Planetary nebulae are the final stage in the life of sun-like stars. When they run out of the fuel available to them, they eject the material on their surface into space, while the core collapses to become a white dwarf.
The ejected material is then illuminated by the ultraviolet radiation emitted by the central white dwarf. This reveals the structure of these wonderful celestial objects. One of the most beautiful and complex planetary nebulae is NGC 5189. It is located 1800 light-years from Earth in the constellation Musca.
Discovered in 1826 by James Dunlop, the nebula has long puzzled scientists. Its shape may resemble that of a barred spiral galaxy, but until the 1960s it was actually classified as an emission nebula. It was only after the first spectroscopic observations that its nature as a planetary nebula was established.
NGC 5189 has a four-lobed structure characterized by thin filaments and denser regions. To explain its shape, astronomers have hypothesized that a binary star system lies at its center, but this has never been observed. The secondary star orbiting the dying star (the white dwarf) would have influenced the motion of the gas, causing it to take on its current shape.
Credits: NASA, ESA, Hubble.
Post a Comment