Tag: astronomy

Update on the ongoing research of the closest supernovae in a decade

12:47 pm

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

Link here. Though the press release from UC-Berkeley focuses mostly of research being done by its astronomers, it also provides a very good overview of what all astronomers worldwide have been learning since Supernova SN 2023ixf was first discovered by amateur astronomer Koichi Itagaki in Japan on May 19, 2023 in the Pinwheel Galaxy, only 20 million light years away. This tidbit is probably the most significant:

Another group of astronomers led by Ryan Chornock, a UC Berkeley adjunct associate professor of astronomy, gathered spectroscopic data using the same telescope at Lick Observatory. Graduate student Wynn Jacobson-Galán and professor Raffaella Margutti analyzed the data to reconstruct the pre- and post-explosion history of the star, and found evidence that it had shed gas for the previous three to six years before collapsing and exploding. The amount of gas shed or ejected before the explosion could have been 5% of its total mass — enough to create a dense cloud of material through which the supernova ejecta had to plow.

Such data is going to help astronomers better predict when a star is about to go boom, by identifying similar behavior.

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Hacker attack on Gemini North telescope in Hawaii shuts down many U.S.-run telescopes

9:34 am

A attack by hackers against the Gemini North telescope in Hawaii on August 1, 2023 has forced the National Science Foundation (NSF) to shut down all the telescopes it operates.

NOIRLab, the NSF-run coordinating center for ground-based astronomy, first announced the detection of an apparent cyberattack on its Gemini North telescope in Hilo, Hawaii, in a 1 August press release. Whatever happened may have placed the instrument in physical jeopardy. “Quick reactions by the NOIRLab cyber security team and observing teams prevented damage to the observatory,” the center’s release said.

In response to the incident, NOIRLab powered down all operations at the International Gemini Observatory, which runs the Hilo telescope and its twin, Gemini South, on Cerro Pachón mountain in Chile. (The latter was already offline for a planned outage.) Together, the two 8.1-meter telescopes have revealed vast swaths of celestial wonders—from the birth of supernovae to the closest known black hole to Earth.

Normally, NOIRLab’s computer systems let astronomers remotely operate a variety of other optical ground-based telescopes. But on 9 August the center announced it had also disconnected its computer network from the Mid-Scale Observatories (MSO) network on Cerro Tololo and Cerro Pachon in Chile. This action additionally made remote observations impossible at the Víctor M. Blanco 4-meter and SOAR telescopes. NOIRLab has stopped observations at eight other affiliated telescopes in Chile as well.

The attack has shut down ten telescopes entirely, some of which are the largest in the world, while other telescopes are operating but only allowing in-person operations.

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Scientists: Neptune’s clouds appear to ebb and grow in conjunction with sunspot cycle

9:24 am

Graph showing correlation between Neptune's clouds and the sunspot cycle

Scientists have now discovered what appears to be a link between the coming and going of clouds on Neptune to the Sun’s 11-year-long sunspot cycle, despite Neptune receiving only 1/900th the sunlight of the Earth.

To monitor the evolution of Neptune’s appearance, Chavez and her team analyzed images taken from 1994 to 2022 using Keck Observatory’s second generation Near-Infrared Camera (NIRC2) paired with its adaptive optics system (since 2002), as well as observations from Lick Observatory (2018-2019) and the Hubble Space Telescope (since 1994). In recent years the Keck Observatory observations have been complemented by images taken as part of Keck Observatory’s Twilight Observing Program and by Hubble Space Telescope images taken as part of the Outer Planet Atmospheres Legacy (OPAL) program.

The data revealed an intriguing pattern between changes in Neptune’s cloud cover and the solar cycle – the period when the Sun’s magnetic field flips every 11 years, causing levels of solar radiation to fluctuate. When the Sun emits more intense ultraviolet (UV) light, specifically the strong hydrogen Lyman-alpha emission, more clouds appear on Neptune about two years later. The team further found a positive correlation between the number of clouds and the ice giant’s brightness from the sunlight reflecting off it.

“These remarkable data give us the strongest evidence yet that Neptune’s cloud cover correlates with the Sun’s cycle,” said de Pater. “Our findings support the theory that the Sun’s UV rays, when strong enough, may be triggering a photochemical reaction that produces Neptune’s clouds.”

The graph to the right shows the correlation between the clouds and the sunspot cycle. The paper is available here.

This conclusion remains uncertain because of the overall sparseness of the data. Yet, it is intriguing, and also underlines the importance of the Sun on the Earth’s climate. If the solar cycle can impact Neptune’s climate so significantly from 2.8 billion miles away, it certainly must have a major impact on the Earth’s climate at only 100 million miles distance.

