Tag: astronomy

British scientists get their own Bennu sample to study

9:16 am

The British History Museum has now received a small sample of material from the asteroid Bennu, brought back to Earth by the planetary probe OSIRIS-REx.

The first two years of research at the Natural History Museum will focus on non-destructive tests, such as X-ray diffraction and electron microscopy to learn about Bennu’s mineral composition and structure. The largest grains in the sample are on the order of millimetres wide, while the smallest are mere dust particles. “It doesn’t sound like a lot of material, but it’s plenty to work with,” King said.

The museum is home to one of the world’s leading meteorite collections, and the staff are well-used to handling small amounts of extremely precious materials from outer space. Unlike meteorites that have been baked and battered on their fiery passage through Earth’s atmosphere, the dust and rocky fragments from Bennu were brought to Earth in pristine condition, allowing scientists a rare glimpse of the unaltered asteroid.

The last sentence says it all. Up until recently, researchers have had a distorted view of the overall make-up of asteroids because the oldest kinds, carbonaceous chondrite, are the most delicate and get significantly changed by their passage through the Earth’s atmosphere. The samples from Bennu and Ryugu are changing this, and will eventually revolutionize the understanding scientists have of our present solar system.

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China delays till ’25 the launch of its Hubble-class optical space telescope

9:34 am

China today revealed that it is delaying the the launch of its Xuntian space telescope from early next year to 2025.

Zhan Hu, project scientist of Xuntian space telescope system, revealed that the delay was necessary for the team to finalize a preflight “engineering qualification model.” This model will undergo rigorous performance tests early next year. Despite the setback, China is making significant strides by domestically developing all five instruments for Xuntian, a first for the country, Scientific American reported.

The optical telescope, designed to somewhat comparable to Hubble, is intended to fly close to China’s Tiangong-3 space station where astronauts will periodically fly over to do maintenance and repair. Its primary mirror, two meters in diameter, is only slightly smaller than Hubble’s 2.4 meter mirror.

The article says the launch was supposed to happen before the end of this year, but that is incorrect. The launch has been targeting the spring of 2024 since February.

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Webb: Needles scattered near the center of the Milky Way

9:14 am

Needles in space
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Scientists today released a new false-color infrared image taken by the Webb Space Telescope of a region about 300 light years from the center of the Milky Way, dubbed Sagittarius-C. That picture is to the right, cropped, reduced and sharpened to post here. The blue or cyan regions are ionized hydrogen clouds, and with this image were revealed to be much more extensive than expected. The orange blob near the center is a densely packed cluster of protostars, the starlight blocked by the cloud of material.

The most interesting feature however are the needle-like structures within that ionized hydrogen, oriented in all directions in a manner that looks completely random. Though such needles have been seen previously, the data here is far more detailed, and might eventually help astronomers figure out what the heck these features are and what caused them.

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Gamma ray burst 1.9 billion light years away was powerful enough to affect Earth’s atmosphere

9:34 am

One of the most powerful gamma ray bursts (GRBs) ever detected was so powerful that despite occurring about 1.9 billion light years away it was powerful enough to affect Earth’s atmosphere.

On 9 October 2022, for 7 minutes, high energy photons from a gigantic explosion 1.9 billion light-years away toasted one side of Earth as never before observed. The event, called a gamma ray burst (GRB), was 70 times brighter than the previous record holder. But what astronomers dub the “BOAT”—the brightest of all time—did more than provide a light show spanning the electromagnetic spectrum. It also ionized atoms across the ionosphere, which spans from 50 to 1000 kilometers in altitude, researchers say. The findings highlight the faint but real risk of a closer burst destroying Earth’s protective ozone layer.

“It was such a massive event, it affected all levels of the atmosphere,” says solar physicist Laura Hayes of the European Space Agency (ESA).

None of these consequences were harmful or even noticeable to any life on Earth, but the data proved without question that a GRB close by within the Milky Way could have been the cause of one or more of the past extinction events. It also proved that a future such nearby explosion could do the same again.

At present astronomers think that GRBs are caused either by the collapse of a massive star into a black hole, during a supernovae event, or by the merger of two neutron stars. Neither conclusion is proved as yet, though the evidence has eliminated most other theories.

For astronomers this GRB was significant because its strength allowed many different telescopes and detectors to record it, in many different wavelengths. Having such a wealth of information helps them better figure out what happened when the burst occurred.

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Scientists: More evidence cosmic rays come from nearby supernova remnants

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The uncertainty of science: According to high energy data from an instrument on ISS, astronomers found more evidence that the cosmic rays that enter our solar system likely come from nearby supernova remnants.

Current theory posits that the aftermath of supernovae (exploding stars), called supernova remnants, produce these high energy electrons, which are a specific type of cosmic ray. Electrons lose energy very quickly after leaving their source, so the rare electrons arriving at CALET with high energy are believed to originate in supernova remnants that are relatively nearby (on a cosmic scale), Cannady explains.

