Revisiting Proxima with ESPRESSO". Astronomy & Astrophysics. 639: A77. arXiv:2005.12114. Bibcode:2020A&A...639A..77S. doi:10.1051/0004-6361/202037745. ISSN 0004-6361.
- ^ a b Damasso, Mario; Del Sordo, Fabio; Anglada-Escudé, Guillem; et al. (15 January 2020). "A low-mass planet candidate orbiting Proxima Centauri at a distance of 1.5 AU". Science Advances. 6 (3). eaax7467. Bibcode:2020SciA....6.7467D. doi:10.1126/sciadv.aax7467. PMC 6962037. PMID 31998838.
- ^ a b Benedict, G. Fritz; McArthur, Barbara E. (16 June 2020). "A Moving Target—Revising the Mass of Proxima Centauri c". Research Notes of the AAS. 4 (6): 86. Bibcode:2020RNAAS...4...86B. doi:10.3847/2515-5172/ab9ca9.
- ^ "Naming of Exoplanets". IAU. Retrieved 12 August 2020.
- ^ Overbye, Dennis (31 December 2020). "Was That a Dropped Call From ET? - A spooky radio signal showed up after a radio telescope was aimed at the next star over from our sun". The New York Times. Retrieved 31 December 2020.
- ^ Innes, R. T. A. (October 1915). "A Faint Star of Large Proper Motion". Circular of the Union Observatory Johannesburg. 30: 235–236. Bibcode:1915CiUO...30..235I. This is the original Proxima Centauri discovery paper.
- ^ a b Glass, I. S. (July 2007). "The discovery of the nearest star". African Skies. 11: 39. Bibcode:2007AfrSk..11...39G.
- ^ Glass, I.S. (2008). Proxima, the nearest star (other than the Sun). Cape Town: Mons Mensa. Archived from the original on 12 September 2017. Retrieved 6 September 2016.
- ^ Queloz, Didier (29 November 2002). "How Small are Small Stars Really?". European Southern Observatory. eso0232; PR 22/02. Retrieved 29 January 2018.
- ^ a b Alden, Harold L. (1928). "Alpha and Proxima Centauri". Astronomical Journal. 39 (913): 20–23. Bibcode:1928AJ.....39...20A. doi:10.1086/104871.
- ^ Innes, R. T. A. (September 1917). "Parallax of the Faint Proper Motion Star Near Alpha of Centaurus. 1900. R.A. 14h22m55s.-0s 6t. Dec-62° 15'2 0'8 t". Circular of the Union Observatory Johannesburg. 40: 331–336. Bibcode:1917CiUO...40..331I.
- ^ Voûte, J. (1917). "A 13th magnitude star in Centaurus with the same parallax as α Centauri". Monthly Notices of the Royal Astronomical Society. 77 (9): 650–651. Bibcode:1917MNRAS..77..650V. doi:10.1093/mnras/77.9.650.
- ^ Shapley, Harlow (1951). "Proxima Centauri as a flare star". Proceedings of the National Academy of Sciences of the United States of America. 37 (1): 15–18. Bibcode:1951PNAS...37...15S. doi:10.1073/pnas.37.1.15. PMC 1063292. PMID 16588985.
- ^ Kroupa, Pavel; Burman, R. R.; Blair, D. G. (1989). "Photometric observations of flares on Proxima Centauri". PASA. 8 (2): 119–122. Bibcode:1989PASAu...8..119K. doi:10.1017/S1323358000023122.
- ^ Haisch, Bernhard; Antunes, A.; Schmitt, J. H. M. M. (1995). "Solar-like M-class X-ray flares on Proxima Centauri observed by the ASCA satellite". Science. 268 (5215): 1327–1329. Bibcode:1995Sci...268.1327H. doi:10.1126/science.268.5215.1327. PMID 17778978. S2CID 46660210.
- ^ a b c Guedel, M.; Audard, M.; Reale, F.; Skinner, S. L.; Linsky, J. L. (2004). "Flares from small to large: X-ray spectroscopy of Proxima Centauri with XMM-Newton". Astronomy and Astrophysics. 416 (2): 713–732. arXiv:astro-ph/0312297. Bibcode:2004A&A...416..713G. doi:10.1051/0004-6361:20031471. S2CID 7725125.
