Weird ‘Sub-Neptune’ Exoplanet Discovered by NASA (And It May Not Be Alone)

Using the first three months of publicly available data from NASA’s TESS mission, scientists have confirmed a new planet known as HD 21749b, a “sub-Neptune” three times bigger and 23 times more massive than Earth. HD 21749b lies about 53 light-years from Earth and orbits a star about the the size of the sun. (NASA/MIT/TESS)

NASA’s newest planet-hunting probe has bagged another alien world, the eighth confirmed find for the young mission.

The Transiting Exoplanet Survey Satellite (TESS) has discovered a planet orbiting the star HD 21749, which lies about 53 light-years from Earth in the faint constellation Reticulum, scientists announced today (Jan. 7).

The world, known as HD 21749b, is a weirdo, at least by the standards of our own solar system. It’s a “sub-Neptune” about three times bigger than Earth, which means it’s likely gaseous rather than rocky. But HD 21749b is made of denser stuff than the gaseous worlds we’re used to, because it’s 23 times more massive than Earth. [NASA’s TESS Exoplanet-Hunting Mission in Pictures]


Recommended PRODUCTS
  • Discover One Weird Trick That Forces Your Body To Eliminate Hemorrhoids In 48 Hours
  • Learn How to get lean in 21 days and stay that way forever...
  • Are you frustrated that your expensive karoke player does not let you play.
  • Become A Certified Usui Reiki Healing Master With The Latest Reiki Certification Program.
  • The scientifically proven way of adding inches of real height at any age.
  • Learn How To Attract the Man of Your Dreams And Receive A Marriage Proposal In Few Months
  • Quickly cure your acid reflux and enjoy permanent freedom from heartburn
  • Discover The Weird Trick That Reversed The Cellulite Of A 59 Year Old Mother of 3
  • Know how to eliminate bacterial vaginosis forever in 72 hour.
  • Discover How To Add 20lbs To Your Bench Press, 15lbs To Deadlift, And 20lbs To Your Squat In 3 Months
  • Quickly Cure Panic Attacks And Anxiety In Less Than 60 Seconds - Guaranteed
  • Discovered The Secret To Get Dirt Cheap Lumber and Power Tools For Your Woodworking Projects.
  • Discover How Your Beliefs and Emotions Affect Your Ability To Achieve All Your Goals And Dreams.
  • Dont Let Social Anxiety Control Your Life Any Longer. Start Living.
  • Find the 7 shocking secrets I discovered after starting 5 blogs and raking-in 35,000
  • Clickbank Ads
     

    “We think this planet wouldn’t be as gaseous as Neptune or Uranus, which are mostly hydrogen and really puffy,” discovery team leader Diana Dragomir, a postdoctoral researcher at the Massachusetts Institute of Technology’s Kavli Institute for Astrophysics and Space Research, said in a statement. “The planet likely has a density of water, or a thick atmosphere.”

    HD 21749b completes one orbit of its host star, which is nearly as bright as our sun, every 36 Earth days. The exoplanet likely has an average surface temperature around 300 degrees Fahrenheit (150 degrees Celsius), discovery team members said.

    The researchers also detected hints of another, smaller planet in the system, a planet that would have an orbital period of 7.8 days. If this world is confirmed, it will be the first roughly Earth-size planet found by TESS.

    TESS launched to Earth orbit in April 2018 on a mission to find alien worlds circling stars in our solar system’s neighborhood. Like NASA’s recently deceased Kepler space telescope, which is responsible for about 70 percent of all known exoplanet discoveries to date, TESS uses the “transit method.” That is, it looks for tiny dips in starlight caused when planets cross their host stars’ faces from the satellite’s perspective.

    TESS does this work by carving the sky up into overlapping sectors, studying each one for 27 days at a time. The satellite will cover virtually the entire sky by the end of its two-year prime mission. (During its main mission, by contrast, Kepler stared continuously at the same small patch of sky, monitoring the brightness of about 150,000 relatively distant stars simultaneously.)

    This shifting focus makes it tough for TESS to find planets that lie far from their host stars and therefore take a long time to complete one orbit. Indeed, HD 21749b is very far-flung for TESS; two other smallish worlds found by the mission have orbital periods of 11 hours and 6.3 days, respectively.

