Universe Today

July 30, 2023July 30, 2023 by Brian Koberlein

New Simulation Reveals the Churning Interiors of Giant Stars

A simulation of convection within a star. Credit: E.H. Anders et al

On a basic level, a star is pretty simple. Gravity squeezes the star trying to collapse it, which causes the inner core to get extremely hot and dense. This triggers nuclear fusion, and the heat and pressure from that pushes back against gravity. The two forces balance each other while a star is in its main sequence state. Easy peasy. But the details of how that works are extremely complex. Modeling the interior of a star accurately requires sophisticated computer models, and even then it can be difficult to match a model to what we see on the surface of a star. Now a new computer simulation is helping to change that.

July 29, 2023July 29, 2023 by Brian Koberlein

Chinese Scientists Complete a Concept Study for a 6-Meter Space Telescope to Find Habitable Exoplanets

Illustration of the proposed Tainlin Spacecraft. Credit: CNSA

We have discovered more than 5,400 planets in the universe. These worlds range from hot jovians that closely orbit their star to warm ocean worlds to cold gas giants. While we know they are there, we don’t know much about them. Characteristics such as mass and size are fairly straightforward to measure, but other properties such as temperature and atmospheric composition are more difficult. So the next generation of telescopes will try to capture that information, including one proposed telescope from the Chinese National Space Administration.

July 29, 2023July 29, 2023 by Carolyn Collins Petersen

Astronomers are Watching a Planet Get its Atmosphere Blasted Away into Space

This artist's illustration shows a planet (dark silhouette) passing in front of the red dwarf star AU Microscopii. The planet is so close to the eruptive star a ferocious blast of stellar wind and blistering ultraviolet radiation is heating the planet's hydrogen atmosphere, causing it to escape into space. The illustration is based on measurements made by the Hubble Space Telescope. Credits: NASA, ESA, and Joseph Olmsted (STScI)

What do you get when a hot young world orbits a wildly unstable young red dwarf? For AU Microsopii b, the answer is: flares from the star tearing away the atmosphere. That catastrophic loss happens in fits and starts, “hiccuping” out its atmosphere at one point and then losing practically none the next.

July 28, 2023July 28, 2023 by Andy Tomaswick

Could Aging Wine Become The First Major Space Manufacturing Business?

In capitalist societies, resources are primarily directed at solving problems, and one of the biggest hurdles facing space development is its ability to directly solve the problems of the majority of humanity back on Earth. So far, we’ve taken some cautious commercial steps, primarily through satellite monitoring and communication technologies. Some think that space tourism is the “killer app” that will kickstart the commercialization of space. But to really have a sustainable business model, humans need to make something in space that they are unable to make on Earth. This article is the first in a series where we will look at what those possible first manufactured goods are. And in this case, the good isn’t something that might immediately be thought of as high-tech.

July 28, 2023July 28, 2023 by Carolyn Collins Petersen

JWST Pierces Through a Thick Nebula to Reveal Newly Forming Binary Stars

The NASA/ESA/CSA James Webb Space Telescope has captured a high-resolution image of a tightly bound pair of actively forming binary stars, known as Herbig-Haro 46/47, in near-infrared light. NASA, ESA, CSA, J. DePasquale (STScI), CC BY-SA 3.0 IGO

In 1985, the physicist Heinz Pagels wrote that star birth was a “veiled and secret event.” That’s because the stellar crêches hide the action. But, ever since the advent of infrared astronomy, astronomers have been able to lift that veil. In particular, the Hubble Space Telescope has studied these systems and now, the Webb Telescope (JWST) gives regular detailed views of stellar nurseries.

July 28, 2023July 28, 2023 by Matt Williams

If Rogue Planets are Everywhere, How Could We Explore Them?

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Image Credit: ESO/M. Kornmesser/S. Guisard

At one time, astronomers believed that the planets formed in their current orbits, which remained stable over time. But more recent observations, theory, and calculations have shown that planetary systems are subject to shake-ups and change. Periodically, planets are kicked out of their star systems to become “rogue planets,” bodies that are no longer gravitationally bound to any star and are adrift in the interstellar medium (ISM). Some of these planets may be gas giants with tightly bound icy moons orbiting them, which they could bring with them into the ISM.

