Astronomers have found another strange exoplanet in a distant solar system. This ones an oddball because its size is intermediate between Earth and Neptune, yet its 50% more massive than Neptune.
Astronomers have found what they call puff planets in other Solar Systems. Those are planets that are a few times more massive than Earth, but with radii much larger than Neptunes. But this planet is the opposite of that: its much more massive than Neptune, but it also has a much smaller radius. Super-dense, not super-puffy.
This oddball planet is calling into question our understanding of how planets form.
Astronomers with the National Science Foundation NOIRLab studied the planet and presented their findings in a paper titled The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b. Lead author is Gudmundur Stefansson, a postdoctoral fellow at Princeton University. The paper will be published in The Astronomical Journal and is available at arxiv.org.
The Kepler mission found the planet in 2016. It orbits K2-25, an M-dwarf star in the Hyades star cluster. K2-25b orbits its star every 3.5 days. According to this study, it has a mass of about 24.5 Earth masses, and a radius of about 3.4 Earth radii. In the intro to their study, the authors write that These properties are compatible with a rocky core enshrouded by a thin hydrogen-helium atmosphere (5% by mass).
The planet caught the interest of astronomers partly because its a sub-Neptune planet. A sub-Neptune can have either a mass larger than Neptunes along with a smaller radius, like this one, or it can be less massive than Neptune, but with a larger radius. Either way, sub-Neptunes conflict with our models of planet formation. Understanding how these types of planets form is a critical question right now, on the frontier of exoplanet science.
K2-25b is unusual, said lead researcher Gudmundur Stefansson, a postdoctoral fellow at Princeton University. The planet is dense for its size and age, in contrast to other young, sub-Neptune-sized planets that orbit close to their host star, said Stefansson in a press release. Usually these worlds are observed to have low densities and some even have extended evaporating atmospheres. K2-25b, with the measurements in hand, seems to have a dense core, either rocky or water-rich, with a thin envelope.
Astronomical models show that large planets form with a rocky core first. The initial mass for a core is modest, perhaps only 5 to 10 times more massive than the Earth itself. Then gas gathers around the core, creating a gaseous envelope thats hundreds of times more massive than Earth. The gas giant Jupiter likely formed this way.
But a planets like K2-25b seem to show that our understanding is incomplete. It appears to have an enormously massive rocky core, with very little gaseous envelope. Its unusual properties pose a couple questions: How did it end up with such a massive rocky core? And, since it has such a massive core, how come it doesnt have a large gaseous envelope?
While we dont fully understand how K2-25band other planets like itform, this planet is a sort of natural laboratory for studying them. Given its known age and well characterized orbital parameters, the authors write in their paper, K2-25b is a benchmark system to study M-dwarf planet formation and subsequent dynamics, giving us further insights into the formation and migration mechanisms that produce other hot Neptune exoplanets.
Given its large core, it shouldve acquired an enormous gaseous envelope. That fact that it didnt gives rise to several possibilities. One of those possibilities, the authors suggest, is that the rocky core formed through mergers. To explain its currently observed mass, we surmise that K2-25b could be the product of planet merging events of smaller planetary cores to produce a more massive planet.
That explanation also has the added benefit of accounting for the planets orbital eccentricity. They write: Such a dynamical environment could have excited K2-25b into an eccentric orbit, and K2-25b could be in the process of migrating to a shorter period orbit through tidal interactions with the host star.
Discoveries like this one are frequently the result of technological advances. Instruments like SPHERE, on the European Southern Observatorys (ESO) Very Large Telescope (VLT), are responsible for many recent discoveries. But in this case, the piece of technology that made it possible was a $500 off-the-shelf diffuser. Lead researcher Gudmundur Stefansson developed a way of using Engineered Diffusers in his doctoral thesis.
An Engineered Diffuser spreads out the light from a star so that it covers more pixels on the camera. That allows the brightness of the star during the planets transit to be measured more accurately, which results in a higher-precision measurement of the size of the orbiting planet, among other parameters. The innovative diffuser allowed us to better define the shape of the transit and thereby further constrain the size, density and composition of the planet, said Jayadev Rajagopal, an astronomer at NOIRLab who was also involved in the study.
K2-25b is posing some important questions for astronomers. Answers to these questions will have to wait, but maybe not for too long. K2-25b is a prime candidate for follow-up observations with the James Webb Space Telescope. The Webb will have powerful onboard coronagraphs which will block out the light of exo-suns, making it easier to see the orbiting planets. Itll also observe in infrared, something that itll excel at from its position at L2.
The Gemini South Telescopes GHOST (Gemini High Resolution Optical SpecTrograph) also has K2-25b on its list of targets. Its a spectrograph with a wide simultaneous wavelength coverage at high observational efficiency according to the website. Itll be very effective at observing the atmosphere of planets like this one.
More observations with GHOST and the JWST may not answer all the questions that K2-15b poses about planet formation. But they will expand the boundaries of what we do and dont know about it. In the mean-time, maybe more astronomers will come up with low-budget ways of addressing them.
The diffuser that made this study so effective was used with the WIYN 0.9-meter Telescope at Kitt Peak National Observatory (KPNO). The 3.5-meter telescope at Apache Point Observatory (APO) in New Mexico was also part of the study. The National Optical-Infrared Astronomy Research Laboratory(NOIRLab) includes the Gemini Observatory, the Kitt Peak Obsevatory, as well as several other facilities and the upcoming Vera C. Rubin Observatory.
