Astronomers have taken a look at a previously unknown planet orbiting one of the closest stars to Earth.
Researchers have noticed the bright spot near Alpha Centauri A, one of several stars that swing so tightly around each other that it looks like one in the southern constellation of Centaurus. The stars form a binary system called 4.37 light-years later, just a stone’s throw away in cosmic terms.
So tentative is the observation that scientists only refer to it as a ‘planetary candidate’, and aware that the bright spot in the dark of space may be evidence of alien asteroids, streaks of dust, or more prosaic, is an unforeseen mistake in their equipment.
“We detected something,” said Pete Klupar, chief engineer of the Breakthrough Initiatives. This is a series of space projects funded by Yuri Milner, an entrepreneur in Silicon Valley. “It could be an artifact in the machine, or a planet, or asteroids or dust.”
The international team observed the star as part of the experiment “New Earths in the Alpha Centauri Region” (Near), supported by Breakthrough Watch, an attempt to find and study rocky planets on Earth around Alpha Centauri and other nearby stars .
To search for planets around the star, the astronomers used the Very Large Telescope, or VLT, which is operated by the European Southern Observatory from Cerro Paranal in the Atacama Desert in Chile. The scientists were aided by a new corona graph on the instrument that blocks the light from Alpha Centauri, making it easier to see worlds around the orbit.
Klupar compares the device to the erasure of the sun with an inch at the arm. The procedure allows for unprecedented sensitivity to planets directly to the solar system. “We’re trying to see a flashlight next to a lighthouse,” he said.
The team writes in Nature Communications and describes how infrared observations for 100 hours in May and June 2019 showed a bright spot that they could not explain. If confirmed by further observations as a planet, the observation would be the first to image an exoplanet directly around a nearby star.
‘Many people say that planets cannot form in this kind of binary form, and that is one reason why we are careful to claim that it is actually a planet. But if it is, it will be about the size of Neptune, “he added. The planet will lie in the habitable zone of the star, where the liquids can form water, and it will take about a decade to complete an orbit.
Neptune is about four times the size of Earth and does not have a solid surface. Instead, it has a core of the earth that is enveloped by a thick soup of water, ammonia and methane, and the latter gas makes it blue like Uranus.
Prof Beth Biller, who studies exoplanets at the Institute of Astronomy at the University of Edinburgh, said the researchers had an interesting candidate, but that they had to be justifiable.
“It will take a separate, independent investigation to really confirm this one,” she said. ‘If confirmed, it could detect the dust disk around the star or an actual planet. Both will be very interesting outcomes. ”
Klupar said the team would like to see again later this year whether the candidate planet has moved to the predictions that indicate it. But he said fresh observations may not be possible as the coronavirus pandemic continues to rage.