The study’s results are “a strong indicator that the paradigm that we have for understanding these high-energy electrons—that they come from supernova remnants and that they are accelerated the way that we think they are—is correct,” Cannady says. The findings “give insight into what’s going on in these supernova remnants, and offer a way to understand the galaxy and these sources in the galaxy better.”

The results however do not prove this. Nor do they eliminate the possibility that cosmic rays might also come from other sources outside our galaxy. At present the data is simply too uncertain.

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Galaxies within galaxies within galaxies

9:54 am

Galaxies within galaxies
Click for original image.

Time another cool galaxy image! The picture to the right, cropped, reduced, sharpened, and annotated to post here, was taken by the Hubble Space Telescope as part of a survey project of galaxies where past supernovae had occurred. From the caption:

The location of this faded supernova was observed as part of a study of multiple hydrogen-rich supernovae, also known as type II supernovae, in order to better understand the environments in which certain types of supernovae take place.

Though the picture’s resolution was reduced to post here, I have also included insets at the full released resolution of three of background galaxies, one of which (on the uppermost right) appears to have a second smaller galaxy either associated with it or is another background galaxy even farther away. Such background galaxies are always seen Hubble images, which starkly tell us that the universe is far vaster than we can imaging, with more stars than we can conceive.

The galaxy featured here is interesting in its own right. Though it appears to be a spiral galaxy, its arms are very indistinct, suggesting that is sits between that of an elliptical galaxy (no arms, just a cloud of stars) and a spiral (with well-defined arms).

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Chandra X-rays a giant hand in space

3:54 pm

A cosmic hand
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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Chandra X-ray Observatory, with data from the orbiting IXPE producing the lines that indicate the orientation of the magnetic field lines.

The image was part of research studying what the scientists call Pulsar Wind Nebulae (PWNe).

[E]arly-on when the new-born pulsar is still deep in its parent supernova remnant, or at late times after it has escaped to the relatively uniform interstellar medium, the pulsar wind is often uniform around the pulsar spin or velocity axis. In projection on the sky such structures have bilateral symmetry, that is, the two halves mirror each other. This makes them look (vaguely) like animals. This has led to many PWNe collecting animal monikers (‘The Mouse’, ‘The Dragonfly’, ‘The Rabbit’ – we are guilty of some of these…).

In between these early and late phases, the story is often more complex and the PWN interaction with the supernova shock wave leads to complicated morphologies. One of the prime examples is the PWN in the supernova remnant RCW 89 (also known as MSH 15-5(2)). Here the complex interactions form the PWN into the `Cosmic Hand’. Wanting to map the magnetic fields which structure this hand, the IXPE team took a long hard stare at MSH 15-5(2) and its central pulsar.

The scientists admit that the match between IXPE’s data and the structure of the hand is not really a surprise, but confirming the match was necessary if they are ever going to figure out the fundamental laws that govern magnetic fields, laws that presently are not well understood, at all.

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A spiral galaxy giving birth to a lot of stars

10:01 am

A spiral galaxy giving birth to a lot of stars
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Time for another cool galaxy image! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope, and shows what some informally refer to as the “‘Spanish Dancer Galaxy’ because the “vivid and dramatic swirling lines of its spiral arms … evoke the shapes and colours of a dancer’s moving form. ”

Though this galaxy’s two main arms cause it to resemble a barred galaxy, it lacks a central bar, suggesting it is young. The numerous reddish and pink regions in the arms, all of which are thought to be star-forming regions, also suggest the galaxy is young, still giving birth to many stars.

It is located about 60 million light years away, and is part of what scientists label the Doradus galaxy group, which contains less than a hundred galaxies. In comparison, a galaxy cluster is much larger, containing hundreds to thousands of galaxies.

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An infrared view of the Crab Nebula by Webb

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Webb's image of the Crabb compared to Hubble's
Click for original image.

Using the Webb Space Telescope astronomers have taken the first detailed infrared image of the Crab Nebula, the remnant from a supernova that occurred in 1054 AD.

The two pictures on the right compare Webb’s false color infrared view with a natural light Hubble image in optical wavelengths, taken in 2005. From the press release:

The supernova remnant is comprised of several different components, including doubly ionized sulfur (represented in red-orange), ionized iron (blue), dust (yellow-white and green), and synchrotron emission (white). In this image, colors were assigned to different filters from Webb’s NIRCam and MIRI: blue (F162M), light blue (F480M), cyan (F560W), green (F1130W), orange (F1800W), and red (F2100W).

