MessageToEagle.com - Located at a distance of about 13 000 light-years from Earth, in the heart of the Milky Way in the constellation of Scorpius, a yellow hypergiant with a diameter about a thousand times bigger than our Sun could soon face its final days and die.

Despite its enormous size, the star has not been identified as yellow hypergiant until recently.

When the stars explodes, astronomers will have a new opportunity to study a supernova explosions in our galaxy.

Astronomers have used ESO's Very Large Telescope to image the monster star, known as IRAS 17163-3907, a colossal star that belongs to one of the rarest classes of stars in the Universe, the yellow hypergiants.

"This object was known to glow brightly in the infrared but, surprisingly, nobody had identified it as a yellow hypergiant before," said Eric Lagadec (European Southern Observatory), who led the team that produced the new images.

The observations of the star and the discovery of its surrounding shells were made using the VISIR infrared camera on the VLT.

The pictures are the first of this object to clearly show the material around it and reveal two almost perfectly spherical shells.

Click on image to enlarge

This chart shows the location of the rare yellow hypergiant star IRAS 17163-3907 within the constellation of Scorpius (The Scorpion).

This map shows most of the stars visible to the unaided eye under good conditions and the location of the star itself is marked with a red circle. Although this object appears very bright in the infrared sky it is faint in visible light and hard to find in the very rich star-fields of the centre of the Milky Way.
Credit: ESO, IAU and Sky & Telescope

If the Fried Egg Nebula were placed in the centre of the Solar System the Earth would lie deep within the star itself and the planet Jupiter would be orbiting just above its surface.

The much larger surrounding nebula would engulf all the planets and dwarf planets and even some of the comets that orbit far beyond the orbit of Neptune.

The outer shell has a radius of 10 000 times the distance from the Earth to the Sun.

Yellow hypergiants are in an extremely active phase of their evolution, undergoing a series of explosive events — this star has ejected four times the mass of the Sun in just a few hundred years.

The material flung out during these bursts has formed the extensive double shell of the nebula, which is made of dust rich in silicates and mixed with gas.

This activity also shows that the star is likely to soon die an explosive death — it will be one of the next supernova explosions in our galaxy.

Supernovae provide much-needed chemicals to the surrounding interstellar environment and the resulting shock waves can kick start the formation of new stars.

The Very Large Telescope mid-IR instrument, VISIR, captured this delicious image of the Fried Egg Nebula through three mid-infrared filters that are here coloured blue, green and red.

After burning all their hydrogen all stars of ten solar masses or more become red supergiants.

This phase ends when the star has finished burning all of its helium.

Some of these high-mass stars then spend just a few million years in the post-red supergiant phase as yellow hypergiants, a relatively short time in the life of a star, before rapidly evolving into another unusual type of star called a luminous blue variable.

These hot and brilliant stars are continuously varying in brightness and are losing matter due to the strong stellar winds they expel.

But this is not the end of the star's evolutionary adventure, as it may next become a different kind of unstable star known as a Wolf-Rayet star before ending its life as a violent supernova

Click on image to enlarge

M1-67 is the youngest wind-nebula around a Wolf-Rayet star, called WR124, in our Galaxy. These Wolf-Rayet stars start their lives with dozens of times the mass of our Sun, but loose most of it through a powerful wind, which is ultimately responsible for the formation of the nebula.

Ten years ago, Hubble Space Telescope observations revealed a wealth of small knots and substructures inside the nebula. The same team, led by Cédric Foellmi (ESO), has now used ESO's Very Large Telescope (VLT) to watch how these structures have evolved and what they can teach us about stellar winds, their chemistry, and how they mix with the surrounding interstellar medium, before the star will eventually blow everything away in a fiery supernova explosion.

The image is based on FORS1 data obtained by the Paranal Science team with the VLT through 2 wide (B and V) and 3 narrow-band filters.
Credit: ESO

Video credit: ESO, Nick Risinger (skysurvey.org) and Digitized Sky Survey 2. Music: John Dyson (from the album Moonwind)

This zoom video sequence starts with the spectacular view of the central parts of the Milky Way. As we close in on the constellation of Scorpius, one of the richest parts of the sky, many clusters and nebula appear. The final sequence closes in on an apparently unremarkable star, IRAS 17163-3907, which has been found by recent VLT observations to be a rare yellow hypergiant star, surrounded by two shells.

MessageToEagle.com based on material provided by ESO

Follow MessageToEagle.com for the latest news on Facebook and Twitter !

Recommend this article: