Tag: astronomy

Astronomers discover supernovae that apparently exploded twice

10:55 am

Double detonation supernova
Click for original picture.

Using the ground-based Very Large Telescope (VLT) in Chile, astronomers have discovered evidence suggesting a star apparently exploded twice went it went supernova several hundred years ago.

They detected this possibility by looking at the remnant of that blast, shown to the right. It shows a double halo, indicated by the blue and orange colors. The blue however is seen in both shells. As noted by the VLT’s press notice:

Calcium is shown in blue, and it is arranged in two concentric shells. These two layers indicate that the now-dead star exploded with a double-detonation.

This type of supernova, dubbed type 1a, occurs when a white dwarf sucks matter from its closely orbiting stellar companion. That material piles up on the surface of the star until it reaches critical mass and explodes, causing the supernova.

The two shells, suggesting a double detonation, fits a theory proposed for this process. From the paper’s abstract:

Our analysis reveals that the outer calcium shell originates from the helium detonation at the base of the outer envelope, while the inner shell is associated with the carbon–oxygen core detonation. This morphological distribution of intermediate-mass elements agrees qualitatively with the predicted signature of the double detonation of a sub-Chandrasekhar-mass white dwarf from a hydrodynamical explosion simulation.

In other words, the outer shell resulted from the explosion caused by the helium ripped from the companion star, with the resulting shockwave detonating the second explosion inside the white dwarf’s core.

That’s the theory at least. This data supports it, but it certainly doesn’t prove it.

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Webb detects unexpected “little red dots” in the early universe

11:52 am

The uncertainty of science: Using the Webb Space Telescope astronomers have begun to compile a small catalog of what they call “little red dots” [LRDs], objects in the very early universe that are very small, too small to be galaxies and are thus a mystery.

A team of astronomers recently compiled one of the largest samples of LRDs to date, nearly all of which existed during the first 1.5 billion years after the big bang. They found that a large fraction of the LRDs in their sample showed signs of containing growing supermassive black holes.

“We’re confounded by this new population of objects that Webb has found. We don’t see analogs of them at lower redshifts, which is why we haven’t seen them prior to Webb,” said Dale Kocevski of Colby College in Waterville, Maine, and lead author of the study. “There’s a substantial amount of work being done to try to determine the nature of these little red dots and whether their light is dominated by accreting black holes.”

The present most popular theory to explain the dots, based on the available data, is that the dots are newly formed black holes, their red light caused by material falling into the hole at millions of miles per hour. That theory has of course problems. For example, it doesn’t explain why we don’t see these dots in more recent times. Nor does it explain why the dots are dim in X-rays, a radiation expected from accreting black holes.

As always, the press release claims that this discovery does not “break” the present cosmological theories for the formation of the universe, but at the same time, it does illustrate our overall lack of knowledge about that early universe. We really don’t know very much, which means any theories we have are likely wrong simply due to our present ignorance.

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Baby stars illuminating the dust that surrounds them

10:03 am

Baby stars illuminating dark dust
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 showing the wispy bluish clouds made of dark dust that we can only see because the dust is illuminated by the reflected light from the five red and blue stars nearby. Think of the Moon, lit only by the reflected light of the Sun.

The photo however was not taken to study the clouds, but these baby stars, located in one of the closest star forming regions of the Milky Way.

GN 04.32.8 is a small part of the stellar nursery known as the Taurus Molecular Cloud. At only roughly 480 light-years from Earth in the constellation Taurus, it’s one of the best locations for studying newly forming stars. This reflection nebula is illuminated by the system of three bright stars in the centre of this image, mainly the variable star V1025 Tauri in the very centre. One of those stars overlaps with part of the nebula: this is another variable star that is named HP Tauri, but is classified as a T Tauri star, for its similarity to yet another variable star elsewhere in the Taurus Molecular Complex. T Tauri stars are very active, chaotic stars at an early stage of their evolution, so it’s no surprise that they appear in a prolific stellar nursery like this one! The three stars are also named HP Tau, HP Tau G2 and HP Tau G3; they’re believed to be gravitationally bound to each other, forming a triple system.

