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List of stars close to the Sun

Sphere of influence of the Sun

 Automatic translationAutomatic translation Category: stars
Updated January 10, 2015

The space is huge, but the space between the gravitational areas of the 100 billion stars in our Milky Way, is relatively small.
The nearest star to the Sun is only 4.24 light years, it is called Proxima Centauri or α Centauri C, but it is not a bright star is a red dwarf and absolute magnitude  The absolute magnitude indicates the actual brightness of a celestial object, while the apparent magnitude depends on the distance of the object. The absolute magnitude of a star is defined as the apparent magnitude the star would have a distance of reference of 10 parsecs (≈32.6 light years) and in the absence of interstellar extinction (dustless between the object and the observer). A gain with a magnitude, corresponds to 2.5 times less brilliance. Example: the magnitude 1 of an object, is 2.5 times less bright than magnitude 2.  +15.49 and apparent magnitude The brightness measured from Earth of a star or other celestial object is expressed in apparent magnitude. The magnitude scale is logarithmic and reversed, that is to say, the lowest magnitudes correspond to the brightest objects. A gain with a magnitude, corresponds to 2.5 times less brilliance. Example: the magnitude 1 of an object, is 2.5 times less bright than magnitude 2.  +11.05, which seems to revolve around its two neighbors, α Centauri A and α Centauri B. Its visible light brightness equals 0.0056% that of the Sun, it radiates most of its light energy (85%) in the infrared.
For a star shines it must produce nuclear reactions in its center. To do this it must reach a minimum weight, 8% of the mass of the Sun (M☉). Below this mass, are brown dwarfs or planets. Proxima Centauri with a mass equal to 12% M☉ shines slightly. It will exist long after the sun because it consumes very little fuel and low will shine for tens of billions of years. Due to its proximity, α Centauri A is the fourth brightest star in the night sky, after Sirius, Canopus and Arcturus is a yellow dwarf of spectral type G2V. G means that it is a yellow dwarf with a surface temperature between 5300 K and 6000 K, like our Sun.
What is a light year?
A light year is ≈10 000 billion km. This distance seems great but the Oort cloud This remote and invisible region of the Solar System is located at 7500 billion km. It hosts billions of light icy body, to the limit of the attraction of the Sun can be disturbed by the slightest gravitational force, of the nearest stars of the solar system., a region of the solar system, is located ≈7500 billion km and contains billions of icy bodies at the boundary of the attraction of the Sun.
Gravitation is a universal force that curves the space over long distances. The gravitational influence of the Sun is therefore "no limit", however it decreases gradually until another mass curves space to it, and imposes its gravitational attraction.
The stars closest to the Sun are located about 4 light years, is the Alpha Centauri system, the system is twice as massive (≈2.13 M☉) that the solar system.
How far the gravitational confrontation between these two massive objects, will therefore take place?
In other words, where is the limit of influence of our Sun?
Although these two objects do not turn one around the other one could use r ≈ a√3 (m/3M) is the simplified formula of the Hill sphere, where r is the radius of the Hill sphere and a the semi-major axis.
So to get an idea of the gravitational boundary is written in Excel:
=4,24*((1/(3*2,13))^(1/3))
The radius of the Hill sphere of the Alpha Centauri system (the heavier object) is ≈ 4.24 multiplied by cube root of (m/3M) = 2.28 light years.
The gravitational influence zone of the solar system thus dies approximately 4.24 - 2.28 = 1.96 light years. A celestial object (dwarf or floating exoplanet) could remain in the vicinity of the boundary between the two systems without being caught by one of the two.

 
Star
Designation
Stellar
Class
magnitude
app./abs.
Distance
(ly)
     
Sun G2V-26.744.800
α Centauri AG2V0.014.344.39
α Centauri BK1V1.345.704.39
SiriusA1V-1.461.428.58
ε EridaniK2V3.726.1810.50
61 Cygni AK5.0V5.207.4911.40
61 Cygni BK7.0V6.058.3111.40
Procyon AF5IV-V0.342.6511.50
ε IndiK5Ve4.696.8911.80
τ CetiG8Vp3.495.6811.90
Groombridge 1618K7.0V6.608.1615.90
40 Eridani AK1Ve4.435.9216.50
70 Ophiuchi AK1Ve4.245.7116.60
70 Ophiuchi BK5Ve6.017.4816.60
AltairA71V-V0.762.2016.70
σ DraconisK0V4.675.8718.80
Gliese 570K5Ve5.726.8619.00
η CassiopeiaeG3V3.464.5919.40
36 Ophiuchi AK1Ve5.076.1819.50
36 Ophiuchi BK1Ve5.116.2219.50
36 Ophiuchi CK5Ve6.337.4519.50
HR 7703K3V5.326.4119.60
82 EridaniG8V4.265.3519.80
δ PavonisG7V3.554.6219.90
Gliese 892K3V5.576.5021.30
ξ Bootis AG8Ve4.725.5921.9
ξ Bootis BK4Ve6.977.8421.9
Gliese 667 A K3V6.297.0722.70
Gliese 667 BK5V7.248.0222.70
HR 753 AK3V5.796.5023.50
Gliese 33K2V5.746.3824.30
β HydriG2IV2.823.4524.40
107 PisciumK1V5.245.8724.40
μ Cassiopeiae AG5VI5.175.7824.60
TW Piscis AustriniK5Ve6.487.0724.90
FomalhautA1V1.171.7425.10
Gliese 673K7V7.548.1025.20