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Webb confirms galaxy as one of the earliest known in the universe

9:27 am

The uncertainty of science: Using the spectroscopic instrument on the Webb Space Telescope, scientists have confirmed that one of the first galaxies found by Webb, dubbed Maisie’s Galaxy after the daughter of one scientist, is one of the earliest known in the universe, existing only 390 million years after when cosmologies say the Big Bang happened.

The data also showed that another one of these early galaxies spotted by Webb did not exist 250 million years after the Big Bang, but one billion years after, a date that better fits the theories about the early universe, based on the nature of this galaxy.

It turns out that hot gas in CEERS-93316 was emitting so much light in a few narrow frequency bands associated with oxygen and hydrogen that it made the galaxy appear much bluer than it really was. That blue cast mimicked the signature Finkelstein and others expected to see in very early galaxies. This is due to a quirk of the photometric method that happens only for objects with redshifts of about 4.9. Finkelstein says this was a case of bad luck. “This was a kind of weird case,” Finkelstein said. “Of the many tens of high redshift candidates that have been observed spectroscopically, this is the only instance of the true redshift being much less than our initial guess.”

Not only does this galaxy appear unnaturally blue, it also is much brighter than our current models predict for galaxies that formed so early in the universe. “It would have been really challenging to explain how the universe could create such a massive galaxy so soon,” Finkelstein said. “So, I think this was probably always the most likely outcome, because it was so extreme, so bright, at such an apparent high redshift.”

This science team is presently using Webb’s spectroscope to study ten early galaxies in order to better determine their age. Expect more results momentarily.

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Scientist creates longest time-lapse movie of exoplanet circling its star

9:37 am

A scientist at Northwestern University has used seventeen years of data to create the longest time-lapse movie yet of an exoplanet circling its star, Beta Pictoris, which is located 63 light years away.

Constructed from real data, the footage shows Beta Pictoris b — a planet 12 times the mass of Jupiter — sailing around its star in a tilted orbit. The time-lapse video condenses 17 years of footage (collected between 2003 and 2020) into 10 seconds. Within those seconds, viewers can watch the planet make about 75% of one full orbit.

“We need another six years of data before we can see one whole orbit,” said Northwestern astrophysicist Jason Wang, who led the work. “We’re almost there. Patience is key.”

I have embedded the video below. Because the star in the center is so bright, its light is blocked out, so that this part of the planet’s orbit is represented by the “X” in the video.
» Read more

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Astronomers: Binary system creates tidal waves on star’s surface 3x larger than our own Sun

9:32 am

Tidal waves on star's surface

Based on computer simulations, astronomers believe that the monthly light changes in a binary star system are partly caused by gigantic tidal waves on the surface of the system’s larger star, waves that are three times higher than the diameter of our own Sun.

The larger star in the system is nearly 35 times the mass of the Sun and, together with its smaller companion star, is officially designated MACHO 80.7443.1718 — not because of any stellar brawn, but because the system’s brightness changes were first recorded by the MACHO Project in the 1990s, which sought signs of dark matter in our galaxy.

Most heartbeat stars vary in brightness only by about 0.1%, but MACHO 80.7443.1718 jumped out to astronomers because of its unprecedentedly dramatic brightness swings, up and down by 20%. “We don’t know of any other heartbeat star that varies this wildly,” says MacLeod.

To unravel the mystery, MacLeod created a computer model of MACHO 80.7443.1718. His model captured how the interacting gravity of the two stars generates massive tides in the bigger star. The resulting tidal waves rise to about a fifth of the behemoth star’s radius, which equates to waves about as tall as three Suns stacked on top of each other, or roughly 2.7 million miles high.

The image on the right is a screen capture from the computer simulation. The bulges on the right side of the larger star are the hypothesized tidal waves.

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A ghostly bullseye galaxy

11:18 am

A ghostly bullseye
Click for original image.

A cool image to start the week! The picture to the right, cropped and reduced to post here, was taken by the Hubble Space Telescope as part of a survey scientists are doing using Hubble, attempting to get high resolution images of every galaxy within about 30 million light years of the Milky Way. Prior to this census Hubble had covered about 75% of these galaxies. This particular galaxy is called a lenticular galaxy.

Lenticular galaxies like NGC 6684 (lenticular means lens-shaped) possess a large disc but lack the prominent spiral arms of galaxies like the Andromeda Galaxy. This leaves them somewhere between elliptical galaxies and spiral galaxies, and lends these galaxies a diffuse, ghostly experience. NGC 6684 also lacks the dark dust lanes that thread through other galaxies, adding to its spectral, insubstantial appearance.