In comparing the images, it appears the scientists chose colors for the Webb image to more or less match those of Hubble’s natural color picture. However, as the press release notes:

Additional aspects of the inner workings of the Crab Nebula become more prominent and are seen in greater detail in the infrared light captured by Webb. In particular, Webb highlights what is known as synchrotron radiation: emission produced from charged particles, like electrons, moving around magnetic field lines at relativistic speeds. The radiation appears here as milky smoke-like material throughout the majority of the Crab Nebula’s interior.

This feature is a product of the nebula’s pulsar, a rapidly rotating neutron star. The pulsar’s strong magnetic field accelerates particles to extremely high speeds and causes them to emit radiation as they wind around magnetic field lines. Though emitted across the electromagnetic spectrum, the synchrotron radiation is seen in unprecedented detail with Webb’s NIRCam instrument.

The release also notes this remarkable but somewhat unfortunate fact:

Scientists will have newer Hubble data to review within the next year or so from the telescope’s reimaging of the supernova remnant. This will mark Hubble’s first look at emission lines from the Crab Nebula in over 20 years, and will enable astronomers to more accurately compare Webb and Hubble’s findings.

In 2005 repeated Hubble images of the Crab revealed that its filaments and radiation were stormy, with constant activity. The scientists actually produced a movie of those changes. It was expected that new images would be taken at regular intervals to track that activity. Apparently it was not, either because no scientist was interested or the committee that assigns time on Hubble decided this wasn’t important enough reseach.

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Is a recently discovered near Earth asteroid a piece from the Moon?

10:38 am

The uncertainty of science: Researchers now think they have enough information to claim that a recently discovered near Earth asteroid, dubbed Kamo`oalewa, could actually be a piece of the Moon, flung from it during a asteroid impact in the past few million years.

The 2021 study found that Kamo`oalewa’s spectrum was unlike that of other near-Earth asteroids but matched most closely that of the moon. Based on this, the team hypothesized that the asteroid could have been ejected from the lunar surface as a result of a meteoroidal impact.

In the new study, Malhotra and her team wanted to determine the feasibility for a knocked-off piece of the moon to get into this quasi-satellite orbit – a phenomenon that is quite unlikely, Malhotra said. Moon fragments that have enough kinetic energy to escape the Earth-moon system also have too much energy to land in the Earth-like orbits of quasi-satellites, she said.

With numerical simulations that accurately account for the gravitational forces of all the solar system’s planets, Malhotra’s group found that some lucky lunar fragments could actually find their way to such orbits. Kamo`oalewa could be one of those fragments created during an impact on the moon in the past few million years, according to the study.

The scientists add that the asteroid’s solar orbit, which keeps its flying in relative formation with the Earth for millions of years, strengthens this hypothesis.

It must be noted that this remains an unconfirmed hypothesis. A spacecraft would have to visit Kamo’oalewa and obtain samples to study to confirm it.

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New data better maps the supernova remnant SN1006

10:50 am

SN1006, as seen in X-rays
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Using data from both the Chandra X-ray Observatory and the Imaging X-ray Polarimetry Explorer (IXPE), scientists have now better mapped the magnetic field and the remnant from the supernova that occurred in 1006 AD.

The false color image to the right shows this data. From the caption:

The red, green, and blue elements reflect low, medium, and high energy X-rays, respectively, as detected by Chandra. The IXPE data, which measure the polarization of the X-ray light, is show in purple in the upper left corner, with the addition of lines representing the outward movement of the remnant’s magnetic field.

From the press release:

Researchers say the results demonstrate a connection between the magnetic fields and the remnant’s high-energy particle outflow. The magnetic fields in SN 1006’s shell are somewhat disorganized, per IXPE’s findings, yet still have a preferred orientation. As the shock wave from the original explosion passes through the surrounding gas, the magnetic fields become aligned with the shock wave’s motion. Charged particles are trapped by the magnetic fields around the original point of the blast, where they quickly receive bursts of acceleration. Those speeding high-energy particles, in turn, transfer energy to keep the magnetic fields strong and turbulent.

At present scientists really do not understand the behavior of stellar-sized magnetic fields. It is very complex, involving three dimensional movements that are hard to measure, as well as electromagnetic processes that are not well understood. While this new data doesn’t provide an explanation, it does tell us better what is actually happening. The theories will follow.

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Swirling galactic-sized streams surrounding a pair of supermassive black holes

1:25 pm

Swirling galactic arms surrounding two supermassive black holes

Time for another galactic cool image! The picture to the right, reduced and sharpened to post here, was released today by the Gemini South ground-based telescope in Chile. It shows the streams of gas and stars that swirl around a pair of supermassive black holes at the center of this galaxy, located only 90 million light years away.

The image reveals vast swirling bands of interstellar dust and gas resembling freshly-spun cotton candy as they wrap around the merging cores of the progenitor galaxies. From the aftermath has emerged a scattered mix of active starburst regions and sedentary dust lanes encircling the system.

