Sometimes, its our closest neighbors that are the most difficult to spy on. Case in point: The Luhman 16 AB system, which is the third-closest stellar system to our Sun, yet was not discovered until 2013. After three years of subsequent monitoring, a stack of 12 images taken with the Hubble Space Telescope (HST) has confirmed that the system is composed of two brown dwarfs and no third companion, as was originally suspected.
A team of astronomers led by Luigi Bedin watched the two visible stars, Luhman 16 A and Luhman 16 B, over the course of three years between August 22, 2014, and October 4, 2016. During this time, HST has imaged the system 12 times (with a thirteenth proposed visit in August 2018). Using these images, they were able to determine several orbital parameters of the stars, as well as more accurately measure their distance and search for any potential exoplanets in the system. Their results have been accepted for publication in the Monthly Notices of the Royal Astronomical Society.
Bedin and his team used their sequence of Hubble images to watch the two brown dwarfs dance across the sky. In particular, they were looking for a third potential body in the system, such as a large exoplanet, which had been indicated by the stars motion in previous observations with the European Southern Observatory's Very Large Telescope. However, according to Bedins group, the new Hubble measurements rule out the presence of a third body in the system, all the way down to planets of Neptunes mass with a period between one and two years. Thus, if the system does harbor exoplanets, they must be smaller than Neptune and take longer than one to two Earth years to circle their sun.
Brown dwarfs are often called failed stars because they are too small to sustain the fusion processes that create energy inside stars. While these bodies can sometimes fuse a hydrogen isotope known as deuterium, even this phase doesnt last very long, relatively speaking, leaving the star to essentially cool off over cosmic time and grow dark.
However, astronomers know that there are many more low-mass objects in the universe than high-mass ones. Thus, because of their increased number, these lower-mass objects are an extremely fertile place to look for exoplanets.
Luhman A and B circle each other once every two to four decades, with a distance between them of about 3 astronomical units (three times the distance between the Sun and Earth). The system itself is located within about 2 parsecs of the Sun, or 6.5 light-years. Only the Alpha Centauri system and Barnard's Star are closer.
Because the Luhman 16 AB system is so close to the Sun, its the perfect place to study brown dwarfs, which are hard to see because theyre both small and dim, up close. Bedins team plans to continue their study of the stars to both improve the precision of their measured orbital parameters and to search for ever-smaller, Earth-sized exoplanets in the system.
Read the rest here:
Hubble spies on nearby brown dwarfs - Astronomy Magazine
- I Spy With My Little Eye… - November 7th, 2009 [November 7th, 2009]
- A Crack Opens in the Ethiopian Landscape, Preparing the Way for a New Sea | 80beats - November 8th, 2009 [November 8th, 2009]
- The Politics of Addiction | The Intersection - November 8th, 2009 [November 8th, 2009]
- Finally! An iPhone App That Lets You Track Your Bathroom Habits | Discoblog - November 8th, 2009 [November 8th, 2009]
- Don’t Pack Your Bags Yet—New Planet-Finder Hobbled by Electronic Glitch | 80beats - November 8th, 2009 [November 8th, 2009]