The unknown is whether this is the state of a galaxy prior to becoming a spiral, or it is what it looks like as it transitions from a spiral to an elliptical. This particular galaxy is likely the latter, as it lacks the dust, but this does not have to be the rule.

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Scientists release infrared image of the Ring nebula, taken by Webb

10:23 am

The Ring Nebula, in false color by Webb
Click for original image.

Scientists yesterday released the first false-color infrared image of the Ring nebula taken by the Webb Telescope. That image, cropped to post here, is to the right. From the press release, which is heavy with platitudes but little information:

Approximately 2,600 lightyears away from Earth, the nebula was born from a dying star that expelled its outer layers into space. What makes these nebulae truly breath-taking is their variety of shapes and patterns, that often include delicate, glowing rings, expanding bubbles or intricate, wispy clouds. These patterns are the consequence of the complex interplay of different physical processes that are not well understood yet. Light from the hot central star now illuminates these layers.

Just like fireworks, different chemical elements in the nebula emit light of specific colours. This then results in exquisite and colourful objects, and furthermore allows astronomers to study the chemical evolution of these objects in detail.

It appears this image was produced using Webb’s near infrared instrument. Further data from its mid-infrared instrument has not yet been released. For a Hubble image of the Ring Nebula, in optical light that the human eye sees, go here.

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Despite good first images from Euclid, the orbiting telescope has a problem

10:05 am

Even though the first light images from Euclid have been sharp and exactly what astronomers want, the orbiting telescope designed to make a 3D map of billions of galaxies has an issue that will likely put some limits to that map.

When the telescope started booting up, ESA observers were concerned by the appearance of light markings on the first images relayed to Earth. This, it confirmed, was due to sunlight filtering into the telescope, “probably through a tiny gap”.

A correction to Euclid’s position was able to offset this issue. It means that while the ESA is confident Euclid will be fine to proceed with its mapping mission, particular orientations for the telescope may not be possible.

A limitation like this means that the telescope will not being able to look in some directions and get mapping images. Thus, the overall map will have gaps, though it appears at this moment that the scientists think those gaps will not seriously impact the telescope’s overall work. We shall see.

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New software detects its first potentially dangerous asteroid

9:32 am

New software designed to detect asteroids, developed for use with the Rubin Observatory presently being built in Chile, has successfully discovered its first potentially hazardous asteroid (PHA) using data from another smaller operational ground-based telescope.

The discovered asteroid is 600 feet long, large enough to pose a real threat should it ever hit the Earth. Fortunately, the data says that though its orbit can take it as close as 140,000 miles there is no impact likely in the foreseeable future.

When the Rubin telescope begins its planned ten year survey of the entire night sky in 2025, this software is expected to almost triple the number of known potentially-hazardous-asteroids, from 2,350 to almost 6,000.

Funded primarily by the U.S. National Science Foundation and the U.S. Department of Energy, Rubin’s observations will dramatically increase the discovery rate of PHAs. Rubin will scan the sky unprecedentedly quickly with its 8.4-meter mirror and massive 3,200-megapixel camera, visiting spots on the sky twice per night rather than the four times needed by present telescopes. But with this novel observing “cadence,” researchers need a new type of discovery algorithm to reliably spot space rocks.

Thus, the development of this new software.

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Eruption on comet results in its tail splitting as it brightens by 100x

9:28 am

On July 20, 2023 the Comet 12P/Pons-Brooks suddenly erupted for the first time in almost seven decades, making it a hundred times brighter than normal while splitting its tail in two.

As of July 26, the comet’s coma had grown to around 143,000 miles (230,000 kilometers) across, or more than 7,000 times wider than its nucleus, which has an estimated diameter of around 18.6 miles (30 km), Richard Miles, an astronomer with the British Astronomical Association who studies cryovolcanic comets, told Live Science in an email.

But interestingly, an irregularity in the shape of the expanded coma makes the comet look as though it has sprouted horns. Other experts have also likened the deformed comet to the Millennium Falcon, one of the iconic spaceships from Star Wars, Spaceweather.com reported.

It is believed the tail’s shape is the result of the shape of the comet’s nucleus, which probably had a solid ridge acting as a barrier to material at that point.

The comet, which orbits the Sun every 71 years, will make its closest approach to Earth in the spring of 2024, when it will likely be visible to the naked eye.

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Euclid’s first images look good

9:19 am

Scientists have determined that the first test images from the two cameras on the recently launched orbiting Euclid space telescope are sharp and as expected.

