Space and astronomy news
Astronomers have found plenty of white dwarf stars surrounded by debris disks. Those disks are the remains of planets destroyed by the star as it evolved. But they’ve found one intact Jupiter-mass planet orbiting a white dwarf.
Are there more white dwarf planets? Can terrestrial, Earth-like planets exist around white dwarfs?
Continue reading “White Dwarfs Could Support Life. So Where are All Their Planets?”
Debris disks are quite common in the Universe. Young stars have protoplanetary disks from which planets form. Black holes have accretion disks that are the source of the galactic jets. Supernova remnants can form a disk around neutron stars. So what about white dwarfs?
Continue reading “JWST Looks at the Debris Disc Around a White Dwarf”
One of the things astronomers would love to see is planets forming around other stars. That would help us understand our own Solar System better. But it all happens behind a veil of obscuring dust. The James Webb Space Telescope has the power to see through the veil.
A team of astronomers pointed the JWST at the well-known star Fomalhaut and its dusty debris disk. They found more complexity than they imagined, including hints of planets forming among all that dust and debris.
Continue reading “Webb Examined an Asteroid Belt and Found More Than it Bargained For”
According to the most widely-accepted theory, planetary systems form from large clouds of dust and gas that form disks around young stars. Over time, these disks accrete to create planets of varying size, composition, and distance from their parent star. In the past few decades, observations in the mid- and far-infrared wavelengths have led to the discovery of debris disks around young stars (less than 100 million years old). This has allowed astronomers to study planetary systems in their early history, providing new insight into how systems form and evolve.
This includes the SpHere INfrared survey for Exoplanets (SHINE) consortium, an international team of astronomers dedicated to studying star systems in formation. Using the ESO’s Very Large Telescope (VLT), the SHINE collaboration recently directly imaged and characterized the debris disk of a nearby star (HD 114082) in visible and infrared wavelengths. Combined with data from NASA’s Transiting Exoplanet Space Satellite (TESS), they were able to detect a gas giant many times the size of Jupiter (a “Super-Jupiter”) embedded within the disk.
Continue reading “Astronomers Directly Image Debris Disk and find a Jupiter-Sized Planet Orbiting a Sunlike Star”
Over the next decade, several very powerful telescopes will come online. Observing time on these ‘scopes will be in high demand, and their range of targets will span a whole host of topics in astronomy, astrophysics, and cosomology.
One of the topics near the top of the list is exoplanets.
But how will astronomers know where to spend their precious exoplanet observing time?
Continue reading “Another Collection of Newly Forming Planetary Systems. This Time from the Gemini Planet Imager”
The history of our Solar System is punctuated with collisions. Collisions helped create the terrestrial planets and end the reign of the dinosaurs. And a massive collision between Earth and an ancient body named Theia likely created the Moon.
Now astronomers have found of evidence of a collision between two exoplanets in a distant solar system.
Continue reading “Astronomers See the Wreckage from a Collision Between Exoplanets”
When stars like our Sun exhaust their hydrogen fuel, they enter what is known as their Red-Giant-Branch (RGB) phase. This is characterized by the star expanding to several times it original size, after which they shed their outer layers and become compact white dwarfs. Over the next few billion years, it is believed that these stars will slowly consume any objects and dust rings still close enough to be influenced by their gravity.
However, a citizen scientist named Melina Thévenot recently made a surprising discovery when observing a white dwarf system. Based on data from the Wide-field Infrared Survey Explorer (WISE) mission, this star has been a white dwarf for billions of years, but still has multiple rings of dust around it. Known as LSPM J0207+3331 (or J0207), this discovery could force researchers to reconsider models of planetary systems.
Continue reading “The Oldest and Coldest White Dwarf Ever Found has Bizarre Dust Rings Around it”
KIC 8462852 (aka. Tabby’s Star) captured the world’s attention back in September of 2015 when it was found to be experiencing a mysterious drop in brightness. A week ago (on May 18th), it was announced that the star was at it again, which prompted observatories from all around the world to train their telescopes on the star so they could observe the dimming as it happened.
And just like before, this mysterious behavior has fueled speculation as to what could be causing it. Previously, ideas ranged from transiting comets and a consumed planet to alien megastructures. But with the latest studies to be produced on the subject, the light curve of the star has been respectively attributed to the presence of a debris disk and Trojan asteroids in the system and a ring system in the outer Solar System. Continue reading “New Ideas for the Mysterious Tabby’s Star: a Gigantic Planet or a Planet With Rings”
A team using the Hubble Space Telescope has imaged circumstellar disk structures (CDSs) around three stars similar to our Sun. The stars are all G-type solar analogs, and the disks themselves share similarities with our Solar System’s own Kuiper Belt. Studying these CDSs will help us better understand their ring-like structure, and the formation of solar systems.