Table : list of nearest bright stars within 25 light years of the Sun and whose absolute magnitude is 8.5 minimum. Distances are from the Hipparcos catalog of stars (ESA). The magnitude scale is logarithmic and reversed, for example, a star of magnitude 5 is 2.5 times less bright than a star of magnitude 6. To understand the colors of stars see the stars categories.

 Star close to the Sun, alpha centauri

Image : nearby stars. The nearest star to the Sun is only 4.24 light years, it is called Proxima Centauri or α Centauri C, but it is not a bright star is a red dwarf and absolute magnitude +15.49 and apparent magnitude +11.05, which seems to revolve around its two neighbors, α Centauri A and α Centauri B. the big bright star on the front foot of the Centaur is the triple star system Alpha Centauri.

 pc The parsec is the distance at which one astronomical unit (AU) subtends an angle of one arcsecond.ly A light year is equal to the distance that light travels in a vacuum in a year, is exactly equal to 9 460 895 288 762 850 meters. A light year is approximately 63,241 AU.au Founded in 1958, it is the distance unit used to measure distances to objects in the solar system, this distance is equal to the distance from Earth to the Sun. The value of the astronomical unit is exactly 149 597 870 700 m, at its General Assembly held in Beijing from 20 to 31 August 2012, the International Astronomical Union (IAU) adopted a new definition of the astronomical unit, unit of length used by astronomers around the world to express the dimensions of the solar system. One will retain about 150 million kilometers. Mercury: 0.38 AU, Venus 0.72 AU, Earth: 1.00 AU, March: 1.52 AU, Asteroid Belt: 2 to 3.5 AU, Jupiter 5.21 AU, Saturn: 9 54 ua, Uranus: 19.18 ua, Neptune: 30.11 ua, Kuiper Belt: 30 to 55 AU, the Oort Cloud: 50,000 AU.km Kilometer (symbol km) is a unit of length multiple of the meter. 1 km = 1000 m. Kilometer is used to measure distances on the scale of man, that of the Earth.
pc The parsec is the distance at which one astronomical unit (AU) subtends an angle of one arcsecond.13,262062653,09x1013
ly A light year is equal to the distance that light travels in a vacuum in a year, is exactly equal to 9 460 895 288 762 850 meters. A light year is approximately 63,241 AU.0,3071632419,46x1012
au Founded in 1958, it is the distance unit used to measure distances to objects in the solar system, this distance is equal to the distance from Earth to the Sun. The value of the astronomical unit is exactly 149 597 870 700 m, at its General Assembly held in Beijing from 20 to 31 August 2012, the International Astronomical Union (IAU) adopted a new definition of the astronomical unit, unit of length used by astronomers around the world to express the dimensions of the solar system and the universe. One will retain about 150 million kilometers. Mercury: 0.38 AU, Venus 0.72 AU, Earth: 1.00 AU, March: 1.52 AU, Asteroid Belt: 2 to 3.5 AU, Jupiter 5.21 AU, Saturn: 9 54 ua, Uranus: 19.18 ua, Neptune: 30.11 ua, Kuiper Belt: 30 to 55 AU, the Oort Cloud: 50,000 AU.4,85x10-61,58x10-511,50x108
km Kilometer (symbol km) is a unit of length multiple of the meter. 1 km = 1000 m. Kilometer is used to measure distances on the scale of man, that of the Earth. 3,24x10-141,06x10-136,68x10-91

Table : equivalences between the distance units (parsec, light year, astronomical unit and km).

nota : Red dwarfs are small stars (0.08 and 0.4 solar mass) red and discrete, the surface temperature is low (between 2500 and 5000 K), which is why they glow in the red or orange.
These stars among the most numerous of the Universe, consume very little nuclear fuel (hydrogen) and thus have a very long life, estimated between tens and 1000 billion years. They contract and heat up slowly until all their hydrogen is consumed. Proxima Centauri or Alpha Centauri C, the nearest star to us is a red dwarf, and some twenty of the thirty other nearby stars in the solar system.
Red dwarfs: Proxima Centauri, Regulus C

See also

     
      
      
 
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