April 26, 2024

“Marshmallow” World Discovered: Giant Fluffy Planet Orbiting a Cool Red Dwarf Star

Artist impression of an ultra fluffy gas giant world orbiting a red dwarf star. The world, called TOI-3757 b, is the fluffiest gas giant planet ever found around this type of star. Named TOI-3757 b, the exoplanet is the fluffiest gas giant planet ever found around this type of star.
Till now we have actually not had a big sufficient sample of planets to find close-in gas planets in a robust manner.”
TOI-3757bs star has a lower abundance of heavy components compared to other M-dwarfs with gas giants, and this might have resulted in the rocky core forming more slowly, postponing the onset of gas accretion and for that reason impacting the planets overall density.

” Giant planets around red dwarf stars have generally been believed to be hard to form,” states Shubham Kanodia, a researcher at Carnegie Institution for Sciences Earth and Planets Laboratory and first author on a paper published in The Astronomical Journal. “So far this has actually only been looked at with little samples from Doppler surveys, which normally have discovered giant worlds even more far from these red dwarf stars. Till now we have actually not had a large adequate sample of worlds to find close-in gas worlds in a robust way.”
There are still inexplicable secrets surrounding TOI-3757 b, the big one being how a gas-giant world can form around a red dwarf star, and specifically such a low-density planet. Kanodias team, however, believes they may have an option to that secret.
From the ground of the Kitt Peak National Observatory (KPNO), a Program of NSFs NOIRLab, the Wisconsin-Indiana-Yale-NOIRLab (WIYN) 3.5-meter Telescope seemingly considers the Milky Way as it spills from the horizon. KPNO is located in the Arizona-Sonoran Desert on the Tohono Oodham Nation and this clear view of part of the Milky Ways galactic airplane shows the beneficial conditions in this environment that are required to see faint celestial objects. These conditions, which include low levels of light pollution, a sky darker than a magnitude of 20, and dry climatic conditions, have allowed scientists in the WIYN Consortium to pursue observations of galaxies, nebulas, and exoplanets as well as many other astronomical targets using the WIYN 3.5-meter Telescope and its brother or sister telescope the WIYN 0.9-meter Telescope.
They propose that the extra-low density of TOI-3757 b might be the result of two factors. The very first relates to the rocky core of the planet; gas giants are thought to start as massive rocky cores about 10 times the mass of Earth, at which point they rapidly draw in large amounts of neighboring gas to form the gas giants we see today. TOI-3757bs star has a lower abundance of heavy aspects compared to other M-dwarfs with gas giants, and this may have resulted in the rocky core forming more gradually, delaying the start of gas accretion and therefore impacting the worlds total density.
The 2nd element might be the worlds orbit, which is tentatively thought to be somewhat elliptical. There are times it gets closer to its star than at other times, leading to considerable excess heating that can trigger the worlds environment to bloat.
NASAs Transiting Exoplanet Survey Satellite (TESS) initially found the world. Kanodias team then made follow-up observations utilizing ground-based instruments, consisting of NEID and NESSI (NN-EXPLORE Exoplanet Stellar Speckle Imager), both housed at the WIYN 3.5-meter Telescope; the Habitable-zone Planet Finder (HPF) on the Hobby-Eberly Telescope; and the Red Buttes Observatory (RBO) in Wyoming.
TESS surveyed the crossing of this world TOI-3757 b in front of its star, which enabled astronomers to determine the planets size to be about 150,000 kilometers (100,000 miles) or about just slightly larger than that of Jupiter. The world finishes one complete orbit around its host star in just 3.5 days, 25 times less than the closest planet in our Solar System– Mercury– which takes about 88 days to do so.
The astronomers then utilized NEID and HPF to determine the stars apparent motion along the line of sight, likewise called its radial velocity. These measurements provided the planets mass, which was computed to be about one-quarter that of Jupiter, or about 85 times the mass of the Earth. Knowing the size and the mass allowed Kanodias group to compute TOI-3757 bs typical density as being 0.27 grams per cubic centimeter (about 17 grams per cubic feet), which would make it less than half the density of Saturn (the lowest-density planet in the Solar System), about one quarter the density of water (meaning it would drift if positioned in a giant tub filled with water), or in fact, comparable in density to a marshmallow.
” Potential future observations of the environment of this world utilizing NASAs new James Webb Space Telescope could help shed light on its puffy nature,” states Jessica Libby-Roberts, a postdoctoral scientist at Pennsylvania State University and the second author on this paper.
” Finding more such systems with huge worlds– which were as soon as thought to be exceptionally uncommon around red overshadows– is part of our goal to understand how planets form,” says Kanodia.
The discovery highlights the value of NEID in its ability to confirm a few of the candidate exoplanets currently being discovered by NASAs TESS mission, offering crucial targets for the brand-new James Webb Space Telescope (JWST) to act on and begin identifying their atmospheres. This will in turn notify astronomers what the planets are made of and how they formed and, for possibly habitable rocky worlds, whether they might be able to support life.
Reference: “TOI-3757 b: A low-density gas giant orbiting a solar-metallicity M dwarf” by Shubham Kanodia, Jessica Libby-Roberts, Caleb I. Cañas, Joe P. Ninan, Suvrath Mahadevan, Gudmundur Stefansson, Andrea S. J. Lin, Sinclaire Jones, Andrew Monson, Brock A. Parker, Henry A. Kobulnicky, Tera N. Swaby, Luke Powers, Corey Beard, Chad F. Bender, Cullen H. Blake, William D. Cochran, Jiayin Dong, Scott A. Diddams, Connor Fredrick, Arvind F. Gupta, Samuel Halverson, Fred Hearty, Sarah E. Logsdon, Andrew J. Metcalf, Michael W. McElwain, Caroline Morley, Jayadev Rajagopal, Lawrence W. Ramsey, Paul Robertson, Arpita Roy, Christian Schwab, Ryan C. Terrien, John Wisniewski and Jason T. Wright, 5 August 2022, The Astronomical Journal.DOI: 10.3847/ 1538-3881/ ac7c20.

Red dwarf stars are the tiniest and dimmest members of so-called main-sequence stars– stars that transform hydrogen into helium in their cores at a stable rate. They are “cool” compared to stars like our Sun, red dwarf stars can be very active and erupt with effective flares. This can remove orbiting worlds of their environments, making this galaxy a relatively inhospitable area to form such a gossamer world.

Artist impression of an ultra fluffy gas giant world orbiting a red dwarf star. The world, named TOI-3757 b, is the fluffiest gas giant world ever found around this type of star. ZamaniKitt Peak National Observatory telescope assists identifies that Jupiter-like Planet is the lowest-density gas giant ever detected around a red dwarf.
A gas giant exoplanet with the density of a marshmallow has been found in orbit around a cool red dwarf star. A suite of huge instruments was used to make the observations, including the NASA-funded NEID radial-velocity instrument on the WIYN 3.5-meter Telescope at Kitt Peak National Observatory, a Program of NSFs NOIRLab. Called TOI-3757 b, the exoplanet is the fluffiest gas giant planet ever discovered around this type of star.
Utilizing the WIYN 3.5-meter Telescope at Kitt Peak National Observatory in Arizona, astronomers have observed an uncommon Jupiter-like planet in orbit around a cool red dwarf star. Found in the constellation of Auriga the Charioteer around 580 light-years from Earth, this world, identified as TOI-3757 b, is the lowest-density planet ever found around a red dwarf star and is estimated to have an average density comparable to that of a marshmallow.