Image of the Day: One-Light-Year Tall ‘Ninjas’ of the Carina Nebula


This image is a composite of Hubble Space Telescope observations, taken in 2005 and 2010, of the dark pillars of cool gas and dust in the Carina Nebula region. The immense nebula lies an estimated 7,500 light-years away in the southern constellation Carina. The "Ninja" figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, according to NASA experts, however, these clouds are typically much less dense than Earth's atmosphere.The entire Carina Nebula spans over 300 light years and lies about 7,500 light-years away in the constellation of Carina. NGC 3372, known as the Great Nebula in Carina, is home to massive stars and changing nebula. Eta Carinae, the most energetic star in the nebula, was one of the brightest stars in the sky in the 1830s, but then faded dramatically. 

These one-light-year-tall Ninjas of cold hydrogen and dust, imaged by the Hubble Space Telescope, are located in the Carina Nebula. Violent stellar winds and powerful radiation from massive stars are sculpting the surrounding nebula. Inside the dense structures, new stars may be born.

Eta Carinae is a highly luminous hypergiant star. Estimates of its mass range from 100–150 times the mass of the Sun, and its luminosity is about four million times that of the Sun.

This object is currently the most massive star that can be studied in great detail. Several other known stars may be more luminous and more massive, but data on them is far less robust. Stars with more than 80 times the mass of the Sun produce more than a million times as much light as the Sun. They are quite rare—only a few dozen in a galaxy as big as ours—and they flirt with disaster near the Eddington limit, i.e., the outward pressure of the irradiation is almost strong enough to counteract gravity. Stars that are more than 120 solar masses exceed the theoretical Eddington limit, and their gravity is barely strong enough to hold in its radiation and gas, resulting in a possible supernova or hypernova in the near future.

Eta Carinae's effects on the nebula can be seen directly. The dark globules -Ninjas- in the above image and some other less visible objects have tails pointing directly away from the massive star. The entire nebula would have looked very different before the Great Eruption in the 1840s surrounded Eta Carinae with dust, drastically reducing the amount of ultravioletlight it put into the nebula.

Via NASA, ESA, and the Hubble Heritage Project (STScI/AURA)


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