- ^ "IAU Working Group on Star Names (WGSN)". International Astronomical Union. Retrieved 22 May 2016.
- ^ "Naming Stars". International Astronomical Union. Retrieved 3 March 2018.
- ^ "Proxima Centauri UV flux distribution". ESA & The Astronomical Data Centre at CAB. Retrieved 11 July 2007.
- ^ Kaler, Jim. "Rigil Kentaurus". University of Illinois. Retrieved 3 August 2008.
- ^ Sherrod, P. Clay; Koed, Thomas L. (2003). A complete manual of amateur astronomy: tools and techniques for astronomical observations. Courier Dover Publications. ISBN 978-0-486-42820-8.
- ^ Howard, Ward S.; Tilley, Matt A.; Corbett, Hank; Youngblood, Allison; Loyd, R. O. Parke; Ratzloff, Jeffrey K.; Law, Nicholas M.; Fors, Octavi; Del Ser, Daniel; Shkolnik, Evgenya L.; Ziegler, Carl; Goeke, Erin E.; Pietraallo, Aaron D.; Haislip, Joshua (2018). "The First Naked-eye Superflare Detected from Proxima Centauri". The Astrophysical Journal. 860 (2): L30. arXiv:1804.02001. Bibcode:2018ApJ...860L..30H. doi:10.3847/2041-8213/aacaf3. S2CID 59127420.
- ^ "Seeing Stars in 3D: The New Horizons Parallax Program". pluto.jhuapl.edu. 29 January 2020. Retrieved 25 May 2020.
- ^ "Parallax measurements for Wolf 359 and Proxima Centauri". German Aerospace Center. Retrieved 19 January 2021.
- ^ Kamper, K. W.; Wesselink, A. J. (1978). "Alpha and Proxima Centauri". Astronomical Journal. 83: 1653–1659. Bibcode:1978AJ.....83.1653K. doi:10.1086/112378.
- ^ Binney, James; Scott Tremaine (1987). Galactic dynamics. Princeton, New Jersey: Princeton University Press. p. 8. ISBN 978-0-691-08445-9.
- ^ Leggett, S. K. (1992). "Infrared colors of low-mass stars". Astrophysical Journal Supplement Series. 82 (1): 351–394, 357. Bibcode:1992ApJS...82..351L. doi:10.1086/191720.
- ^ Queloz, Didier (29 November 2002). "How Small are Small Stars Really?". European Southern Observatory. Retrieved 5 September 2016.
- ^ Zurlo, A.; Gratton, R.; Mesa, D.; Desidera, S.; Enia, A.; Sahu, K.; Almenara, J. -M.; Kervella, P.; Avenhaus, H.; Girard, J.; Janson, M.; Lagadec, E.; Langlois, M.; Milli, J.; Perrot, C.; Schlieder, J. -E.; Thalmann, C.; Vigan, A.; Giro, E.; Gluck, L.; Ramos, J.; Roux, A. (2018). "The gravitational mass of Proxima Centauri measured with SPHERE from a microlensing event". Monthly Notices of the Royal Astronomical Society. 480 (1): 236. arXiv:1807.01318. Bibcode:2018MNRAS.480..236Z. doi:10.1093/mnras/sty1805. S2CID 118971274.
- ^ Zombeck, Martin V. (2007). Handbook of space astronomy and astrophysics (Third ed.). Cambridge, UK: Cambridge University Press. pp. 109. ISBN 978-0-521-78242-5.
- ^ Benedict, G. F., McArthur, B., Nelan E, Story D, Whipple AL, Shelus PJ, Jefferys WH, Hemenway PD, Franz OG (1998). "Photometry of Proxima Centauri and Barnard's Star using Hubble Space Telescope fine guidance sensor 3: a search for periodic variations". The Astronomical Journal. 116 (1): 429–439. arXiv:astro-ph/9806276. Bibcode:1998AJ....116..429B. doi:10.1086/300420. S2CID 15880053.
