Dynamics of a massive binary at birth
Journal article, 2019

Almost all massive stars have bound stellar companions, existing in binaries or higher-order multiples(1-5). While binarity is theorized to be an essential feature of how massive stars form(6), essentially all information about such properties is derived from observations of already formed stars, whose orbital properties may have evolved since birth. Little is known about binarity during formation stages. Here we report high-angular-resolution observations of 1.3 mm continuum and H30 alpha recombination line emission, which reveal a massive protobinary with apparent separation of 180 au at the centre of the massive star-forming region IRAS 07299-1651. From the line-of-sight velocity difference of 9.5 km s(-1) of the two protostars, the binary is estimated to have a minimum total mass of 18 solar masses, consistent with several other metrics, and maximum period of 570 yr, assuming a circular orbit. The H30 alpha line from the primary protostar shows kinematics consistent with rotation along a ring of radius of 12 au. The observations indicate that disk fragmentation at several hundred astronomical units may have formed the binary, and much smaller disks are feeding the individual protostars.

Author

Yichen Zhang

RIKEN

Jonathan Tan

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

Tanaka

Osaka University

National Astronomical Observatory of Japan

James M. De Buizer

NASA Ames Research Center

Mengyao Liu

University of Virginia

Maria T. Beltran

Istituto nazionale di astrofisica (INAF)

Kaitlin Kratter

University of Arizona

Diego Mardones

University of Chile (UCH)

Guido Garay

University of Chile (UCH)

NATURE ASTRONOMY

2397-3366 (ISSN)

Vol. 3 6 517-523

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.1038/s41550-019-0718-y

More information

Latest update

8/26/2019