Hubble Caldwell 27, Crescent NebulaAlso called the Crescent Nebula or NGC 6888, Caldwell 27 holds a massive, incredibly hot star at its heart.Credits: NASA, ESA, Brian D. Moore and J. Jeff Hester (Arizona State University) Download Share Tags Hubble Space TelescopeImage CreditNASA, ESA, Brian D. Moore and J. Jeff Hester (Arizona State University)Size1024x1038px