Astronomers have found five objects that line stars with planets, the newest example of an enigmatic rare group of celestial bodies called brown dwarf.
Brown dwarfs are frequently referred to as “failed stars” since there is not enough mass to ignite.
But researchers in recent decades have wondered if there is more than only a slightly heavier dwarf than a star.
In building a wide range of bodies, astronomers hope to better handle all the strange permutations of materials the universe can give them.
Nolan Grieves, an astronomer at the Swiss University of Geneva and lead author of the new research, said “It’s all about answering broader questions. What are the different types of star systems? and how do they form various planet systems?”
A Hunt for a Planet Turns Up Another
Grievances and collaborators used NASA Transiting Exoplanet Survey Satellite data to scan the sky for planets, and to watch stars watch subtle dimming that occurs when planets pass by.
A few of the shadows in Jupiter size caught their attention during their investigation. They noticed something strange when they followed it with a 1.2meter telescope at La Silla Observatory in Chile.
The team measured the speed at which the host stars wobbled under the gravity of their faint comrades and found that their putative planets possessed monstrous masses – 77 to 98 times Jupiter’s mass.
This volume places them so close to the upper edge of the brown dwarf mass line that what each object is, is difficult to say with confidence.
“Maybe some are more probably stars,” said Grieves, “but in the [Brown Dwarfs] realm they’re right.”
The Brown Dwarf Desert
As astronomers developed ever more sophisticated watching methods for stars to wobble and flicker, they identified thousands of strange, wonderful orbiting worlds.
But they found relatively few middleweight objects among a sky filled with heavenly bodies, especially those that weigh about 13 to 80 times the mass of Jupiter.
These bodies are not planets because they have enough weight to mix deuterium atoms (a heavy hydrogen version) with fusion and to warm themselves.
But they are also not stars, as they have no mass to fuse proper hydrogen sustainably and shine for thousands of years.
Curiously, only dozens of these objects were reliably located and explained by researchers
Something seems to stop the production of brown dwarfs in a universe full of stars and planets.
“It’s strange because the detection of smaller exoplanets is easier,” says Grieves. “Truly, this is a physical phenomenon.”
Some scientists suspect that there are no intermediate items – the “brown dwarf desert” – because this category actually covers two similar but separate groups.
They argue that the heaviest dwarfs are indeed failed star. Once upon a time, a gas cloud collapsed, but not enough mass was collected together to fuse hydrogen and brilliance.
In the meantime, the lighter dwarfs may be more like super planets. They might have coalesced from the polished disc that a young star is ringing.
Then the mass was hovered so well that the deuterium could be merged.
Ironically, astronomers need more to find out, what makes the brown dwarf desert so desolate.
Five New Dwarfs
The scientists cannot draw comprehensive conclusions from only five new examples. The handful of objects nevertheless offer some indices that align with theories of common brown dwarf.
For example, the not-quite-stars are supposed to cool and shrink over time. The astronomers compared the age and size of four brown dwarfs in order to test this theory. The largest dwarfs were found to be younger, while the smaller dwarfs were older – as suggested by the theory.
Five also agree that two types of brown dwarfs actually exist: failed stars and super planets. Stars with a wider range of items for sculpting waves expect super planets to be more common around them.
Failed stars could, meanwhile, have more erratic orbits because they have not matured in a dusty disc’s calming cradle.
The new brown Dwarf candidates tended to look like the failed stars in the mass ceiling.
Although the line between planets and stars remains blurred, Griev hopes that future observations will shed light on more brown dwarfs.
