Latest news with #astrophysicist
Yahoo
3 days ago
- General
- Yahoo
A Super-Tiny Star Gave Birth to a Giant Planet And We Don't Know How
A giant conundrum has been found orbiting a teeny tiny red dwarf star just a fifth of the size of the Sun. Such small stars were thought to be incapable of producing giant planets. But there, in its orbit, appears to be unmistakable evidence of an absolute unit: a gas giant around the size of Saturn. TOI-6894b, as the exoplanet is named, has 86 percent of the radius of Jupiter. At just 23 percent of the radius and 21 percent of the mass of the Sun, its parent TOI-6894 is the smallest star yet around which a giant world has been found. "I was very excited by this discovery," says astrophysicist Edward Bryant of the University of Warwick in the UK, who led the large international research team. "We did not expect planets like TOI-6894b to be able to form around stars this low-mass. This discovery will be a cornerstone for understanding the extremes of giant planet formation." Planets are born from the material that's left over from the formation processes of its host star. Stars form when a dense clump of material in a cloud of gas and dust collapses under gravity. Material from that cloud spools around the spinning protostar in a disk that feeds the star's growth; when the star is large enough to push the material away with its stellar wind, growth stops. The remaining material is what makes planets. The dust clumps together, gradually building worlds that end up orbiting the star. Here's the thing, though. The amount of material in the disk is thought to be proportional to the mass of the star. The reason tiny red dwarf stars shouldn't be able to make giant planets is because there just oughtn't be enough material to do so. Nevertheless, these strange, 'impossible' systems show up from time to time, suggesting not just that giant planets can form around tiny stars, but that the process is not all that uncommon. We don't have a good handle on just how common it is, so Bryant and his team embarked on a mission to scour TESS data for clues. "I originally searched through TESS observations of more than 91,000 low-mass red-dwarf stars looking for giant planets," he says. "Then, using observations taken with one of the world's largest telescopes, ESO's VLT, I discovered TOI-6894b, a giant planet transiting the lowest mass star known to date to host such a planet." Exoplanets are usually found via a technique known as the transit method. When an exoplanet orbiting a star passes between us, the observers, and the star, that star's light dims minutely. Astronomers can determine the presence of an exoplanet by looking for periodic dips in the star's light. It's usually a tiny signal that takes quite a bit of analysis to find. When the researchers looked at TOI-6894, they found its light dimming by an absolutely whopping 17 percent. According to the team's observations of the transits, that would make the diameter of the star about 320,000 kilometers (200,000 miles), while the exoplanet is around 120,000 kilometers across. Follow-up observations to see how much this giant exoplanet's gravity affects the orbital motion of the star revealed the mass of TOI-6894b. It's just 17 percent of the mass of Jupiter, suggesting an exoplanet atmosphere that is light and fluffy. This is exciting for a few reasons. Because the exoplanet has such deep transits, it's a perfect candidate for atmosphere study. During those transits, some of the star's light filters through the diffuse atmosphere. As it does so, it can become altered by the atoms and molecules therein, allowing scientists to literally see what TOI-6894b is made of. A team of astronomers has already applied for time with JWST to perform these atmospheric studies. Because the exoplanet is quite cool (temperature wise, but also just in general), they expect to find a lot of methane. "This system provides a new challenge for models of planet formation, and it offers a very interesting target for follow-up observations to characterize its atmosphere," says astrophysicist Andrés Jordán of the Millennium Institute of Astrophysics in Chile. Hopefully, these studies will also shed some light on how TOI-6894b formed. There are two scenarios astronomers prefer for gas giants: a gradual accumulation of material from the bottom up, or the direct collapse of an instability in the protoplanetary disk. Based on the team's observations, neither scenario quite works. More detail on the composition of TOI-6894b could help tease out which is the more likely pathway for the formation of giant worlds orbiting tiny stars. "It's an intriguing discovery. We don't really understand how a star with so little mass can form such a massive planet!" says astrophysicist Vincent Van Eylen of University College London. "This is one of the goals of the search for more exoplanets. By finding planetary systems different from our Solar System, we can test our models and better understand how our own Solar System formed." The discovery has been published in Nature Astronomy. Water Discovered Around a Young, Sun-Like Star For First Time June's Full Moon Will Be The Lowest in The Sky For Decades. Here's Why. The Milky Way Might Not Crash Into The Andromeda Galaxy After All
Gizmodo
25-05-2025
- Science
- Gizmodo
Does Light Traveling Through Space Wear Out?
