Its estimated mass is at least 1.07 times that of Earth. 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. Proxima Centauri has two known exoplanets and one candidate exoplanet: Proxima Centauri b, Proxima Centauri d and the disputed Proxima Centauri c. The 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. 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. 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. Its actual diameter is about one-seventh (14%) the diameter of the Sun. Because of Proxima Centauri's proximity to Earth, its angular diameter can be measured directly. Proxima Centauri is a red dwarf star with a mass about 12.5% of the Sun's mass ( M ☉), and average density about 33 times that of the Sun. 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 member of the Alpha Centauri star system, being identified as component Alpha Centauri C, and is 2.18° to the southwest of the Alpha Centauri AB pair. With a quiescent apparent magnitude of 11.13, it is too faint to be seen with the unaided eye. It was discovered in 1915 by Robert Innes and is the nearest-known star to the Sun. Its Latin name means the 'nearest of Centaurus'. 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. doi:10.False color Hubble Space Telescope WFPC2 image taken in 2013. Sensitivity and specificity of the body mass index for the diagnosis of overweight/obesity in elderly. Vasconcelos Fde A, Cordeiro BA, Rech CR, Petroski EL. Current body composition measurement techniques. Race-Ethnicity-Specific Waist Circumference Cutoffs for Identifying Cardiovascular Disease Risk Factors. Zhu S, Heymsfield SB, Toyoshima H, Wang Z, Pietrobelli A, Heshka S. National Heart, Lung, and Blood Institute. What’s New in Understanding the Risk Associated With Body Size and Shape? Pears, Apples, and Olives on Toothpicks. Golzarri-Arroyo L, Mestre LM, Allison DB. Ethnic Differences in BMI and Disease Risk. Body Mass Index Versus Body Fat Percentage in Prospective National Football League Athletes: Overestimation of Obesity Rate in Athletes at the National Football League Scouting Combine. Provencher MT, Chahla J, Sanchez G, et al. Yourself at the same time of day, when you know you’ll be consistently hydrated, to avoid inaccurate measurements.Ĭenters for Disease Control and Prevention. Note that the technology smart scales use requires a constant level of hydration in the body. These scales measure body fat by sending a harmless electrical current through your body.
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