What is most noteworthy about NGC 7727 is undoubtedly its twin galactic nuclei, each of which houses a supermassive black hole, as confirmed by astronomers using the European Southern Observatory’s Very Large Telescope (VLT). Astronomers now surmise the galaxy originated as a pair of spiral galaxies that became embroiled in a celestial dance about one billion years ago. Stars and nebulae spilled out and were pulled back together at the mercy of the black holes’ gravitational tug-of-war until the irregular tangled knots we see here were created.

The black holes themselves are 154 and 6.3 million solar masses respectively, and are presently about 1,600 light years apart. Scientists calculate that they will merge in about 250 million years. Each once formed the center of its own galaxy. Now both galaxies have merged, creating this three-dimensional whirlpool of arms.

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A dance of three galaxies

10:40 am

Three galaxies merging
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope. Though it appears to show two galaxies interacting with each other, other spectroscopic data proves there are actually three large galaxies in the picture. From the caption:

The two clearly defined galaxies are NGC 7733 (smaller, lower right) and NGC 7734 (larger, upper left). The third galaxy is currently referred to as NGC 7733N, and can actually be spotted in this picture if you look carefully at the upper arm of NGC 7733, where there is a visually notable knot-like structure, glowing with a different colour to the arm and obscured by dark dust. This could easily pass as part of NGC 7733, but analysis of the velocities (speed, but also considering direction) involved in the galaxy shows that this knot has a considerable additional redshift, meaning that it is very likely its own entity and not part of NGC 7733.

All three galaxies are quite close to each other, which means they are in the long process of merging together into one larger galaxy.

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Scientists: The activity at the few known fast radio bursts suggests they resemble earthquakes

8:57 am

By analyzing 7,000 fast radio bursts (FRBs) detected from the three known FRBs, two scientists have found that the behavior appears to resemble the main quake and aftershocks seen in earthquakes.

The duo found that the arrival times of bursts from FRB20121102A showed a high degree of correlation, with many more bursts arriving within a second of each other than would be expected if the generation of bursts were completely random. This correlation faded away at longer timescales, with bursts separated by over a second arriving completely at random.

They drew similarities with this behaviour to how earthquakes produce secondary aftershocks in the hours or days following a tremor, but then become completely unpredictable once an episode of aftershocks passes. Moreover, they found that the rate of these FRB “aftershocks” follows the same Omori-Utsu law that characterises the occurrence of earthquake aftershocks on Earth. The law states that shortly after a large earthquake, the rate of aftershocks remains constant over a brief period of minutes to hours, after which the aftershock rate drops, decaying as roughly the inverse of the time since the main shock.

As always there is uncertainty about this conclusion. The magnitudes of the main quake and the pre- and after-shocks do not follow the curve pattern of earthquakes. Instead pre- and after-shocks can be as powerful.

The present theory is that FRBs are quakes in the crust of neutron stars, though this remains unconfirmed.

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Astronomers detect what they think is the most distant known fast radio burst yet

9:50 am

The uncertainty of science: Using ground-based radio and optical telescopes, astronomers think they have detected the most distant known fast radio burst yet, coming from a galaxy thought to be eight billion light years away.

On 10 June 2022, CSIRO’s ASKAP radio telescope on Wajarri Yamaji Country was used to detect a fast radio burst, created in a cosmic event that released, in milliseconds, the equivalent of our Sun’s total emission over 30 years.

“Using ASKAP’s array of dishes, we were able to determine precisely where [in the sky] the burst came from,” says Dr Ryder, the first author on the paper. “Then we used the European Southern Observatory (ESO) Very Large Telescope (VLT) in Chile to search for the source galaxy, finding it to be older and further away than any other FRB source found to date, and likely within a small group of merging galaxies.”

Note that the scientists have not actually measured the distance of this burst. They assume it sits at the same distance of the group of merging galaxies that surround it. Only about fifty fast radio bursts have so far been detected. As yet there is no accepted explanation as to what causes them, though knowing their assumed distance helps narrow the possibilities significantly.

The scientists also think they can use the energy from this burst to measure the intervening matter between it and Earth, and thus get a better estimate of the mass of the universe.

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Astronomers detect nano-sized quartz crystals in atmosphere of exoplanet

9:33 am

Using both the Hubble and Webb space telescopes in space, astronomers have detected nano-sized quartz crystals in the atmosphere of a Jupiter-class exoplanet orbiting its star every 3.7 days.

Silicates (minerals rich in silicon and oxygen) make up the bulk of Earth and the Moon as well as other rocky objects in our solar system, and are extremely common across the galaxy. But the silicate grains previously detected in the atmospheres of exoplanets and brown dwarfs appear to be made of magnesium-rich silicates like olivine and pyroxene, not quartz alone – which is pure SiO2.

