Space and astronomy news
![An artist's conception of a brown dwarf. A new study identifies CK Vulpeculae as the remnant of a collison between a brown dwarf and a white dwarf. Image: By NASA/JPL-Caltech (http://planetquest.jpl.nasa.gov/image/114) [Public domain], via Wikimedia Commons](https://www.universetoday.com/wp-content/uploads/2018/10/Artist’s_conception_of_a_brown_dwarf_like_2MASSJ22282889-431026-2000x1200.jpg)
The only thing worse than drifting through space for an eternity is doing it alone. Observations with the Hubble Space Telescope show that brown dwarfs that once had companions suffer that fate. Binary brown dwarfs that were once bound to each other tend to drift apart as time passes.
Continue reading “Brown Dwarf Pairs Drift Apart in Old Age”
What are the atmospheric compositions of cold brown dwarf stars? This is what a recent study published in The Astronomical Journal hopes to address as an international team of researchers used NASA’s James Webb Space Telescope (JWST) to investigate the coldest known brown dwarf star, WISE J085510.83?071442.5 (WISE 0855). This study holds the potential to help astronomers better understand the compositions of brown dwarf stars, which are also known as “failed stars” since while they form like other stars, they fail to reach the necessary mass to produce nuclear fusion. So, what was the motivation behind using JWST to examine the coldest known brown dwarf star?
Continue reading “Brrr. JWST Looks at the Coldest Brown Dwarf”
Astronomers have used JWST to find a brown dwarf with polar auroras like the Earth, or Jupiter. This is surprising because the brown dwarf, dubbed W1935, is a free-floating object, meaning it isn’t part of another star system. Therefore, there’s no solar wind available to generate any Northern Lights. Instead, the auroras are seemingly generated from methane emissions in the planet’s atmosphere, interacting with the interstellar plasma. Another theory is that it perhaps has an active but unseen moon contributing to the emissions.
Continue reading “A Solo Brown Dwarf Found With Auroras”
When you launch humanity’s most powerful telescope, you expect results. The JWST has delivered excellent results by detecting ancient galaxies, identifying chemicals in exoplanet atmospheres, and peering into star-forming regions with more detail and clarity than any other telescope.
But every time a new telescope is about to enter service, astronomers tell us they’re excited not only about the expected results but also about the surprising results. And like other telescopes, the JWST has also delivered some surprises. While going about its business, the JWST has discovered 21 brown dwarfs.
Continue reading “JWST Accidentally Found 21 Brown Dwarfs”
Astronomers have discovered an intense binary star system located about 1,400 light years away. It contains a brown dwarf with 80 times the mass of Jupiter which is bound closely with an incredibly hot white dwarf star. Observations have shown the brown dwarf is tidally locked to the white dwarf, allowing the daytime surface temperatures on the brown dwarf to reach 8,000 Kelvin (7,700 Celsius, 14,000 Fahrenheit) — which is much hotter than the surface of the Sun, which is about 5,700 K (5,427 C, 9,800 F). The brown dwarf’s nightside, on the other hand, is about 6,000 degrees K cooler.
Continue reading “This Brown Dwarf is 2,000 Degrees Hotter Than the Sun”
Nuclear fusion is what separates stars from planets. Stars are massive enough to fuse hydrogen in their cores, while planets are not. But in between these two categories are brown dwarfs, which are massive enough to experience some nuclear fusion, just not hydrogen. The largest of them are hot and star-like. The smallest of them are barely warm enough to bake a pizza.
Continue reading “Your Oven Gets Hotter Than This Star”
In 1958, the first satellites launched by the United States (Explorer 1 and 3) detected a massive radiation belt around planet Earth. This confirmed something that many scientists suspected before the Space Age began: that energetic particles emanating from the Sun (solar wind) were captured and held around the planet by Earth’s magnetosphere. This region was named the Van Allen Belt in honor of University of Iowa professor James Van Allen who led the research effort. As robotic missions explored more of the Solar System, scientists discovered similar radiation belts around Jupiter, Saturn, Uranus, and Neptune.
Given the boom in extrasolar planet research, scientists have eagerly awaited the day when a Van Allen Belt would be discovered around an exoplanet. Thanks to a team of astronomers led by the University of California, Santa Cruz (UCSC) and the National Radio Astronomy Observatory (NRAO), that day may have arrived! Using the global High Sensitivity Array (HSA), the team obtained images of persistent, intense radio emissions from an ultracool dwarf star. These revealed the presence of a cloud of high-energy particles forming a massive radiation belt similar to what scientists have observed around Jupiter.
Continue reading “An Astronomical First! A Radiation Belt Seen Outside the Solar System”
The Universe is over 13 billion years old, so a 12-year slice of that time might seem uneventful. But a timelapse movie from NASA shows how much can change in just over a decade. Stars pulse, asteroids follow their trajectories, and distant black holes flare as they pull gas and dust toward themselves.
Continue reading “NASA Provides a Timelapse Movie Showing How the Universe Changed Over 12 Years”
In its first few months of operation, the James Webb Space Telescope (JWST) is already proving that it was well worth the wait! To date, it has provided astronomers with the most detailed and precise images of the cosmos, conducted observations of iconic galaxies and nebulae, peered to the very edge of the Universe, and obtained spectra from distant exoplanets. These resulting images, made public through the JWST Early Release Science (ERS) program, have provided a good cross-section of what this next-generation observatory can do.
Among its many objectives, the JWST will provide valuable insights into the formation and evolution of exoplanet systems through direct imaging. Using data from the ERS, an international team of astronomers and astrophysicists conducted a direct imaging study of a brown dwarf companion (VHS 1256-1257 b) orbiting within a triple brown dwarf system approximately 69.0 light-years away. The spectra they obtained from this body provided a detailed composition of its atmosphere, which included an unexpected find – clouds made of silicate minerals (aka. sand)!
Continue reading “Webb Scans a Nearby Brown Dwarf and Finds it has Clouds Made of Sand”
Astronomers have a brown dwarf problem. They should be seeing a lot more of these objects, which are cooler than stars but hotter than planets. Yet, there have only been about 40 directly imaged over the past few decades. Why aren’t astronomers finding more of them? It helps to remember that brown dwarfs are dim, low-temperature objects. They don’t stand out in a crowded starfield. If they’re too close to their stars, the starlight hides them from our view. They’re much better observed in the infrared part of the electromagnetic spectrum. All these characteristics make hunting for them difficult.
Continue reading “A New Technique Finds a Bundle of Brown Dwarfs”