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Proxima Centauri

Proxima Centauri
New shot of Proxima Centauri, our nearest neighbour.jpg
Proxima Centauri as seen by Hubble
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Centaurus
Pronunciation /ˌprɒksɪmə sɛnˈtɔːr/ or US /ˌprɒksɪmə sɛnˈtɔːr.ɪ/
Right ascension 14h 29m 42.94853s
Declination −62° 40′ 46.1631″
Apparent magnitude (V) 11.13
Characteristics
Spectral type M6Ve
Apparent magnitude (J) 5.357 ± 0.023
U−B color index 1.26
B−V color index 1.82
Variable type UV Ceti ("flare star")
Astrometry
Radial velocity (Rv) −22.4 ± 0.5 km/s
Proper motion (μ) RA: −3775.75 mas/yr
Dec.: 765.54 mas/yr
Parallax (π) 768.13 ± 1.04mas
Distance 4.246 ± 0.006 ly
(1.302 ± 0.002 pc)
Absolute magnitude (MV) 15.60
Details
Mass 0.123 ± 0.006 M
Radius 0.141 ± 0.007 R
Luminosity (bolometric) 0.0017 L
Luminosity (visual, LV) 0.00005 L
Surface gravity (log g) 5.20 ± 0.23 cgs
Temperature 3,042 ± 117 K
Metallicity [Fe/H] 0.21 dex
Rotation 82.6±0.1 days
Rotational velocity (v sin i) < 0.1 km/s
Age 4.85 Gyr
Other designations
Alpha Centauri C, CCDM J14396-6050C, GCTP 3278.00, GJ 551, HIP 70890, LFT 1110, LHS 49, LPM 526, LTT 5721, NLTT 37460, V645 Centauri
Database references
SIMBAD data

Coordinates: Sky map14h 29m 42.9487s, −62° 40′ 46.141″

Proxima Centauri (from Latin, meaning "nearest [star] of Centaurus") or Alpha Centauri C is a red dwarf, a small low-mass star, about 4.25 light-years from the Sun in the constellation of Centaurus. It was discovered in 1915 by the Scottish astronomer Robert Innes, the Director of the Union Observatory in South Africa, and is the nearest-known star to the Sun. With an apparent magnitude of 11.05, it is too faint to be seen with the naked eye. Proxima Centauri may form a third component of the Alpha Centauri binary star system, but at a separation of 15,000 ± 700AU its orbital period is likely greater than 500,000 years.

Because of Proxima Centauri's proximity to Earth, its angular diameter can be measured directly. It is about one-seventh the diameter of the Sun. It has a mass about an eighth of the Sun's mass (M), and its average density is about 40 times that of the Sun. Although it has a very low average luminosity, Proxima is a flare star that undergoes random 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 mixing of the fuel at Proxima Centauri's core through convection and its relatively low energy-production rate mean that it will be a main-sequence star for another four trillion years, or nearly 300 times the current age of the universe.


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Wikipedia

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