The result from this team, which also includes researchers from NASA’s Ames Research Center and NASA’s Goddard Space Flight Center, puts a new spin on our understanding of how exoplanet clouds form and evolve. “We fully expected to see magnesium silicates,” said co-author Hannah Wakeford, also from the University of Bristol. “But what we’re seeing instead are likely the building blocks of those, the tiny ‘seed’ particles needed to form the larger silicate grains we detect in cooler exoplanets and brown dwarfs.”

These tiny quartz crystals are condensing out in the clouds themselves, due to the high temperatures and pressures there. The exoplanet itself is unusual because though its mass is one half that of Jupiter, its volume is seven times larger. This gives it a very large and deep atmosphere, thus providing the environment for crystal formation.

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Software patch saves Europe’s Euclid space telescope

10:03 am

Engineeers have successfully saved Europe’s new recently launched Euclid space telescope by installing a software patch that fixed the telescope’s inability to orient itself properly for long periods.

Shortly after launching on 1 July, the European space observatory Euclid started performing tiny, unexpected pirouettes. The problem revealed itself during initial tests of the telescope’s automated pointing system. If left unfixed, it could have severely affected Euclid’s science mission and led to gaps in its map of the Universe.

Now the European Space Agency (ESA) says that it has resolved the issue by updating some of the telescope’s software. The problem occurred when the on board pointing system mistook cosmic noise for faint stars in dark patches of sky, and directed the spacecraft to reorient itself in the middle of a shot.

The new software essentially reduces the amount of light that enters the pointing system, so that the noise is no longer detected. This means that observations however will have to be longer to obtain the same data, extending the mission.

Euclid’s goal is a follow-up on Europe’s Gaia mission, to map 1.5 billion galaxies in three dimensions. Gaia did it with the stars in the Milky Way. Euclid is looking deeper, requiring far greater precision and accuracy in pointing.

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Astronomers detect baffling blue transient far outside any galaxy

11:32 am

Transient in intergalactic space
Click for original image.

Using a variety of telescopes, astronomers have discovered a baffling short-term object that brightens quickly in blue light and then fades.

What makes this discovery even more baffling is that though other such Luminous Fast Blue Optical Transients (LFBOT) have been discovered, all have been within galaxies, while this new discovery is in intergalactic space, as shown by the red bars in the picture to right, taken by the Hubble Space Telescope and cropped, reduced, and sharpened to post here. From the caption:

[An LFBOT] shines intensely in blue light and evolves rapidly, reaching peak brightness and fading again in a matter of days, unlike supernovae which take weeks or months to dim. Only a handful of previous LFBOTs have been discovered since 2018. The surprise is that this latest transient, seen in 2023, lies at a large offset from both the barred spiral galaxy at right and the dwarf galaxy to the upper left. Only Hubble could pinpoint its location. And, the results are leaving astronomers even more confounded because all previous LFBOTs have been found in star-forming regions in the spiral arms of galaxies. It’s not clear what astronomical event would trigger such a blast far outside of a galaxy.

The frequent discovery of such short term transients in the past decade is because there are now many telescopes dedicated to making daily surveys of the entire sky. In the past such quick events were always missed.

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A nearby active galaxy, viewed head on by Hubble

9:39 am

Active galaxy
Click for original image.

Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope and is the third of a seven-day celebration of galaxies by the Hubble science team. Previous images in the series can be found here. From the caption for this particular image:

At the center of NGC 6951 lies a supermassive black hole surrounded by a ring of stars, gas, and dust about 3,700 light-years across. This “circumnuclear ring” is between 1 and 1.5 billion years old and has been forming stars for most of that time. Scientists hypothesize that interstellar gas flows through the dense, starry bar of the galaxy to the circumnuclear ring, which supplies new material for star formation. Up to 40 percent of the mass in the ring comes from relatively new stars that are less than 100 million years old. Spiral lanes of dust, shown in dark orange, connect the center of the galaxy to its outer regions, contributing more material for future star formation.

This galaxy, located about 78 million light years away, has also seen six different supernovae in the past quarter century. Compare that with the Milky Way, which has not seen a supernova now in more than four hundred years.

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Hubble data shows expansion of supernova remnant

9:57 am

Cygnus loop filament

Astronomers have created a four-second long movie using Hubble images collected over twenty years that shows the expansion of one filament in the Cygnus Loop supernova remnant, the explosion of which is thought to have occurred 20,000 years ago.

The picture above is one frame of that movie. The filament is estimated to be two light years in length.

By analyzing the shock’s location, astronomers found that the shock hasn’t slowed down at all in the last 20 years, and is speeding into interstellar space at over half a million miles per hour – fast enough to travel from Earth to the Moon in less than half an hour. While this seems incredibly fast, it’s actually on the slow end for the speed of a supernova shock wave.

