Spiral arms of molecular gas, dust identified around 'baby twin' stars

The astronomers have recently observed the spiral arms of gas and dust as a nursery of Twin Stars around "baby twin" stars, binary protostars.

With the Atacama Large Millimeter/submillimeter Array (ALMA) observation, astronomers led by Shigehisa Takakuwa, Associate Research Fellow at the Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), Taiwan, stated that for the first time these observational results unveiled the mechanism of the birth and growth of binary stars, which are ubiquitous throughout the universe.

They also identified gas motions to supply materials to the twin.

The research team observed the baby-twin star L1551 NE [1], located in the constellation of Taurus at a distance of 460 light years, with a 1.6 times better imaging resolution and a 6 times better sensitivity than those of their previous observations with the SubMillimeter Array (SMA).

They observed L1551 NE in the emission from dust at a 0.9-mm wavelength, a tracer of distribution of interstellar materials, and carbon monoxide molecular emission, which can be used to study gas motion with the Doppler Effect.

They found a gas component associated with each binary star (the two central components can be seen in Figure 1), and a disk surrounding both stars, a circumbinary disk, with a radius of 300 au. The radius corresponds to 10 times the orbital radius of Neptune in our solar system.

For the first time, they succeeded in imaging the detailed structures of the circumbinary disk, and found that the circumbinary disk consists of a southern U-shaped feature and northern emission protrusions pointing to the northwest and the northeast.

The study is published in The Astrophysical Journal.