Eagle-eyed viewers might notice the small, squashed, orange spot, just left of centre below the clouds of the nebula, that’s crossed by a dark line. This is a newly-formed protostar, hidden in a protoplanetary disc that obstructs some of its light. Because the disc is edge-on to us, it’s an ideal candidate for study. Astronomers are using Hubble here to examine it closely, seeking to learn about the kinds of exoplanets that might be formed in discs like it.

As beautiful as this image is, it is that tiny protostar near the bottom that likely attracts the most interest from astronomers.

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Webb takes infrared image of exoplanet

9:32 am

Webb's image of exoplanet

Using the Webb Space Telescope astronomers have now successfully taken an infrared false-color image of Saturn-sized exoplanet orbiting a young star about half the mass of the Sun and about 111 light years away.

The image is to the right, cropped and reduced to post here. The star, its light blocked out, is indicated by the circle with the star in the middle. The exoplanet is the orange blob to the upper right, sitting inside the blue accretion disk that surrounds the star, photographed in optical light by the Very Large Telescope in Chile.

You can read the paper here. The scientists rejected the possibility that this was a background galaxy after doing computer modeling, based on the data available. From their paper:

Dedicated N-body simulations were conducted for a planet with a mass of 0.34 [mass of Jupiter], located at 52 au [astronomical units] around the 0.46 [solar mass] central star. This value is consistent with the measured projected separation, assuming that the planet and the ≈13°-inclined disk are coplanar. The simulation also included a disk of 200,000 planetesimals, distributed between 20 and 130 au. These parameters were selected to roughly match the boundaries of the observed disk.

Note too that the picture to the right has been significantly enhanced by the press department at JPL, based on the actual data shown in the paper itself. These fact underline the uncertainties involved in this discovery.

Nonetheless, it is a good result, and suggests we are looking at the formation process of a new solar system surrounding a very young baby star.

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Astronomers look at the Andromeda Galaxy in many wavelengths

3:11 pm

Andromeda across many wavelengths
Click for full images.

Astronomers using both old and new and ground- and space-based telescopes have created a full set of observations of the Andromeda Galaxy (also known as M31) across five different wavelengths, producing one of the most complete views of the galaxy so far.

This new composite image contains data of M31 taken by some of the world’s most powerful telescopes in different kinds of light. This image includes X-rays from NASA’s Chandra X-ray Observatory and ESA’s (European Space Agency’s) XMM-Newton (represented in red, green, and blue); ultraviolet data from NASA’s retired GALEX (blue); optical data from astrophotographers using ground based telescopes (Jakob Sahner and Tarun Kottary); infrared data from NASA’s retired Spitzer Space Telescope, the Infrared Astronomy Satellite, COBE, Planck, and Herschel (red, orange, and purple); and radio data from the Westerbork Synthesis Radio Telescope (red-orange).

Each type of light reveals new information about this close galactic relative to the Milky Way. For example, Chandra’s X-rays reveal the high-energy radiation around the supermassive black hole at the center of M31 as well as many other smaller compact and dense objects strewn across the galaxy.

The contrast in emissions between different wavelengths is certainly striking. The radio, infrared, and ultraviolet data clearly delineate the galaxy’s arms where star formation is occurring. The X-ray highlights the galaxy’s central black hole.

This press release is clearly intended to lobby against the cuts at NASA, especially considering that several of these images (Galax, Spitzer) are not new. At the same time, it does demonstrate the need to look at the heavens across the entire electromagnetic spectrum. It seems to me that the astronomical community should begin to consider other methods of funding for this work, other than just the federal government, and in fact they prove this point themselves by the use of images above from some smaller ground-based telescopes not funded by American tax dollars.

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A graceful spiral galaxy

2:35 pm

A graceful spiral galaxy
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 project to study galaxies with very active central supermassive black holes.

