Space news topic and space related news

Started by Tsanten Eywa 'eveng, September 23, 2011, 03:31:21 PM

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Toliman


Toliman


Toliman

ARCHIVAL DATA REVEALS EARLIEST STAGES OF A DRAMATIC EVENT
https://hubblesite.org/contents/news-releases/2020/news-2020-07

Astronomers searching archival data from NASA's Kepler exoplanet hunting mission identified a previously unknown dwarf nova that underwent a super-outburst, brightening by a factor of 1,600 times in less than a day. While the outburst itself has a theoretical explanation, the slow rise in brightness that preceded it remains a mystery. Kepler's rapid cadence of observations were crucial for recording the entire event in detail.
The dwarf nova system consists of a white dwarf star with a brown dwarf companion. The white dwarf is stripping material from the brown dwarf, sucking its essence away like a vampire. The stripped material forms an accretion disk around the white dwarf, which is the source of the super-outburst. Such systems are rare and may go for years or decades between outbursts, making it a challenge to catch one in the act.

Toliman

ALMA catches beautiful outcome of stellar fight
https://www.almaobservatory.org/en/audiences/alma-catches-beautiful-outcome-of-stellar-fight/

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, have spotted a peculiar gas cloud that resulted from a confrontation between two stars. One star grew so large it engulfed the other which, in turn, spiralled towards its partner provoking it into shedding its outer layers.

Like humans, stars change with age and ultimately die. For the Sun and stars like it, this change will take it through a phase where, having burned all the hydrogen in its core, it swells up into a large and bright red-giant star. Eventually, the dying Sun will lose its outer layers, leaving behind its core: a hot and dense star called a white dwarf.

"The star system HD101584 is special in the sense that this 'death process' was terminated prematurely and dramatically as a nearby low-mass companion star was engulfed by the giant," said Hans Olofsson of the Chalmers University of Technology, Sweden, who led a recent study, published in Astronomy & Astrophysics, of this intriguing object.




Toliman

Something new about my favourite galaxy :)

HUBBLE INDICATES THE STATELY SOMBRERO UNDERWENT MAJOR MERGERS
https://hubblesite.org/contents/news-releases/2020/news-2020-08

Like a desperado in the Wild West, the broad "brim" of the Sombrero galaxy's disk may conceal a turbulent past. The Sombrero (M104) has never been a galaxy to fit the mold. It has an intriguing mix of shapes found in disk-shaped spiral galaxies, as well as football-shaped elliptical galaxies. The story of its structure becomes stranger with new evidence from the Hubble Space Telescope indicating the Sombrero is the result of major galaxy mergers, though its smooth disk shows no signs of recent disruption.

The galaxy's faint halo offers forensic clues. It's littered with innumerable stars that are rich in heavier elements (called metals), because they are later-generation stars. Such stars are usually only found in a galaxy's disk. They must have been tossed into the halo through mergers with mature, metal-rich galaxies in the distant past. The iconic galaxy now looks a bit more settled in its later years. It is now so isolated, there is nothing else around to feed on. This finding offers a new twist on how galaxies assemble themselves in our compulsive universe.

Surprising new data from NASA's Hubble Space Telescope suggests the smooth, settled "brim" of the Sombrero galaxy's disk may be concealing a turbulent past. Hubble's sharpness and sensitivity resolves tens of thousands of individual stars in the Sombrero's vast, extended halo, the region beyond a galaxy's central portion, typically made of older stars. These latest observations of the Sombrero are turning conventional theory on its head, showing only a tiny fraction of older, metal-poor stars in the halo, plus an unexpected abundance of metal-rich stars typically found only in a galaxy's disk, and the central bulge. Past major galaxy mergers are a possible explanation, though the stately Sombrero shows none of the messy evidence of a recent merger of massive galaxies.

"The Sombrero has always been a bit of a weird galaxy, which is what makes it so interesting," said Paul Goudfrooij of the Space Telescope Science Institute (STScI), Baltimore, Maryland. "Hubble's metallicity measurements (i.e.: the abundance of heavy elements in the stars) are another indication that the Sombrero has a lot to teach us about galaxy assembly and evolution."

