You find an object in astronomy that looks impossible. Two very clear factual statements about it, called A and B, are mutually conflicting. If A is true, B cannot.
Some people who make breathless videos with terrible lighting and use the word "sheeple" claim that all of science is wrong.
A scientist looks at this and says,Huh. One or both of my assumptions must be wrong.
Let's talk about HD 93521. A team of astronomer studied it because it presents a problem.
It is the most massive and Luminous stellar classification. It is shooting out light at a rate 100,000 times that of the Sun. Even though it is over 4,000 light years away, you could easily see it in the constellation of Leo Minor with a pair of binoculars.
We have models of how stars behave based on a number of factors. HD 93521 has a mass of 17 Suns, making it a beast.
It has an age of about 5 million years, plus or minus a couple.
All good. But. Our galaxy is shaped like a disk of light years thick. All the gas and dust is located in that disk, so stars form there. It can be seen that HD93521 is 3,500 light years away from where all that star birth is.
The amount of time it would take for it to get to its current position from the disk is 39 minutes.
That is much, much longer than 5 million years. How could it be that it is only 5 million years old?
Is all of science correct? Is one or both of these facts incorrect?
I will go with the latter because I hate rhetorical questions. It turns out that HD 93521 is not real. It is lying about its age.
The basic contradiction is how long it took to get there. A bit of spin is the big clue. A lot of spin.
HD 93521 is a fast rotator and it spins very quickly. The light can be split into individual colors by taking the spectrum. The edge of the star headed toward us has a blue shift and the opposite edge has a red shift. The features we normally see in it are widened by this, because the star spins faster. HD 93521 is spinning at a rate of 435 kilometers per second at its equator.
That is staggering. The Sun is spinning at 2 km/s. Yes, two. The star is over 6 times the size of the Sun and spins more than 200 times faster. The star would be torn apart if it spun faster. Stars aren't born spinning that fast, so something must have spun it up.
The astronomer think that HD 93521 didn't start out life as a star. It was two stars.
It may have been born in the disk of two stars. The mass of the Sun would have been 8 times that. Something ejected them from the sky. They may have been born in a cluster of stars and encountered a single higher-mass star, which flung them away.
Over time, they got too close together and merged into a single star. The most famous example is V838 Monocerotis, and others are also known.
When two stars collide, the merger causes a huge amount of inertia into the remaining object, like when an ice skater spins quickly. The final post-merger star may have lost mass due to the slow rotation of the two stars, as they spun up so much that it almost flew itself apart.
The left star is so flattened that it is a spinning star. It is as wide as 20% through its equator, according to models. It would look like someone is sitting on a beach ball if you were next to it.
The apparent paradoxes are resolved by that. Stars with 8 times the Sun's mass live longer than those with 17 years. They may have been born about 40 million years ago and merged about 5 million years ago.
The idea still fits because of the uncertainty in the mass estimates and the fact that it could have 16 times the mass of the Sun.
There are other solitary stars that have rapid rotation, and they may be the result of mergers. Some unusual structures could be explained by this.
When it comes to science fact, paradoxes are fun to play with in science fiction, but you can be sure the Universe doesn't play that way. When you see one, ask yourself if it makes sense that the Universe is wrong or that you are.
bet on the Universe knowing what it is doing You just need to understand what's happening.
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