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Astronomers have discovered a pair of star-like objects orbiting each other extremely quickly, with an entire ‘year’ lasting just 1.9 Earth hours. Catchily named ZTF J2020+5033, the system consists of one object which is definitely a small star, and another that straddles the boundary between star and planet. The two objects appear to be very old, and understanding how they came to be orbiting so close together is teaching astronomers more about how solar systems change and evolve.

The planet-like object in the pair is classified as a Brown dwarf: a failed star without enough mass to jumpstart stellar fusion in its core. But this particular object is right on the boundary between a brown dwarf and a star, so astronomers can’t be sure which it is for sure, though they suspect the latter because it is so much dimmer than its partner.

The brown dwarf’s orbital period is seven times faster than the previous record-holding brown dwarf. It is so close to its partner that both could easily orbit each other inside our Sun. But a paper released this month suggests that they didn’t form like this.

“Both components must have been significantly larger when they were young than they are today, implying that the orbit has shrunk significantly,” the authors write.

Understanding that process is key to unlocking some of the secrets of solar system formation. The primary mechanism at work, they believe, is something called magnetic braking.

Stars have powerful magnetic fields. When solar flares and coronal mass ejections and other phenomena related to solar wind eject material from a star, the material is captured by the magnetic fields. It is carried out far from the star, eventually escaping altogether. But before it escapes, the material continues to spin with the star and its magnetic field. Just like a figure skater throwing their arms out to spin slower, this material slows a star’s spin.

In a binary system, the magnetic fields of both stars work together to slow their orbital period around each other, like two figure skaters holding hands with arms outreached.

Over millennia, not only do the stars lose mass, they also circle closer and closer together.

Current models used by astronomers suggest that magnetic braking is most pronounced in stars that are fully convective: they are massive enough that the convection zone of the star extends all the way into its interior.

But this binary pair is made up of two very small stars that are not fully convective.

Structure of Stars artists impression 1
An illustration of the convective zone of massive stars. Credit: ESO.

“This strongly suggests that magnetic braking remains efficient below the fully convective boundary in at least some stars, contrary to the common assumption in many binary evolution models,” the paper argues.

That means that we might need to change how we think about the future evolution of binary pairs.

ZTF J2020+5033, for example, is expected to pass the Roche limit in 1.3 billion years, according to current models. At that time, the brown dwarf will be ripped apart by the gravity of its partner as it gets too close. But if magnetic braking is indeed in effect for these small stars, that timeline will come much faster, within just tens of millions of years.

The implications are clearly significant.

To get a better understanding of what’s going on, astronomers need to find more close-orbiting binary star-brown dwarf pairs, to make sure this isn’t just an outlier. But that’s easier said than done. Although they are expected to be common, brown dwarfs are so dim that they are difficult to find, resulting in what astronomers call a “brown dwarf desert” in their data sets.

Luckily, there are three new instruments that will excel at finding exactly these objects: Palomar Observatory’s wide-field infrared transient explorer (WINTER), which began operations in 2021; the Vera Rubin Observatory, expected to begin surveying in 2024; and the Nancy Grace Roman Space Telescope, launching in 2027.

Learn More:

Kareem El-Badry, Kevin B. Burdge, Jan van Roestel, and Antonio C. Rodriguez. “A transiting brown dwarf in a 2
Did you miss our previous article…
https://mansbrand.com/some-metal-meteorites-have-a-tiny-magnetic-field-but-how/

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Review: Patagonia R1 Air Full-Zip Hoody

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15 hours ago

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September 27, 2023

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Tet19 047 Me on Teton Crest Trail copy cropped 8

Hooded Fleece Jacket
Patagonia R1 Air Full-Zip Hoody
$179, 12.5 oz./354g (men’s medium)
Sizes: men’s XS-XXL, women’s XXS-XL, kids XS-XXL
backcountry.com

As I’ve repeatedly written at this blog, virtually no piece of outdoor apparel offers more versatility than a highly breathable, midweight insulation layer; arguably, the only “layer” you will wear more is your skin. Find a highly breathable midweight jacket that’s soft and fits like it was custom made for your torso and you have a winner. Patagonia’s R1 Air Full-Zip Hoody could play that role for almost any outdoor user, from hard-core backpackers, climbers, and backcountry skiers to the average dayhiker and fitness walker, as I found wearing it on backpacking trips in Glacier National Park and the Canadian Rockies, not to mention countless days around town and at home.

At 12.5 ounces/354 grams (men’s medium), this midweight fleece is designed for wearing as an outer or middle layer in a huge range of cool to cold temperatures, including activities and seasons as diverse as hiking or climbing in virtually any mountains in any month of the year, southern climes from fall through spring, or for any winter activity—skiing, hiking, running, walking, you pick.