Toliman

How Newborn Stars Prepare for the Birth of Planets
https://www.almaobservatory.org/en/press-release/how-newborn-stars-prepare-for-the-birth-of-planets/

An international team of astronomers used two of the most powerful radio telescopes in the world to create more than three hundred images of planet-forming disks around very young stars in the Orion Clouds. These images reveal new details about the birthplaces of planets and the earliest stages of star formation.

Most of the stars in the Universe are accompanied by planets. These planets are born in rings of dust and gas, called protoplanetary disks. Even very young stars are surrounded by these disks. Astronomers want to know exactly when these disks start to form, and what they look like. But young stars are very faint, and there are dense clouds of dust and gas surrounding them in stellar nurseries. Only highly sensitive radio telescope arrays can spot the tiny disks around these infant stars amidst the densely packed material in these clouds.

For this new research, astronomers pointed both the Atacama Large Millimeter/submillimeter Array (ALMA) and the National Science Foundation's Karl G. Jansky Very Large Array (VLA) to a region in space where many stars are born: the Orion Molecular Clouds. This survey, called VLA/ALMA Nascent Disk and Multiplicity (VANDAM), is the largest survey of young stars and their disks to date.

Toliman

ALMA Spots Metamorphosing Aged Star
https://www.almaobservatory.org/en/press-release/alma-spots-metamorphosing-aged-star/

An international team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) captured the very moment when an old star first starts to alter its environment. The star has ejected high-speed bipolar gas jets which are now colliding with the surrounding material; the age of the observed jet is estimated to be less than 60 years. These are key features to understand how the complex shapes of planetary nebulae are formed.
Sun-like stars evolve to puffed-up Red Giants in the final stage of their lives. Then, the star expels gas to form a remnant called a planetary nebula. There is a wide variety in the shapes of planetary nebulae; some are spherical, but others are bipolar or show complicated structures. Astronomers are interested in the origins of this variety, but the thick dust and gas expelled by an old star obscure the system and make it difficult to investigate the inner-workings of the process.

To tackle this problem, a team of astronomers led by Daniel Tafoya in Chalmers University of Technology, Sweden, pointed ALMA at W43A, an old star system in the constellation Aquila, the Eagle.

Thanks to ALMA's high resolution, the team obtained a very detailed view of the space around W43A. "The most notable structures are its small bipolar jets," says Tafoya, the lead author of the research paper published by the Astrophysical Journal Letters. The team found that the velocity of the jets is as high as 175 km per second, which is much higher than previous estimations. Based on this speed and the size of the jets, the team calculated the age of the jets to be less than a human life-span.

"Considering the youth of the jets compared to the overall lifetime of a star, it is safe to say we are witnessing the 'exact moment' that the jets have just started to shove through the surrounding gas," explains Tafoya. "When the jets carve through the surrounding material in some 60 years, a single person can watch the progress in their life."

In fact, the ALMA image clearly maps the distribution of dusty clouds entrained by the jets, which is telltale evidence that it is impacting on the surroundings.

The team assumes that this entrainment is the key to form a bipolar-shaped planetary nebula. In their scenario, the aged star originally ejects gas spherically and the core of the star loses its envelope. If the star has a companion, gas from the companion pours onto the core of the dying star, and a portion of this new gas forms the jets. Therefore, whether or not the old star has a companion is an important factor to determine the structure of the resulting planetary nebula.

"W43A is one of the peculiar so called 'water fountain' objects," says Hiroshi Imai at Kagoshima University, Japan, a member of the team. "Some old stars show characteristic radio emissions from water molecules. We suppose that spots of these water emissions indicate the interface region between the jets and the surrounding material. We named them 'water fountains,' and it could be a sign that the central source is a binarity system launching a new jet."

"There are only 15 'water fountain' objects identified to date, despite the fact that more than 100 billion stars are included in our Milky Way Galaxy," explains José Francisco Gómez at Instituto de Astrofísica de Andalucía, Spain. "This is probably because the lifetime of the jets is quite short, so we are very lucky to see such rare objects."




archaic

Pasha, an Avatar story, my most recent fanfic, Avatar related, now complete.

The Dragon Affair my last fanfic, non Avatar related.

Toliman

Kea tìkin :)

This part of astrophysic is very interesting for me :)

Toliman

In the Valley of Radius: TESS found an interesting planetary system
https://engnews24h.com/in-the-valley-of-radius-tess-found-an-interesting-planetary-system/

Astronomers like multiplanetary systems. If two or more planets orbit a star, we have planets that originated from the same protoplanetary disk at the same star but faced different conditions. This allows scientists to study the origin and evolution of planetary systems.