Two versions of the movie are at the link, with the longer providing excellent context.

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Webb takes an infared look at Saturn

10:36 am

Webb's five images of Saturn
Webb’s five images of Saturn. Click for original.

Using the Webb Space Telescope, scientists have obtained five infrared images of Saturn to get a more detailed look at the gas giant’s atmosphere and the molecules within it.

The image to the right is Figure 1 from the paper, showing the location of those five images on Saturn, placed over a much higher resolution Hubble Space Telescope optical image. The graph on the bottom shows the molecules revealed from spectroscopic data obtained by Webb’s infrared view. From the abstract:

We show evidence that a stratospheric circulation pattern detected by Cassini during northern winter has now fully reversed in northern summer, with the low-latitude stratosphere being cool and depleted in aerosols due to summertime upwelling. MIRI [Webb’s mid-infrared instrument] provides access to spectral regions that were not possible with the Cassini spacecraft, particularly in the 5–7 μm region where reflected sunlight and thermal emission blend together. Ammonia and phosphine are enriched at Saturn’s equator, suggesting strong mixing from the deeper troposphere. MIRI’s high sensitivity enables the first identification of previously unseen emission propane bands, along with the first measurements of the distribution of several gaseous species: tropospheric water, and stratospheric ethylene, benzene, methyl, and carbon dioxide.

The paper notes that this work still has uncertainty because when the infrared images were taken engineers were still working out the kinks for using Webb. Nonetheless, the results illustrate the large potential for future planetary discoveries from Webb.

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Nearest supernova in a decade confirms such stars lose mass prior to exploding

10:03 am

Gemini North image of supernova in Pinwheel Galaxy
Arrow points to supernova. Click for original image,
taken by the Gemini North telescope in Hawaii.

Astronomers making a detailed analysis of the data from the nearest supernova in a decade, SN 2023ixf and located in the Pinwheel Galaxy only 20 million light years away, has confirmed what other research had suggested, that such stars lose significant mass prior to exploding.

Within hours of going supernova, core-collapse supernovae produce a flash of light that occurs when the shock wave from the explosion reaches the outer edge of the star. SN 2023ixf, however, produced a light curve that didn’t seem to fit this expected behavior. To better understand SN 2023ixf’s shock breakout, a team of scientists led by CfA postdoctoral fellow Daichi Hiramatsu analyzed data from the 1.5m Tillinghast Telescope, 1.2m telescope, and MMT at the Fred Lawrence Whipple Observatory, a CfA facility located in Arizona, as well as data from the Global Supernova Project— a key project of the Las Cumbres Observatory, NASA’s Neil Gehrels Swift Observatory, and many others. This multi-wavelength study, which was published this week in The Astrophysical Journal Letters, revealed that, in sharp contradiction to expectations and stellar evolution theory, SN 2023ixf’s shock breakout was delayed by several days.

“The delayed shock breakout is direct evidence for the presence of dense material from recent mass loss,” said Hiramatsu, adding that such extreme mass loss is atypical of Type II supernovae. “Our new observations revealed a significant and unexpected amount of mass loss— close to the mass of the Sun— in the final year prior to explosion.”

The press release overstates the surprise of this discovery. Research in the last two decades of massive stars that are thought to be the progenitors of supernovae has shown that they lose mass in great amounts during eruptions. It was therefore not that surprising that this star experienced its own eruption prior to going supernova.

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Small group of astronomers call for renaming the Magellanic Clouds, accusing Magellan of racism

9:38 am

They’re coming for you next: A new group of about fifty astronomers are now demanding that the Magellanic Clouds in the southern hemisphere be renamed because they don’t like it that Magellan was both a man of his time and also a white European explorer.

Magellan’s name is not fitting, astronomer Mia de los Reyes and colleagues argue. The leader of the first expedition to successfully circle the globe, Magellan enslaved and killed Indigenous people encountered on the voyage, which set out from Spain in 1519.

“Because we’re naming things in the night sky, which belongs to everyone, we think that it’s important to have names that reflect all of humanity,” says de los Reyes, of Amherst College in Massachusetts. She calls for the name change in an opinion piece published September 12 in Physics. Magellan’s voyage helped pave the way for Spanish colonialism in South America, Guam and the Philippines, says de los Reyes, who is Filipino American. “Many people see Magellan as a villain in the Philippines.”

No matter that Magellan was a great explorer who sacrificed his life to finally prove without doubt that the Earth was a sphere. No matter that he was the first person to document the existence of the Magellanic Clouds, which is why they are named for him. He was white and a European, and thus his place in history must be cancelled forever.

It also should not matter that the claims against Magellan are partly true, though magnified greatly into a slander by the use of Marxist terms. His prime mission was one of exploration, and the natives he kidnapped were taken not for purposes of slavery but to provide further documentation of what he had discovered.