Tet19 047 Me on Teton Crest Trail copy cropped 9
Hi, I’m Michael Lanza, creator of The Big Outside. Click here to sign up for my FREE email newsletter. Join The Big Outside to get full access to all of my blog’s stories. Click here for my e-guides to classic backpacking trips. Click here to learn how I can help you plan your next trip.

The Patagonia R1 Air Full-Zip Hoody.
” data-image-caption=”The Patagonia R1 Air Full-Zip Hoody.
” data-medium-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?fit=300%2C200&ssl=1″ data-large-file=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?fit=900%2C600&ssl=1″ src=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?resize=900%2C600&ssl=1″ alt=”The Patagonia R1 Air Full-Zip Hoody.” class=”wp-image-60252″ srcset=”https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?resize=1024%2C683&ssl=1 1024w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?resize=300%2C200&ssl=1 300w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?resize=768%2C512&ssl=1 768w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?resize=150%2C100&ssl=1 150w, https://i0.wp.com/thebigoutside.com/wp-content/uploads/2023/09/Patagonia-R1-Air-Full-Zip-Hoody.jpg?w=1200&ssl=1 1200w” sizes=”(max-width: 900px) 100vw, 900px” data-recalc-dims=”1″ />The Patagonia R1 Air Full-Zip Hoody.

It kept me warm without overheating—rarely even breaking a sweat—wearing it over one base layer while hiking with a full pack, uphill and downhill, on cool, generally calm mornings and some windy afternoons during a weeklong, nearly 70-mile September backpacking trip in Glacier National Park, and hiking in chilly, very strong wind on three-day hikes on both the Skyline Trail in Jasper National Park and the Nigel, Cataract, and Cline Passes Route in the White Goat Wilderness of the Canadian Rockies in the first week of August.

On those backpacking trips, I also wore it in camp both as an outer layer and, when temps dropped, under a down jacket—meaning the R1 Air Hoody doubled as an on-trail layer and a camp layer that allowed me to bring a lighter puffy and forego a midweight, long-sleeve shirt. To frame it another way: The R1 Air Hoody cut my layering system weight by replacing or reducing two other layers. Few pieces of apparel offer more versatility while reducing your pack weight.

I also wore it on breezy, cool evenings in the 50s between waves of thunderstorms
Did you miss our previous article…
https://mansbrand.com/gaia-is-now-finding-planets-could-it-find-another-earth/

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Gaia is Now Finding Planets. Could it Find Another Earth?

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2 days ago

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September 26, 2023

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Giant Planet Detection

The ESA launched Gaia in 2013 with one overarching goal: to map more than one billion stars in the Milky Way. Its vast collection of data is frequently used in published research. Gaia is an ambitious mission, though it seldom makes headlines on its own.

But that could change.

Gaia relies on astrometry for much of its work, and astrometry is the measurement of the position, distance, and motions of stars. It’s so sensitive that it can sometimes detect the slight wobble a planet imparts to its much more massive star. Gaia detected its first two transiting exoplanets in 2021, and it’s expected to find thousands of Jupiter-size exoplanets beyond our Solar System.

But new research takes it even further. It shows that Gaia should be able to detect Earth-like planets up to 30 light-years away.

The new paper is “The Possibility of Detecting our Solar System Through Astrometry,” and is available on the pre-press site arxiv.org. It has a single author: Dong-Hong Wu from the Department of Physics, Anhui Normal University, Wuhu, Anhui, China.

Astronomers find most exoplanets with the transit method. A spacecraft like TESS monitors a section of the sky and looks at many stars at once. When a planet passes between us and one of the stars, it’s called a transit. It creates a dip in starlight that TESS’s sensitive instruments can detect. When TESS detects multiple, predictable dips, it signifies a planet.

But that’s not the only way to detect them. Astrometry can do it too, and that’s Gaia’s way.

Astrometry has an advantage over other methods. Gaia can more accurately determine an exoplanet’s orbital parameters. This doesn’t mean the other methods aren’t valuable. They obviously are. But as the paper’s author explains, “Neither the transit nor radial velocity method provides complete physical parameters of one planet, and both methods prefer to detect planets close to the central star. On the contrary, the astrometry method can provide a three-dimensional characterization of the orbit of one planet and has the advantage of detecting planets far away from the host star.” Astrometry’s advantages are clear.

If other technological planetary civs exist—and that’s a big if—then it’s not outrageous to think they have technology similar to Gaia’s. While Gaia is impressive, there are improvements on the horizon that will make astrometry even more precise. The author asks a question in his paper: If ETIs (ExtraTerrestrial Intelligences) are using advanced astrometry equal to or even surpassing Gaia’s, “…which of them could discover the planets in the solar system, even the Earth?”