One of the major challenges of current exoplanet research is radius valley. For sun-like stars, the lower planet occurrence rate is about 1.7 to 2.0 Earth radii, and for smaller stars there is a similar gap between 1.5 and 1.7 Earth.

The radius valley is probably related to the transition between stone planets and planets with a significant envelope of hydrogen and helium. It is possible that some planets with a significant envelope will lose this envelope due to ultraviolet radiation from nearby stars and their radius will shrink so that they will clean up the area within the radius valley.

The LTT 3780 Planetary System can help us clarify these issues. TESS has discovered two planets in a red dwarf, 72 light-years away.

LTT 3780 p orbits a star with a period of 0.77 days, the planet LTT 3780 c with a period of 12.2 days.

Two studies have been published about the planetary system:

1) In addition to TESS data, Ryan Cloutier and his team used spectral measurements from the HARPS spectrograph in Chile and HARPS-N in the Canary Islands. According to their measurements he has planet b radius 1.33 Earth and mass at least 3.12 ± 0.51 Earth, planet c radius 2.3 Earth and weight 8.5 ± 1.6 Earth.
2) Grzegorz Nowak and his team used the CARMENES spectrograph on Calar Alto and reached slightly different values, especially in weight. In case of planet b it is 2.3 Earth and in case of planet c 6.2 Earth.
Of course, the density of planets also varies. Cloutier et al. reported 7300 and 3900 kg / m3Nowak et al. 5240 and 2450 kg / m3.

But the conclusions are the same. The first planet will have a composition similar to Earth and the second will probably have an envelope of hydrogen and helium.

The radii of the planets are close to the valley of the radius, making them an ideal laboratory to test theories about this phenomenon.

The first planet receives 106 times more radiation than the Earth at the Sun, the distant planet only 2.6 times. Planet c could be looked at in the future by James Webb's Space Telescope to explore its atmosphere.

TESS data indicate the possible existence of a third planet, though this is not conclusive. Further observations will be needed.

Toliman

SLIME MOLD SIMULATIONS USED TO MAP THE DARK MATTER HOLDING THE UNIVERSE TOGETHER
https://hubblesite.org/contents/news-releases/2020/news-2020-11

FEASTING BEHAVIOR OF BRAINLESS ORGANISMS SHOWS ASTRONOMERS WHERE TO POINT THE HUBBLE TELESCOPE
A simple single-cell organism that may be growing on your lawn is helping astronomers probe the largest structures in the universe.

These organisms, called slime mold, feed on dead plant material, and they have an uncanny ability to seek out food sources. Although brainless, the organism's "genius" at creating efficient networks to reach their food goal has caught the attention of scientists. Researchers have recreated the slime mold's behavior in computer algorithms to help solve large-scale engineering problems such as finding the most efficient traffic routes in large cities, solving mazes, and pinpointing crowd evacuation routes.

A team of astronomers has now turned to slime mold to help them trace the universe's large-scale network of filaments. Built by gravity, these vast cobweb structures, called the cosmic web, tie galaxies and clusters of galaxies together along faint bridges of gas and dark matter hundreds of millions of light-years long.

To trace the filaments, the research team designed a computer algorithm informed by slime-mold behavior. The team seeded the algorithm with the charted positions of 37,000 galaxies and ran it to generate a filamentary map. The astronomers then used archival observations from the Hubble Space Telescope to detect and study the faint gas permeating the web at the predicted locations.

The behavior of one of nature's humblest creatures is helping astronomers probe the largest structures in the universe.

The single-cell organism, known as slime mold (Physarum polycephalum), builds complex filamentary networks in search of food, finding near-optimal pathways to connect different locations. In shaping the universe, gravity builds a vast cobweb structure of filaments tying galaxies and clusters of galaxies together along faint bridges hundreds of millions of light-years long. There is an uncanny resemblance between the two networks: one crafted by biological evolution, and the other by the primordial force of gravity.

