Protoplanetary discs

Why do M-class red dwarfs appear to disperse their protoplanetary discs more slowly than other stars? Credit: ESO

Peter Pan discs: the planetary systems that never grow up

An eye-shaped nebula, the remains of a star forming molecular cloud that is being torn apart by the supergiant at it's center. The glowing parts of the planet's atmosphere in the lower left are portions of atmosphere that were ionized either because of meteorite impacts or massive volcanic eruptions. This is a young planetary system, still in the heavy bombardment stage of its formation, so impacts are still very common. The ring of glowing debris around the planet are the remains of it's other moons, which were obliterated in a series of collisions.

How did the Solar System form?

There are several gaps in the gas surrounding the star which could have been created by planets passing through
Credit: ESO

ALMA discovers trio of exoplanets

An image of the newborn planet and its host star. The dark circle at the centre is a mask that blocks the light of the central star so astronomers can see the fainter disc and planet. The planet is the bright spot to the right of the black circle. Image Credit: ESO/A. Müller et al.

Newborn planet captured orbiting star

Below this artist's illustration are three images captured by Chandra showing evidence that a clump of material has been blasted out of a double star system at high speeds. X-ray: NASA/CXC/PSU/G.Pavlov et al; Illustration: NASA/CXC/M.Weiss

Pulsar punches hole in companion star disc

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Distant exoplanet defies planet formation theory

These three planetary discs have been observed with the SPHERE instrument, mounted on ESO’s Very Large Telescope. The observations were made in order to shed light on the enigmatic evolution of fledgling planetary systems. The central parts of the images appear dark because SPHERE blocks out the light from the brilliant central stars to reveal the much fainter structures surrounding them.

Young solar systems shaped by growing planets

This is a Hubble Space Telescope photo of a vast, complex dust structure, about 150 billion miles across, enveloping the young star HR 4796A. A bright, narrow inner ring of dust is already known to encircle the star and may have been corralled by the gravitational pull of an unseen giant planet. This newly discovered huge dust structure around the system may have implications for what this yet-unseen planetary system looks like around the 8-million-year-old star, which is in its formative years of planet construction. The debris field of very fine dust was likely created from collisions among developing infant planets near the star, evidenced by a bright ring of dusty debris seen 7 billion miles from the star. The pressure of starlight from the star, which is 23 times more luminous than the Sun, then expelled the dust far into space.

Dusty disc reveals young planets

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have found telltale differences between the gaps in the gas and the dust in discs around four young stars. These new observations are the clearest indications yet that planets with masses several times that of Jupiter have recently formed in these discs. This schematic diagram shows how the dust (brown) and gas (blue) is distributed around the star, and how a young planet is clearing the central gap.

Evidence for young planets in stellar discs

This artist's concept illustrates a solar system that is a much younger version of our own. Dusty disks, like the one shown here circling the star, are thought to be the breeding grounds of planets, including rocky ones like Earth. Astronomers using NASA's Spitzer Space Telescope spotted some of the raw ingredients for DNA and protein in one such disk belonging to a star called IRS 46. The ingredients, gaseous precursors to DNA and protein called acetylene and hydrogen cyanide, were detected in the star's inner disk, the region where scientists believe Earth-like planets would be most likely to form.

Disc gaps could be ‘cosmic illusions’

growing starMAIN

Astronomers discover young planetary system

ALMA detected the organic molecules in the outer edges of the system, in a region similar to our Kuiper Belt. Credit: B. Saxton (NRAO/AUI/NSF)

Organic molecules found round distant star

Artist’s concept of planets forming around a young star
Credit: David A. Hardy/www.astroart.org

Spiral arms could solve planet formation problem