Infant Solar System Observed by Astronomers

A nascent solar system has been detected by astronomers. They noticed an infant star in the constellation Tauraus surrounded by a swirling disk of dust and gas that is more than 450 light years from Earth.

Consisting of about one fifth of the mass of the Sun, the star mostly draws the materials from its surroundings. According to the scientists, the disk of dust and gas that surrounds the young star contains at least enough mass to make seven Jupiters, the largest planet in our Solar System.

"This very young object has all the elements of a solar system in the making," said John Tobin, of the National Radio Astronomy Observatory.

Tobin and his team studied L1527 IRS present in the stellar nursery called the Taurus Cloud with the help of Sub millimeter Array and the Combined Array for Millimeter-wave Astronomy Cloud.

The youngest solar system that is still in the stage of formation is no more than 300,000 years old unlike the Sun that is 4.6 billion years of age.

 "It may be even younger, depending on how fast it accumulated mass in the past," Tobin explained.

The young star is one of the closest examples of the earliest stage of star formation. The dust and the carbon monoxide that are circling the object were measured with the help of millimeter wave observatories.

They were the first observers to conclusively show that the young star is surrounded by a rotating disk of material, and the first to be able to measure the mass of the protostar itself.

By measuring the Doppler shift of radio waves coming from carbon monoxide in the disk, they were able to show that the rotation speed in the disk changes with the material's distance from the star in the same fashion that the orbital speeds of planets change with distance from the Sun.

This pattern, called Keplerian rotation, "marks one of the first essential steps toward forming planets, because the disk is supported by its own rotation, will mediate the flow of material onto the protostar and allow the planet formation process to begin," said Hsin-Fang Chiang of the University of Illinois and the Institute for Astronomy of the University of Hawaii.

"This is the youngest protostar found thus far to show that characteristic in a surrounding disk," Tobin said. "In many ways, this system looks much like we think our own Solar System looked when it was very young," he added.

Previous observations from the Gemini Observatory suggested the presence of a large disk surrounding the protostar. This motivated Tobin and his team to pursue high-resolution millimeter-wave observations, confirming the presence of the disk and measuring its rotation.

"ALMA's advanced capabilities will allow us to study more such objects at greater distances," Tobin said. "With ALMA, we will be able to learn more about how the disks form and how quickly the young stars grow to their full size, and gain a much better understanding of how stars and their planetary systems begin their lives," he added.

The latest finding is published in the Journal Nature.