The blue image is a cartoon that represents the full extent of the far-ultraviolet emission: ISRO

Indian astrophysicists were treated to what they called the "most spectacular objects in the sky" when they discovered ultraviolet wings around the Butterfly Nebula, captured using Ultraviolet Imaging Telescope (UVIT) of AstroSat. A nebula is an interstellar cloud of dust, and gases.

Located 3,800 light years from Earth in the Scorpius constellation, Butterfly Nebula or NGC 6302, is a planetary nebula that is shaped like the wings of the butterfly.

The Indian Institute of Astrophysics (IIA) has been investigating planetary nebulae in the ultraviolet light.

Planetary nebulae are structures that are formed during the final stages of stars like the Sun. As the stars burn up all the hydrogen or helium, they expand and turn red, these are referred to as giant stars.

As these giant stars go through further stages, they continue to shed outer layers thereby revealing an inner hot core called the white dwarf. The white dwarf then heats up and shines in the form of planetary nebula.

When astronomers first observed the nebulae, they had a striking resemblance to planets and hence named them 'planetary'.

An illustration, posted by the ISRO, shows the butterfly nebula. The blue image is a cartoon that represents the full extent of the far-ultraviolet emission.

"Researchers argue that the extended far-ultraviolet light is due to cold hydrogen molecules in the gas present in the outer parts of the nebula which are excited by the central star. They suspect that these far-ultraviolet structures of the planetary nebula point to the possible presence of two central stars in a binary system that are gravitationally bound," the ISRO statement said.

The findings of the study have been published in the journal Astronomy & Astrophysics.