The team behind the study was led by Glenn Schneider of the Seward Observatory at the University of Arizona. They used the Hubble’s Space Telescope Imaging Spectrograph to capture the images. The stars in the study are HD 207917, HD 207129, and HD 202628.
Theoretical models of circumstellar disk dynamics suggest the presence of CDSs. Direct observation confirms their presence, though not many of these disks are within observational range. These new deep images of three solar analog CDSs are important. Studying the structure of these rings should lead to a better understanding of the formation of solar systems themselves.
Debris disks like these are separate from protoplanetary disks. Protoplanetary disks are a mixture of both gas and dust which exist around younger stars. They are the source material out of which planetesimals form. Those planetesimals then become planets.
Protoplanetary disks are much shorter-lived than CDSs. Whatever material is left over after planet formation is typically expelled from the host solar system by the star’s radiation pressure.
In circumstellar debris disks like the ones imaged in this study, the solar system is older, and the planets have already formed. CDSs like these have lasted this long by replenishing themselves. Collisions between larger bodies in the solar system create more debris. The resulting debris is continually ground down to smaller sizes by repeated collisions.
This process requires gravitational perturbation, either from planets in the system, or by binary stars. In fact, the presence of a CDSs is a strong hint that the solar system contains terrestrial planets.
The three disks in this study were viewed at intermediate inclinations. They scatter starlight, and are more easily observed than edge-on disks. Each of the three circumstellar disk structures possess “ring-like components that are more massive analogs of our solar system’s Edgeworth–Kuiper Belt,” according to the study.
The study authors expect that the images of these three disk structures will be studied in more detail, both by themselves and by others in future research. They also say that the James Webb Space Telescope will be a powerful tool for examining CDSs.
Read more: It’s Complicated: Hubble Survey Finds Unexpected Diversity in Dusty Discs Around Nearby Stars
Growing up, my sister played video games and I read books. Now that she has a one-year-old daughter we constantly argue over how her little girl should spend her time. Should she read books in order to increase her vocabulary and stretch her imagination? Or should she play video games in order to strengthen her hand-eye coordination and train her mind to find patterns?
I like to believe that I did so well in school because of my initial unadorned love for books. But I might be about to lose that argument as gamers prove their value in science and more specifically astronomy.
Take a quick look through Zooniverse and you’ll be amazed by the number of Citizen Science projects. You can explore the surface of the moon in Moon Zoo, determine how galaxies form in Galaxy Zoo and search for Earth-like planets in Planet Hunters.
In 2011 two citizen scientists made big news when they discovered two exoplanet candidates — demonstrating that human pattern recognition can easily compliment the powerful computer algorithms created by the Kepler team.
But now we’re introducing yet another Citizen Science project: Disk Detective.
Planets form and grow within dusty circling planes of gas that surround young stars. However, there are many outstanding questions and details within this process that still elude us. The best way to better understand how planets form is to directly image nearby planetary nurseries. But first we have to find them.
“Through Disk Detective, volunteers will help the astronomical community discover new planetary nurseries that will become future targets for NASA’s Hubble Space Telescope and its successor, the James Webb Space Telescope,” said the chief scientist for NASA Goddard’s Sciences and Exploration Directorate, James Garvin, in a press release.
NASA’s Wide-field Infrared Survey Explorer (WISE) scanned the entire sky at infrared wavelengths for a year. It took detailed measurements of more than 745 million objects.
Astronomers have used complex computer algorithms to search this vast amount of data for objects that glow bright in the infrared. But now they’re calling on your help. Not only do planetary nurseries glow in the infrared but so do galaxies, interstellar dust clouds and asteroids.
While there’s likely to be thousands of planetary nurseries glowing bright in the data, we have to separate them from everything else. And the only way to do this is to inspect every single image by eye — a monumental challenge for any astronomer — hence the invention of Disk Detective.
Brief animations allow the user to help classify the object based on relatively simple criteria, such as whether or not the object is round or if there are multiple objects.
“Disk Detective’s simple and engaging interface allows volunteers from all over the world to participate in cutting-edge astronomy research that wouldn’t even be possible without their efforts,” said Laura Whyte, director of Citizen Science at the Adler Planetarium in Chicago, Ill.
The project is hoping to find two types of developing planetary environments, distinguished by their age. The first, known as a young stellar object disk is, well, young. It’s less than 5 million years old and contains large quantities of gas. The second, known as a debris disk, is older than 5 million years. It contains no gas but instead belts of rocky or icy debris similar to our very own asteroid and Kupier belts.
So what are you waiting for? Head to Disk Detective and help astronomers understand how complex worlds form in dusty disks of gas. The book will be there when you get back.
The original press release may be found here.