disk instability Archives

November 26, 2024November 26, 2024 by Evan Gough

The Hubble and FU Orionis: a New Look at an Old Mystery

This is an artist's concept of the early stages of the young star FU Orionis (FU Ori) outburst, surrounded by a disk of material. A team of astronomers has used the Hubble Space Telescope's ultraviolet capabilities to learn more about the interaction between FU Ori's stellar surface and the accretion disk that has been dumping gas onto the growing star for nearly 90 years. NASA-JPL, Caltech

In 1936 astronomers watched as FU Orionis, a dim star in the Orion constellation, brightened dramatically. The star’s brightness increased by a factor of 100 in a matter of months. When it peaked, it was 100 times more luminous than our Sun.

Astronomers had never observed a young star brightening like this.

February 6, 2024February 7, 2024 by Evan Gough

Some Young Planets Are Flattened Smarties, not Spheres.

This image from supercomputer simulations shows how some exoplanets form as 'flattened Smarties' rather than spheres. It shows the same planet from the top (left) and the side (right.) The images are from supercomputer simulations of planetary formation. Image Credit: Fenton and Stamatellos 2024.

One of contemporary astronomy’s most pressing questions concerns planet formation. We can see more deeply than ever into very young solar systems where planets are taking shape in the disks around young stars. But our view is still clouded by all the gas and dust in these young systems.

The picture of planet formation just got cloudier with the discovery that some young planets are shaped like flattened candies rather than spheres.

January 10, 2024January 10, 2024 by Evan Gough

The Youngest Planetary Disks Ever Seen

The evolutionary sequence of protoplanetary disks with substructures, from the ALMA CAMPOS survey. These wide varieties of planetary disk structures are possible formation sites for young protoplanets. Image Credit: Hsieh et al. in prep.

How long does planet formation take? Maybe not as long as we thought, according to new research. Observations with the Atacama Large Millimetre/submillimetre Array (ALMA) show that planet formation around young stars may begin much earlier than scientists thought.

March 7, 2023March 7, 2023 by Evan Gough

TESS Shows That Even Small Stars Can Host Giant Planets

Massive planets can form around low-mass stars, but they're rare. Image Credit: NASA

Can low-mass stars play host to giant, Jupiter-sized planets? Theories of planet formation suggest that it’s highly unlikely. But a team of scientists in the UK found that it’s possible, though rare.

April 5, 2022April 5, 2022 by Evan Gough

Hubble Has Been Watching This Planet Form for 13 Years

Researchers were able to directly image newly forming exoplanet AB Aurigae b over a 13-year span using Hubble’s Space Telescope Imaging Spectrograph (STIS) and its Near Infrared Camera and Multi-Object Spectrograph (NICMOS). In the top right, Hubble’s NICMOS image captured in 2007 shows AB Aurigae b in a due south position compared to its host star, which is covered by the instrument’s coronagraph. The image captured in 2021 by STIS shows the protoplanet has moved in a counterclockwise motion over time. Credits: Science: NASA, ESA, Thayne Currie (Subaru Telescope, Eureka Scientific Inc.); Image Processing: Thayne Currie (Subaru Telescope, Eureka Scientific Inc.), Alyssa Pagan (STScI)

Hubble’s most remarkable feature might be its longevity. The Hubble has been operating for almost 32 years and has fed us a consistent diet of science—and eye candy—during that time. For 13 of its 32 years, it’s been checking in on a protoplanet forming in a young solar system about 530 light-years away.

Planet formation is always a messy process. But in this case, the planet’s formation is an “intense and violent process,” according to the authors of a new study.