- ^ Suárez Mascareño, A.; Rebolo, R.; González Hernández, J. I.; Esposito, M. (September 2015). "Rotation periods of late-type dwarf stars from time series high-resolution spectroscopy of chromospheric indicators". Monthly Notices of the Royal Astronomical Society. 452 (3): 2745–2756. arXiv:1506.08039. Bibcode:2015MNRAS.452.2745S. doi:10.1093/mnras/stv1441. S2CID 119181646.
- ^ Yadav, Rakesh K.; et al. (December 2016). "Magnetic Cycles in a Dynamo Simulation of Fully Convective M-star Proxima Centauri". The Astrophysical Journal Letters. 833 (2): 6. arXiv:1610.02721. Bibcode:2016ApJ...833L..28Y. doi:10.3847/2041-8213/833/2/L28. S2CID 54849623. L28.
- ^ a b Adams, Fred C.; Laughlin, Gregory; Graves, Genevieve J. M. Red dwarfs and the end of the main sequence (PDF). Gravitational collapse: from massive stars to planets. Revista Mexicana de Astronomía y Astrofísica. pp. 46–49. Retrieved 24 June 2008.
- ^ "Proxima Centauri: the nearest star to the Sun". Harvard-Smithsonian Center for Astrophysics. 30 August 2006. Retrieved 9 July 2007.
- ^ E. F., Guinan; Morgan, N. D. (1996). "Proxima Centauri: rotation, chromospheric activity, and flares". Bulletin of the American Astronomical Society. 28: 942. Bibcode:1996AAS...188.7105G.
- ^ Wargelin, Bradford J.; Drake, Jeremy J. (2002). "Stringent X-ray constraints on mass loss from Proxima Centauri". The Astrophysical Journal. 578 (1): 503–514. Bibcode:2002ApJ...578..503W. doi:10.1086/342270.
- ^ a b Wood, B. E.; Linsky, J. L.; Müller, H.-R.; Zank, G. P. (2001). "Observational estimates for the mass-loss rates of α Centauri and Proxima Centauri using Hubble Space Telescope Lyα spectra". The Astrophysical Journal. 547 (1): L49–L52. arXiv:astro-ph/0011153. Bibcode:2001ApJ...547L..49W. doi:10.1086/318888. S2CID 118537213.
- ^ Stauffer, J. R.; Hartmann, L. W. (1986). "Chromospheric activity, kinematics, and metallicities of nearby M dwarfs". Astrophysical Journal Supplement Series. 61 (2): 531–568. Bibcode:1986ApJS...61..531S. doi:10.1086/191123.
- ^ Pulliam, Christine (12 October 2016). "Proxima Centauri Might Be More Sunlike Than We Thought". Smithsonian Insider. Retrieved 7 July 2020.
- ^ Cincunegui, C.; Díaz, R. F.; Mauas, P. J. D. (2007). "A possible activity cycle in Proxima Centauri". Astronomy and Astrophysics. 461 (3): 1107–1113. arXiv:astro-ph/0703514. Bibcode:2007A&A...461.1107C. doi:10.1051/0004-6361:20066027. S2CID 14672316.
- ^ Wood, B. E.; Linsky, J. L.; Muller, H.-R.; Zank, G. P. (2000). "Observational estimates for the mass-loss rates of Alpha Centauri and Proxima Centauri using Hubble Space Telescope Lyman-alpha spectra". Astrophysical Journal. 537 (2): L49–L52. arXiv:astro-ph/0011153. Bibcode:2000ApJ...537..304W. doi:10.1086/309026. S2CID 119332314.
- ^ Lurie, John C.; Henry, Todd J.; Jao, Wei-Chun; Quinn, Samuel N.; Winters, Jennifer G.; Ianna, Philip A.; Koerner, David W.; Riedel, Adric R.; Subasavage, John P. (2014). "The Solar neighborhood. XXXIV. A search for planets orbiting nearby M dwarfs using astrometry". The Astronomical Journal. 148 (5): 91. arXiv:1407.4820. Bibcode:2014AJ....148...91L. doi:10.1088/0004-6256/148/5/91. S2CID 118492541.
