Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2024 August 28
A picture of a starfield with red emission nebulae is shown.
Toward the right is a point of light that is Cygnus X-1, a nearby
black hole. Above the black hole is a blue-shaded bow shock wave
in the surrounding gas.
Please see the explanation for more detailed information.

Tulip Nebula and Black Hole Cygnus X-1
Image Credit & Copyright: Anirudh Shastry

Explanation: When can you see a black hole, a tulip, and a swan all at once? At night -- if the timing is right, and if your telescope is pointed in the right direction. The complex and beautiful Tulip Nebula blossoms about 8,000 light-years away toward the constellation of Cygnus the Swan. Ultraviolet radiation from young energetic stars at the edge of the Cygnus OB3 association, including O star HDE 227018, ionizes the atoms and powers the emission from the Tulip Nebula. Stewart Sharpless cataloged this nearly 70 light-years across reddish glowing cloud of interstellar gas and dust in 1959, as Sh2-101. Also in the featured field of view is the black hole Cygnus X-1, which is also a microquasar because it is one of strongest X-ray sources in planet Earth's sky. Blasted by powerful jets from a lurking black hole, its fainter bluish curved shock front is only faintly visible beyond the cosmic Tulip's petals, near the right side of the frame.

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