Both VIS and NISP provided these unprocessed raw images. Compared to commercial products, the cameras are immensely more complex. VIS comprises 36 individual CCDs with a total of 609 megapixels and produces high-resolution images of billions of galaxies in visible light. This is how astronomers determine their shape. The first images already give an impression of the abundance that the data will provide.

NISP’s detector consists of 16 chips with a total of 64 megapixels. It operates in the near-infrared at wavelengths between 1 and 2 microns. In addition, NISP serves as a spectrograph, which splits the light of the captured objects similar to a rainbow and allows for a finer analysis. These data will allow the mapping of the three-dimensional distribution of galaxies.

Knowing that 3D distribution will allow scientists to better determine the nature of both dark energy (related to the acceleration of the universe’s expansion) and dark matter (related to an undiscovered mass that affects the formation and shape of galaxies).

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Scientists think they have finally discovered what makes the Sun’s corona so hot

10:31 am

Using data from Europe’s Solar Orbiter spacecraft, scientists now think they have finally pinpointed the process that causes the Sun’s corona — its atmosphere — to be many times hotter than its surface.

For decades, scientists have been struggling to explain why temperatures in the sun’s outer atmosphere, the corona, reach mind-boggling temperatures of over 1.8 million degrees Fahrenheit (one million degrees Celsius). The sun’s surface has only about 10,000 degrees F (6,000 degrees C), and with the corona farther away from the source of the heat inside the star, the outer atmosphere should, in fact, be cooler.

New observations made by the Europe-led Solar Orbiter spacecraft have now provided hints to what might be behind this mysterious heating. Using images taken by the spacecraft’s Extreme Ultraviolet Imager (EUI), a camera that detects the high-energy extreme ultraviolet light emitted by the sun, scientists have discovered small-scale fast-moving magnetic waves that whirl on the sun’s surface. These fast-oscillating waves produce so much energy, according to latest calculations, that they could explain the coronal heating.

You can read the paper here [pdf]. The results have not yet been confirmed, but if so it will solve one of the space age’s oldest scientific mysteries.

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Astronomers chemically map a significant portion of the Milky Way

10:19 am

The chemistry of the Milky Way's nearby spiral arms
Red indicates areas with lots of heavier elements, blue indicates
areas dominated by hydrogen and helium. Click for original image.

Astronomers have now used today’s modern survey telescopes — on Earth and in space — to map the chemistry of a large portion of the Milky Way’s nearby spiral arms, revealing that the arms themselves are rich in heavier elements, indicating greater age and the right materials to produce new stars and solar systems like our own.

If the Milky Way’s spiral arms trigger star births as predicted, then they should be marked by young stars, aka metal-rich stars. Conversely, spaces between the arms should be marked by metal-poor stars.

To confirm this theory, as well as create his overall map of metalicity, Hawkins first looked at our solar system’s galactic backyard, which include stars about 32,000 light years from the sun. In cosmic terms, that represents our stellar neighborhood’s immediate vicinity.

Taking the resultant map, the researcher compared it to others of the same area of the Milky Way created by different techniques, finding that the positions of the spiral arms lined up. And, because he used metalicity to chart the spiral arms, hitherto unseen regions of the Milky Way’s spiral arms showed up in Hawkins’ map. “A big takeaway is that the spiral arms are indeed richer in metals,” Hawkins explained. “This illustrates the value of chemical cartography in identifying the Milky Way’s structure and formation. It has the potential to fully transform our view of the Galaxy.”

You can read the science paper here [pdf]. Based on this initial mapping effort, it appears that it will not be long before a large percentage of our own galaxy will be mapped in this manner.

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Optical image of accretion disk around baby star, taken by ground-based VLT

10:59 am

Stellar accretion disk
Click for original image.

Scientists today released an optical image of the accretion disk that surrounds a baby star about 5,000 light years away, taken by ground-based Very Large Telescope (VLT) in Chile and enhanced by data from the Atacama Large Millimeter/submillimeter Array (ALMA), also in Chile.

That image, reduced to post here, is to the right. The bright blue spot in the center is the main star, with the smaller dot to the lower left a companion star. From the press release:

The VLT observations probe the surface of the dusty material around the star, while ALMA can peer deeper into its structure. “With ALMA, it became apparent that the spiral arms are undergoing fragmentation, resulting in the formation of clumps with masses akin to those of planets,” says Zurlo.

Astronomers believe that giant planets form either by ‘core accretion’, when dust grains come together, or by ‘gravitational instability’, when large fragments of the material around a star contract and collapse. While researchers have previously found evidence for the first of these scenarios, support for the latter has been scant.

This data suggests that the latter is being observed, the first time gravitational instability has been identified as it is happening. You can read the scientist’s research paper here [pdf].

