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Stories about: stellar velocity

New Theory on How Spiral Galaxies Got Their Arms Ever since astronomers started differentiating between spiral and elliptical galaxies, they have wondered what precisely makes some galaxies develop their trademark arms, while others remain without them. Our own galaxy, the Milky Way, is a spiral one, featuring two, or, according to new studies, four arms. A team of... 22 August 2009 03:49 GMT