My telescope, set up for astrophotography in my light-polluted San Diego backyard, was pointed at a galaxy unfathomably far from Earth. My wife, Cristina, walked up just as the first space photo streamed to my tablet. It sparkled on the screen in front of us. 'That's the Pinwheel galaxy,' I said. The name is derived from its shape–albeit this pinwheel contains about a trillion stars. The light from the Pinwheel traveled for 25 million years across the universe–about 150 quintillion miles–to get to my telescope. My wife wondered: 'Doesn't light get tired during such a long journey?' Her curiosity triggered a thought-provoking conversation about light. Ultimately, why doesn't light wear out and lose energy over time? Let's talk about light I am an astrophysicist, and one of the first things I learned in my studies is how light often behaves in ways that defy our intuitions. Light is electromagnetic radiation: basically, an electric wave and a magnetic wave coupled together and traveling through space-time. It has no mass. That point is critical because the mass of an object, whether a speck of dust or a spaceship, limits the top speed it can travel through space. But because light is massless, it's able to reach the maximum speed limit in a vacuum–about 186,000 miles (300,000 kilometers) per second, or almost 6 trillion miles per year (9.6 trillion kilometers). Nothing traveling through space is faster. To put that into perspective: In the time it takes you to blink your eyes, a particle of light travels around the circumference of the Earth more than twice. As incredibly fast as that is, space is incredibly spread out. Light from the Sun, which is 93 million miles (about 150 million kilometers) from Earth, takes just over eight minutes to reach us. In other words, the sunlight you see is eight minutes old. Alpha Centauri, the nearest star to us after the Sun, is 26 trillion miles away (about 41 trillion kilometers). So by the time you see it in the night sky, its light is just over four years old. Or, as astronomers say, it's four light years away. With those enormous distances in mind, consider Cristina's question: How can light travel across the universe and not slowly lose energy? Actually, some light does lose energy. This happens when it bounces off something, such as interstellar dust, and is scattered about. But most light just goes and goes, without colliding with anything. This is almost always the case because space is mostly empty–nothingness. So there's nothing in the way. When light travels unimpeded, it loses no energy. It can maintain that 186,000-mile-per-second speed forever. It's about time Here's another concept: Picture yourself as an astronaut on board the International Space Station. You're orbiting at 17,000 miles (about 27,000 kilometers) per hour. Compared with someone on Earth, your wristwatch will tick 0.01 seconds slower over one year. That's an example of time dilation–time moving at different speeds under different conditions. If you're moving really fast, or close to a large gravitational field, your clock will tick more slowly than someone moving slower than you, or who is further from a large gravitational field. To say it succinctly, time is relative. Now consider that light is inextricably connected to time. Picture sitting on a photon, a fundamental particle of light; here, you'd experience maximum time dilation. Everyone on Earth would clock you at the speed of light, but from your reference frame, time would completely stop. That's because the 'clocks' measuring time are in two different places going vastly different speeds: the photon moving at the speed of light, and the comparatively slowpoke speed of Earth going around the Sun. What's more, when you're traveling at or close to the speed of light, the distance between where you are and where you're going gets shorter. That is, space itself becomes more compact in the direction of motion–so the faster you can go, the shorter your journey has to be. In other words, for the photon, space gets squished. Which brings us back to my picture of the Pinwheel galaxy. From the photon's perspective, a star within the galaxy emitted it, and then a single pixel in my backyard camera absorbed it, at exactly the same time. Because space is squished, to the photon the journey was infinitely fast and infinitely short, a tiny fraction of a second. But from our perspective on Earth, the photon left the galaxy 25 million years ago and traveled 25 million light years across space until it landed on my tablet in my backyard. And there, on a cool spring night, its stunning image inspired a delightful conversation between a nerdy scientist and his curious wife. Jarred Roberts, Project Scientist, University of California, San Diego. This article is republished from The Conversation under a Creative Commons license. Read the original article.