    “It’s the coolest small planet that we know of around a star this bright,” Dragomir said.

    “We know a lot about atmospheres of hot planets, but because it’s very hard to find small planets that orbit farther from their stars and are therefore cooler, we haven’t been able to learn much about these smaller, cooler planets,” she added. “But here, we were lucky and caught this one and can now study it in more detail.” [The Strangest Alien Planets (Gallery)]

    The team initially spotted an intriguing signal from the HD 21749 system in TESS’s “sector 1” data. It was unclear whether this signal was caused by a planet or variations in the host star’s activity, so Dragomir and her colleagues analyzed observations taken by another instrument, the High Accuracy Radial velocity Planet Searcher (HARPS), a spectrograph installed on a telescope at the European Southern Observatory’s La Silla Observatory in Chile.

    A different group of astronomers had studied the HD 21749 system a decade ago using HARPS, which finds planets by noticing the tiny wobbles that their gravitational tugs induce in their host stars. Those researchers had also detected a signal, but they couldn’t conclusively attribute it to a planet, Dragomir said.

    In the HARPS data, she and her team found that the HD 21749 signal repeats every 36 days. They determined that they should be able to find the signal again, in TESS’s “sector 3” data — which they succeeded in doing. (The TESS data analyzed by the team was gathered from July 25 through Oct. 14 of last year.)

    Dragomir and her team also used observations made by the Planet Finder Spectrograph, which is installed on the Magellan II Telescope in Chile, to confirm the discovery and help nail down HD 21749b’s mass and orbital parameters.

    “There was quite some detective work involved, and the right people were there at the right time,” Dragomir said. “But we were lucky and we caught the signals, and they were really clear.”

    The researchers announced the find today at the 233rd meeting of the American Astronomical Society in Seattle. They have also submitted their discovery paper to Astrophysical Journal Letters.

    TESS is just getting started. The mission has already flagged several hundred planet candidates, and its confirmed finds will run into the thousands when all is said and done, NASA officials have said. And some of these worlds will be close enough to Earth for astronomers to study the planets using powerful instruments, such as NASA’s $8.9 billion James Webb Space Telescope, which is scheduled to launch in 2021.

    Originally published on Space.com.

    Original Article : HERE ; This post was curated & posted using : RealSpecific

     


    Recommended PRODUCTS
  • Discover One Weird Trick That Forces Your Body To Eliminate Hemorrhoids In 48 Hours
  • Learn How to get lean in 21 days and stay that way forever...
  • Are you frustrated that your expensive karoke player does not let you play.
  • The toxic food ingredient daily reveals 3 newly discovered toxic food ingredients.
  • Learn how you can easily create mobile apps to generate passive income.
  • Reveals 1 Unusual Tip To Eliminate Excessive Sweating Forever In 48 Hours
  • Latest restaurant management information and restaurant marketing ideas for owners and managers
  • Quickly Cure Panic Attacks And Anxiety In Less Than 60 Seconds - Guaranteed
  • Discover The Practical, Tested Advice To Overcome Shyness Or Social Anxiety From Your Life
  • It attacks the root cause of your problem - something no other 'all-natural' ED cure does.
  • The Best RSS Autoblog Tool For Blogger Blogspot Blog.
  • A Truly Unique Extract Of The Greatest Methodologies For Keeping The Body And Mind Young And Agile.
  • The most important secret ever discovered for making women approach you and flirt with you.
  • Melt Away Manboobs And Replaces Them With A Flat, Sculpted Chest
  • The Latest Boat Design Software Start building your dream Boat In 5 Mins
  • Clickbank Ads
     

    Thank you for taking the time to read our article.

    If you enjoyed our content, we'd really appreciate some "love" with a share or two.

    And ... Don't forget to have fun!

    Recommended

    Moto Theme V2 Single Site

    Create Absolutely Any Type of Profit-Making Marketing Page in under 5 Minutes, By Using The World’s Best WordPress Marketing Theme!

    Socifeed AGENCY

    Socifeed AGENCY ONE-TIME - Developer, Agency, Outsourcer and Virtual Assistant License PLUS... MORE AUTOMATION. One-Time Launch Special Price Today! Increases To $497.00!

    Engage Shops - White Label - Unlimited

    Monetize Any Instagram Feed On The Web

    Leave a Reply