What sets UGC 11397 apart from a typical spiral lies at its centre, where a supermassive black hole containing 174 million times the mass of the Sun is growing. As a black hole ensnares gas, dust, and even entire stars from its vicinity, this doomed matter heats up and puts on a fantastic cosmic light show. Material trapped by the black hole emits light from gamma rays to radio waves and can brighten and fade without warning. But in some galaxies, including UGC 11397, thick clouds of dust hide much of this energetic activity from view in optical light. Despite this, UGC 11397’s actively growing black hole was revealed through its bright X-ray emission — high-energy light that can pierce the surrounding dust. This led astronomers to classify it as a Type 2 Seyfert galaxy, a category used for active galaxies whose central regions are hidden from view in visible light by a doughnut-shaped cloud of dust and gas.

To me what sets this galaxy apart is its natural beauty. It also reminds me of the universe’s vastness. Located about 250 million light years away, those hazy spiral arms represent millions of stars, many of which likely harbor planets and maybe even life.

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The new Rubin telescope releases its first images

9:34 am

Section of the Virgo cluster, as seen by Rubin
Click to see all first look images.

The new Vera Rubin telescope, located in Chile and designed to provide a high resolution survey of the southern sky every three nights, has now released its first images.

Rubin Observatory will … be the most efficient and effective Solar System discovery machine ever built. Rubin will take about a thousand images of the Southern Hemisphere sky every night, allowing it to cover the entire visible Southern sky every three to four nights. In doing so, it will find millions of unseen asteroids, comets and interstellar objects. Rubin will be a game changer for planetary defense by spotting far more asteroids than ever before, potentially identifying some that might impact the Earth or Moon.

The image to the right, cropped, reduced, and sharpened to post here, shows a small section of the Virgo cluster of galaxies, about 50 million light years away.

The telescope’s vast survey data of the sky will also be used to attempt to determine the nature of both dark matter and dark energy.

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Clickspring – Recreating the ancient engineering that built the Antikythera Mechanism

6:01 pm

An evening pause: For background, the Antikythera Mechanism is an archaeological artifact from ancient Greece:

The Antikythera Mechanism is the oldest known scientific computer, built in Greece at around 100 BCE. Lost for 2000 years, it was recovered from a shipwreck in 1901. But not until a century later was its purpose understood: an astronomical clock that determines the positions of celestial bodies with extraordinary precision.

Today’s pause shows how this very complex mechanism, that includes many metal gears, might have been made by hand, without electricity and our modern tools.

Hat tip Cotour.

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New nova spotted and now visible to the naked eye

2:39 pm

Astronomers have now spotted a brand new nova in the southern hemisphere that has quickly brightened so that is now just visible to the naked eye.

On June 12th (June 12.9 UT), the All-Sky Automated Survey for Supernovae (ASAS-SN) discovered a new 8.7-magnitude stellar object in Lupus. Not long after, Yusuke Tampo, with the South African Astronomical Observatory (University of Cape Town), obtained a spectrum of the “new star” and identified it as a classical nova based on its spectral features and dramatic increase in brightness.

The nova went through a slew of temporary names — AT 2025nlr, ASASSN-25cm, and N Lup 2025 — until receiving its official designation V462 Lupi on June 16th. Since discovery, the nova has brightened rapidly. As of 3 p.m. Eastern Time June 17th, it’s at magnitude 6.1, and visible without optical aid from a dark-sky location. Its rise has been phenomenal when you consider that prior to the explosion, the progenitor star was approximately magnitude 22.3 (in the blue band) according to American Association for Variable Stars (AAVSO) observer Sebastián Otero, who dug up an older image from a photographic plate.

Though in the southern hemisphere, this nova star is also visible in the northern hemisphere to the mid-latitudes. The article at the link provides some details if you wish to try spotting it.

Novae occur when a central heavy white dwarf star robs enough material from its closely orbiting stellar companion. When enough material piles up on the surface of the white dwarf it goes critical, resulting in a thermonuclear explosion strong enough to produce the nova.

