Rigel

Rigel is the brightest star in the constellation Orion and the siebthellste the night sky. Its name comes from the Arabic رجل الجوزاء اليسرى Ridschl Dschauza 'al- Yusri, left foot in the Middle '. Although it is lighter than α Orionis ( Betelgeuse ), it is called in astronomy as β Orionis. The reason is that Betelgeuse (as almost all of the red supergiants ) an irregular variables, and Rigel in every now and then maximum can exceed. Rigel is part of the Wintersechsecks.

In the ancient Egyptian language was called Rigel " Seba -en- Saw ", which translates to " Fußstern " or " star toes " means. As the main star and namesake of the ancient Egyptian constellation Sah, he played an important role in ancient Egyptian mythology.

Description

The distance Rigel is 650-900 light years; the Hipparcos satellite measured it with 770 light-years, at such distances the error range of the Hipparcos measurements, however, lies at about 20 %.

Rigel is a multiple star system. The main component of Rigel A is a giant star of spectral type B8. The star of luminosity class Ia is located in the transition phase from the Blue Giant to red supergiant. It radiates with the approximately 46,000 -fold luminosity of the sun, so it is by Betelgeuse ( 135,000 -fold) and Antares ( 90,000 -fold) of the strongest luminous star within a distance of 1000 light years from us. The next even brighter star is at a distance of about 1600-3200 light years the main star of the swan Deneb.

Rigel A is located in the transition to red - supergiant stage and has some variability in its apparent brightness. These weak, irregular variability is typical of supergiants; while its brightness by about 30% ( because of the logarithmic definition of apparent brightness ) in a mean period of 25 days. For the smaller components Rigel B / C, which form a bound binary star system itself is bluish-white main sequence star of spectral type B9 and 128 times the luminosity of the sun. The only dim Rigel D probably heard on a late K spectral subtype. As the component D is almost eclipsed, no exact values ​​in terms of its physical properties can be specified previously.

The main star Rigel A and the binary star system Rigel B / C orbit the common center of gravity at a distance of 2000 AU. The components Rigel B and C orbit each other in 28 AU distance. Rigel D is about 10,000 AU from Rigel A removed. Which barycenter he circles, could not yet be clearly established.

Rigel is located in a region that is rich in interstellar matter, and brings luminosity due to its several dust clouds shine. One of them is the Witch Head Nebula, called IC 2118th

Observation

While already the multiple system components Rigel A and the binary system can be B / C resolved with a telescope of 6 cm lens opening, one would need for a separation of the components of the double star system Rigel B / C at least 90 cm opening and upward, which in reality but fails due to the atmospheric turbulence. The angular distance between the 0.12 m bright Rigel A and only 6.6 m bright Rigel B / C system is 9.5 " and the position angle of 204 °.

Environment

Rigel is also associated with the Orion Nebula M 42 in connection which, although it is in the same region of the sky, but about twice as far away. If you follow but Rigel's spatial movement in accordance with its adopted ages back, so I get close to the fog. Therefore, Rigel is sometimes viewed as distant member of the Orion OB1 star association, a loose collection of stars of spectral types O and B, which also includes a number of other bright stars of Orion. More often, however, Rigel is considered a member of the Taurus - Orion -R1 - Star Association, and the Orion OB1 star association reserved the underlying spatially closer to their stars.

Rigel in fiction

In the Star Trek universe, the Rigel system is the most densely populated star system in known space.

Rigel 7 is discussed in episode 16 of Season 14 and in the ninth episode of Season 23 of The Simpsons.