HIP 68468 Is A Sun Look Alike, “Death Star” That Likes To Eat Planets
Two new exo planets have been discovered orbiting a star about 300 light years away from the Earth and they seem to hold a dark history. The Star, HIP 68468 is a ‘solar twin’ as it is very similar to the sun in terms of temperature, age and composition. The interesting thing about this particular star is that it seems to have consumed one of the planets that once orbited it and hence the term "Death Star" is being used for it.
Death Star HIP 68468 and the surrounding planets
This particular star was studied by a team of astronomers that was led by Jorge Melendez at the University of São Paulo in Brazil. They studied the star using a 3.6 meter telescope at the La Silla Observatory in Chile. During this time, the team detected two new exo planet candidates orbiting the Death Star. One of the planets is being referred to as the HIP 68468c and is actually a super-Neptune. This term is used for an astronomical object that is greater than Neptune. The HIP 68468c earned this status as it has a mass that is 50% larger than Neptune and is roughly 26 times the mass of the Earth.
The other potential candidate is the HIP 68468b and is a super-Earth and I am sure you may have guessed what this means. It is greater than Earth but smaller than the giants, Uranus and Neptune. This planet is actually the first super-Earth that has been discovered orbiting a solar twin. Hence the astronomers are a little excited about this. On closer inspection of the orbit, it was observed that signs of a third planet existed.
The remains of the dead star
While studying the composition, it was found that 4 times more lithium was found and this is not normal for a star that is only around 6 billion years old. Apart from this there was clear evidence that there was a surplus of refractory elements. So what happened here? "It can be very hard to know the history of a particular star, but once in a while we get lucky and find stars with chemical compositions that likely came from in-falling planets," says astronomer Debra Fischer from Yale University, who was not involved in the research. "That's the case with HIP 68468. The chemical remains of one or more planets are smeared in its atmosphere."
The idea that a star ate a planet seems pretty absurd on some levels but this phenomenon is more common than you think. The scientists currently are monitoring more than 60 solar twins and approximately 15% of these have excess lithium. According to Melendez, "This suggests that about 15 percent of stars like the Sun must have devoured planets." Well, if the Sun look alike did devour a planet, is it possible that the Sun will do the same? It may seem scary but projections suggest the Sun will swallow Mercury, Venus and maybe even Earth in a billion years or so. Talk about ways that the Earth will be destroyed.
The planets at risk
A research was published earlier this year that suggested that the Solar System once had a super-Earth and it may have fallen prey to the Sun when it strayed too close. Going back to the HIP 68468, it seems that the surviving planets may be at risk of getting swallowed. This is because they are in very tight orbits around the star and have moved inwards from where they were before. The HIP 68468b is most at risk as it is orbiting the star at 0.03 times the distance between Earth and the Sun and goes around the star in just three days! "It's as if we saw a cat sitting next to a bird cage," says Fischer. "If there are yellow feathers sticking out of the cat's mouth, it's a good bet that the cat swallowed a canary."
The bird and the cat, is the perfect analogy for this moment.