Wide-field view: Red Carbon Star U Antliae | Digitized Sky Survey 2
This image from the Digitized Sky Survey 2 shows the very red carbon star U Antliae and its surroundings. It is located about 900 light years from Earth in the constellation Antlia. Around 2,700 years ago, U Antliae went through a short period of rapid mass loss. During this period of only a few hundred years, the material making up the shell seen in the new ALMA data was ejected at high speed. Examination of this shell in further detail also shows some evidence of thin, wispy clouds known as filamentary substructures.
U Antliae is an extremely red C-type carbon star. Carbon stars are cool, luminous red giants with atmospheres containing more carbon than oxygen, giving them a striking red appearance and a key role in enriching the galaxy with carbon. These stars are further reddened by strong mass loss and dust that forms around the star. U Antliae is calculated to have an effective surface temperature of 2,800 K, although the light that reaches us has an appearance more like that from a black body with a temperature of 2,300 K surrounded by dust at a temperature of 72 K. It emits most of its radiation in the infrared and although it is only about 500 times brighter than the sun at visual wavelengths, its bolometric luminosity is 8,000 times higher than the Sun's. Bolometric luminosity is the total electromagnetic power a star radiates across all wavelengths, expressed in watts. It is a crucial measure of a star's true luminosity, as it accounts for all wavelengths, including gamma rays, x-rays, ultraviolet, visible, infrared, and radio waves.
Release Date: Sept. 20, 2017
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