Latest news with #Ophiuchus
Forbes
4 days ago
- Science
- Forbes
Planet Formation Theory Is Still Ensnared By A Chicken Or Egg Problem
In the rush to understand the formation history of solar systems like ours, one big conundrum still ensnares this field of research. That is, how protostellar disks form their very first planets. We don't yet know how that first planet gets formed, Nienke van der Marel an astronomer at Leiden University in The Netherlands, tells me in her office. We understand how clumping can be caused by physical forces within the disk once there's a planet in that disk, van der Marel tells me, but the biggest question is still how that first planet formed. Ongoing observations by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile's Northern Atacama Desert are largely responsible for the lion's share of our current knowledge about how protoplanetary disks form from millimeter-sized particles and grow into full-fledged planetary systems like ours. In 2013, using some of the first ALMA observations van der Marel and colleagues detected the existence of a dust trap in a protoplanetary disk around the young A-type star Oph-IRS 48, located some 400 light-years away in the Northern constellation of Ophiuchus. A dust trap is a location where millimeter-sized pebbles, are concentrated in one part of the disk, and where they can continue to grow all the way from planetesimals (planetary building blocks ranging from a few km to a few hundred km in diameter) to full-fledged planets. That first planet will carve a gap along its orbit and then at the outer edge of that gap, you naturally get a maximum in the density and a bump in the gas density, says van der Marel. So now, the pebbles that come from the outer disk still drift inwards, but then at that maximum pressure location, they get trapped, she says. But as soon as these particles reach typical pebble sizes (1 mm across), they will start to experience drag forces from the gas in the disk and rapidly move inwards toward the star, says van der Marel. Disappearing Pebbles So, within a hundred years, any pebble that you form out here in the outer region of the disk has moved all the way inwards and onto the star and is lost; it doesn't have time to continue growing all the way to planetesimals, says van der Marel. So, you need something that stops the pebbles from drifting inwards, she says. And the phenomenon that was proposed to stop it was a dust trap, says van der Marel. Planetary Disk Pressure Bumps 'Pressure bumps' or 'dust traps' present in the disk will halt these inward moving pebbles and trap them, says van der Marel. This whole idea creates a major chicken or egg problem, because if you need a planet to create dust traps, then dust traps are necessary to form planetesimals and planets, she says. Alternative Scenarios If indeed planets are the only source of dust traps, then we do have a chicken or egg problem to form the first planet, Olja Panic, an astrophysicist at the University of Leeds in the U.K., tells me in Reykjavik. But recent research has been directed towards identifying possible scenarios under which these dust traps can arise without the need for planets to cause them, says Panic. This could include various types of gravitational disk instabilities, whether generated from a passing star or during the disk's earliest formation. It is also possible that there are other mechanisms that create the first dust traps, such as magnetic fields, ionization structures (which would arrange molecules so that they have a net electrical charge), or even planetary snowlines. That is, regions in a young planetary disk where temperatures are so cold that water, ammonia, carbon monoxide or even methane can freeze into ice grains. Some researchers posit that this increase in ice density might even trigger the formation of gas giant planets like Jupiter. The idea is that these first dust traps would then concentrate these planetary pebbles until the first planet forms within the dust trap. But that has yet to be confirmed observationally. When Might This Problem Be Solved? Although ALMA's array of 66 telescopes work have allowed astronomers to see incredible detail in these disks of gas and dust around young stars, future telescopes will reveal even more detail about how these stars spawn planets. In the coming decades, a lot of new telescopes will teach us more about the composition of exoplanets which may also tell us how they form, says van der Marel. Just like ALMA, the Next Generation Very Large Array (NGVLA) in New Mexico is another up and coming radio array which will observe at even longer wavelengths where we can trace even larger dust grains, she says. That may help us to understand where most planet formation takes place, says van der Marel. Is our solar system an anomaly? We don't have the data right now to say for certain whether we are an anomaly or not, says van der Marel.
