planet formation tagged posts

This artist’s impression of the water snowline around the young star V883 Orionis, as detected with ALMA. Credit: A. Angelich (NRAO/AUI/NSF)/ALMA (ESO/NAOJ/NRAO)

A violent outburst by the young star V883 Orionis has given astronomers their first view of a water “snowline” in a protoplanetary disk – the transition point around the star where the temperature and pressure are low enough for water ice to form. An abrupt increase in the brightness of the star “flash heated” the inner portion of the disk, pushing the water snowline out much farther than normal, enabling astronomers to image it with ALMA. Under normal conditions, the water snowline would be much too close to the protostar to observe directly, even with ALMA’s remarkable resolution.

Typically, heat from a young Sun-like star preve...

This false-color image from a sub-millimeter interferometric telescope shows the circumstellar disk of gas and dust that surrounds star CI Tau. Credit: Stephane Guilloteau/University of Bordeaux

Jupiter-like ‘CI Tau b’ orbits 2 million-year-old star in constellation Taurus. In contradiction to the long-standing idea that larger planets take longer to form, US astronomers today announced the discovery of a giant planet in close orbit around a star so young that it still retains a disk of circumstellar gas and dust.

“For decades, conventional wisdom held that large Jupiter-mass planets take a minimum of 10 million years to form,” said Christopher Johns-Krull. “That’s been called into question over the past decade” CI Tau b is at least 8X larger than Jupiter, ~450 light years from Earth...

This is an ALMA image of the dust disk around HL Tauri. Credit: ALMA (ESO/NAOJ/NRAO)

A new analysis of ALMA data for young star HL Tauri provides yet more firm evidence of baby planets around the star. 2 gaps in the gas disk around HL Tauri were uncovered. The locations of these gaps in the gas match the locations of gaps in the dust found in the ALMA high resolution image taken in 2014. This discovery supports the idea that planets form in much shorter timescales than previously thought and prompts a reconsideration of alternative planet formation scenarios.

In November 2014, ALMA released a startling image of HL Tauri and its dust disk. This image, the sharpest ever taken for this kind of object, clearly depicts several gaps in the dust disk around the star...

The University of Chicago’s Sean Mills (left) and Daniel Fabrycky describe the complex orbital structure of the Kepler-223 expolanetary system in the May 11, 2016 Advance Online edition of Nature. Credit: Nancy Wong

The 4 planets of Kepler-223 star system seem to have little in common with planets of Earth’s own solar system. And yet a new study shows Kepler-223 system is trapped in an orbital configuration that Jupiter, Saturn, Uranus, and Neptune may have broken from in the early history of the solar system. “Exactly how and where planets form is an outstanding question in planetary science,” said Sean Mills. “Our work essentially tests a model for planet formation for a type of planet we don’t have in our solar system...