- ^ Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M.; Grewing, M.; van Leeuwen, F.; van der Marel, H.; Mignard, F.; Murray, C. A.; Le Poole, R. S.; Schrijver, H.; Turon, C.; Arenou, F.; Froeschlé, M.; Petersen, C. S. (July 1997). "The Hipparcos catalogue". Astronomy and Astrophysics. 323: L49–L52. Bibcode:1997A&A...323L..49P.
- ^ Kirkpatrick JD, Davy J, Monet DG, Reid IN, Gizis JE, Liebert J, Burgasser AJ (2001). "Brown dwarf companions to G-type stars. I: Gliese 417B and Gliese 584C". The Astronomical Journal. 121 (6): 3235–3253. arXiv:astro-ph/0103218. Bibcode:2001AJ....121.3235K. doi:10.1086/321085. S2CID 18515414.
- ^ Williams, D. R. (10 February 2006). "Moon Fact Sheet". Lunar & Planetary Science. NASA. Retrieved 12 October 2007.
- ^ Benedict, G. F.; Mcarthur, B.; Nelan, E.; Story, D.; Jefferys, W. H.; Wang, Q.; Shelus, P. J.; Hemenway, P. D.; Mccartney, J.; Van Altena, Wm. F.; Duncombe, R.; Franz, O. G.; Fredrick, L. W. Astrometric stability and precision of fine guidance sensor #3: the parallax and proper motion of Proxima Centauri (PDF). Proceedings of the HST calibration workshop. pp. 380–384. Retrieved 11 July 2007.
- ^ a b García-Sánchez, J.; Weissman, P. R.; Preston, R. A.; Jones, D. L.; Lestrade, J.-F.; Latham, D. W.; Stefanik, R. P.; Paredes, J. M. (2001). "Stellar encounters with the solar system" (PDF). Astronomy and Astrophysics. 379 (2): 634–659. Bibcode:2001A&A...379..634G. doi:10.1051/0004-6361:20011330.
- ^ Bobylev, V. V. (March 2010). "Searching for stars closely encountering with the solar system". Astronomy Letters. 36 (3): 220–226. arXiv:1003.2160. Bibcode:2010AstL...36..220B. doi:10.1134/S1063773710030060. S2CID 118374161.
- ^ Bailer-Jones, C. A. L. (March 2015). "Close encounters of the stellar kind". Astronomy & Astrophysics. 575: 13. arXiv:1412.3648. Bibcode:2015A&A...575A..35B. doi:10.1051/0004-6361/201425221. S2CID 59039482. A35.
- ^ Allen, C.; Herrera, M. A. (1998). "The galactic orbits of nearby UV Ceti stars". Revista Mexicana de Astronomía y Astrofísica. 34: 37–46. Bibcode:1998RMxAA..34...37A.
- ^ Kroupa, Pavel (1995). "The dynamical properties of stellar systems in the Galactic disc". MNRAS. 277 (4): 1507–1521. arXiv:astro-ph/9508084. Bibcode:1995MNRAS.277.1507K. doi:10.1093/mnras/277.4.1507. S2CID 15557806.
- ^ a b Wertheimer, Jeremy G.; Laughlin, Gregory (2006). "Are Proxima and α Centauri gravitationally bound?". The Astronomical Journal. 132 (5): 1995–1997. arXiv:astro-ph/0607401. Bibcode:2006AJ....132.1995W. doi:10.1086/507771. S2CID 16650143.
- ^ Johnston, Kathryn V.; Hernquist, Lars; Bolte, Michael (1996). "Fossil signatures of ancient accretion events in the halo". The Astrophysical Journal. 465: 278. arXiv:astro-ph/9602060. Bibcode:1996ApJ...465..278J. doi:10.1086/177418. S2CID 16091481.
