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Proxima Centauri:
The Nearest Star to the Sun
Chandra and XMM-Newton observations of the red dwarf star Proxima Centauri have shown that its surface is in a state of turmoil. Flares, or explosive outbursts, occur almost continually. This behavior can be traced to Proxima Centauri's low mass, about a tenth that of the Sun. In the cores of low mass stars, nuclear fusion reactions that convert hydrogen to helium proceed very slowly, and create a turbulent, convective motion throughout their interiors. This motion stores up magnetic energy which is often released explosively in the star's upper atmosphere where it produces flares in X-rays and other forms of light.
The same process produces X-rays on the Sun, but the magnetic energy is released in a less explosive manner through heating loops of gas, with occasional flares. The difference is due to the size of the convection zone, which in a more massive star such as the Sun, is smaller and closer to its surface.
Red dwarfs are the most common type of star. They have masses between about 8% and 50% of the mass of the Sun. Though they are much dimmer than the Sun, they will shine for much longer - trillions of years in the case of Proxima Centauri, compared to the estimated 10 billion-year lifetime of the Sun.
X-rays from Proxima Centauri are consistent with a point-like source. The extended X-ray glow is an instrumental effect. The nature of the two dots above the image is unknown - they could be background sources.
| Fast Facts for Proxima Centauri:
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Credit
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NASA/CXC/SAO |
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Scale
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1.5 arcmin per side |
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Category
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White Dwarf Stars & Normal Stars |
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Coordinates
(J2000)
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RA 14h 29m 42.90s | Dec -62º
40' 46.10" |
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Constellation
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Centaurus |
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Observation
Date
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May 07, 2000
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Observation
Time
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8 hrs |
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Obs.
ID
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49899 |
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Obs. ID PI
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J.L.Linsky |
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Instrument
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ACIS
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Color Code
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Intensity
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References
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B. Wargelin and J. Drake 2002, Astrophysical J. 578, 503
M. Gudel et al. Astronomy and Astrophysics, 416, 713 |
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Distance Estimate
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4 light years from the Sun |
| Release
Date |
November 9, 2004 |
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