Daily Mail
17-05-2025
- Entertainment
- Daily Mail
EXCLUSIVE Bachelor star Matt Agnew reveals new romance as he opens up about dating life struggles and the moment he was admitted to a mental health hospital: 'I just hit rock bottom'
Matt Agnew has struck up a new romance with a mystery woman and revealed he is officially off the dating market. The Bachelor star, 37, is a bachelor no more as he opened up about his love life in a wide ranging interview with Daily Mail Australia on Friday. While he didn't let slip any detail about his new love, he did reveal the difficulties he faced while dating in the public eye—and the shocking moment he 'hit rock bottom'. 'I'm prioritising my love life, yes, love life. I'm seeing someone. So not actively dating,' he said when asked how he was currently fairing in the dating pool. 'I have prioritised it. Not actively dating. Yeah, seeing someone,' he repeated, doing his best to keep the details private—and for good reason. He went on to say dating as a public figure brought with it a whole host of obstacles he never had to worry about before shooting to fame on The Bachelor in 2019. 'It's challenging. It's one of the reasons I am so fiercely private despite the fact I went on national television to date,' the astrophysicist said. 'I am fiercely private about my dating life because it is much harder to date while in the public eye.' Matt went on to say starring in the Channel Ten matchmaking series has forced him to become more aware of whether people only want to date him for the 'novelty' of it. 'In terms of trying to discern and understand people's intentions, it's not as hard as it sounds,' he said when asked how he figures out who is in it for the right reasons. 'People are usually forthcoming about the fact they have watched [ The Bachelor ]. 'It ends up being quite obvious early on if a person is more interested in the novelty of finding out what happened on the show.' Matt went on to say his 'ideal scenario' was meeting someone on the dating apps who didn't recognise him and didn't watch The Bachelor. He said people who had no idea who he was were more likely to want to get to know him on a more personal level away from his public persona. Though the awkward moment would always come around when he had to break the news of his TV fame to them. 'Usually if we progress to exchange social media details... having 130,000 followers and a blue tick usually prompts questions,' he said. 'That's usually the natural point I say, "Look, I was on television a few years ago." It's usually that point I bring it up.' While Matt has never had a preference dating someone either in the public eye or out of the public eye, he said there are benefits to being with another media personality. 'I've dated both people who have been in the media and entertainment circle and those who are not. There are definitely differences,' he explained. 'When dating people who have been in the public eye in that sort of entertainment, social media orbit, there is an extra level of understanding about things. 'It makes certain things easier if you attend an event together, there is a sense of how things like a red carpet works. It seems really trivial, but it can be intimidating. 'I've had in the past where I've been on a few dates with someone, it's gone really well, and they've said they can't deal with the public stuff.' 'It's unfortunate when it happens, because if that is the only thing stopping us then it's frustrating,' he added. Matt's love life has long been the topic of headlines after he broke Abbie Chatfield's heart on the 2019 series of The Bachelor, though they are now close friends. The handsome bachelor chose to pursue a relationship with Chelsie McLeod, though they announced their split just a few months after the finale. He later confirmed he was dating comedian Gen Fricker, before revealing he was again single not long after. Over the years, he has been romantically linked to several different people, such as 'croissant queen' Kate Reid and openly gay MasterChef star Khanh Ong. However, Matt denied both those relationships, taking particular exception to the fact people kept reading into his close and affectionate friendship with Khanh. Thankfully, despite his past love woes, it seems Matt is now very happy with his current mystery partner. While he didn't wish to say how long the pair have been together, the TV star sounded content with where his life, both in and out of love, has progressed. Which is quite the relief, as Matt said that wasn't the case just a handful of years ago. 'My lowest point was in 2021. I just hit rock bottom,' he said when the topic of mental health came up—something Matt is a very public advocate for. 'I was experiencing really strong suicidal ideation. At times, I acted on those things. 'On the very fortunate case I was unsuccessful, I managed to pull myself out of the hole. 'One of the reasons I got through was the love and support of friends and family, and also having the financial means to seek out additional professional health care. 'I ended up being admitted into a mental health hospital for several weeks. That's not something every Australian has access to.' Matt went on to acknowledge how privileged he feels to have had the means and support network to seek help in his darkest moment. 'I'm lucky to have a loving unit to support me. It's not something every Australian has,' he said. 'It's really hard for me to see what the best way for people to get through the dark times are because some people aren't in as fortunate spots. 'I hope everyone has friends, family and a loving support network to help nurse them through and get them off rock bottom, but that's unfortunately not always the case.' Matt said his passion for 'normalising' mental illness to help those battling with it was a big part of the reason he teamed up with MYOB and its new Solo app. Solo by MYOB is the all-in-one business admin app for Australian sole operators. Customers get access to an online community of fellow sole traders to share advice and practical tips, fostering collaboration and reducing isolation. According to the company, 60 per cent of male sole trader respondents agree they are physically or mentally exhausted by the demands of being a sole trader. While 54 per cent feel lonely or isolated at times as a male sole trader, which Matt says can worsen the effects of mental illness. 'It's something I've been very vocal about for a long time. A large portion of that is attributed to my own experiences battling mental illness over the years,' Matt said. 'I was first diagnosed with anxiety over two decades ago when I was 12 or 13 years old. It's something I've managed over my lifetime. 'More recently, I've had depression and bipolar diagnoses as well. It's something I've battled with personally. 'I've had some really dark moments I have been quite candid and open about publicly. Talking about it, I think, is still really important to normalise those conversations. 'Make people battling their own mental illnesses feel there is nothing wrong with them.' If you or someone you know is struggling, please contact Lifeline for 24 hour support at 13 11 14.