The cosmic web is the large-scale backbone of the cosmos, consisting primarily of the mysterious substance known as dark matter and laced with gas, upon which galaxies are built. Dark matter cannot be seen, but it makes up the bulk of the universe's material. The existence of a web-like structure to the universe was first hinted at in the 1985 Redshift Survey conducted at the Harvard-Smithsonian Center for Astrophysics. Since those studies, the grand scale of this filamentary structure has grown in subsequent sky surveys. The filaments form the boundaries between large voids in the universe.


Toliman

Findings From NASA's Juno Update Jupiter Water Mystery
https://www.nasa.gov/feature/jpl/findings-from-nasas-juno-update-jupiter-water-mystery

NASA's Juno mission has provided its first science results on the amount of water in Jupiter's atmosphere. Published recently in the journal Nature Astronomy, the Juno results estimate that at the equator, water makes up about 0.25% of the molecules in Jupiter's atmosphere — almost three times that of the Sun. These are also the first findings on the gas giant's abundance of water since the agency's 1995 Galileo mission suggested Jupiter might be extremely dry compared to the Sun (the comparison is based not on liquid water but on the presence of its components, oxygen and hydrogen, present in the Sun).

An accurate estimate of the total amount of water in Jupiter's atmosphere has been on the wish lists of planetary scientists for decades: The figure in the gas giant represents a critical missing piece to the puzzle of our solar system's formation. Jupiter was likely the first planet to form, and it contains most of the gas and dust that wasn't incorporated into the Sun.

The leading theories about its formation rest on the amount of water the planet soaked up. Water abundance also has important implications for the gas giant's meteorology (how wind currents flow on Jupiter) and internal structure. While lightning — a phenomenon typically fueled by moisture — detected on Jupiter by Voyager and other spacecraft implied the presence of water, an accurate estimate of the amount of water deep within Jupiter's atmosphere remained elusive.

Toliman

QUASAR TSUNAMIS RIP ACROSS GALAXIES
https://hubblesite.org/contents/news-releases/2020/news-2020-10

BLISTERING RADIATION FROM ACTIVE BLACK HOLE SNOWPLOWS IMMENSE AMOUNTS OF MECHANICAL ENERGY THROUGH SPACE

The weather forecast for galaxies hosting monster, active black holes is blustery. Engorged by infalling material, a supermassive black hole heats so much gas that it can shine 1,000 times brighter than its host galaxy. But that's not all.

Hubble astronomers found that the region around the black hole emits so much radiation that it pushes out material at a few percent the speed of light (a speed fast enough to travel from Earth to the Moon in a few minutes). This material slams into a host galaxy's lanes of gas and dust, preventing the formation of new stars. The torrential winds are snowplowing the equivalent of hundreds of solar masses of material each year. And, the forecast is that this stormy weather will continue for at least ten million years.

Using the unique capabilities of NASA's Hubble Space Telescope, a team of astronomers has discovered the most energetic outflows ever witnessed in the universe. They emanate from quasars and tear across interstellar space like tsunamis, wreaking havoc on the galaxies in which the quasars live.

Quasars are extremely remote celestial objects, emitting exceptionally large amounts of energy. Quasars contain supermassive black holes fueled by infalling matter that can shine 1,000 times brighter than their host galaxies of hundreds of billions of stars.

As the black hole devours matter, hot gas encircles it and emits intense radiation, creating the quasar. Winds, driven by blistering radiation pressure from the vicinity of the black hole, push material away from the galaxy's center. These outflows accelerate to breathtaking velocities that are a few percent of the speed of light.

Toliman

The Strange Orbits of 'Tatooine' Planetary Disks
https://www.almaobservatory.org/en/press-release/the-strange-orbits-of-tatooine-planetary-disks/

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have found striking orbital geometries in protoplanetary disks around binary stars. While disks orbiting the most compact binary star systems share very nearly the same plane, disks encircling wide binaries have orbital planes that are severely tilted. These systems can teach us about planet formation in complex environments.

In the last two decades, thousands of planets have been found orbiting stars other than our Sun. Some of these planets orbit two stars, just like Luke Skywalker's home Tatooine. Planets are born in protoplanetary disks – we now have wonderful observations of these thanks to ALMA – but most of the disks studied so far orbit single stars. 'Tatooine' exoplanets form in disks around binary stars, so-called circumbinary disks.

