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spiral galaxy

What is the Whirlpool Galaxy?

A galaxy with some of the clearest spiral arms in the sky, first galaxy ever seen with a spiral shape (1845).

Worth knowing about the Whirlpool Galaxy

You see the Whirlpool Galaxy as it was about 28 million years ago.

Why it stands out
Its companion, NGC 5195, is joined to it by a faint bridge of stars; its pull is thought to be what keeps the Whirlpool’s arms so sharp.
Its name and its story
In 1845, Lord Rosse’s giant telescope (the “Leviathan of Parsonstown”) was the first to see a spiral shape in a “nebula” — decades before anyone knew these were separate galaxies, a mystery not settled until Hubble measured Cepheids in Andromeda in the 1920s.
The Whirlpool Galaxy (M51) — A model, seen from the Earth, with north up.
The numbers
Acrossabout 91,000 light-years
Distance from usabout 28 million light-years
How big it looksabout 11 arcminutes — the full Moon is about 30

We use about 28 million light-years, from the tip of the red-giant branch (McQuinn et al. 2016). Cepheids together with supernova 2005cs give 24.46 million (Csörnyei et al. 2023).

How anyone knows this

Things like it

The Milky Wayspiral galaxyNaked eyeThe Andromeda Galaxy (M31)spiral galaxyNaked eyeThe Triangulum Galaxy (M33)spiral galaxyBinocularsBode’s Galaxy (M81)spiral galaxyBinocularsThe Sombrero Galaxy (M104)spiral galaxyBinocularsThe Pinwheel Galaxy (M101)spiral galaxy150 mm telescope

Games it appears in

Show the Whirlpool Galaxy in the model🧭 Where is the Whirlpool Galaxy?🕒 When can I see the Whirlpool Galaxy?📖 How the galaxies fit together🌙 Plan an evening outside