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Infrared Webb image of a binary baby star system and its surrounding jets and nebula

10:47 am

Webb infrared image of HH 46/47
Click for original image.

Cool image time! The infrared picture to the right, cropped, reduced, and sharpened to post here, was taken by the Webb Space Telescope of the jets and nebula of the Herbig–Haro object dubbed HH 46/47, thought to contain a pair of baby stars under formation.

The most striking details are the two-sided lobes that fan out from the actively forming central stars, represented in fiery orange. Much of this material was shot out from those stars as they repeatedly ingest and eject the gas and dust that immediately surround them over thousands of years.

When material from more recent ejections runs into older material, it changes the shape of these lobes. This activity is like a large fountain being turned on and off in rapid, but random succession, leading to billowing patterns in the pool below it. Some jets send out more material and others launch at faster speeds. Why? It’s likely related to how much material fell onto the stars at a particular point in time.­­­

The stars’ more recent ejections appear in a thread-like blue. They run just below the red horizontal diffraction spike at 2 o’clock. Along the right side, these ejections make clearer wavy patterns. They are disconnected at points, and end in a remarkable uneven light purple circle in the thickest orange area. Lighter blue, curly lines also emerge on the left, near the central stars, but are sometimes overshadowed by the bright red diffraction spike.

To see optical images of HH 46/47 as well as some further background, go here. It is one of the most studied HH objects, which is why it was given priority in Webb’s early observation schedule.

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Spirals within spirals

8:58 am

Spirals within spirals
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and annotated to post here, was taken by the Hubble Space Telescope as part of two different research projects that are studying galaxies where supernovae previously occurred. This particular galaxy is estimated to be about 192 million light years away, and is a classic example of a barred spiral.

Despite appearing as an island of tranquillity in this image, UGC 12295 played host to a catastrophically violent explosion — a supernova — that was first detected in 2015. This supernova prompted two different teams of astronomers to propose Hubble observations of UGC 12295 that would sift through the wreckage of this vast stellar explosion.

Supernovae are the explosive deaths of massive stars, and are responsible for forging many of the elements found here on Earth. The first team of astronomers used Hubble’s Wide Field Camera 3 (WFC3) to examine the detritus left behind by the supernova in order to better understand the evolution of matter in our Universe.

The second team of astronomers also used WFC3 to explore the aftermath of UGC 12295’s supernova, but their investigation focused on returning to the sites of some of the best-studied nearby supernovae. Hubble’s keen vision can reveal lingering traces of these energetic events, shedding light on the nature of the systems that host supernovae.

What struck me about this picture however were the many smaller spiral galaxies scattered nearby and behind UGC 12295, with one face-on spiral highlighted near the top. I can count at least three or four other background spiral galaxies, all reddish in color likely because their light has been shifted to the red due to their distance.

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Hubble image shows several dozen boulders flung from Dimorphos

9:40 am

Boulders drifting from Dimorphos
Click for original image.

Using the Hubble Space Telescope, astronomers have photographed several dozen boulders that were flung off of the asteroid Dimorphos following the impact by the space probe DART. The picture to the right, reduced and brightened to more clearly show those boulders, was taken on December 19, 2022, four months after DART’s impact.

These are among the faintest objects Hubble has ever photographed inside the Solar System. The ejected boulders range in size from 1 meter to 6.7 meters across, based on Hubble photometry. They are drifting away from the asteroid at around a kilometre per hour.

The blue streak is the dust tail that has streamed off of Dimorphos since the impact, pushed away from the sun by the solar wind.

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The possibility of more than one exoplanet sharing the same orbit

9:27 am

PDS 70, as seen by ALMA
The Trojan debris clouds around PDS 70, as seen by ALMA

The uncertainty of science: Astronomers have detected evidence that suggests the possibility of more than one exoplanet sharing the same orbit around PDS 70, a star 400 light years away.

This young star is known to host two giant, Jupiter-like planets, PDS 70b and PDS 70c. By analysing archival ALMA observations of this system, the team spotted a cloud of debris at the location in PDS 70b’s orbit where Trojans are expected to exist.

Trojans occupy the so-called Lagrangian zones, two extended regions in a planet’s orbit where the combined gravitational pull of the star and the planet can trap material. Studying these two regions of PDS 70b’s orbit, astronomers detected a faint signal from one of them, indicating that a cloud of debris with a mass up to roughly two times that of our Moon might reside there.

The press release — as well as most news reports — touts the possibility that they have found a second planet in this orbit. They have not, and are likely not going to. As noted above, the data indicates the presence of “a cloud of debris”, which is most likely a clustering of Trojan asteroids, just as the more than 12,000 asteroids we see in the two Trojan points in Jupiter’s orbit.