- ^ a b c d e Anglada-Escudé, Guillem; Amado, Pedro J.; Barnes, John; Berdiñas, Zaira M.; Butler, R. Paul; Coleman, Gavin A. L.; de la Cueva, Ignacio; Dreizler, Stefan; Endl, Michael; Giesers, Benjamin; Jeffers, Sandra V.; Jenkins, James S.; Jones, Hugh R. A.; Kiraga, Marcin; Kürster, Martin; López-González, Marίa J.; Marvin, Christopher J.; Morales, Nicolás; Morin, Julien; Nelson, Richard P.; Ortiz, José L.; Ofir, Aviv; Paardekooper, Sijme-Jan; Reiners, Ansgar; Rodríguez, Eloy; Rodrίguez-López, Cristina; Sarmiento, Luis F.; Strachan, John P.; Tsapras, Yiannis; Tuomi, Mikko; Zechmeister, Mathias (25 August 2016). "A terrestrial planet candidate in a temperate orbit around Proxima Centauri" (PDF). Nature. 536 (7617): 437–440. arXiv:1609.03449. Bibcode:2016Natur.536..437A. doi:10.1038/nature19106. PMID 27558064. S2CID 4451513.
- ^ Li, Yiting; et al. (14 December 2017). "A Candidate Transit Event around Proxima Centauri". Research Notes of the AAS. 1 (1). 49. arXiv:1712.04483. Bibcode:2017RNAAS...1...49L. doi:10.3847/2515-5172/aaa0d5. S2CID 119034883.
- ^ Kervella, Pierre; Arenou, Frédéric; Schneider, Jean (2020). "Orbital inclination and mass of the exoplanet candidate Proxima c". Astronomy & Astrophysics. 635: L14. arXiv:2003.13106. Bibcode:2020A&A...635L..14K. doi:10.1051/0004-6361/202037551. ISSN 0004-6361. S2CID 214713486.
- ^ Bixel, A.; Apai, D. (21 February 2017). "Probabilistic Constraints on the Mass and Composition of Proxima b". The Astrophysical Journal Letters. 836 (2): L31. arXiv:1702.02542. Bibcode:2017ApJ...836L..31W. doi:10.3847/2041-8213/aa5f51. hdl:10150/623234. ISSN 2041-8205. S2CID 119469149.
- ^ Endl, M. & Kürster, M. (2008). "Toward detection of terrestrial planets in the habitable zone of our closest neighbor: Proxima Centauri". Astronomy and Astrophysics. 488 (3): 1149–1153. arXiv:0807.1452. Bibcode:2008A&A...488.1149E. doi:10.1051/0004-6361:200810058. S2CID 55095650.
- ^ Kürster, M.; Hatzes, A. P.; Cochran, W. D.; Döbereiner, S.; Dennerl, K.; Endl, M. (1999). "Precise radial velocities of Proxima Centauri. Strong constraints on a substellar companion". Astronomy & Astrophysics Letters. 344: L5–L8. arXiv:astro-ph/9903010. Bibcode:1999A&A...344L...5K.
- ^ Saar, Steven H.; Donahue, Robert A. (1997). "Activity-related Radial Velocity Variation in Cool Stars" (PDF). Astrophysical Journal. 485 (1): 319–326. Bibcode:1997ApJ...485..319S. doi:10.1086/304392. S2CID 17628232.
- ^ Schultz, A. B.; Hart, H. M.; Hershey, J. L.; Hamilton, F. C.; Kochte, M.; Bruhweiler, F. C.; Benedict, G. F.; Caldwell, John; Cunningham, C.; Wu, Nailong; Franz, O. G.; Keyes, C. D.; Brandt, J. C. (1998). "A possible companion to Proxima Centauri". Astronomical Journal. 115 (1): 345–350. Bibcode:1998AJ....115..345S. doi:10.1086/300176.
- ^ Schroeder, Daniel J.; Golimowski, David A.; Brukardt, Ryan A.; Burrows, Christopher J.; Caldwell, John J.; Fastie, William G.; Ford, Holland C.; Hesman, Brigette; Kletskin, Ilona; Krist, John E.; Royle, Patricia; Zubrowski, Richard. A. (2000). "A Search for Faint Companions to Nearby Stars Using the Wide Field Planetary Camera 2". The Astronomical Journal. 119 (2): 906–922. Bibcode:2000AJ....119..906S. doi:10.1086/301227.
