A Baby Icy Giant Planet Is Growing Nearby

Observations of the icy giant planet, which is probably a bit more massive than Neptune, will help us better understand planet formation.

AsianScientist (Sep. 22, 2016) – Astronomers have found signs of a growing icy giant planet around TW Hydrae, a nearby young star, using the Atacama Large Millimeter-submillimeter Array (ALMA) in Japan. Their findings are published in Astrophysical Journal Letters.

A number of extrasolar planets have been found in the past two decades and they show a wide variety of characteristics. However, it is still unclear how this diversity emerges and in particular, how icy giant planets such as Uranus and Neptune form.

To study planet formation more closely, a research team led by Dr. Takashi Tsukagoshi at Ibaraki University, Japan, observed the young star TW Hydrae. This star, estimated to be ten million years old, is one of the closest young stars to the Earth. Because the planet around TW Hydrae is relatively near and its axis of rotation points roughly in the Earth’s direction, it is one of the most favorable planets for investigating planet formation.

Recent ALMA observations have revealed multiple gaps in the disk (dust and debris in orbit) around TW Hydrae. From ALMA observations at two radio frequencies, the researchers calculated the mass of the unseen planet based on the width and depth of the 22 astronomical unit (au) gap and estimated that the planet is probably a little more massive than Neptune. One au is about 150 million kilometers, or the distance between Earth and the Sun.

To better estimate the mass of the young planet, the team now plans to observe the polarization of radio waves and measure the amount of gas in the disk around TW Hydrae.


The article can be found at: Tsukagoshi et al. (2016) A Gap with a Deficit of Large Grains in the Protoplanetary Disk around TW Hya.

———

Source: National Astronomical Observatory of Japan.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Related Stories from Asian Scientist