MPIA: Radio Detection of Lonely Planet Disk Shows Similarity with Stars

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First Radio Detection of Lonely Planet Disk Shows Similarities between Stars and Planet-like Objects
Max Planck Institute for Astronomy | 2017 May 18

[img3="Artists' impression of the gas and dust disk around the planet-like object OTS44. First radio observations indicate that OTS44 has formed in the same way as a young star. Image: Johan Olofsson (U Valparaiso & MPIA)"]http://www.mpia.de/4317456/zoom-1494936186.jpg[/img3][hr][/hr]

First radio observations of the lonely, planet-like object OTS44 reveal a dusty protoplanetary disk that is very similar to disks around young stars. This is unexpected, given that models of star and planet formation predict that formation from a collapsing cloud, forming a central object with surrounding disk, should not be possible for such low-mass objects. Apparently, stars and planet-like objects are more similar than previously thought. ...

A new study of the lonely, planet-like object OTS44 has provided evidence that this object has formed in a similar way as ordinary stars and brown dwarfs – a surprising result that challenges current models of star and planet formation. The study by a group of astronomers, led by Amelia Bayo of the University of Valparaiso and involving several astronomers from the Max Planck Institute for Astronomy, used the ALMA observatory in Chile to detect dust from the disk surrounding OTS44.

This detection yielded mass estimates for the dust contained in the disk, which place OTS44 in a row with stars and brown dwarfs (that is, failed stars with too little mass for sustained nuclear fusion): All these objects, it seems, have rather similar properties, including a similar ratio between the mass of dust in the disk and the mass of the central object. The findings supplement earlier research that found OTS44 is still growing by drawing matter from its disk onto itself – another tell-tale similarity between the object and young stars. ...

First Millimeter Detection of the Disk around a Young, Isolated, Planetary-mass Object - Amelia Bayo et al

• Astrophysical Journal Letters 841(1):L11 (2017 May 20) DOI: 10.3847/2041-8213/aa7046
  arXiv.org > astro-ph > arXiv:1705.06378 > 18 May 2017

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<<OTS 44 is a free-floating planetary-mass object or brown dwarf located at 550 light-years in the constellation Chamaeleon. It is among the lowest-mass free-floating substellar objects, with approximately 11.5 times the mass of Jupiter, or approximately 1.1% that of the Sun. Its radius is not very well known and is estimated to be 23–57% that of the Sun. OTS 44 was discovered in 1998 by Oasa, Tamura, and Sugitani as a member of the star-forming region Chamaeleon I. Based upon infrared observations with the Spitzer Space Telescope and the Herschel Space Observatory, OTS 44 emits an excess of infrared radiation for an object of its type, suggesting it has a circumstellar disk of dust and particles of rock and ice. This disk has a mass of at least 10 Earth masses. Observations with the SINFONI spectrograph at the Very Large Telescope show that the disk is accreting matter at the rate of approximately 10−11 of the mass of the Sun per year. It could eventually develop into a planetary system.>>