Astrometrical precision is calculated in microarcseconds, and precision decreases with distance. The ESA says that Gaia can measure a star’s position within 24 microarcseconds for objects 4000 times fainter than the naked eye. That’s like measuring the thickness of a human hair from 1000 km away. But that’s not precise enough for Wu’s scenario. His work is based on even more advanced astrometry, the type we’ll likely have in the near future. “If the astrometry precision is equal to or better than ten microarcseconds, all 8,707 stars located within 30 pcs of our solar system possess the potential to detect the four giant planets within 100 years.”

This is the heart of Wu’s paper. The 30-parsec (approx. 100 light-years) region contains almost 9,000 stars, and if an ETI from one of those stars has powerful enough astrometry, then it could detect Jupiter, Saturn, Uranus, and Neptune. The only drawback is they’d have to observe our Solar System for nearly a century to make sure the signal was clear.

This figure from the research shows how long it would take for an ETI with advanced astrometry to detect our Solar System's four giant planets. 1,” the author writes. Image Credit: Wu 2023.” class=”wp-image-163369″ srcset=”https://www.universetoday.com/wp-content/uploads/2023/09/Giant-Planet-Detection.png 492w, https://www.universetoday.com/wp-content/uploads/2023/09/Giant-Planet-Detection-374×580.png 374w, https://www.universetoday.com/wp-content/uploads/2023/09/Giant-Planet-Detection-161×250.png 161w” sizes=”(max-width: 492px) 100vw, 492px” />
This figure from the research shows how long it would take for an ETI with advanced astrometry to detect our Solar System’s four giant planets. “We find that all the four giants in our solar system could be detected and well-characterized as long as they are observed for at least 90 years with SNR > 1,” the author writes. Image Credit: Wu 2023.

There are 8707 stars within 100

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Finally! Astronomers are Starting to See the First Galaxies Coming Together With JWST

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September 26, 2023

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total stellar mass1100 1024x686 1

One of the James Webb Space Telescope’s principal science goals is to observe the epoch where we think that the first galaxies were created, to understand the details of their formation, evolution, and composition. With each deep look back in time, the telescope seems to break its own record for the most distant galaxy ever seen. Science papers are now are starting to trickle in, as astronomers are finally starting to collect enough data from JWST to build a deeper understanding of the early Universe.

In a new study published in Nature Astronomy, a team of researchers in Denmark believe they have observed some of the very first, earliest galaxies with JWST. These galaxies are so old, they are likely still in the process of being formed.

Galaxy Ratios

One known standard is that the ratio between galaxies and their heavy elements has held constant in the local Universe through the last 12 billion years of history, or about 5/6 of the age of the Universe. But with JWST, astronomers are now seeing that the youngest galaxies look different. They don’t have that same ratio of stars to heavier elements because they haven’t gone through the cycles of star formation and star death yet, enriching gas clouds with metals, i.e., elements heavier than hydrogen and helium.

total stellar mass1100 1024x686 2
This plot shows the observed galaxies in an “element-stellar mass diagram”: The farther to the right a galaxy is, the more massive it is, and the farther up, the more heavy elements it contains. The gray icons represent galaxies in the present-day Universe, while the red show the new observations of early galaxies. These ones clearly have much less heavy elements than later galaxies, but agree roughly with theoretical predictions, indicated by the blue band. Credit: Kasper Elm Heintz, Peter Laursen.

For this study, the astronomers looked at 16 galaxies, some of the earliest galaxies ever observed. Their observations revealed that the chemical abundances in these galaxies are one-fourth of that seen in galaxies that were formed later. In their paper, the astronomers wrote that “these findings suggest that galaxies at this time are still intimately connected with the intergalactic medium and subject to continuous infall of pristine gas, which effectively dilutes their metal abundances.”

As gravity gathered together the first clumps of gas,the first stars and galaxies were formed.

“When we analyzed the light from 16 of these first galaxies, we saw that they had significantly less heavy elements, compared to what you’d expect from their stellar masses and the amount of new stars they produced,” said Kasper Elm Heintz, leader of the study and assistant professor at the Cosmic Dawn Center at the Niels Bohr Institute and DTU Space in Copenhagen, Denmark, in a press release.

These results, the astronomers say, are in stark contrast to the current model where galaxies evolve in a form of equilibrium throughout most of the history of the Universe, where there is a relationship between how many stars have formed and how many heavy elements have formed.

galaksedannelse1100 1024x817 1
Illustration of galaxy formation: Diffuse gas from intergalactic space plummets toward the center, sparking star formation and becoming part of the galaxy’s rotating disk. When stars die, they return their gas to the galaxy (and the intergalactic space), now enriched with heavy elements. Credit: Tumlinson et al. (2017)
Did you miss our previous article…
https://mansbrand.com/why-build-megastructures-just-move-planets-around-to-make-habitable-worlds/

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