Nonetheless, this is the first detection of what appears to be a Trojan clustering in the accretion disk of a young star.

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Scientists discover in archival data a slowly pulsing object that has been beating since 1988

8:48 am

The uncertainty of science: Using archival data, scientists have discovered a previously undetected but very strange slowly pulsing object that has been doing so since 1988.

Astronomers have found an ultra-slow, long-lasting source of radio-wave pulses, and they are perplexed as to its true nature. While “regular” radio pulsars have very short periods, from seconds down to just a few milliseconds, this source emits a brief pulse of radio waves about three times per hour. What’s more, it has been doing this for decades. “I do not think we can say yet what this object is,” says Victoria Kaspi (McGill University), a pulsar researcher who was not involved in the new study.

Natasha Hurley-Walker (Curtin University, Australia) and her colleagues discovered the mysterious source in data from the Murchison Widefield Array (MWA) observatory in Western Australia. They carried out follow-up observations with the MWA and with other radio observatories in Australia and South Africa. Known as GPM J1839-10, the tardy blinker is located at a distance of some 18,500 light-years away in the constellation Scutum. Archival data from the Very Large Array in New Mexico and the Indian Giant Metrewave Radio Telescope reveal that it has been pulsating at least since 1988, with a period of just under 22 minutes (1,318.1957 seconds, to be precise).

In a sense, the object is a pulsar, since on a very basic level it does what all pulsars do, send a radio beat in our direction in a precise pattern. The problem is that according to present theories that say pulsars are actually magnetized neutron stars rotating quickly, this object is rotating too slowly to be one.

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Astronomers detect white dwarf star with two faces

9:13 am

The uncertainty of science: Astronomers using ground-based telescopes have discovered a white dwarf star in which the surface chemistry of its two hemispheres are very different, one strongly dominated by hydrogen while the other instead dominated by helium.

The team used the Low Resolution Imaging Spectrometer (LRIS) on the Keck I Telescope to view Janus in optical wavelengths (light that our eyes can see) as well as the Near-Infrared Echellette Spectrograph (NIRES) on the Keck II Telescope to observe the white dwarf in infrared wavelengths. The data revealed the white dwarf’s chemical fingerprints, which showed the presence of hydrogen when one side of the object was in view (with no signs of helium), and only helium when the other side swung into view.

The article lists a lot of proposed explanations, most of which suggest the star’s magnetic field is acting to segregate the materials. All assume these observations are certain and that there is no mixing at all, something we should doubt considering the resolution of the data (a mere point that is rotating).

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Extremely Large Telescope in Chile marks halfway point in construction

9:51 am

The Extremely Large Telescope (ELT) has now celebrated the halfway point in its construction, with completion targeting 2028 when its 39-meter mirror will make it by far the largest telescope in the world.

The 39-meter diameter, or 127 feet or 1,535 inches, is about four times larger than the largest telescope that presently exists, the 10-meter telescope in the Canary Islands. By the time ELT begins operations however the 21-meter Giant Magellan Telescope (GMT) in Chile should also be in operation.

Sadly, the Thirty Meter Telescope (TMT) in Hawaii will likely not exist, even though it had intended to begin construction before ELT and GMT and be operational now. Leftist opponents in Hawaii have shut construction down now for almost eight years, with little signs of it ever proceeding.

Not that any of this really matters. In the near term, ground-based astronomy on Earth is going to become increasingly impractical and insufficient, first because of the difficulties of making good observations though the atmosphere and the tens of thousands of satellites expected in the coming decades, and second because new space-based astronomy is going to make it all obsolete. All it will take will be to launch one 8-meter telescope on Starship and ELT will become the equivalent of a buggy whip.

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Final close-out of all science research at Arecibo

9:38 am

The National Science Foundation (NSF) is proceeding with the final close-out of all science research at the now shuttered Arecibo radio telescope, ending all funding for the remaining science instruments that still function and letting go all scientists on staff as of August 14th.

In October 2022, NSF announced it would not rebuild the giant telescope, saying it was following community recommendations for the best use of scarce research dollars. It is now shutting down most of the smaller instruments as well. As scientists depart, “all the expertise associated with instruments is leaving,” Brisset says. Olga Figueroa-Miranda, director of the observatory, says people from UCF, Puerto Rico’s Metropolitan University, and Yang Enterprises, an engineering firm, will be let go, including herself. She has yet to find a new position.

The NSF has budgeted money to turn the telescope’s visitor center into a science education facility, but this is not likely to be very successful, as there will be no scientists at this somewhat remote location, which will in itself discourage any traffic.

