See dozens of planet-forming disks in groundbreaking survey



Check out the stunning new images of planet-forming disks around young stars. These observations showcase 86 young stars from three gas clouds in our Milky Way galaxy.

  • A new study looked at 86 young stars and their planet-forming disks in three gas clouds of the Milky Way.
  • It’s one of the largest surveys of planet-forming disks, showing a wide variety of shapes and sizes.
  • The study showed that multi-star systems were less likely to have large, planet-forming disks.

ESO published this original article on March 5, 2024. Edits by EarthSky.

Survey of planet-forming disks

The European Southern Observatory said on March 5 that its Very Large Telescope (ESO’s VLT) in Chile has captured images of planet-forming disks, in one of the largest-ever surveys of these disks. The research focused on observations of more than 80 young stars believed to have planets forming around them. The new observations have given astronomers new data and unique insights into how planets might arise in different regions of our home galaxy, the Milky Way.

Christian Ginski of the University of Galway, Ireland, is a lead author of one of three new papers published on March 5, 2024, in Astronomy & Astrophysics. Ginski said:

This is really a shift in our field of study. We’ve gone from the intense study of individual star systems to this huge overview of entire star-forming regions.

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Planet formation is varied

To date, astronomers have found more than 5,000 planets orbiting stars other than our sun. And often they’re within systems markedly different from our own solar system. To understand where and how this diversity arises, astronomers must observe the dust- and gas-rich disks that envelop young stars. These are the very cradles of planet formation. And they’re best found in huge gas clouds where the stars themselves are forming.

Much like mature planetary systems, the new images showcase the extraordinary diversity of planet-forming disks. Ginski said:

Some of these disks show huge spiral arms, presumably driven by the intricate ballet of orbiting planets.

Antonio Garufi of the Arcetri Astrophysical Observatory, Italian National Institute for Astrophysics (INAF), and lead author of one of the papers, added:

Others show rings and large cavities carved out by forming planets, while yet others seem smooth and almost dormant among all this bustle of activity.

Here are 10 of the 86 young stars from the new survey. The stars lie in 3 different star-forming gas clouds inside our Milky Way galaxy. The disks are scaled to appear roughly the same size in this composition. Image via ESO/ C. Ginski/ A. Garufi/ P.-G. Valegård et al.

Focusing on 3 gas clouds and their planet-forming disks

The team studied a total of 86 stars across three different star-forming regions of our galaxy. The first two regions are Taurus and Chamaeleon I. Both lie around 600 light-years from Earth. The third is Orion, a gas-rich cloud about 1,600 light-years from us. Scientists already knew it as the birthplace of several stars more massive than the sun. The observations were gathered by a large international team, comprising scientists from more than 10 countries.

The team gleaned several key insights from the data. For example, in Orion they found stars in groups of two or more were less likely to have large planet-forming disks. This is a significant result because most stars in our galaxy have companions. In addition, the uneven appearance of the disks suggests the possibility of massive planets embedded within. This could be what’s causing the disks to warp and become misaligned.

While planet-forming disks can extend for distances hundreds of times greater than the distance between Earth and the sun, their location several hundreds of light-years from us makes them appear as tiny pinpricks in the night sky. So the team used the Spectro-Polarimetric High-contrast Exoplanet Research instrument (SPHERE) mounted on ESO’s VLT. SPHERE’s state-of-the-art extreme adaptive optics system corrects for the Earth’s turbulent atmosphere, yielding crisp images of the disks.

Thus, the team was able to image disks around stars with masses as low as half the mass of the sun. That size is typically too faint for most other instruments available today. Additional data for the survey were obtained using the VLT’s X-shooter instrument. The X-shooter allowed astronomers to determine how young and how massive the stars are. And the Atacama Large Millimeter/submillimeter Array (ALMA) helped the team understand more about the amount of dust surrounding some of the stars.

Images of the 3 gas clouds

A gas cloud with wisps in yellow on black and insets showing some of the planet-forming disks inside.
Here’s the gas-rich cloud of Orion, roughly 1,600 light-years from Earth. The Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) instrument mounted on ESO’s Very Large Telescope (VLT) imaged 23 stars in the Orion region, detecting planet-forming disks around 10 of them. The uneven appearance of some of the disks in this region suggests that massive planets are embedded within them, since these could cause the disks to warp and become misaligned. The background image is an infrared view of Orion from the Infrared Astronomical Satellite. Image via ESO/ P.-G. Valegård et al./ IRAS.
Yellow-brown wisps on a black background with many insets showing planet-forming disks.
This is the Taurus gas cloud, roughly 600 light-years from Earth. SPHERE also captured these 43 stars in the Taurus region. The background image is an infrared view of Taurus captured by the Infrared Astronomical Satellite. Image via ESO/ A.Garufi et al./ IRAS.
Yellowy-tan wisps with 14 insets showing planet-forming disks.
The third gas cloud studied was Chamaeleon I, also 600 light-years from Earth. Here, SPEHRE captured 20 stars, detecting disks around 13. The background image is an infrared view of Chamaeleon I captured by the Herschel Space Observatory. Image via ESO/ C. Ginski et al./ ESA/ Herschel.

Deeper images to come

As technology advances, the team hopes to delve even deeper into the heart of planet-forming systems. The large 39-meter mirror of ESO’s forthcoming Extremely Large Telescope (ELT), for example, will enable the team to study the innermost regions around young stars. These are areas where rocky planets like our own might be forming.

For now, these spectacular images provide researchers with a treasure trove of data to help unpick the mysteries of planet formation. Per-Gunnar Valegård, of the University of Amsterdam, the Netherlands, led the Orion study. Valegård hopes the images will inspire his pupils to become scientists in the future and said:

It is almost poetic that the processes that mark the start of the journey towards forming planets and ultimately life in our own solar system should be so beautiful.

Focusing on one of the disks

Dark center with blue and orange spiral swirls making up a disk shape.
This composite image shows a planet-forming disk in the Taurus region. Yellow represents infrared observations from SPHERE. Blue is from the Atacama Large Millimeter/submillimeter Array (ALMA). These facilities allow astronomers to map dust distribution around this and other stars in different but complementary ways. SPHERE captures light from the host star that has been scattered by the dust around it; ALMA registers radiation directly emitted by the dust itself. These observations combined help astronomers understand how planets may form in the dusty disks surrounding young stars. Image via ESO/ A. Garufi et al./ R. Dong et al./ ALMA (ESO/NAOJ/NRAO).

Bottom line: A new survey looked at 86 young stars and their planet-forming disks in three gas clouds in our own Milky Way. See them here.

Sources:

The SPHERE view of the Chamaeleon I star-forming region: The full census of planet-forming disks with GTO and DESTINYS programs

The SPHERE view of the Taurus star-forming region: The full census of planet-forming disks with GTO and DESTINYS programs

Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): The SPHERE view of the Orion star-forming region

Via ESO



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