Astronomers detect youngest known solar systems in the Milky Way

November 30th, 2007 - 3:41 pm ICT by admin  

Washington, Nov 30 (ANI): Astronomers have discovered what might be some of the youngest solar systems in the Milky Way.
The star systems are around the young stars UX Tau A and LkCa 15, that are located in the Taurus star formation region just 450 light years away.
“They’re baby stars,” said professor Nuria Calvet. “The sun, for comparison, is a middle-aged star at 4.5 billion years old,” he added.
According to Calvet, this research adds new insights to the study of solar systems.
“We are looking for our history,” said Calvet. “We are looking for the history of solar systems, trying to understand how they form,” he added.
Researchers detected the solar systems using NASA’s Spitzer Telescope, which measures levels of infrared radiation. With its help, they noticed gaps in the protoplanetary disks of gas and dust surrounding these stars, which were most likely caused by infant planets sweeping those areas clear of debris.
“Previously, astronomers were seeing holes at the centers of protoplanetary disks and one of the theories was that the star could be photoevaporating that material,” said Espaillat, first author of the paper.
Photoevaporation refers to the process of heating up the dust and gas in the surrounding cloud until it evaporates and dissipates.
“We found that in some stars, including these two, instead of a hole, there’s a gap,” said Espaillat. “It’s more like a lane has been cleared within the disk, which is not consistent with photoevaporation. The existence of planets is the most probable theory that can explain this structure,” he added.
The infrared orbiting telescope which discovered these solar systems, observes energy at wavelengths invisible to optical telescopes. This allowed astronomers to study these “pre-main sequence stars” in a deeper way.
A main sequence star is an average adult star, like the sun, which burns by converting hydrogen into helium. Pre-main sequence stars like UX Tau A and LkCa 15 haven’t yet established this conversion process. They derive energy from gravitational contraction. UX Tau A and LkCa 15 are both about 1 million years old. (ANI)

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