- ^ Lurie, John C.; Henry, Todd J.; Jao, Wei-Chun; Quinn, Samuel N.; Winters, Jennifer G.; Ianna, Philip A.; Koerner, David W.; Riedel, Adric R.; Subasavage, John P. (November 2014). "The Solar Neighborhood. XXXIV. a Search for Planets Orbiting Nearby M Dwarfs Using Astrometry". The Astronomical Journal. 148 (5): 12. arXiv:1407.4820. Bibcode:2014AJ....148...91L. doi:10.1088/0004-6256/148/5/91. S2CID 118492541. 91.
- ^ Chang, Kenneth (24 August 2016). "One star over, a planet that might be another Earth". New York Times. Retrieved 24 August 2016.
- ^ Knapton, Sarah (24 August 2016). "Proxima b: Alien life could exist on 'second Earth' found orbiting our nearest star in Alpha Centauri system". The Telegraph. Telegraph Media Group. Retrieved 24 August 2016.
- ^ "Proxima b is our neighbor ... better get used to it!". Pale Red Dot. 24 August 2016. Retrieved 24 August 2016.
- ^ Aron, Jacob. August 24, 2016. Proxima b: Closest Earth-like planet discovered right next door. New Scientist. Retrieved August 24, 2016.
- ^ "Follow a Live Planet Hunt!". European Southern Observatory. 15 January 2016. Retrieved 24 August 2016.
- ^ Feltman, Rachel (24 August 2016). "Scientists say they've found a planet orbiting Proxima Centauri, our closest neighbor". The Washington Post.
- ^ Mathewson, Samantha (24 August 2016). "Proxima b By the Numbers: Possibly Earth-Like World at the Next Star Over". Space.com. Retrieved 25 August 2016.
- ^ Witze, Alexandra (24 August 2016). "Earth-sized planet around nearby star is astronomy dream come true". Nature. pp. 381–382. Bibcode:2016Natur.536..381W. doi:10.1038/nature.2016.20445. Retrieved 24 August 2016.
- ^ Liu, Hui-Gen; et al. (January 2018). "Searching for the Transit of the Earth-mass Exoplanet Proxima Centauri b in Antarctica: Preliminary Result". The Astronomical Journal. 155 (1): 10. arXiv:1711.07018. Bibcode:2018AJ....155...12L. doi:10.3847/1538-3881/aa9b86. S2CID 54773928. 12.
- ^ a b Billings, Lee (12 April 2019). "A Second Planet May Orbit Earth's Nearest Neighboring Star". Scientific American. Retrieved 12 April 2019.
- ^ a b c Wall, Mike (12 April 2019). "Possible 2nd Planet Spotted Around Proxima Centauri". Space.com. Retrieved 12 April 2019.
- ^ Benedict, Fritz (2 June 2020). "Texas Astronomer Uses 25-year-old Hubble Data to Confirm Planet Proxima Centauri c". McDonald Observatory. University of Texas.
- ^ Gratton, R.; et al. (June 2020). "Searching for the near-infrared counterpart of Proxima c using multi-epoch high-contrast SPHERE data at VLT". Astronomy & Astrophysics. 638: A120. arXiv:2004.06685. Bibcode:2020A&A...638A.120G. doi:10.1051/0004-6361/202037594. S2CID 215754278.
- ^ Anglada, Guillem; Amado, Pedro J; Ortiz, Jose L; Gómez, José F; Macías, Enrique; Alberdi, Antxon; Osorio, Mayra; Gómez, José L; Itziar de Gregorio-Monsalvo; Pérez-Torres, Miguel A; Anglada-Escudé, Guillem; Berdiñas, Zaira M; Jenkins, James S; Jimenez-Serra, Izaskun; Lara, Luisa M; López-González, Maria J; López-Puertas, Manuel; Morales, Nicolas; Ribas, Ignasi; Richards, Anita M. S; Rodríguez-López, Cristina; Rodriguez, Eloy (2017). "ALMA Discovery of Dust Belts Around Proxima Centauri". The Astrophysical Journal. 850 (1): L6. arXiv:1711.00578. Bibcode:2017ApJ...850L...6A. doi:10.3847/2041-8213/aa978b. S2CID 13431834.