- In Controversial Scent Lineups, a Dog’s Nose Picks Out the Perp | 80beats - November 8th, 2009 [November 8th, 2009]
- Are You a Cognitive Miser? | Cosmic Variance - November 8th, 2009 [November 8th, 2009]
- The Secret Lives and Loves of Great White Sharks | 80beats - November 8th, 2009 [November 8th, 2009]
- Britain’s New Protected Minority: Tree-Huggers | Discoblog - November 8th, 2009 [November 8th, 2009]
- Inspired by Maple Seeds, a Robotic Whirligig Takes To The Skies | Discoblog - November 8th, 2009 [November 8th, 2009]
- New Statesman on Accommodationism | The Intersection - November 8th, 2009 [November 8th, 2009]
- Laser-Powered Robot Climbs to Victory in the Space-Elevator Contest | 80beats - November 8th, 2009 [November 8th, 2009]
- Checking Back In With SEAPLEX | The Intersection - November 8th, 2009 [November 8th, 2009]
- Podcast: An Embarrassment of Genomes | The Loom - November 8th, 2009 [November 8th, 2009]
- A Baby Neutron Star, Swaddled in a Carbon Atmosphere | 80beats - November 8th, 2009 [November 8th, 2009]
- Butterfliiiies… iiinnnn… SPPPAAAAACCCCEEEEE! | Bad Astronomy - November 8th, 2009 [November 8th, 2009]
- My Slate Dialogue with Michael Specter Begins | The Intersection - November 8th, 2009 [November 8th, 2009]
- Musical, Fahrvergnügen-Inspired Staircase Makes Commuters Less Lazy | Discoblog - November 8th, 2009 [November 8th, 2009]
- Laser-Etched Fruit Is an Answer in Search of a Problem | Discoblog - November 8th, 2009 [November 8th, 2009]
- Ares and the carnivals | Bad Astronomy - November 8th, 2009 [November 8th, 2009]
- Toddler Gets a Telescoping, Prosthetic Arm Bone That Grows With Him | 80beats - November 8th, 2009 [November 8th, 2009]
- Neutered HIV Virus Delivers Treatment to Fatally Ill Boys | 80beats - November 8th, 2009 [November 8th, 2009]
- Specter’s First Reply: Denialism Kills People | The Intersection - November 8th, 2009 [November 8th, 2009]
- LRO sees a Moonslide | Bad Astronomy - November 8th, 2009 [November 8th, 2009]
- Al Gore’s New Book: A Focus on Solutions | The Intersection - November 8th, 2009 [November 8th, 2009]
- The Universe Has Us in Its Crosshairs | Bad Astronomy - November 8th, 2009 [November 8th, 2009]
- Makers of Universes | Cosmic Variance - November 8th, 2009 [November 8th, 2009]
- Can Your Pet Catch & Spread Swine Flu? Yes, If Your Pet’s a Ferret | 80beats - November 8th, 2009 [November 8th, 2009]
- Droid 2.0 Vs iPhone | The Intersection - November 8th, 2009 [November 8th, 2009]
- Tangled Bank News: An Excerpt and More | The Loom - November 8th, 2009 [November 8th, 2009]
- LHC Shut Down By Wayward Baguette, Dropped by Bird Saboteur | Discoblog - November 8th, 2009 [November 8th, 2009]
- Careidolia | Bad Astronomy - November 8th, 2009 [November 8th, 2009]
- Slate Reply to Specter Up–We Need a National Dialogue on Synthetic Biology | The Intersection - November 8th, 2009 [November 8th, 2009]
- Pray this doesn’t get passed | Bad Astronomy - November 8th, 2009 [November 8th, 2009]
- You Can’t Make This Stuff Up | Cosmic Variance - November 8th, 2009 [November 8th, 2009]
- Mother Tongue, Indeed: Newborn’s Cries Mimic Mama’s Accent | 80beats - November 8th, 2009 [November 8th, 2009]
- Ripped From the Journals: The Biggest Discoveries of the Week | 80beats - November 8th, 2009 [November 8th, 2009]
- Alternative Landscapes | The Loom - November 8th, 2009 [November 8th, 2009]
- Can an iPhone App Decipher Your Baby’s Cries? | Discoblog - November 8th, 2009 [November 8th, 2009]
- Reminder: Carl Sagan Day | Bad Astronomy - November 8th, 2009 [November 8th, 2009]