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Scientists claim discovery of most distant supermassive black hole yet

9:28 am

The overwhelming uncertainty of some science: Using data from the infrared Webb Space Telescope, scientists are now claiming they have discovered most distant supermassive black hole yet, sitting at the center of an active galaxy only about a half billion years after the Big Bang. From the press release:

The galaxy, CEERS 1019, existed just over 570 million years after the big bang, and its black hole is less massive than any other yet identified in the early universe. Not only that, they’ve easily “shaken out” two more black holes that are also on the smaller side, and existed 1 and 1.1 billion years after the big bang. Webb also identified eleven galaxies that existed when the universe was 470 to 675 million years old. The evidence was provided by Webb’s Cosmic Evolution Early Release Science (CEERS) Survey, led by Steven Finkelstein of the University of Texas at Austin. The program combines Webb’s highly detailed near- and mid-infrared images and data known as spectra, all of which were used to make these discoveries.

CEERS 1019 is not only notable for how long ago it existed, but also how relatively little its black hole weighs. This black hole clocks in at about 9 million solar masses, far less than other black holes that also existed in the early universe and were detected by other telescopes. Those behemoths typically contain more than 1 billion times the mass of the Sun – and they are easier to detect because they are much brighter. (They are actively “eating” matter, which lights up as it swirls toward the black hole.) The black hole within CEERS 1019 is more similar to the black hole at the center of our Milky Way galaxy, which is 4.6 million times the mass of the Sun. This black hole is also not as bright as the more massive behemoths previously detected. Though smaller, this black hole existed so much earlier that it is still difficult to explain how it formed so soon after the universe began.

I have great doubts about this research, especially because the press release makes no effort to explain how the black holes were identified. Black holes emit no light, and were only first confirmed by watching the orbits of stars or objects near them over long periods of time. More distant supermassive black holes in the center of galaxies were later guessed at by what appears to be the relationship between the size of a galaxy’s nucleus and the presence of a black hole. Astronomers also assume that a very active and energetic galaxy (such as a quasar) is a sign a supermassive black hole exists at the center.

These primitive galaxies have only been observed at most a handful of times. They are so distant that they only are at most a few pixels wide. Spectra from these objects can tell us roughly how far away they are, and thus how close to the Big Bang they are thought to be, but it is impossible to say with any certainty that there is a black hole there.

I am made even more skeptical by this press release claim: “Webb’s data are practically overflowing with precise information that makes these confirmations so easy to pull out of the data.” Such language makes me suspicious that there is an underlying effort to justify Webb’s expense with this release by overstating its capabilities.

The press release provides links to the research. Take a look. I’d be glad if someone could clearly show me why I’m wrong to be so doubtful.

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Scientists: Quasar data shows time running five times slower in the early universe

8:53 am

The uncertainty of science: According to new research using data from almost 200 quasars collected over the two decades, scientists now believe they have detected the difference between the rate of time now and as we see it in the early universe.

“Looking back to a time when the universe was just over a billion years old, we see time appearing to flow five times slower,” said lead author of the study, Professor Geraint Lewis from the School of Physics and Sydney Institute for Astronomy at the University of Sydney. “If you were there, in this infant universe, one second would seem like one second – but from our position, more than 12 billion years into the future, that early time appears to drag.”

…Professor Lewis worked with astro-statistician Dr Brewer to examine details of 190 quasars observed over two decades. Combining the observations taken at different colours (or wavelengths) – green light, red light and into the infrared – they were able to standardise the ‘ticking’ of each quasar. Through the application of Bayesian analysis, they found the expansion of the universe imprinted on each quasar’s ticking.

“With these exquisite data, we were able to chart the tick of the quasar clocks, revealing the influence of expanding space,” Professor Lewis said.

These results further confirm Einstein’s picture of an expanding universe but contrast earlier studies that had failed to identify the time dilation of distant quasars. [emphasis mine]

I have highlighted the word “exquisite” because it is a favorite buzzword of scientists when they are trying to oversell conclusions that carry many uncertainties. As good as this data might be, it is still incredibly sparse, and the interpretation of it requires many assumptions.

Nonetheless, these results are likely correct, in some manner, because they match well with Einstein’s predictions. It is also most likely that there are many errors and incorrect aspects to those results that the scientists do not yet understand. Above all, confirmation bias remains a concern.

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More evidence found suggesting supernovae occurred near the solar system during its formation

9:22 am

Scientists have now detected more evidence that suggests a supernovae occurred very close to our solar system during its early period of formation.

Astronomers have for decades found such evidence inside meteorites. Small spherical inclusions called chondrules are thought by some to have formed when the heat of a nearby supernova caused melting. The new study finds more evidence in isotopes also found in primitive meteorites dubbed short-lived radionuclides (SLRs).

