Eta Carinae


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Eta Carinae

(kă-ree -nee, -nÿ, -rÿ -nee) (η Car) One of the most luminous and unstable stars in the Galaxy, lying at a distance of 2000 parsecs in the constellation Carina. It displays a large variation in magnitude at very irregular periods. Halley cataloged it as a 4th-magnitude star in 1677. From 1835 to 1845 it outshone every star except Sirius, reaching a magnitude of –0.8 in 1843; it has since faded, the magnitude range having been between 5.9 and 7.9 since 1880. Eta Carinae is an example of a luminous blue variable. It is surrounded by a shell of cool dust that emits strongly at a wavelength of 20 μm. The decrease in light output observed after 1843 is assumed to have been caused by the ejection of the dust. The dust obscures the light output of the star (which may well have remained constant), converting the light to infrared radiation. Eta Carinae's total luminosity is about five million times that of the Sun, its temperature is 29 000 K, and its mass is about 120 solar masses. It is surrounded by a small cloud of ejected gas (the Keyhole nebula) that contains a high abundance of nitrogen, indicating that much nucleosynthesis has taken place.
References in periodicals archive ?
One of the things Carina Nebula is most known for is Eta Carinae, a system of two stars that is one of the biggest and brightest in the galaxy.
Around midnight the Southern Cross and Eta Carinae regions beckoned irresistibly from above the southern horizon.
TEHRAN (FNA)- Long-term observations with the Hubble Space Telescope revealed that Eta Carinae, a very massive star system that has puzzled astronomers since it erupted in a supernova-like event in the mid 19th century, has a past that's much more violent than they thought.
NASA MISSION/ETA CARINAE: Eta Carinae is a binary system containing the most luminous and massive star within 10,000 light-years.
But here's the truth: if you were looking out of a starship's window in the midst of the Eta Carinae Nebula, it would look not like its dazzling Hubble panorama but about as it looks in a richest-field telescope under a rural sky.
Eta Carinae is currently about 5th magnitude, but when observed by La Caille in the 1750s it was shining at 2.
The most famous example is Eta Carinae, a star 7,500 light-years from Earth which, for a brief time in the mid-1800s, unleashed into space a shell of gas 10 times the mass of the sun and became the second-brightest star in the night sky.
The Carina Nebula is some 7500 lightyears from Earth and hosts some of the most massive and luminous stars in our Galaxy, including double-star system eta Carinae, which boasts over 100 times the mass of our Sun.
Papers address high-mass star formation by gravitational collapse of massive cores, the binarity of Eta Carinae, metallicity-dependent Wolf-Rayet winds, and an overview of cosmic infrared background and Population III, among other topics.
Instead of Alpha Orionis, Eta Carinae, or Alpha Centauri they say Alpha Orion, Eta Carina, and (presumably) Alpha Centaurus.
At more than 100 solar masses and 4 million times the luminosity of our Sun, Eta Carinae is one of the most massive and luminous stars in our galaxy.
Or maybe Eta Carinae, a star 100 times more massive than the sun and 7,500 light-years away.