Whether the nova will continue to brighten remains unknown, but I guarantee that a plethora of amateur astronomers will watching to find out.

Hat tip to BtB’s stringer Jay.

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Astronomers claim radio data detects much of the universe’s “missing mass”

10:55 am

The uncertainty of science: Using radio data from 60 fast radio bursts scattered across the sky, astronomers think they have detected the signature of much of the universe’s “missing mass” that has until now been ascribed to some unknown material dubbed dark matter but in fact is mostly ordinary matter that was previously unobserved.

The results show that about 76% of baryonic matter is in the intergalactic medium, 15% is in the halos around galaxies and the rest is inside stars or cold galactic gas.

From the paper’s abstract:

Approximately half of the Universe’s dark matter resides in collapsed halos; significantly less than half of the baryonic matter (protons and neutrons) remains confined to halos. A small fraction of baryons are in stars and the interstellar medium within galaxies. The majority are diffuse (<10−3 cm−3) and ionized (neutral fraction <10−4), located in the intergalactic medium (IGM) and in the halos of galaxy clusters, groups and galaxies.

In other words, the dark matter is simply ordinary matter made up of ionized “diffuse ionized gas” that ” is notoriously difficult to measure.”

One major uncertainty of this result is its dependence on fast radio bursts. The scientists claim the sixty bursts they used came from distances ranging from 12 million to 9 billion light years, but it is unclear how they determined those distances. We do not currently know the source of fast radio bursts, which means we also do not really know exactly where they occur or how distant they are from us. This research however relies on that uncertain knowledge, because it measures the changes to each burst’s radio emissions as it travels through intergalactic space.

Nonetheless, if confirmed this result shouldn’t surprise us. The universe is gigantic and mostly hard to observe. For there to be a gigantic amount of undetected ordinary matter scattered between the galaxies is perfectly reasonable. Inventing something extraordinary — dark matter — is actually a far more unreasonable scientific strategy.

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Scientists increase the odds asteroid 2024 YR4 will impact the Moon in 2032

9:10 am

Asteroid 2024 YR4 in 2032
Click for original image.

Using additional data obtained by the Webb Space Telescope, scientists have now refined the orbit of potentially dangerous asteroid 2024 YR4 and confirmed that while it will almost certainly not hit the Earth in 2032, the odds of it impacting the Moon have increased.

With the additional data, experts from NASA’s Center for Near-Earth Object Studies at the agency’s Jet Propulsion Laboratory in Southern California further refined the asteroid’s orbit. The Webb data improved our knowledge of where the asteroid will be on Dec. 22, 2032, by nearly 20%. As a result, the asteroid’s probability of impacting the Moon has slightly increased from 3.8% to 4.3%. In the small chance that the asteroid were to impact, it would not alter the Moon’s orbit.

The yellow line in the image to the right shows the present range of positions the asteroid could be in as it passes the Moon on that date. It is expected this range will be narrowed further when the asteroid flies past the Earth harmlessly in 2028.

If the asteroid should hit the Moon, the impact will provide scientists a great opportunity to learn more about asteroids and the Moon. If it should miss, it will then be essential to recalculate its orbit to see what will happen on later near approaches, whether the fly-by increased or decreased the chances of a later Earth impact.

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Scientists discover another exoplanet that theories say should not exist

10:20 am

The uncertainty of science: Scientists using telescopes both in orbit and on the ground have discovered a small red dwarf star with only 20% the mass of our Sun with a gas giant exoplanet with about half the mass of Saturn but a bit larger in size.

The problem is that the theory for the formation of such gas giants predicts that they should not form around small red dwarfs such as this star.

The most widely held theory of planet formation is called the core accretion theory. A planetary core forms first through accretion (gradual accumulation of material) and as the core becomes more massive, it eventually attracts gases that form an atmosphere. It then gets massive enough to enter a runaway gas accretion process to become a gas giant.