Like Jupiter, Saturn, Uranus, and Neptune, these satellites could have warm water interiors that might support life. Other research has indicated that rocky planets with plenty of water on their surfaces could also support life through a combination of geological activity and the decay of radionuclides. According to a recent paper by an international team of astronomers, there could be hundreds of rogue planets in our cosmic neighborhood. Based on their first-ever feasibility analysis, they also indicate that deep space missions could explore these unbound objects more easily than planets still bound to their stars.

July 28, 2023July 28, 2023 by Carolyn Collins Petersen

How Did Supermassive Black Holes Grow So Quickly, So Early?

An international team of astronomers using archival data from the NASA/ESA Hubble Space Telescope and other space- and ground-based observatories have discovered a unique object in the distant, early Universe that is a crucial link between young star-forming galaxies and the earliest supermassive black holes. Current theories predict that supermassive black holes begin their lives in the dust-shrouded cores of vigorously star-forming “starburst” galaxies.

Supermassive black holes haunt the cores of many galaxies. Yet for all we know about black holes (not nearly enough!), the big ones remain a mystery, particularly when they began forming. Interestingly, astronomers see them in the early epochs of cosmic history. That raises the question: how did they get so big when the Universe was still just a baby?

July 28, 2023July 28, 2023 by Alan Boyle

How Will We the Find First Signs of Alien Life — and When?

Astronomers have detected thousands of planets, including dozens that are potentially habitable. To winnow them down, they need to understand their atmospheres and other factors. (NASA Illustration)

When will we find evidence for life beyond Earth? And where will that evidence be found? University of Arizona astronomer Chris Impey, the author of a book called “Worlds Without End,” is betting that the first evidence will come to light within the next decade or so.

But don’t expect to see little green men or pointy-eared Vulcans. And don’t expect to get radio signals from a far-off planetary system, as depicted in the 1992 movie “Contact.”

Instead, Impey expects that NASA’s James Webb Space Telescope — or one of the giant Earth-based telescopes that’s gearing up for observations — will detect the spectroscopic signature of biological activity in the atmosphere of a planet that’s light-years away from us.

“Spectroscopic data is not as appealing to the general public,” Impey admits in the latest episode of the Fiction Science podcast. “People like pictures, and so spectroscopy never gets its fair due in the general talk about astronomy or science, because it’s slightly more esoteric. But it is the tool of choice here.”

https://radiopublic.com/fiction-science-GAxyzK

July 28, 2023July 28, 2023 by Brian Koberlein

Clumps Around a Young Star Could Eventually Turn Into Planets Like Jupiter

The young star V960 Mon and its surrounding dusty material, seen by SPHERE (left) and ALMA (right). Credit: ESO/ALMA (ESO/NAOJ/NRAO)/Weber et al

From the dust, we rise. Vortices within the disks of young stars bring forth planets that coalesce into worlds. At least that’s our understanding of planetary evolution, and new images from the Atacama Large Millimeter/submillimeter Array (ALMA) and the Very Large Telescope’s Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) further support this.

July 27, 2023July 28, 2023 by Laurence Tognetti

Have We Seen the First Glimpse of Supermassive Dark Stars?

Three dark star candidates, JADES-GS-z13-0 (top), JADES-GS-z12-0 (middle), and JADES-GS-z11-0 (bottom) were originally identified as galaxies by the JWST Advanced Deep Extragalactic Survey (JADES) team. Recently, a team of researchers have hypothesized these candidates could be “dark stars,” which are theoretical objects far more massive and brighter than our sun, and allegedly powered by demolishing particles of dark matter. (Credit: NASA/European Space Agency)

A recent study published in the Proceedings of the National Academy of Sciences (PNAS) examines what are known as dark stars, which are estimated to be much larger than our Sun, are hypothesized to have existed in the early universe, and are allegedly powered by the demolition of dark matter particles. This study was conducted using spectroscopic analysis from NASA’s James Webb Space Telescope (JWST), and more specifically, the JWST Advanced Deep Extragalactic Survey (JADES), and holds the potential to help astronomers better understand dark stars and the purpose of dark matter, the latter of which continues to be an enigma for the scientific community, as well as how it could have contributed to the early universe.