The Dolphin’s Head Nebula is in the photo highlighted by NASA on the website Astronomy Picture of the Day this Wednesday (29). It is cataloged as “Sh2-308” and was formed by a Wolf-Rayet type star, a class known for its energetic stars and dozens of times more massive than the Sun.
Located about 5,000 light-years from us in the constellation Canis Major, the Canis Major, Sh2-308 is a nebula that ended this bubble shape thanks to EZ Canis Majoris, the bright star that appears near the center. from the nebula.
It emits high-speed stellar winds that “push” with it slower-moving matter left over from an earlier phase of the star’s evolutionary process. The radiation emitted by it, intense and constant, causes the bubble to expand more and more.
Currently, the nebula’s edges are about 60 light-years apart. In the photo, there are light and diffuse color emissions, which indicate the glow of ionized oxygen atoms in shades of blue.
Wolf-Rayet type stars
Wolf-Rayet stars are known for their evolutionary processes, which cause them to lose mass rapidly. Typically, they are more than 25 solar masses and have short lifetimes, making them rare objects. Their winds are so intense that they release about 10 solar masses of matter from stars every million years, traveling at over 3,000 km/s.
Astronomers believe that the winds from these stars, like the one responsible for the nebula pictured above, are caused by radiation pressure. They have average temperatures above 249,000°C, and they shine so brightly that their luminosity can reach millions of times that of the Sun.
So far, there are about 220 such stars known in the Milky Way, but estimates suggest that there may be thousands of them, most of which appear to be hidden by dust.
Source: ETC