In this theory, the formation of gas giants is harder around low-mass stars because the amount of gas and dust in a protoplanetary disc around the star (the raw material of planet formation) is too limited to allow a massive enough core to form, and the runaway process to occur.

Yet the existence of TOI-6894b (a giant planet orbiting an extremely low-mass star) suggests this model cannot be completely accurate and alternative theories are needed.

You can read the paper here. The exoplanet orbits the star every 3.37 days, and each transit across the face of the star has been easily detected by numerous telescopes. Further spectroscopic observations using the Webb Space Telescope will be able to characterize the exoplanet’s atmosphere more fully.

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Two giant clusters of galaxies on target for second collision

3:55 pm

Colliding galaxy clusters
Click for full image.

Using telescopes both on Earth and in space, astronomers now think two giant clusters of galaxies that had collided previously have now stopping flying from each other and are on target for second collision.

The annotated image to the right shows what we can see today. The two blue blobs near the center are the two galaxy clusters.

The galaxy cluster PSZ2 G181.06+48.47 (PSZ2 G181 for short) is about 2.8 billion light-years from Earth. Previously, radio observations from the LOw Frequency ARray (LOFAR), an antenna network in the Netherlands, spotted parentheses-shaped structures on the outside of the system. In this new composite image, X-rays from Chandra (represented in purple) and ESA’s XMM-Newton (blue) have been combined with LOFAR data (red) and an optical image from the Pan-STARRS telescope of the stars in the field of view.

These structures are probably shock fronts — similar to those created by jets that have broken the sound barrier — likely caused by disruption of gas from the initial collision about a billion years ago. Since the collision they have continued traveling outwards and are currently separated by about 11 million light-years, the largest separation of these kinds of structures that astronomers have ever seen.

Now, data from NASA’s Chandra and ESA’s XMM-Newton, a mission with NASA contributions, is providing evidence that PSZ2 G181 is poised for another collision. Having a first pass at ramming each other, the two clusters have slowed down and begun heading back toward a second crash.

When such giant object collide what really interacts the most is the gas and dust between the stars. The motions of the stars and galaxies of course get distorted by the pull of gravity, but there are almost never any crashes.

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New ground-based images of the Sun’s surface

9:37 am

The Sun's surface, as seen by Inouye Solar Telescope
Click for original image.

Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken using the Inouye Solar Telescope in Hawaii. It shows the granule surface of the Sun at very high resolution, resolving objects as small as 12 miles across.

The team used the Inouye’s Visible Broadband Imager (VBI) instrument operating in the G-band, a specific range of visible light especially useful for studying the Sun because it highlights areas with strong magnetic activity, making features like sunspots and fine-scale structures like the ones in the study easier to see. The setup allows researchers to observe the solar photosphere at an impressive spatial resolution better than 0.03 arcseconds (i.e., about 20 kilometers on the Sun). This is the sharpest ever achieved in solar astronomy.

The scientists then used computer simulations to confirm that the smallest features, curtains of plasma raising along the walls of the granules, are linked to fluctuations in the Sun’s magnetic field.

As interesting and cutting edge this research is, the language of the press release seems more aimed at touting this telescope then describing new science. Practically every sentence uses words like “unmatched,” “unparalleled,” “unique,” and “unprecedented” (multiple times), and then ended with this quote:

“This is just one of many firsts for the Inouye, demonstrating how it continues to push the of solar research,” says NSO [National Solar Observatory] Associate Director for the NSF [National Science Foundation’s] Inouye Solar Telescope, Dr. David Boboltz. “It also underscores Inouye’s vital role in understanding the small-scale physics that drive space weather events that impact our increasingly technological society here on Earth.”

I have noticed this phenomenon recently in many government press releases. It appears that the releases issued in the past month have become less about real research and are more designed to lobby the public against any possible budget cuts proposed by the Trump administration.

