Universe Today (Page 29)

JWST Finds the Smallest Free-Floating Brown Dwarf Star formation is happening all around us in the Universe. However, there is still plenty we don’t know about it, including, as a recent press release points out, something that every astronomy textbook points out – we don’t know the size of the smallest star. Most current answers in those textbooks refer to an object known as a brown dwarf, a cross between a star and a giant planet. Recently, the James Webb Space Telescope (JWST) found what is believed to be the smallest brown dwarf ever discovered – and it weighs in at only 3-4 times theRead More →

Planets Orbiting Pulsars Should Have Strange and Beautiful Auroras. And We Could Detect Them We have been treated to some amazing aurora displays over recent months. The enigmatic lights are caused by charged particles from the Sun rushing across space and on arrival, causing the gas in the atmosphere to glow. Now researchers believe that even on exoplanets around pulsars we may just find aurora, and they may even be detectable.  Pulsars are the remains of super massive stars that have reached the end of their life. During most of a stars life, they synthesise heavier and heavier elements in their core, the outward forceRead More →

How Do Superflares Get So Powerful? We live with a star that sends out flares powerful enough to disrupt things here on Earth. Telecommunications, power grids, even life itself, are affected by strong solar activity. But, the Sun’s testy outbursts are almost nothing compared to the superflares emitted by other stars. Why do flares happen? And what’s going on at distant stars to ramp up the power of their flares? The answer sounds simple: it’s physics. Or, to be more accurate, solar and stellar physics. Essentially, a flare is a release of magnetic energy from an active region on a star. On the Sun, weRead More →

Solar Storms Could Cause Mayhem to Trains The rail service here in the UK is often the brunt of jokes. If it’s not the wrong type of rain, or the leaves are laying on the tracks the wrong way then it’s some other seemingly ludicrous reason that the trains are delayed, or even cancelled. A recent study by scientists at the University of Lancaster suggest that even the solar wind might cause train signals to be incorrectly triggered with potentially disastrous consequences. The solar wind has been responsible for numerous displays of northern lights over recent months. The fast moving electrically charged particles from theRead More →

We’ve Entered a New Era: The Lunar Anthropocene For almost half a century, the term “Anthropocene” has been informally used to describe the current geological epoch. The term acknowledges how human agency has become the most significant factor when it comes to changes in Earth’s geology, landscape, ecosystems, and climate. According to a new study by a team of geologists and anthropologists, this same term should be extended to the Moon in recognition of humanity’s exploration (starting in the mid-20th century) and the growing impact our activities will have on the Moon’s geology and the landscape in the near future. The study was conducted byRead More →

The Positions of Stars on an Ancient Navigation Device Tell us When it was Made Astrolabes serve two purposes. First, they are useful as an astronomical tool, especially for finding a ship’s latitude. But second, they are works of art in themselves. Besides having to be precise, many are beautiful. They are even seeing a resurgence in popularity as collectors lap up even those made by modern manufacturing processes because of their aesthetic appeal. Now, a new paper adds to their uses – a self-referential ability to mark what year they were made by the patterns of the stars they reference. Emmanuel Davoust is aRead More →

Three Baby Stars Found at the Heart of the Milky Way The core of our Milky Way is buzzing with stars. Recently astronomers reported that it contains at least one ancient star that formed outside our galaxy. Now, an international research team reports finding a grouping of very young ones there, as well. Their presence upends ideas about star birth in that densely packed region of space. These stellar youngsters live in a dense collection called the “nuclear star cluster” (NSC). It lies about 27,000 light-years away from us and surrounds the area holding the supermassive black hole Sagittarius A*. Observers have long considered theRead More →

Review: Unistellar’s eQuinox 2 Telescope and New Smart Solar Filter I recently had the chance to try out one of Unistellar’s smart telescopes, the eQuinox 2. Unparalleled in its ease of use, I was literally viewing distant nebula, galaxies, and star clusters within 15 minutes of opening the box. I also had the opportunity to try out Unistellar’s new Smart Solar Filter, which I’ll discuss more below. But first, more about the telescope itself: eQuinox 2 telescope. Credit: Unistellar. The eQuinox 2 is incredibly easy to set up and use, thanks to Unistellar’s phone or tablet app where you control the telescope. If you’ve everRead More →

Exomoons Defy Discovery For a long time, we wondered if other stars hosted planets like the Sun does. Finally, in the 1990s, we got our answer. Now, another question lingers. Most of the planets in our Solar System have moons. Do exoplanets have exomoons? Moons are the norm in our Solar System. Only Mercury and Venus, the two planets closest to the Sun, don’t have moons. Mercury is too small to maintain a hold on a moon so close to the Sun, and Venus may have had one in the past and then lost it. On the other end of the scale are our twoRead More →

Why Was it Tricky to Know the Distances to Galaxies JWST Was Seeing? One of the chief objectives of the James Webb Space Telescope (JWST) is to study the formation and evolution of the earliest galaxies in the Universe, which emerged more than 13 billion years ago. To this end, scientists must identify galaxies from different cosmological epochs to explore how their properties have changed over time. This, in turn, requires precise dating techniques so astronomers are able to determine when (in the history of the Universe) an observed galaxy existed. The key is to measure the object’s redshift, which indicates how long its lightRead More →