Like Loading...
Read this article:
A Strange Planet has been Found thats Smaller than Neptune But 50% More Massive - Universe Today
- I Spy With My Little Eye… [Last Updated On: November 7th, 2009] [Originally Added On: November 7th, 2009]
- A Crack Opens in the Ethiopian Landscape, Preparing the Way for a New Sea | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Politics of Addiction | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Finally! An iPhone App That Lets You Track Your Bathroom Habits | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Don’t Pack Your Bags Yet—New Planet-Finder Hobbled by Electronic Glitch | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- In Controversial Scent Lineups, a Dog’s Nose Picks Out the Perp | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Are You a Cognitive Miser? | Cosmic Variance [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Secret Lives and Loves of Great White Sharks | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Britain’s New Protected Minority: Tree-Huggers | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Inspired by Maple Seeds, a Robotic Whirligig Takes To The Skies | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- New Statesman on Accommodationism | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Laser-Powered Robot Climbs to Victory in the Space-Elevator Contest | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Checking Back In With SEAPLEX | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Podcast: An Embarrassment of Genomes | The Loom [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- A Baby Neutron Star, Swaddled in a Carbon Atmosphere | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Butterfliiiies… iiinnnn… SPPPAAAAACCCCEEEEE! | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- My Slate Dialogue with Michael Specter Begins | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Musical, Fahrvergnügen-Inspired Staircase Makes Commuters Less Lazy | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Laser-Etched Fruit Is an Answer in Search of a Problem | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Ares and the carnivals | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Toddler Gets a Telescoping, Prosthetic Arm Bone That Grows With Him | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Neutered HIV Virus Delivers Treatment to Fatally Ill Boys | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Specter’s First Reply: Denialism Kills People | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- LRO sees a Moonslide | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Al Gore’s New Book: A Focus on Solutions | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Universe Has Us in Its Crosshairs | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Makers of Universes | Cosmic Variance [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Can Your Pet Catch & Spread Swine Flu? Yes, If Your Pet’s a Ferret | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Droid 2.0 Vs iPhone | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Tangled Bank News: An Excerpt and More | The Loom [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- LHC Shut Down By Wayward Baguette, Dropped by Bird Saboteur | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Careidolia | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Slate Reply to Specter Up–We Need a National Dialogue on Synthetic Biology | The Intersection [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Pray this doesn’t get passed | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- You Can’t Make This Stuff Up | Cosmic Variance [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Mother Tongue, Indeed: Newborn’s Cries Mimic Mama’s Accent | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Ripped From the Journals: The Biggest Discoveries of the Week | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Alternative Landscapes | The Loom [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Can an iPhone App Decipher Your Baby’s Cries? | Discoblog [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Reminder: Carl Sagan Day | Bad Astronomy [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Are There Pesticides in Your Soup? Dunk a Pollution Dipstick to Find Out. | 80beats [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Log in and Join the Conference [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Conference Ends [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Conference Archive Opens [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Galaxy Zoo [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- .Astronomy 2009 Dates [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- .Astronomy 2009: Programme and venue details [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- .Astronomy Gets Some IYA Love [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- 2009 Posters and Imagery [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- 2009 Sponsors [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- When in Holland… [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The WHAT Cloud? [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- The Jewel Box [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Happy Halloween! [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Ares 1-X Launch [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Confessions of an Alien Hunter [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- LRO Spies Apollo 17 Site [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Mercury in Color [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Hubble and M83 [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Cassini Flyby of Enceladus [Last Updated On: November 8th, 2009] [Originally Added On: November 8th, 2009]
- Preserving A Moth [Science Tattoo] | The Loom [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Another Russian rocket spiral lights up the sky | Bad Astronomy [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- A (Very Gentle) Riddle to Complete Your Saturday [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Darwin Gets Swine Flu: The YouTube Edition | The Loom [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Happy Slothy Holidays | The Loom [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Jetting to Copenhagen | The Intersection [Last Updated On: December 12th, 2009] [Originally Added On: December 12th, 2009]
- Michael Gerson Attempts Thoughtfulness on “ClimateGate,” Then Gives it Up | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Incredible VISTA of the cosmos | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Bundle up Sunday Night to Watch the Geminid Meteor Shower | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- “ClimateGate” a PR Disaster That Will Be “Taught in University Communications Courses” | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Is Google the Guardian Angel of Rainforests? | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- La ciencia es importante. Una vez mas. | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Sensenbrenner Pulls an Inhofe, Asserts Global Warming is an “International Conspiracy” | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Let Kids Eat Dirt: Over-Cleanliness Linked to Heart Disease | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- What Are The Best Science Papers Of The Past Decade? | The Intersection [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Finally! Math Shows How to Cut Evenly Sized Pizza Slices | Discoblog [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Half-baked math | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Can “Biological Passports” Save Sports From Doping? | 80beats [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Aiiiieeee! Slow down! | Bad Astronomy [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]
- Weekly News Roundup: Bad Headlines, Martian moons, and Rotating Houses | Discoblog [Last Updated On: December 13th, 2009] [Originally Added On: December 13th, 2009]