Our son's lost twin might have caused the extinction of the dinosaurs. This sounds weird, but there's evidence in its favor. A popular hypothesis in astronomy proposes that every star starts as a binary pair or a multi-pair system. If it's true, then it raises a critical question: Does the sun also have a twin star? The most probable answer is yes. This is because the sun wasn't born alone; instead, it was born in a litter with at least one sibling.
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The search for the sun's lost twin has been going on for decades. In the 1980s, astronomers proposed that the sun actually had an evil, trouble-making twin called Nemesis that swings past the solar system every 26 to 27 million years. Its gravitational turbulence sends a cloud of comets hurtling our way, and it's possible that the twin was the culprit that kicked an asteroid into Earth's orbit, which eventually collided with our planet, triggering the fifth mass extinction event.
Sky surveys spanning years turned up with no trace of Nemesis, but studies conducted in recent years have collected plenty of evidence that our sun was far from being alone. In 2017, researchers mapped the radio waves leaking out of a dense cocoon of dust in the Perseus constellation. This dust cloud lies about 600 light years away from Earth and contains a nursery of young stars.
.png "Sun's Long-Lost Twin")
The primary goal of this survey was to look for relative populations of young single stars and binaries of all separations in the molecular cloud. For that, the team ran a series of statistical models concerning both single and binary stars within the cloud. The survey included stars younger than half a million years old, referred to as class zero stars, along with class 1 stars that are a little older and lie between 0.5 and 1 million years.
These data were combined with the available information on the shapes of the surrounding cloud of dust. As a result, scientists found 45 lonely stars, 19 binary systems, and five systems with more than two stars. Moreover, it appeared that all sun-like stars formed as wide binaries initially separated by 500 astronomical units. That's about 17 times the distance between Neptune and the sun. However, things changed over the first million years of the star's life. After that, the systems either shrunk into a truly binary system or broke apart, possibly what happened with the sun and Nemesis. This means that Nemesis probably escaped and mixed with other stars in our region of the Milky Way. So, even if the sun has a twin, it's certainly not easily visible in our neighborhood.
.png "Sun's Long-Lost Twin")
.png "Sun's Long-Lost Twin")
The search for the sun's lost twin has been going on for decades. In the 1980s, astronomers proposed that the sun actually had an evil, trouble-making twin called Nemesis that swings past the solar system every 26 to 27 million years. Its gravitational turbulence sends a cloud of comets hurtling our way, and it's possible that the twin was the culprit that kicked an asteroid into Earth's orbit, which eventually collided with our planet, triggering the fifth mass extinction event.
Sky surveys spanning years turned up with no trace of Nemesis, but studies conducted in recent years have collected plenty of evidence that our sun was far from being alone. In 2017, researchers mapped the radio waves leaking out of a dense cocoon of dust in the Perseus constellation. This dust cloud lies about 600 light years away from Earth and contains a nursery of young stars.
.png "Sun's Long-Lost Twin")
The primary goal of this survey was to look for relative populations of young single stars and binaries of all separations in the molecular cloud. For that, the team ran a series of statistical models concerning both single and binary stars within the cloud. The survey included stars younger than half a million years old, referred to as class zero stars, along with class 1 stars that are a little older and lie between 0.5 and 1 million years.
These data were combined with the available information on the shapes of the surrounding cloud of dust. As a result, scientists found 45 lonely stars, 19 binary systems, and five systems with more than two stars. Moreover, it appeared that all sun-like stars formed as wide binaries initially separated by 500 astronomical units. That's about 17 times the distance between Neptune and the sun. However, things changed over the first million years of the star's life. After that, the systems either shrunk into a truly binary system or broke apart, possibly what happened with the sun and Nemesis. This means that Nemesis probably escaped and mixed with other stars in our region of the Milky Way. So, even if the sun has a twin, it's certainly not easily visible in our neighborhood.
.png "Sun's Long-Lost Twin")
Still, this theoretical troublemaker is considered a reason behind the 27 million-year cycle of extinctions on Earth. Only a few potential solar siblings have been found to date. One of the most popular candidates in this hunt is HD186302. It is a G-type main-sequence star slightly bigger than the Sun. The yellow dwarf was discovered in 2017 with the help of precise astrometric data collected by Gaia. To make things more exciting, HD186302 has almost similar chemical abundance as the Sun. Also, it's roughly about the same age, around 4.5 billion years. That's strong evidence that it's the sun's long-lost twin. But still, more evidence is needed to confirm. Some siblings are most likely out there, but we need to find out where exactly they reside.
There are billions of stars in the Milky Way scattered widely, making the search even more complicated. Even about 25 years ago, it was proposed that a red dwarf star lies 1.5 light years away. It periodically travels through the icy outer limits of our solar system and stirs up material with its gravity, knocking a few space boulders our way. The exact birthplace of the sun is unknown, so every stellar sibling identified will act as a pathway to unravel the Solar System's mystery. If Sun 2.0 exists, Earth 2.0 might also be revolving around it. This would eventually be a giant leap in our hunt for extraterrestrial life. If you learned something new from this article, make sure to follow us for more.
There are billions of stars in the Milky Way scattered widely, making the search even more complicated. Even about 25 years ago, it was proposed that a red dwarf star lies 1.5 light years away. It periodically travels through the icy outer limits of our solar system and stirs up material with its gravity, knocking a few space boulders our way. The exact birthplace of the sun is unknown, so every stellar sibling identified will act as a pathway to unravel the Solar System's mystery. If Sun 2.0 exists, Earth 2.0 might also be revolving around it. This would eventually be a giant leap in our hunt for extraterrestrial life. If you learned something new from this article, make sure to follow us for more.