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New calculations suggest Andromeda might not collide with Milky Way

9:00 am

The uncertainty of science: Scientists using new data from the Hubble Space Telescope as well as Europe’s Gaia space telescope, combined with many computer models, have determined that the 2012 prediction that the Andromeda galaxy would collide with Milky Way in five billion years was much more uncertain. From the abstract of the paper:

[W]e consider the latest and most accurate observations by the Gaia and Hubble space telescopes, along with recent consensus mass estimates, to derive possible future scenarios and identify the main sources of uncertainty in the evolution of the Local Group over the next 10 billion years. We found that the next most massive Local Group member galaxies — namely, M33 and the Large Magellanic Cloud—distinctly and radically affect the Milky Way — Andromeda orbit. Although including M33 increases the merger probability, the orbit of the Large Magellanic Cloud runs perpendicular to the Milky Way–Andromeda orbit and makes their merger less probable.

In the full system, we found that uncertainties in the present positions, motions and masses of all galaxies leave room for drastically different outcomes and a probability of close to 50% that there will be no Milky Way–Andromeda merger during the next 10 billion years. Based on the best available data, the fate of our Galaxy is still completely open.

The press release at the first link above makes it sounds as the previous prediction of a collision had been fully accepted as certain by the entire astronomical community, and that is balder-dash. It was simply the best guess at the time, highly uncertain. This new prediction — that we really don’t know what will happen based on the data available — is simply the newest best guess.

This new analysis however is certainly more robust and honest.

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Trump budget proposes putting a final end to the delayed and blocked Thirty Meter Telescope

12:01 pm

There is a lot more to report, and I will do so in a day or so, but I thought it worthwhile to quickly note the the proposed science cuts in the proposed Trump budget for 2026 includes the elimination of all funds for Thirty Meter Telescope (TMT) in Hawaii.

In the budget request, NSF [National Science Foundation]… says it will back only one of the two $3 billion optical telescopes that the astrophysics community wants to build. That honor goes to the Giant Magellan Telescope already under construction in Chile. Its competitor, the Thirty Meter Telescope (TMT), “will not advance to the Final Design Phase and will not receive additional commitment of funds from NSF,” according to the budget request.

The NSF has never had enough money to finance both telescopes. The fact that TMT has been blocked for more than a decade by DEI protesters in Hawaii, with the aid of the state government (controlled entirely by Democrats), makes funding it pointless, and a waste of the taxpayers’ money. It long past time to pull the plug.

As I say, there is a lot more details to report in this budget proposal, including its effort to slash a lot of science government spending, but that will have to wait for later essays. I can promise you one thing, however: I will not do what the rest of the press does, and write a knee-jerk propaganda piece in support of that spending. The science mafia at NASA and the NSF and other agencies has funded a lot of junk in the last few decades. It is time for a reckoning.

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Webb spots a new record-setting galaxy, only 280 million years after the Big Bang

3:11 pm

MoM Z14
The galaxy MoM z14, as seen in the infrared
by Webb. Click for original image.

The uncertainty of science: Using the Webb Space Telescope, astronomers have now identified a galaxy that formed only 280 million years after the Big Bang, far earlier than their theories of the origins of the universe had predicted.

“The broader story here is that JWST was not expected to find any galaxies this early in the history of the universe, at least not at this stage of the mission,” van Dokkum said. “There are, very roughly, over 100 more relatively bright galaxies in the very early universe than were expected based on pre-JWST observations.”

The data suggests MoM z14 is 50 times smaller than the Milky Way, contains nitrogen and carbon, and appears to be forming stars. The data also found little neutral hydrogen surrounding the galaxy, which also contradicts those same cosmological theories. According to those theories, the early universe should be filled with neutral hydrogen.

The nitrogen and oxygen are also there earlier than expected, and suggest there will be more such galaxies, including some even closer to the Big Bang.

Hat tip BtB’s stringer Jay.

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Astronomers discover a star radiating in X-rays and radio in ways that fit no known explanation

10:14 am

ASKAP J1832 circled. Note the red arc denoting the supernovae remnant
ASKAP J1832 circled. Note the red arc denoting
the supernovae remnant. Click for original image.