Forbes
24-07-2025
- General
- Forbes
See Today's New Moon Reveal The Zodiac's Forgotten 13th Constellation
Wallpaper with constellation Ophiuchus in night sky What is the 13th constellation? Not many people know about Ophiuchus (pronounced 'Oh-few-cuss'), the serpent bearer, a vast constellation of summer — but they should. Not only is it sizeable, but by rights, it should be a star sign because, like Leo, Aquarius and Sagittarius, it's on the zodiac. This week is ideal for finding Ophiuchus in the night sky, with today — the date of the new moon — the best night. With the moon lost in the glare of the sun, the night sky will be moonless. What Is Ophiuchus? One of the zodiac's most overlooked constellations, Ophiuchus, is an ancient star pattern that sits between the better-known constellations of Scorpius and Sagittarius. Like the 12 zodiac signs celebrated in horoscopes, the sun passes through Ophiuchus from Nov. 29 to Dec. 18 each year. Where And When To Look Head out after dark on July 24 — or anytime this week when the moon is not in the sky — and look toward the south. In between the prominent stars of the Summer Triangle (above) and the stinger of Scorpius (below) is Ophiuchus. Its stars are fainter, but with dark skies, they're within reach — particularly if you observe from away from light pollution. The easiest way to see Ophiuchus is to begin by finding Rasalhague, its brightest star. What You'll See Ophiuchus isn't very bright, but it stretches impressively across the summer sky. Its brightest star, Rasalhague, lies near the top of the constellation and shines at magnitude 2.1 — bright enough to catch the eye. If you're familiar with the Summer Triangle, try adding Rasalhague as a fourth point to create a 'Summer Diamond' pattern. While you won't be able to see it, inside the stars of Ophiuchus is Barnard's Star, which, at six light-years from the sun, is the fourth-closest star system to our own. What's Next In The Night Sky On Friday, July 25, skywatchers have a rare chance to spot a 2%-illuminated waxing crescent moon just after sunset. It will be low in the northwest and begin a string of evenings when a crescent moon will shine after sunset, rising a little higher and becoming a little brighter with each passing night. For exact timings, use a sunrise and sunset calculator for where you are, Stellarium Web for a sky chart and Night Sky Tonight: Visible Planets at Your Location for positions and rise/set times for planets. Wishing you clear skies and wide eyes.
Yahoo
05-05-2025
- Science
- Yahoo
Scientists Spot Thousands of Newborn Stars Fleeing Their Nursery
As humans do from their parents' homes and birds do from their nests, stars leave their so-called stellar nurseries once they're old enough to do so. Unlike Earthly beings, however, it usually takes hundreds of millions of years for stars to age out of their childhood homes. That's why it's strange that, in the constellation Ophiuchus, more than 1,000 newborn stars are fleeing their home after just 20 million years of existence—and no one can explain why they're doing it. This bizarre stellar behavior came to light via the European Space Agency's (ESA) Gaia mission, which captured the biggest and most detailed sky map yet before retiring in March 2025. Gaia made history by measuring the position, distance, spectra, and velocity of nearly 2 billion stars. After researchers at Western Washington University and the University of North Florida developed a method that would allow them to scan Gaia's spectroscopic findings for young, low-mass stars, they found Ophiuchus, also known as Ophion. And within Ophion, they found newly formed stars dispersing in "record time." Gaia's massive troves of stellar data made this discovery possible—and produced this stunning view of the Milky Way. Credit: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO Rapid pace aside, these stars are strange because they're striking out on their own, not sticking to small family clusters. Of course, gravity (not sentimentality) is responsible for stars' typical group behavior: Conditions that make it easy for one star to form usually lead to several new stars, which remain bound together by gravity for "millions or even billions of years," NASA explains. Throughout that great window of time, the stars slowly separate from one another; some even die within the cluster. But Ophion's newborn stars are scattering frantically in different directions. "Ophion is filled with stars that are set to rush out across the galaxy in a totally haphazard, uncoordinated way, which is far from what we'd expect for a family so big," computer scientist and lead study author Dylan Huson told the ESA. "What's more, this will happen in a fraction of the time it'd usually take for such a large family to scatter. It's like no other star family we've seen before." Neither Huson nor his colleagues can definitively say why Ophion's stars are behaving so uniquely, but they have a couple of guesses. Though Ophion is 650 light-years from Earth, it's closer to some other massive clusters of young stars, meaning it's possible that some bizarre energetic interactions between the groups might have triggered the unusual behavior. Supernovae could have also exploded in the region, rushing material past the constellation and forcing the stars to "move far more rapidly and erratically than before," says the ESA. Though Gaia is no longer operational, its vast troves of star data will make it possible for the team to dig deeper into Ophion's oddities.
