Alpha Centauri

The search for extrasolar life requires us to find planets outside the solar system. But since stars are only visible as small dots of light, it will be very difficult to find planets in outer space, since these do not emit light. This is true even for the nearest star, Alpha Centauri, which is about 4.3 light years away (roughly 7,000 times the distance from the sun to Pluto). 

Use this as a unit factor to determine the distance in miles between Alpha Centauri and our solar system. 

P. G. Righetti. The Alpher, Bethe, Gamow of Isoelectric Focusing, the Alpha-Centaury of Electrokinetic Methodologies. I. Electrophoresis, 27(2006) 923-938. 

Centauri because its absolute magnitude is smaller than Alpha Centauri s. The reason for this reversal is that Arcturus is so much further away that it appears dimmer to our eye than Alpha Centauri. ... 

Sir, I first got interested in stars in the late 1960s by watching the TV series Lost in Space. The show describes the travels of a human family exploring strange planets. Their mission was to begin colonization of a planet near the star Alpha Centauri. Unfortunately, their craft went off course, and they lost all contact with Earth. ... 

One day, a villager in Ethiopia entered a strange URL into his web browser http //www.god.ac, the suffix ac represents domain names on planets in the vicinity of Alpha Centauri. At this point, your species discovered God, and we discovered him a few days later. ... 

When you look up into the night sky, you never see red dwarfs. They re faint because of their small size and low temperature. Only the nearest red dwarf stars, up to about 90 light-years away, are visible to even the most powerful earth-based telescopes. Proxima Centauri, a member of the Alpha Centauri triple star system, is a red dwarf, and we ve discussed that it is the closest star to the Earth. Despite its proximity, it is a hundred times too faint to see with the naked eye. In contrast, we can see many larger stars using our eyes, even when these stars are thousands of light-years away. 

Figure 9.1 A drawing of a constellation Taurus from Johann Bayer s Uranometria (Augsburg 1603). Bayer used Greek letters to designate the brightness of stars. The bright star in the Bull s eye became alpha Tauri, just like the brightest star in the constellation Centaur became our familiar alpha Centauri.

Like many red dwarfs, Proxima or Alpha Centauri C is a flare star. Flare stars can brighten suddenly to many times their normal luminosity. The cause is thought to be a sudden and intense outburst of radiation on or above the star s surface. An increase in radio emission is often detected simultaneously with the optical outburst. 

Using a single dimensional equation, estimate the number of steps it would take you. walking at your normal stride, to walk from the Earth to Alpha Centauri, a distance of 4.3 light-years. The speed of light is 1.86 X 10 miles/s. 

Astronomers did not succeed in measuring a parallax angle until 1838, when three astronomers working independently measured the parallaxes of three different stars. Friedrich Bessel in Germany, Thomas Henderson in South Africa, and Friedrich Struve in Russia measured the parallaxes of the stars 61 Cygni, Alpha Centauri, and Vega, respectively. 

The distances to the stars. If the stars are suns, they must be enormously further away. John Michell, the first to be quantitative about this said millions of times in 1767. At least, we would now say. William Herschel refined Michell s method to his star gauging and concluded that the disk was a kilo-light-year or so across. Firm numbers for stellar distances came only with the first measurements of parallax, almost simultaneously in 1838 by Bessel (of the functions), Struve (the middle one of a dynasty), and Henderson (working from South Africa and so able to choose Alpha Centauri for his campaign). 

Alpha Centauri is the star closest to our solar system. It is 4.3 light-years away. How many miles in this A Ught-year is the distance that light travels (in a vacuum) in one year. Assume that space is essentially a vacuum. 

Smaller electronic noses are also available for process monitoring and for greater portability. Two examples are shown in Figure 4, the Alpha Centauri from Alpha MOS and the handheld C320 from Cyrano Sciences. 

The nearest star. Alpha Centauri, is 4.3 light-years from Earth. A light-year is the distance that light travels in one year. How far is Alpha Centauri in kilometers ... 

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