Fig9_1 Rossette Nebula

Fig9_1 Rossette Nebula

Fig. 9.1 . This large, circular emission nebula, or H II region, known as the Rosette Nebula, lies at a distance of about 5,200 light-years from Earth and is about 130 light-years in diameter. Parts of this region include nebulae designated as NGC 2237, NGC 2238, NGC 2239, as well as the open star cluster NGC 2244. The mass of the Rosette Nebula is estimated to be about 10,000 solar masses. Hot O and B stars in the core of the Rosette Nebula exert pressure on the nearby interstellar material, triggering star formation, and heat the surrounding gas to a temperature of about 6 million K, causing it to emit x-rays observed from the Chandra X-ray Observatory. (Courtesy of KPNO/CTIA.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University