Did Our Sun Have a Twin?
New research and evidence help prove the recently created theory that our sun once had a companion. But where is it now?
If you think about it, our universe is as old as time itself. Currently, scientists are researching all sorts of things about the universe. From black holes to antimatter, our universe continues to surprise us with shocking revelations. Astronomers have pointed their telescopes at our sun for over 4 centuries, but this 4.5 billion-year-old star may have had an unseen companion.
Think about what you learned in school: there is one sun and 8 planets in our solar system, Pluto is a dwarf planet, Earth is the only planet with confirmed life, and more. But did you ever hear anything about a second sun? Amir Siraj, the lead author of an article in The Astrophysical Journal Letters, stated that our solar system may have had two suns. Until recently, this second sun had been called Nemesis, named after the Greek goddess of vengeance. This second sun could be the answer to various mysteries about our universe, from the density of the Oort cloud to Planet 9.
The Mystery of the Oort Cloud
One mystery that has been baffling scientists for many years is the mystery of our Oort cloud. This “cloud” is a region of space located right outside of our solar system and acts as a shell. The Oort cloud is made up of billions of objects and pieces of debris that were left from the creation of our solar system. This region is 10,000 to 100,000 astronomical units (AU) away from the sun. Imagine the distance from the Earth to the Sun; this distance is one AU. Now imagine the same distance multiplied by 10,000, and you will get to the inner Oort cloud. Multiply this distance by another 10, and you will reach the outer Oort cloud.
Scientists have observed many comets that seem to have originated from the Oort cloud, but this region of space is so far away that scientists struggle to properly observe it. Modern math has been able to calculate the density of the Oort cloud, but as of now, the calculated size is much larger than it should be. The Oort cloud’s density has a specific ratio with the celestial bodies within it. Our sun and planets combined do not have a strong enough gravitational pull to create an Oort Cloud with such a large magnitude. This begs the question, how is the cloud this big? Recent studies have stated that there must have been another large celestial body in our solar system. This proposed body is our Sun’s twin.
Taking this into account, Harvard students and professors have worked together to create a model of our solar system with two suns. Surprisingly, this model fixed our calculations of the Oort cloud’s properties.
Where is the Second Sun Now?
The solar system with a second sun model helps explain the size of such a large Oort cloud. However, think about it: when you wake up on a Monday for a long, painful day of school or work, do you see two suns in the sky? Why is that, why was there a second sun that we can’t see now?
The answer to this perplexing question is actually quite simple: it’s gone. This second sun, which was once a companion and helper to our sun, is now gone. During the creation of our solar system, this sun was around to help pull in and bulk up the Oort cloud, but over the course of billions of years, this star slowly drifted away, leaving only one star in our solar system. But can a star just drift away?
Think about it this way: every year our moon (Luna) drifts away from the Earth by 1.5 inches. This is caused by the gravitational force exerted by both the Moon and the Earth. Now imagine this same relationship on a much larger scale between two suns. Over the course of billions of years, one sun simply drifted away and could now be anywhere in the Milky Way Galaxy, but not before it lent a final helping hand to its companion star.
Planet 9
Before the second sun slipped away, our solar system had enough gravitational power (with two suns) to grab and pull in an extra planet. As of right now, Planet 9 is a hypothetical planet presumed to orbit our sun far beyond the orbits of Neptune and even Pluto. This planet is believed to exist due to an interesting phenomenon in our solar system.
Far in the reaches of space, there is an unusual cluster of trans-Neptunian objects, which are large objects beyond the orbit of Neptune. This sort of unusual clustering only occurs when there’s a celestial body with enough gravitational power to have these objects fall into an orbit around it. This is strange because current science dictates that there is no large celestial body that far out. That’s why NASA scientists have created a theory that this “Planet 9” is an undiscovered planet in our solar system, which would explain the abnormal clustering of trans-Neptunian objects.
Currently, this is all theoretical. However, this theory will be put to the test in 2021 with the launch of the Rubin Observatory’s Large Synoptic Survey Telescope. This telescope will be powerful enough to observe and either confirm or deny the existence of Planet 9. This would be a major breakthrough in astronomy, so get excited!
The existence of a second sun is just a theory, but if it did exist, it would remove speculations about how the Oort cloud got as big as it did and whether or not the atypical accumulation of trans-Neptunian objects far away from the Sun is because of a 9th planet. As we conduct more research, we’ll get closer to confirming this hypothesis, but as of now, nothing is set-in-stone. The universe is mysterious in many ways, but that’s what makes it interesting.
Want to learn more about this potential ‘second sun’ and ‘Planet 9?’ Check out these websites:
