stellar ghosts
Nasa releases haunting image of three stellar ghosts (Nasa/JPL-Caltech/Harvard-Smithsonian CfA)

Ahead of Halloween 2013, Nasa scientists has released "haunting" images of three stellar ghosts, showing the disintegrating remains of dying stars.

The ghostly planetary nebulas were captured in infrared light by the Spitzer Space Telescope. They show material being ejected from dying stars called the Exposed Cranium Nebula, the Ghost of Jupiter Nebula and the Little Dumbbell Nebula.

Joseph Hora, principal investigator of the Spitzer observing programme at the Harvard-Smithsonian Center for Astrophysics, said: "Some might call the images haunting.

"We look to the pictures for a sense of the history of the stars' mass loss, and to learn how they evolved over time."

The three nebulas formed from stars about the mass of our sun. Billions of years after their inception, these stars start to get old and run out of fuel in their cores, eventually becoming red giants.

"The stars eventually cast off their outer layers, which expand away from the star," Nasa said.

"When ultraviolet light from the core of a dying star energises the ejected layers, the billowy material glows, bringing their beautiful shapes to light.

"The ghostly material will linger for only a few thousand years before ultimately fading into the dark night."

To celebrate their deaths, Nasa published obituaries for the three planetary nebulas:

Exposed Cranium Nebula

Exposed Cranium Nebula
Exposed Cranium Nebula (NASA/JPL-Caltech/Harvard-Smithsonian CfA)

The brain-like orb called PMR 1 has been nicknamed the 'Exposed Cranium' nebula by Spitzer scientists. This planetary nebula, located roughly 5,000 light-years away in the Vela constellation, is host to a hot, massive dying star that is rapidly disintegrating, losing its mass.

The nebula's insides, which appear mushy and red in this view, are made up primarily of ionized gas, while the outer green shell is cooler, consisting of glowing hydrogen molecules.

Ghost of Jupiter Nebula

Ghost of Jupiter Nebula
Ghost of Jupiter Nebula (NASA/JPL-Caltech/Harvard-Smithsonian CfA)

The Ghost of Jupiter, also known as NGC 3242, is located roughly 1,400 light-years away in the constellation Hydra. Spitzer's infrared view shows off the cooler outer halo of the dying star, coloured here in red.

Also evident are concentric rings around the object, the result of material being tossed out periodically during the star's fitful death.

Little Dumbbell Nebula

Little Dumbbell Nebula
Little Dumbbell Nebula (NASA/JPL-Caltech/Harvard-Smithsonian CfA)

This planetary nebula, known as NGC 650, or the Little Dumbbell, is about 2,500 light-years from Earth in the Perseus constellation. Unlike the other spherical nebulas, it has a bipolar or butterfly shape due to a 'waist', or disk, of thick material, running from lower left to upper right.

Fast winds blow material away from the star, above and below this dusty disk. The ghoulish green and red clouds are from glowing hydrogen molecules. The green area is hotter than the red.