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Cassiopeia A

Supernova remnant · Supernova remnant in the constellation Cassiopeia

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Cassiopeia A
Picture: X-ray: NASA/CXC/SAO; IR: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/L. Frattare and K. Arcand, Public domain, via Wikimedia Commons.

About Cassiopeia A

Cassiopeia A is about 11,089 light-years from the Sun, so the light we see from it left about 11,089 years ago.

It is 32,756 light-years from the centre of the Milky Way.

The map lists it as a supernova remnant and shows it among the stars around the Sun, drawn on the plane of the Milky Way.

The youngest known core-collapse supernova remnant in the Galaxy (explosion ~1680).

Key numbers

Distance11,089 light-years (3.40 kpc)
Distance from the Galactic centre32,756 light-years
Galactic coordinatesl = 111.70°, b = -2.10°
Sizeabout 10 light-years across

Where it is

Its place in the universe, from the inside out: Perseus Arm › Milky Way › Local Group › Virgo Supercluster › Laniakea Supercluster › Observable universe.

Zoom out to see it in context: Local Arm, a view about 12,000 light-years across.

From Wikipedia

Cassiopeia A is a supernova remnant (SNR) in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies below 1 GHz.

Excerpt from the Wikipedia article Cassiopeia A, licensed CC BY-SA 4.0.

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