New Delhi:
In a major development, scientists have discovered signs of a baby plane. Based on the distance from the central star and the distribution of tiny dust grains, the baby planet is thought to be an icy giant.
Astronomers spotted the icy giant planet around TW Hydrae, a nearby young star, with the help of Atacama Large Millimetre/submillimetre Array (ALMA) in Chile.
Due to the distance from the central star and the distribution of tiny dust grains, the planet is considered to be an icy giant planet, similar to Uranus and Neptune.
Various extra solar planets have been found in the past two decades and researchers now agree that planets can have a huge array of characteristics.
However, no concrete reason has still been found regarding this diversity.
A research team led by Takashi Tsukagoshi at Ibaraki University in Japan observed the young star TW Hydrae.
This star is estimated to be approximately 10 million years old and is also one of the closest young stars to our own Earth.
Based on the proximity and the reason that the axis of rotation points in Earth's direction, giving us a face-on-view of the developing planetary system, TW Hydrae emerged as a favourable target for studying planet formation.
Past observations have displayed that TW Hydrae is surrounded by a disk made of tiny dust particles. This disk in turn is the site of planet formation.
Furthermore, recent ALMA observations have displayed the presence of multiple gaps in the disk.
Some theoretical studies however suggest that the gaps are evidence of planet formation.
The team observed the disk around TW Hydrae with ALMA in two radio frequencies. Since the ratio of the radio intensities in different frequencies depend on the size of the dust grains, researchers can easily estimate the size of dust grains.
The ratio indicates that smaller, micrometre-sized, dust particles dominate and larger dust particles are absent in the prominent gap with a radius of 22 astronomical units (au).
Theoretical studies have predicted that a gap in the disk is created by a massive planet, and that gravitational interaction and friction between gas and dust particles push the larger dust out from the gap, while the smaller particles remain in the gap. The disk is created by a huge planet, and that gravitational interaction and friction between gas and dust particles push the larger dust out from the gap, while the smaller particles remain in the gap.
The current observation results clearly match these theoretical predictions.
Researchers calculated the mass of the icy giant planet completely based on the width and depth of the 22 AU gap and found that the planet is probably a little bigger than Neptune.
"Combined with the orbit size and the brightness of TW Hydrae, the planet would be an icy giant planet like Neptune," said Tsukagoshi.
Following this result, the team is planning further observations to better understand the formation of planets.