Forbes
05-04-2025
- Science
- Forbes
Astronomers Name ‘Super Venus' Close To Solar System — What To Know
Artist's impression of GJ 1214 b passing in front of its host star. The 'transit method' allows ... More astronomers to study an exoplanet by seeing which wavelengths of light dim when the star's light passes through the exoplanet atmosphere. Astronomers in Japan and Arizona, using data from the James Webb Space Telescope, have revealed a unique type of exoplanet unlike any in the solar system. The exoplanet — defined as a planet orbiting a star other than the sun — is named Enaiposha and is just 48 light-years away, putting it in the solar system's immediate neighborhood. That also makes it close enough for astronomers to see whether it has an atmosphere and what kind. That's exactly what astronomers at the National Astronomical Observatory of Japan and the University of Arizona/Steward Observatory did—and they found something unexpected. The latest data on Enaiposha, also called GJ 1214 b and Gliese 1214 b, suggests it has a carbon-dioxide-rich atmosphere, challenging previous notions about the composition of exoplanets of its size. Though exoplanets tend to be classed as a 'super-Earth' or a 'mini Neptune,' Enaiposha's carbon dioxide-dominated atmosphere makes it more likely to be a 'super Venus.' 'The detected CO2 signal from the first study is tiny, and so it required careful statistical analysis to ensure that it is real,' said Kazumasa Ohno at the National Astronomical Observatory of Japan, who co-led the study. Artist's depiction of the size relationship between Earth and GJ 1214b, also known as Gliese 1214b. Enaiposha has been studied closely since its discovery in 2009, but until JWST came along, astronomers couldn't see through its thick blanket of clouds. That allows it to reflect a lot of its parent star's light, making it cooler than anticipated. By using its Mid-Infrared Instrument, JWST has been able to reveal major new insights into its atmosphere. In May 2023, scientists at the University of Oxford tracked Enaiposha, then described as a 'sub-Neptune,' through an entire orbit of its star, with its changing heat seen as it passed through phases, similar to how we see the moon, Venus and Mercury from Earth. In addition to finding a big temperature difference between the planet's day and night sides, scientists discovered that Enaiposha's atmosphere is enriched with heavier molecules, such as methane and water. The constellation Ophiuchus in the night sky. Enaiposha is in the constellation Ophiuchus (pronounced 'Or-few-cuss), a vast summer constellation and one of 13 that the sun travels through each year. The other 12 are familiar to everyone as signs of the zodiac, so why isn't Ophiuchus one of them? The ancient Babylonians divided the ecliptic—the apparent path of the sun through the sky—into twelve 30° sectors and assigned each one equally to one of the twelve constellations or 'signs' that intersected it. Since 13 is an unlucky number, one was dropped. Ophiuchus got booted out despite the sun spending a long time within it from Nov. 29–Dec. 17 (commonly thought of as Sagittarius despite the sun being in that constellation from Dec. 17–Jan. 20. Wishing you clear skies and wide eyes.
Yahoo
17-03-2025
- Science
- Yahoo
Scientists Discover Four Intriguing Planets Around Closest Single-Star Solar System to Earth
Astronomers have spotted four smaller-than-Earth exoplanets orbiting the closest single-star system to us, called Barnard's Star. As detailed in a new paper published in the journal The Astrophysical Journal Letters, an international team of researchers discovered that the star — a small red dwarf star just 16 percent of our own Sun's mass and just under six light-years from Earth in the constellation Ophiuchus — has four tiny and seemingly rocky worlds orbiting it. According to the astronomers, these exoplanets — which are among the smallest ever discovered — could force us to reevaluate our understanding of how planets form and evolve. The four planets were spotted by the MAROON-X instrument, a highly sensitive piece of equipment attached to the Gemini North telescope at the International Gemini Observatory in Hilo, Hawaii. "It's a really exciting find — Barnard's Star is our cosmic neighbor, and yet we know so little about it," said University of Chicago PhD student and first author Ritvik Basant in a statement. "It's signaling a breakthrough with the precision of these new instruments from previous generations." MAROON-X was specifically designed to detect tiny exoplanets orbiting red dwarf stars by detecting the minuscule back-and-forth motion of a star caused by the gravitational pull of orbiting planets, a trick scientists call the radial velocity technique. Using the instrument, the team discovered four likely rocky exoplanets that are only anywhere from roughly 20 to 30 percent of the mass of Earth each. They orbit their star at an extremely close distance, completing a full revolution in a matter of a few Earth days. The team also used data from a 2024 study, which involved the ESPRESSO instrument at the European Southern Observatory's Very Large Telescope in Chile, to confirm the existence of one of the four exoplanets. Last year, astronomers detected an exoplanet with at least half the mass of Venus orbiting Barnard's Star. "We observed at different times of night on different days," said Basant in the statement. "They're in Chile; we're in Hawai'i. Our teams didn't coordinate with each other at all. That gives us a lot of assurance that these aren't phantoms in the data." One of the four exoplanets spotted by MAROON-X was the smallest to have been discovered using the radial velocity technique, which could set the stage for many future discoveries like it. Unfortunately, the planets are unlikely to harbor life since they're not in Barnard Star's habitable zone, the area around a star where temperatures allow liquid water to exist on a given planet's surface. "With the current dataset, we can confidently rule out any planets more massive than 40 to 60 percent of Earth's mass near the inner and outer edges of the habitable zone," Basant told "Additionally, we can exclude the presence of Earth-mass planets with orbital periods of up to a few years." But that doesn't necessarily mean that will also be the case for other single-star systems like it. As our exoplanet detection methods continue to improve, astronomers are hoping to spot even more rocky worlds, which may still turn out to be habitable. More on Barnard's Star: Astronomers Spot Mysterious Planet Orbiting the Closest Single Star