No human being is perfect, and if we accept these demands to measure the past by these perfect standards we will have to cancel all history forever.

Which by the way is the real point. These radicals aren’t really interested in honoring the right people and taking honor away from the wrong people. What they want to do is to discredit all past Western history, and replace it with a Marxist fantasy that makes believe the achievements of European and Western Civilization never happened.

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Giant Magellan Telescope begins fabricating its seventh mirror

9:23 am

The fabrication of the seventh and last mirror for the Giant Magellan Telescope (GMT) has begun, with its completion and installation expected before the end of the decade.

In the project’s latest development, the Richard F. Caris Mirror Lab at another founding project partner, the University of Arizona, closed the lid on nearly 20 tons of the purest optical glass inside a one-of-a-kind oven housed beneath the stands of the university’s football stadium. The spinning oven will heat the glass to 1,165 degrees Celsius, so that as it melts, it is forced outward to form the mirror’s curved paraboloid surface. Measuring 8.4-meters in diameter—about two stories tall when standing on edge—the mirror will cool over the next three months before moving into the polishing stage.

Once assembled, all seven mirrors will work in concert as one monolithic 25.4-meter mirror—a diameter equal to the length of a full-grown blue whale—resulting in up to 200 times the sensitivity and four times the image resolution of today’s most advanced space telescopes.

A decade ago it was expected that this telescope in Chile would follow the Thirty Meter Telescope (TMT), while also working in parallel with it, with TMT covering the northern hemisphere and GMT covering the southern hemisphere. Now GMT is likely to forever work alone, as TMT remains blocked in Hawaii by the government and anti-western, anti-white protesters, and will likely never be built.

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Webb infrared data suggests Europa’s C02 comes from within

9:41 am

Europa as seen by Webb's near-infrared camera
Europa as seen by Webb’s near-infrared camera.
Click for original image.

Two different research papers, using infrared data from the Webb Space Telescope, have independently concluded that the carbon dioxide previously detected on the surface of Europa is found concentrated in the same region, and has the earmarks of coming from beneath the surface.

In one study, Samantha Trumbo and Michael Brown used the JWST [Webb] data to map the distribution of CO2 on Europa and found the highest abundance of CO2 is located in Tara Regio – a ~1,800 square kilometer region dominated by “chaos terrain,” geologically disrupted resurfaced materials. According to Tumbo and Brown, the amount of CO2 identified within this recently resurfaced region – some of the youngest terrain on Europa’s surface – indicates that it was derived from an internal source of carbon. This implies that the CO2 formed within Europa’s subsurface ocean and was brought to the surface on a geologically recent timescale. However, the authors say that formation of CO2 on the surface from ocean-derived organics or carbonates cannot be entirely ruled out. In either interpretation, the subsurface ocean contains carbon.

In an independent study of the same JWST data, Geronimo Villanueva and colleagues found that the CO2 on Europa’s surface is mixed with other compounds. Villanueva et al. also find the CO2 is concentrated in Tara Regio and interpret that as demonstrating that the carbon on the moon’s surface was sourced from within. The authors measured the ice’s 12C/13C isotopic ratio, but could not distinguish between an abiotic or biogenic source. Moreover, Villanueva et al. searched for plumes of volatile material breaching moon’s icy crust. Although previous studies have reported evidence of these features, the authors did not detect any plume activity during the JWST observations. They argue that plume activity on Europa could be infrequent, or sometimes does not contain the volatile gasses they included in their search.

As always, these conclusion must be viewed with some skepticism, as the data is somewhat sparse and coarse. Webb’s resolution is not enough to truly pinpoint the source location with great accuracy, and the conclusion that the CO2 comes from underground depends on many assumptions. For example, in the image above, the white area roughly corresponds to Tara Regio, but with very large margins.

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Two galaxies merging

11:32 am

Merging galaxies
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of a survey project to photograph the entire Arp catelogue of 338 “peculiar galaxies,” put together by astronomer Halton Arp in 1966. From the caption:

The larger galaxy (in the left of this image) is an extremely energetic galaxy type known as a Seyfert galaxy, which house active galactic nuclei at their cores. Seyfert galaxies are notable because despite the immense brightness of the active core, radiation from the entire galaxy can be observed. This is evident in this image, where the spiraling whorls of the whole galaxy are readily visible. The smaller companion is connected to the larger by a tenuous-seeming ‘bridge’, composed of dust and gas. The colliding galactic duo lie about 465 million light-years from Earth.

Note that if you ignore the blue whorls of the left galaxy, the two bright cores of these merging galaxies are about the same size. As it is unclear how long this merger has been on-going, it is possible that the galaxy on the right, in circling the left galaxy, drew out those whorls and that tenuous bridge. Other scenarios are also possible, however, such as the galaxy on the left stripping and scattering the arms of the galaxy on the right.