Using both the Chandra X-Ray Observatory and the Square Kilometer Array in Australia, astronomers have discovered a star that pulses in both X-rays and and radio frequencies in a manner previously unseen and that fit no known theory.

ASKAP J1832 belongs to a class of objects called “long period radio transients,” discovered in 2022, that vary in radio wave intensity in a regular way over tens of minutes. This is thousands of times longer than the length of the repeated variations seen in pulsars, which are rapidly spinning neutron stars that have repeated variations multiple times a second. ASKAP J1832 cycles in radio wave intensity every 44 minutes, placing it into this category of long period radio transients.

Using Chandra, the team discovered that ASKAP J1832 is also regularly varying in X-rays every 44 minutes. This is the first time that such an X-ray signal has been found in a long period radio transient.

…However, that is not all ASKAP J1832 does. Using Chandra and the SKA Pathfinder, the team found that ASKAP J1832 also dropped off in X-rays and radio waves dramatically over the course of six months. This combination of the 44-minute cycle in X-rays and radio waves in addition to the months-long changes is unlike anything astronomers have seen in the Milky Way galaxy.

The false-color X-ray/radio image to the right shows the star (circled). Based on the data, it is unlikely that the star is a neutron star or a pulsar. Its properties also do not fit with a magnetar (a pulsar with a very strong magnetic field). Though located within a supernova remnant, the astronomers determined this to be a coincidence, the star unrelated to the remnant.

The best explanation so far is that this is a white dwarf with a companion and the strongest magnetic field ever conceived. The astronomers however do not appear enthused by that explanation either.

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A galactic pinwheel

8:39 am

A galactic pinwheel
Click for original image.

It’s cool image time, partly because we have a cool image and partly because there is little news today due to the holiday. The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope and was released today as the science team’s picture of the week. It shows us a classic pinwheel galaxy located approximately 46 million light years away. From the caption:

A spiral galaxy seen face-on. Its centre is crossed by a broad bar of light. A glowing spiral arm extends from each end of this bar, both making almost a full turn through the galaxy’s disc before fading out.

The bright object with the four spikes of light is a foreground star inside the Milky Way and only 436 light years away. The bright orange specks inside the spiral arms are likely star forming regions, with the blue indicating gas clouds.

As for the holiday, I’ll have more to say about Memorial Day later today.

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Astronomers discover a perfect sphere in radio

1:20 pm

Radio object Teleios

Using the array of radio dishes dubbed the Australian Square Kilometre Array, astronomers have made the serendipitous discovery of what appears to be a perfect sphere of radio emissions tens of light years in diameter and tens of thousands of light years away and near the galactic center.

The scientists have dubbed the object Teleios, Greek for ‘complete’ or ‘perfect’. The image to the right is that radio image. Though the astronomers posit that it must have been formed from a supernova explosion, there are problems with that conclusion. From their paper [pdf]:

Unfortunately, all examined scenarios have their challenges, and no definitive Supernova origin type can be established at this stage. Remarkably, Teleios has retained its symmetrical shape as it aged even to such a diameter, suggesting expansion into a rarefied and isotropic ambient medium. The low radio surface brightness and the lack of pronounced polarisation can be explained by a high level of ambient rotation measure (RM), with the largest RM being observed at Teleios’s centre.

In other words, this object only emits in radio waves, is not visible in optical or other wavelengths as expected, and thus doesn’t really fit with any theories describing the evolution of supernova explosions. Yet its nature fits all other possible known space objects even less, such as planetary nebulae, nova remnants, Wolf-Rayet stars, or even super-bubbles of empty space (such as the Local Bubble the solar system is presently in).

Baffled, the scientists even considered the possibility that they had discovered an artificially built Dyson Sphere, but dismissed that idea because Teleios emits no infrared near its boundaries, as such a sphere is expected to do.

At present the best theory remains a supernova remnant, though this remains a poor solution at best.

Hat tip to reader (and my former editor at UPI) Phil Berardelli.

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