IAA: Signs of Planetary System Formation around HD169142

[bystander]

Signs of the Formation of a Planetary System around the Young Star HD 169142
Institute of Astrophysics of Andalusia - Spanish National Research Council (IAA-CSIC) | 2014 Sep 22

Young star HD 169142 displays a disk of gas and dust with two annular gaps possibly due to the formation of planets

[i]Image at 7 mm wavelength of the dusty disk around the star HD 169142 obtained with the Very Large Array (VLA) at 7 mm wavelength. The positions of the protoplanet candidates are marked with plus signs (+) (Osorio et al. 2014, ApJ, 791, L36). The insert in the upper right corner shows, at the same scale, the bright infrared source in the inner disk cavity, as observed with the Very Large Telescope (VLT) at 3.8 micron wavelength (Reggiani et al. 2014, ApJ, 792, L23).[/i]

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Planets are formed from disks of gas and dust that orbit around young stars. Once the “seed” of the planet —composed of a small aggregate of dust— is formed, it will continue to gather material and it will carve out a cavity or gap in the disk along its orbital path.

This transitional stage between the original disk and the planetary system, difficult to study and as yet little known, is precisely what has been observed in the star HD169142 and is discussed in two articles published in The Astrophysical Journal Letters.

"Although in recent years more than seventeen hundred extrasolar planets have been discovered, few of them have been directly imaged, and so far we have never been able to capture an unequivocal image of an still-forming planet”, says Mayra Osorio, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC) heading one of the articles. “In HD 169142 we may be seeing indeed those seeds of gas and dust which will later become planets."

HD169142 is a young star with twice the mass of the Sun and whose disk extends up to two hundred and fifty astronomical units (an astronomical unit, or AU, is a unit equivalent to the distance between the Sun and the Earth: one hundred and fifty million kilometers). The system is in an optimal orientation for the study of planet formation because the disk is seen face-on. ...

Imaging the Inner and Outer Gaps of the Pre-Transitional Disk of HD 169142 at 7 mm - Mayra Osorio et al

• Astrophysical Journal Letters 791(2) L36 (2014 Aug 20) DOI: 10.1088/2041-8205/791/2/L36
  arXiv.org > astro-ph > arXiv:1407.6549 > 24 Jul 2014

Discovery of a Companion Candidate in the HD169142 Transition Disk and the Possibility of Multiple Planet Formation - Maddalena Reggiani et al

• Astrophysical Journal Letters 792(1) L23 (2014 Sep 01) DOI: 10.1088/2041-8205/792/1/L23
  arXiv.org > astro-ph > arXiv:1408.0813 > 04 Aug 2014

An Enigmatic Pointlike Feature within the HD 169142 Transitional Disk - Beth A. Biller et al

• Astrophysical Journal Letters 792(1) L22 (2014 Sep 01) DOI: 10.1088/2041-8205/792/1/L22
  arXiv.org > astro-ph > arXiv:1408.0794 > 04 Aug 2014