Studying the birthplaces of 'Tatooine' planets provides a unique opportunity to learn about how planets form in different environments. Astronomers already know that the orbits of binary stars can warp and tilt the disk around them, resulting in a circumbinary disk misaligned relative to the orbital plane of its host stars. For example, in a 2019 study led by Grant Kennedy of the University of Warwick, UK, ALMA found a striking circumbinary disk in a polar configuration.

"With our study, we wanted to learn more about the typical geometries of circumbinary disks," said astronomer Ian Czekala of the University of California at Berkeley. Czekala and his team used ALMA data to determine the degree of alignment of nineteen protoplanetary disks around binary stars. "The high resolution ALMA data was critical for studying some of the smallest and faintest circumbinary disks yet," said Czekala.

The astronomers compared the ALMA data of the circumbinary disks with the dozen 'Tatooine' planets that have been found with the Kepler space telescope. To their surprise, the team found that the degree to which binary stars and their circumbinary disks are misaligned is strongly dependent on the orbital period of the host stars. The shorter the orbital period of the binary star, the more likely it is to host a disk in line with its orbit. However, binaries with periods longer than a month typically host misaligned disks.


Toliman


Toliman

Earth 2.0? Astronomers Discover Large Exoplanet That Could Have the Right Conditions for Life
https://scitechdaily.com/earth-2-0-astronomers-discover-large-exoplanet-that-could-have-the-right-conditions-for-life/

Super-Earth Exoplanet K2-18b Could Have Right Conditions for Life
http://www.sci-news.com/astronomy/k2-18b-habitability-08171.html

Vawmataw

QuoteAstronomers Discover Large Exoplanet That Could Have the Right Conditions for Life
Ok, when is the launching date? ;D
Fmawn Ta 'Rrta - News IN NA'VI ONLY (Discord)
Traducteur francophone de Kelutral.org, dict-navi et Reykunyu

Toliman

Quote from: Vawmataw on March 27, 2020, 03:46:41 PM
QuoteAstronomers Discover Large Exoplanet That Could Have the Right Conditions for Life
Ok, when is the launching date? ;D
I would like know it too ;D

Toliman

HUBBLE FINDS BEST EVIDENCE FOR ELUSIVE MID-SIZED BLACK HOLE
https://hubblesite.org/contents/news-releases/2020/news-2020-19

HIGH-RESOLUTION IMAGING REVEALS BLACK HOLE'S HIDEOUT IN EXTRA-GALACTIC STAR CLUSTER
Like detectives carefully building a case, astronomers gathered evidence and eliminated suspects until they found the best evidence yet that the death of a star, first witnessed in X-rays, could be traced back to an elusive mid-sized black hole. The result is a long-sought win for astronomy, as the mid-sized "missing link" in the black hole family has thus far thwarted detection. NASA's Hubble Space Telescope was used to follow up on multiple X-ray observations of a suspected tidal disruption event. This is caused when a wayward star comes too close to the gravity well of a black hole and gets shredded by its tidal forces. The intense heat from stellar cannibalism betrays the black hole's presence with a burst of X-rays. Hubble resolved the source region of this X-ray flare as a star cluster outside the Milky Way galaxy. Such clusters have been considered likely places to find an intermediate-mass black hole. The discovery eliminated the possibility that the X-rays came from another type of source within the Milky Way.

Astronomers have found the best evidence for the perpetrator of a cosmic homicide: a black hole of an elusive class known as "intermediate-mass," which betrayed its existence by tearing apart a wayward star that passed too close.

Weighing in at about 50,000 times the mass of our Sun, the black hole is smaller than the supermassive black holes (at millions or billions of solar masses) that lie at the cores of large galaxies, but larger than stellar-mass black holes formed by the collapse of a massive star.

These so-called intermediate-mass black holes (IMBHs) are a long-sought "missing link" in black hole evolution. Though there have been a few other IMBH candidates, researchers consider these new observations the strongest evidence yet for mid-sized black holes in the universe.

It took the combined power of two X-ray observatories and the keen vision of NASA's Hubble Space Telescope to nail down the cosmic beast.

Toliman

Astronomers find 139 new minor planets in the outer solar system
https://astronomy.com/news/2020/03/astronomers-find-139-new-minor-planets-in-the-outer-solar-system

A new method for hunting minor planets uncovered more than a hundred small, distant worlds. And the novel technique could even help resolve the mystery of Planet Nine.