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Nebula

A nebula is a giant cloud of gas (mostly hydrogen and helium) and cosmic dust situated between stars in the interstellar medium. Nebulae serve as sites of stellar birth and death—including emission nebulae that glow from ionized gas, reflection nebulae that scatter starlight, and dark nebulae that obscure background stars.

Source: science.nasa.gov

APODs including "Nebula"

Young Stars, Dark Nebulae

10/01/2025

Young Stars, Dark Nebulae
Image Credit: Long Xin / NASA APOD

An unassuming region in the constellation Taurus holds these dark and dusty nebulae. Scattered through the scene, stars in multiple star systems are forming within their natal Taurus molecular cloud complex some 450 light-years away. Millions of years young and still going through stellar adolescence, the stars are variable in brightness and in the late phases of their gravitational collapse. Known as T-Tauri class stars they tend to be faint and take on a yellowish hue in the image. One of the brightest T-Tauri stars in Taurus, V773 (aka HD283447) is near the center of the telescopic frame that spans over 1 degree. Toward the top is the dense, dark marking on the sky cataloged as Barnard 209.