Wolf-Rayet stars are the last activity of a dying star. The stars are at least 20 times more massive than the Sun.
Stars this massive grow quickly and die early. Wolf-Rayet stars run out of lighter elements to fuse inside its core. Unlike the Sun, which turns hydrogen into helium, Wolf-Rayet stars are burning elements like oxygen to maintain equilibrium. This causes winds of 2.2 million to 5.4 million miles per hour (3.6 million to 9 million kilometers per hour). The winds strip away the outer layers of the Wolf-Rayet star eliminating a lot of its mass.
When the star runs out of elements to fuse, fusion stops and the pressure inside is less than the gravity and the star explodes as supernova.
But while the star is still (barely) alive, it is a Wolf-Rayet
– Ex astris, scientia –
I am and avid amateur astronomer and intellectual property attorney in Pasadena, California and I am a Rising Star as rated by Super Lawyers Magazine. As a former Chief Petty Officer in the U.S. Navy, I am a proud member of the Armed Service Committee of the Los Angeles County Bar Association working to aid all active duty and veterans in our communities. Connect with me on Google +, or by email.