If exoplanet research can be believed, it would mean that there are Milky WayGalaxy could be like a fantastical candy-land.
The first was the discovery exoplanets. Cotton candy density. Astronomers claim they’ve found a world similar to that of marshmallow. They call it the fluffiest exoplanet orbiting a red-dwarf star.
This is crucial. It means that the dwarf stars are close to worlds with substantial gas envelopes. Astronomers suspected previously that these stars might deprive planets orbiting them of large swathes of their atmospheres.
The existence of atmospheres is thought to be one key characteristic of planets that allows life to develop and thrive. This could have implications for our understanding about the habitability of planets orbiting red-dwarf stars.
“Giant Planets around red dwarf star have been traditionally thought to be difficult to form.” Shubham Kanodia is a planetarium astronomerCarnegie Institution for Science’s Earth and Planets Laboratory.
“This has been done so far with very small Doppler samples, which have often found giant planets farther away from red dwarf stars. We haven’t had enough planet samples to be able to identify gas-rich planets close in size.
Red dwarf stars are the Milky Way’s most abundant stars. They’re very small and cool and dim – so dim, in fact, that not a single one can be seen with the naked eye, in spite of making up around 73% of all starsIn the Milky Way
They are smaller than stars like the Sun and burn slower. This means that they have a longer life expectancy. The estimated lifespan of our Sun is about 10 billion years. Expect to live trillions and years for red dwarf stars. Because of their long lives and abundance of red dwarfs stars, life might eventually emerge on a planet orbiting the red dwarf star.
However, red dwarfs are known to be extremely cranky and can bombard any planets they come across with powerful flares. These flares could also irradiate, sterilize, or strip their atmospheres. These stars are so cool that an exoplanet must be in the range of flare-lashing to maintain a temperature that is conducive to living as we know. This is a problem.
This new world might suggest that it may not be. It is called TOI-3757b and is a gas giant that orbits a red dwarf star in Auriga. It is approximately 580 light years away.
TOI-35757b was detected with the TESS space telescope. The telescope detects the dips in the light caused by the planet passing near the star. You can determine how big an exoplanet you are by knowing how bright the star and how much light it blocks. We know that TOI-3757b has a slightly larger than average diameter. Jupiter.
To determine the mass of the exoplanet’s star, researchers searched for changes in the star’s light that showed the gravitational pull exerted on it by the exoplanet. This gave us an estimated mass of 85 Earths, since gravity is directly related to mass.
Jupiter is, in context, around 318 EarthsThe average density of TOI-3757b is 1.33g per cubic centimeter. TOI-37757b has a density of 0.27 grams/cm3. That’s one extremely fluffy exoplanet – so fluffy that it’s unclear how it could have formed so close to its star: it completes one orbit every 3.43 days.
Kanodia and his associates believe that two factors could be at work. First, gas giants are formed with a rocky core around which gas accumulates to create a thick, extended atmosphere. The red dwarf star has a lower level of heavy elements than other red dwarfs with giants gas. This could have caused the formation of the rocky core to take longer and delayed the gas accumulation, which would have affected the world’s density.
The orbit is slightly oval and its distance to the star may vary. It is possible that the atmosphere expands and heats up as it draws nearer to the star.
Other astronomers suggested that puffy exoplanets might be able to extend ring systems like Saturn. But Kanodia and the other researchers found out that TOI-3757b was too close to its star in order to maintain a stable rings system. It is likely just a very puffy atmosphere.
The team is keen to discover and study other marshmallow worlds in the wild, and to learn how they develop and survive in places where it should be hard for them.
“Finding more such systems with giant planets – which were once theorized to be extremely rare around red dwarfs – is part of our goal to understand how planets form,” Kanodia:.
We hope they have enough sugary snacks.
The research of the team has been published in The Astronomical Journal.