- ^ "Proxima Centauri's no good, very bad day". Science Daily. 26 February 2018. Retrieved 1 March 2018.
- ^ MacGregor, Meredith A.; et al. (2018). "Detection of a Millimeter Flare From Proxima Centauri". Astrophysical Journal Letters. 855 (1): L2. arXiv:1802.08257. Bibcode:2018ApJ...855L...2M. doi:10.3847/2041-8213/aaad6b. S2CID 119287614.
- ^ Endl, M.; Kuerster, M.; Rouesnel, F.; Els, S.; Hatzes, A. P.; Cochran, W. D. (18–21 June 2002). Deming, Drake (ed.). Extrasolar terrestrial planets: can we detect them already?. Conference Proceedings, Scientific Frontiers in Research on Extrasolar Planets. Washington, DC. pp. 75–79. arXiv:astro-ph/0208462. Bibcode:2003ASPC..294...75E.
- ^ Tarter, Jill C., Mancinelli RL, Aurnou JM, Backman DE, Basri GS, Boss AP, Clarke A, Deming D (2007). "A reappraisal of the habitability of planets around M dwarf stars". Astrobiology. 7 (1): 30–65. arXiv:astro-ph/0609799. Bibcode:2007AsBio...7...30T. doi:10.1089/ast.2006.0124. PMID 17407403. S2CID 10932355.
- ^ Alpert, Mark (November 2005). "Red star rising". Scientific American. 293 (5): 28. Bibcode:2005SciAm.293e..28A. doi:10.1038/scientificamerican1105-28. PMID 16318021.
- ^ Ward, Peter D.; Brownlee, Donald (2000). Rare Earth: why complex life is uncommon in the universe. Springer Publishing. ISBN 978-0-387-98701-9.
- ^ Khodachenko, Maxim L., Lammer H, Grießmeier J, Leitner M, Selsis F, Eiroa C, Hanslmeier A, Biernat HK (2007). "Coronal Mass Ejection (CME) activity of low mass M stars as an important factor for the habitability of terrestrial exoplanets. I. CME impact on expected magnetospheres of earth-like exoplanets in close-in habitable zones". Astrobiology. 7 (1): 167–184. Bibcode:2007AsBio...7..167K. doi:10.1089/ast.2006.0127. PMID 17407406.
- ^ Gilster, Paul (2004). Centauri dreams: imagining and planning. Springer. ISBN 978-0-387-00436-5.
- ^ Crawford, I. A. (September 1990). "Interstellar Travel: A Review for Astronomers". Quarterly Journal of the Royal Astronomical Society. 31: 377–400. Bibcode:1990QJRAS..31..377C.
- ^ "Spacecraft escaping the Solar System". Heavens Above. Retrieved 25 December 2016.
- ^ a b Beals, K. A.; Beaulieu, M.; Dembia, F. J.; Kerstiens, J.; Kramer, D. L.; West, J. R.; Zito, J. A. (1988). "Project Longshot, an Unmanned Probe to Alpha Centauri" (PDF). NASA-CR-184718. U. S. Naval Academy. Retrieved 13 June 2008.
- ^ Merali, Zeeya (27 May 2016). "Shooting for a star". Science. 352 (6289): 1040–1041. doi:10.1126/science.352.6289.1040. PMID 27230357.
- ^ Popkin, Gabriel (2 February 2017). "What it would take to reach the stars". Nature. 542 (7639): 20–22. Bibcode:2017Natur.542...20P. doi:10.1038/542020a. PMID 28150784.
- ^ O'Callaghan, Jonathan (18 December 2020). "Alien Hunters Discover Mysterious Radio Signal from Proxima Centauri". Scientific American. Retrieved 19 December 2020.