Employees of the European Southern Observatory have published a photograph taken by the VST survey telescope. It shows a nebula and a star that shouldn’t be there.
The emission nebula captured in the image is known as Sh2-46 and Gum 80. It is located about 6,000 light-years from Earth. It is a blue-white giant of spectral O type, one of the brightest but rarest types of luminaries in the Universe. Unlike stars like our Sun, which can live for billions of years, the lifespan of such objects is limited to millions of years, which is quite short by astronomical standards. White-blue giants end their existence as supernovae, giving rise to neutron stars and black holes.
It is due to the powerful emission of HD 165319 that we are able to observe the Sh2-46 nebula. It ionizes its constituent hydrogen atoms, which glow a distinctive red color.
But the most curious part is that HD 165319 is an “impostor”: a star that shouldn’t be there. According to astronomers, it was born elsewhere: in the neighboring Eagle Nebula. It is a young, diffuse star cluster that is home to a large number of regions of active star formation, as well as the famous Pillars of Creation.
Typically, stars born in the Eagle Nebula appear to be bound by gravitational forces, replenishing the cluster. But occasionally, some of them get separated, taking a solo journey through space that can lead them to reach other nebulae. Apparently, this is exactly what happened to HD 165319. The shock wave near it indicates that the star is currently plunging into Sh2-46. Perhaps this nebula will look different when the star eventually passes it and continues its wanderings through the Milky Way.
Earlier we reported on how Hubble photographed a “black pillar” in the Eagle Nebula.
According to ESO