- Are There Pesticides in Your Soup? Dunk a Pollution Dipstick to Find Out. | 80beats - November 8th, 2009 [November 8th, 2009]
- Log in and Join the Conference - November 8th, 2009 [November 8th, 2009]
- Conference Ends - November 8th, 2009 [November 8th, 2009]
- Conference Archive Opens - November 8th, 2009 [November 8th, 2009]
- Galaxy Zoo - November 8th, 2009 [November 8th, 2009]
- .Astronomy 2009 Dates - November 8th, 2009 [November 8th, 2009]
- .Astronomy 2009: Programme and venue details - November 8th, 2009 [November 8th, 2009]
- .Astronomy Gets Some IYA Love - November 8th, 2009 [November 8th, 2009]
- 2009 Posters and Imagery - November 8th, 2009 [November 8th, 2009]
- 2009 Sponsors - November 8th, 2009 [November 8th, 2009]
- When in Holland… - November 8th, 2009 [November 8th, 2009]
- The WHAT Cloud? - November 8th, 2009 [November 8th, 2009]
- The Jewel Box - November 8th, 2009 [November 8th, 2009]
- Happy Halloween! - November 8th, 2009 [November 8th, 2009]
- Ares 1-X Launch - November 8th, 2009 [November 8th, 2009]
- Confessions of an Alien Hunter - November 8th, 2009 [November 8th, 2009]
- LRO Spies Apollo 17 Site - November 8th, 2009 [November 8th, 2009]
- Mercury in Color - November 8th, 2009 [November 8th, 2009]
- Hubble and M83 - November 8th, 2009 [November 8th, 2009]
- Cassini Flyby of Enceladus - November 8th, 2009 [November 8th, 2009]
- Preserving A Moth [Science Tattoo] | The Loom - December 12th, 2009 [December 12th, 2009]
- Another Russian rocket spiral lights up the sky | Bad Astronomy - December 12th, 2009 [December 12th, 2009]
- A (Very Gentle) Riddle to Complete Your Saturday - December 12th, 2009 [December 12th, 2009]
- Darwin Gets Swine Flu: The YouTube Edition | The Loom - December 12th, 2009 [December 12th, 2009]
- Happy Slothy Holidays | The Loom - December 12th, 2009 [December 12th, 2009]
- Jetting to Copenhagen | The Intersection - December 12th, 2009 [December 12th, 2009]
- Michael Gerson Attempts Thoughtfulness on “ClimateGate,” Then Gives it Up | The Intersection - December 13th, 2009 [December 13th, 2009]
- Incredible VISTA of the cosmos | Bad Astronomy - December 13th, 2009 [December 13th, 2009]
- Bundle up Sunday Night to Watch the Geminid Meteor Shower | 80beats - December 13th, 2009 [December 13th, 2009]
- “ClimateGate” a PR Disaster That Will Be “Taught in University Communications Courses” | The Intersection - December 13th, 2009 [December 13th, 2009]
- Is Google the Guardian Angel of Rainforests? | 80beats - December 13th, 2009 [December 13th, 2009]
- La ciencia es importante. Una vez mas. | Bad Astronomy - December 13th, 2009 [December 13th, 2009]
- Sensenbrenner Pulls an Inhofe, Asserts Global Warming is an “International Conspiracy” | The Intersection - December 13th, 2009 [December 13th, 2009]
- Let Kids Eat Dirt: Over-Cleanliness Linked to Heart Disease | 80beats - December 13th, 2009 [December 13th, 2009]
- What Are The Best Science Papers Of The Past Decade? | The Intersection - December 13th, 2009 [December 13th, 2009]
- Finally! Math Shows How to Cut Evenly Sized Pizza Slices | Discoblog - December 13th, 2009 [December 13th, 2009]
- Half-baked math | Bad Astronomy - December 13th, 2009 [December 13th, 2009]
- Can “Biological Passports” Save Sports From Doping? | 80beats - December 13th, 2009 [December 13th, 2009]
- Aiiiieeee! Slow down! | Bad Astronomy - December 13th, 2009 [December 13th, 2009]
- Weekly News Roundup: Bad Headlines, Martian moons, and Rotating Houses | Discoblog - December 13th, 2009 [December 13th, 2009]