Psyche Gives Us Its First Images of Space NASA’s Psyche mission began eight weeks ago when it launched from the Kennedy Space Center. While it won’t reach its objective, the metal-rich asteroid Psyche, until 2029, the spacecraft has already travelled 26 million km (16 million miles.) During that time, it’s already had its share of success as it ticks off items on its checklist of tests. Now, we have our first images from Psyche. And while they don’t show us anything about its eventual target, they give us a behind-the-scenes look at how complex spacecraft prepare themselves as they cruise toward their destinations. When spacecraftRead More →

What Would a Modern “Golden Record” Include? Now that several decades have passed since the launch of Voyager 1 and Voyager 2 in 1977, we look back on that time with a hazy sense of history and what the event meant for humanity’s ongoing odyssey. While the Voyager spacecraft were sober scientific missions, they also carried with them a hint of the deeper yearnings that lie inside humanity’s heart: the Golden Records. The Voyager Golden Records were a message in a bottle to any other intelligent species out there that may stumble on them. While the odds are strongly stacked against that ever happening, theRead More →

Amateur Astronomers Found Planets Crashing Into Each Other Astronomy is one of the sciences where amateurs make regular contributions. Over the years, members of the public have made exciting discoveries and meaningful contributions to the scientific process, either through direct observing, citizen science projects, or through combing through open data from the various space missions. Recently, amateur astronomer Arttu Sainio saw a conversation on X (Twitter) where researchers were discussing the strange behavior of a dimming sun-like star. Intrigued, Arttu decided to look at the data on this star, called Asassn-21qj, on his own. Looking at archival data from NASA’s NEOWISE mission, Sainio was surprisedRead More →

Why 2023 is a Fine Year for the Geminid Meteors One of the best meteor showers of the year, the Geminids puts on a fine display in 2023. December has one more sky watching treat in store for 2023. If skies are clear, watch for what’s rapidly becoming the best annual meteor shower of the year: the Geminid meteors. The Prospects for the Shower in 2023 The radiant of the shower lies very near the bright star Castor in the zodiacal constellation of Gemini the Twins. The 2023 peak occurs on the night of December 13/14th at 00UT (7PM EST) with an estimated peak zenithalRead More →

15 Years of Data Reveal the Events Leading Up to Betelgeuse’s “Great Dimming” Anyone who regularly watches the skies may well be familiar with the constellation Orion the hunter. It is one of the few constellations that actually looks like the thing it is supposed to look like rather than some abstract resemblance. One prominent star is Betelgeuse and back in 2020 it dimmed to a level lower than ever before in recorded history. A team of astronomers have been studying the event with some fascinating results. Betelgeuse is a red supergiant star almost 650 light years from Earth. With a radius of 617 millionRead More →

A Giant Stream of Stars is Flowing in Deep Space The space between galaxies has long been considered a dead area. Single rogue stars may pop stars may pop up here or there, but the majority of this cosmic backward was considered empty by astronomers. But now, a paper from astronomers at various European and California institutions has found a trail of stars flowing between galaxies in a cluster. They’re calling it the Giant Coma Stream, after the Coma Cluster of galaxies where it originates. Observing this cluster back in 1933, Fritz Zwicky, a Swiss astronomer, noticed that the galaxies in the cluster were movingRead More →

Scientists Found Evidence Of A Nearby Kilonova 3.5 Million Years Ago Most of the times astronomers reported dramatic, cataclysmic events like neutron star mergers or the creation of a black hole; they are taking place light years away, typically in in another galaxy. While we can observe their destructive power through the light they emit, they have minimal impact on Earth. However, a relatively recent discovery of certain types of isotopes at the bottom of the ocean hints at one of these events happening fairly close to home. And it probably didn’t happen all that long ago. So, how can isotopes at the bottom ofRead More →

What Could a Next Generation Event Horizon Telescope Do? Telescopes have come a long way in a little over four hundred years! It was 1608 that Dutch spectacle maker Hans Lippershey who was said to be working with a case of myopia and, in working with lenses discovered the magnifying powers if arranged in certain configurations. Now, centuries on and we have many different telescope designs and even telescopes in orbit but none are more incredible than the Event Horizon Telescope (EHT). Images las year revealed the supermassive black hole at the centre of our Galaxy and around M87 but now a team of astronomersRead More →

Iran Sent a Capsule Capable of Holding Animals into Orbit. Despite popular opinion, the first animals in space were not dogs or chimps, they were fruit flies launched by the United States in February 1947. The Soviet Union launched Laika, the first dog into space in November 1957 and now, it seems Iran is getting in on the act. A 500kg capsule known as the “indigenous bio-capsule” with life support capability was recently launched atop the Iranian “Salman” rocket. It has been reported by some agencies that there were animals on board but no official statement has been released. The Iranian Space Agency (ISA) areRead More →

If Our Part of the Universe is Less Dense, Would That Explain the Hubble Tension? In the 1920s, Edwin Hubble and Georges Lemaitre made a startling discovery that forever changed our perception of the Universe. Upon observing galaxies beyond the Milky Way and measuring their spectra, they determined that the Universe was expanding. By the 1990s, with the help of the Hubble Space Telescope, scientists took the deepest images of the Universe to date and made another startling discovery: the rate of expansion is speeding up! This parameter, denoted by Lambda, is integral to the accepted model of cosmology, known as the Lambda Cold DarkRead More →