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Webb captures new infrared image of bi-polar jets shooting from baby star

10:54 am

HH 211 as seen by Webb
Click for original image.

Using the Webb Space Telescope, astronomers have taken a new infrared image of the baby star Herbig-Haro 211 (HH 211), known best for the bi-polar jets that shoot out in opposite directions at very great speeds.

That picture is to the right, reduced and sharpened to post here, and has about 5 to 10 times the resolution of previous infrared images.

The image showcases a series of bow shocks to the southeast (lower-left) and northwest (upper-right) as well as the narrow bipolar jet that powers them. …. The inner jet is seen to “wiggle” with mirror symmetry on either side of the central protostar. This is in agreement with observations on smaller scales and suggests that the protostar may in fact be an unresolved binary star.

Earlier observations of HH 211 with ground-based telescopes revealed giant bow shocks moving away from us (northwest) and moving towards us (southeast) and cavity-like structures in shocked hydrogen and carbon monoxide respectively, as well as a knotty and wiggling bipolar jet in silicon monoxide. Researchers have used Webb’s new observations to determine that the object’s outflow is relatively slow in comparison to more evolved protostars with similar types of outflows.

The team measured the velocities of the innermost outflow structures to be roughly 48-60 miles per second (80 to 100 kilometers per second). However, the difference in velocity between these sections of the outflow and the leading material they’re colliding with — the shock wave — is much smaller. The researchers concluded that outflows from the youngest stars, like that in the center of HH 211, are mostly made up of molecules, because the comparatively low shock wave velocities are not energetic enough to break the molecules apart into simpler atoms and ions.

The baby star at the center of these jets, about a 1,000 light years away, is estimated to be only a few ten thousand years old, and presently has a mass less than a tenth of the Sun. With time it will accrete more matter and become a full-sized star.

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Chandra: New X-ray composite images of galaxies and supernovae remnants

10:51 am

Chandra image
Click for original image.

The science team for the Chandra X-Ray observatory today released five new composite images of two galaxies, two supernovae remnants, and the center of the Milky Way, combining data from multiple telescopes looking in radio, infrared, optical, and X-ray wavelengths.

The image to the right, reduced and sharpened to post here, is one of those pictures. From the press release:

As the galaxy moves through space at 1.5 million miles per hour, it leaves not one — but two — tails behind it. These tails trailing after ESO 137-001 are made of superheated gas that Chandra detects in X-rays (blue). ESO’s Very Large Telescope shows light from hydrogen atoms (red), which have been added to the image along with optical and infrared data from Hubble (orange and cyan).

The inset shows just the Hubble optical image, reduced by about 50%, to get a clearer sense of the galaxy itself. It appears to be a jelly-fish galaxy, flying through space at right angles to its plane and with tendrils of stars trailing off below.

The other four images are as interesting. The full set, including separate images in the individual wavelengths prior to combination, can be found here.

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Astronomers discover two new polar-ring galaxies

9:13 am

Polar ring galaxy
Click for original image.

Using a combination of optical and radio telescopes as well as computer modeling, astronomers think they have identifed polar rings of gas orbiting two different galaxies, adding these to the relatively small population of known polar-ring galaxies.

Polar ring galaxies are unique in that they have an outer ring of gas and stars circling the galaxy at right angles to its plane. A composite image of one of these new galaxies is to the right, cropped, reduced and sharpened to post here. From the press release:

Jayanne English, a member of the WALLABY research team and also an expert in astronomy image-making at the University of Manitoba, developed the first images of these gaseous polar ring galaxies using a combination of optical and radio data from the different telescopes. First, optical and infrared data from the Subaru telescope in Hawaii provided the image for the spiral disk of the galaxy. Then, the gaseous ring was added based on data obtained from the WALLABY survey, an international project using CSIRO’s ASKAP radio telescope to detect atomic hydrogen emission from about half a million galaxies.

The creation of this and other astronomical images are all composite because they include information that our eyes can’t capture. In this particular case, the cold hydrogen gas component, invisible to the human eye, is seen in radio “light” using CSIRO’s ASKAP. The subtle colour gradient of this ring represents the orbital motions of the gas, with purple-ish tints at the bottom tracing gas that moves towards the viewer while the top portion moves away. The emission from the ring was separated from the radio emission emanating from the disk of the galaxy using virtual reality tools, in collaboration with Professor Tom Jarrett (University of Cape Town, South Africa).

As the abstract of the research paper notes, the computer models used “show that the data are consistent with PRGs [polar-ring galaxies] but do not definitively prove that the galaxies are PRGs.” There is much uncertainty, as it is difficult to determine the orientation of some rings relative to their galaxy’s plane.

Nonetheless, these result suggest polar ring galaxies might be more common, and thus might help refine the theories of galaxy formation and merger.

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