ALMA: Evidence for Pair of Infant Planets around Young Star

[bystander]

ALMA Finds Compelling Evidence for Pair of Infant Planets around Young Star
ALMA | NRAO | ESO | NAOJ | 2016 Dec 12

Astronomers now know that our galaxy is teeming with planets, from rocky worlds roughly the size of Earth to gas giants bigger than Jupiter. Nearly every one of these exoplanets has been discovered in orbit around a mature star with a fully evolved planetary system.

New observations with the Atacama Large Millimeter/submillimeter Array (ALMA) contain compelling evidence that two newborn planets, each about the size of Saturn, are in orbit around a young star known as HD 163296. These planets, which are not yet fully formed, revealed themselves by the dual imprint they left in both the dust and the gas portions of the star’s protoplanetary disk.

Previous observations of other young star systems have helped to reshape our understanding of planet formation. For example, ALMA’s images of HL Tauri and TW Hydrae revealed striking gaps and prominent ring structures in the stars’ dusty disks. These features may be the tantalizing first signs that planets are being born. Remarkably, these signs appeared around much younger stars than astronomers thought possible, suggesting that planet formation can begin soon after the formation of a protoplanetary disk. ...

Searching for Baby Planets in a Star’s Dusty Rings
Physics Viewpoints | American Physical Society | 2016 Dec 12

Ringed Structures of the HD 163296 Protoplanetary Disk Revealed by ALMA - Andrea Isella et al

• Physical Review Letters 117(25):1101 (2016 Dec 12) DOI: 10.1103/PhysRevLett.117.251101

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[Seaquest]

Aha! Another example of why the standard model of planet formation seems to need to make room for additional models. Planetary jostling so to speak.

[Chris Peterson]

Aha! Another example of why the standard model of planet formation seems to need to make room for additional models. Planetary jostling so to speak.

I think what we've learned in the last few years is that while planets are common, there is no "the" standard model for planet formation. As you suggest, there seem to be different mechanisms. The only broad conclusion that seems accurate is that planets form out of dusty disks surrounding young stars. But beyond that... the details abound.

[neufer]

Aha! Another example of why the standard model of planet formation seems to need to make room for additional models. Planetary jostling so to speak.

I think what we've learned in the last few years is that while planets are common, there is no "the" standard model for planet formation. As you suggest, there seem to be different mechanisms. The only broad conclusion that seems accurate is that planets form out of dusty disks surrounding young stars. But beyond that... the details abound.

• To-morrow, and to-morrow, and to-morrow,
  Creeps in this petty pace from day to day
  To the last syllable of recorded time,
  And all our yesterdays have lighted fools
  The way to dusty disks.