While SLRs probably existed in the part of the filament where the Sun and Solar System formed, the meteorite samples contained too much of a particular aluminum isotope for the interstellar medium to have been the Solar System’s only SLR source. Cosmic rays, which can convert stable isotopes to radioactive ones, had a better chance of explaining the number of isotopes found in the meteorites. However, it would have taken too long for this process to produce the levels of SLRs found in the early Solar System.

It is most likely that such high SLR levels could have come from either very intense stellar winds, which would have occurred during massive star formation, or from what was left after one of the massive stars went supernova.

You can read the published paper here.

If true, this data adds weight to the possibility that our solar system is somewhat unique, which in turn suggests finding just another like it — with life — might be difficult.

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A spiral galaxy as seen by Hubble

9:40 am

A spiral galaxy as seen by Hubble
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken as part of a research project to use the Hubble Space Telescope to photograph galaxies where supernovae had recently occurred. From the caption:

UGC 11860 lies around 184 million light-years away in the constellation Pegasus, and its untroubled appearance can be deceiving; this galaxy recently played host to an almost unimaginably energetic stellar explosion.

A supernova explosion — the catastrophically violent end of a massive star’s life — was detected in UGC 11860 in 2014 by a robotic telescope dedicated to scouring the skies for transient astronomical phenomena; astronomical objects which are only visible for a short period of time. Two different teams of astronomers used Hubble’s Wide Field Camera 3 to search through the aftermath and unpick the lingering remnants of this vast cosmic explosion.

This Hubble image once again illustrates the vastness of the universe. Note that every single dot surrounding UGC 11860 in this picture is another far more distant galaxy. As much as UGC 11860 is in our local intergalactic neighborhood, it is still so distant that this field of view is small enough that it contains no stars.

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Galaxies at the dawn of time

10:40 am

Link here. The article takes a quick look at six galaxies found by Webb’s infrared view that all less than 650 million years after the Big Bang is thought to have occurred.

None disprove the Big Bang. All however raise serious questions about the cosmological theories that posit that event and the subsequent evolution of the universe. Take a look. It is worthwhile reading.

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Webb takes infrared (heat) image of Saturn

8:41 am

Saturn in infrared
Click for original image.

Using the Webb Space Telescope, scientists on June 25, 2023 took the wonderful false color infrared (heat) image of Saturn above, cropped to post here, as part of a research project [pdf] to take a number of long exposures of the ringed planet in order to test Webb’s ability to see its small moons. From the press release:

Saturn itself appears extremely dark at this infrared wavelength observed by the telescope, as methane gas absorbs almost all of the sunlight falling on the atmosphere. However, the icy rings stay relatively bright, leading to the unusual appearance of Saturn in the Webb image.

…This new image of Saturn clearly shows details within the planet’s ring system, along with several of the planet’s moons – Dione, Enceladus, and Tethys. Additional deeper exposures (not shown here) will allow the team to probe some of the planet’s fainter rings, not visible in this image, including the thin G ring and the diffuse E ring. Saturn’s rings are made up of an array of rocky and icy fragments – the particles range in size from smaller than a grain of sand to a few as large as mountains on Earth.

The picture also shows differences between Saturn’s northern and southern hemispheres, caused by the seasonal differences between the two.

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Using pulsars scientists detect background signal of the universe’s gravitational waves

10:07 am

The uncertainty of science: Using the variations in the precise radio pulses sent out by many pulsars over a fifteen year year astronomers think they have detected the background signal produced by many gravitational waves over time throughout the universe.

Astrophysicists using large radio telescopes to observe a collection of cosmic clocks in our Galaxy have found evidence for gravitational waves that oscillate with periods of years to decades, according to a set of papers published today in The Astrophysical Journal Letters. The gravitational-wave signal was observed in 15 years of data acquired by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) Physics Frontiers Center (PFC), a collaboration of more than 190 scientists from the US and Canada who use pulsars to search for gravitational waves. International collaborations using telescopes in Europe, India, Australia and China have independently reported similar results.

Imagine that each wave is a single wave on the ocean. This detection is the rough equivalent of looking at the ocean’s overall surface and measuring the general roughness of all the waves.

The press is making a big deal about this discovery. It is good science, and will over time provide valuable insights into evolution and merger of black holes, but it is not that big a deal, especially because this research carries with it many assumptions and uncertainties that good scientists recognize. They thus remain somewhat skeptical about the data. Mainstream journalists however consider gravitational waves cool, and so they hype any press release about them, sometimes to the point of absurdity.

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