Tag: astronomy

Study identifies range of interference produced by Starlink satellites

8:58 am

In analyzing about 76 million radio images produced by the new Square Kilometer Array (SKA) in Australia scientists have found within them signals produced by SpaceX’s Starlink satellites.

PhD candidate and study lead Dylan Grigg said the team detected more than 112,000 radio emissions from 1806 Starlink satellites, making it the most comprehensive catalogue of satellite radio emissions at low frequencies to date. “Starlink is the most immediate and frequent source of potential interference for radio astronomy: it launched 477 satellites during this study’s four-month data collection period alone,” Mr Grigg said. “In some datasets, we found up to 30 per cent of our images showed interference from a Starlink satellite.”

Mr Grigg said the issue wasn’t just the number of satellites, but the strength of the signals and the frequencies they were visible at. “Some satellites were detected emitting in bands where no signals are supposed to be present at all, such as the 703 satellites we identified at 150.8 MHz, which is meant to be protected for radio astronomy,” Mr Grigg said. “Because they may come from components like onboard electronics and they’re not part of an intentional signal, astronomers can’t easily predict them or filter them out.”

The researchers were careful to note that SpaceX has been following all international regulations, and that these signals are not a violation of any law or regulation. Further, they emphasized that “Discussions we have had with SpaceX on the topic have been constructive.”

Because many other such constellations are now being launched — with several from China that normally does not negotiate these issues like SpaceX — the scientists want new international regulations imposed to protect their work.

More and more it seems astronomers should simply move their operations into space or the Moon, where such issues will not exist. Getting above the atmosphere and away from our modern technological society provides so many benefits for research the move should be a no-brainer. That it is now also much cheaper to do it (thanks to SpaceX) makes the move even more practical.

For some reason however the idea seems too difficult for many astronomers to fathom.

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First Hubble images of interstellar comet 3I/Atlas released

5:03 pm

Comet 3I/Atlas, taken by Hubble
Click for original.

An undergraduate student has just released the first pictures taken by the Hubble Space Telescope of the interstellar object 3I/Atlas, confirming that it is a comet as indicated by the earlier image taken by the Gemini North telescope.

One of those images, taken only hours ago, is the inset on the map showing the comet’s route through the solar system to the right. The streaks on the image are either stars or cosmic rays. Though this image is of significantly lower quality than the Gemini North picture, it once again shows both the comet’s nucleus and developing coma.

A preprint [pdf] of a new research paper based on data from both telescopes further confirms this conclusion:

[T]hese results suggest that 3I/ATLAS hosts a coma containing large water ice grains, and that its dust continuum is stable over at least week-long timescales. The spectral characteristics further distinguish 3I from known ultrared trans-Neptunian objects and align it more closely with active Jupiter-family comets.

The last conclusion is very significant. Though the path and speed of this interstellar object says it must come from beyond the solar system, its cometary make-up more resembles comets that reside in the inner solar system. These facts strongly imply that there is at least one other solar systems not very different from our own.

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Astronomers detect exoplanet shaping the protoplanetary disk surrounding a baby star

9:41 am

Star with disk
Click for original image.

Astronomers using two different instruments on the Very Large Telescope (VLT) in Chile have now directly detected what they think is an exoplanet as it shapes the spiral arms of a baby star’s protoplanetary disk.

In the case of HD 135344B’s disc, swirling spiral arms had previously been detected by another team of astronomers using SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch), an instrument on ESO’s VLT. However, none of the previous observations of this system found proof of a planet forming within the disc.

Now, with observations from the new VLT’s Enhanced Resolution Imager and Spectrograph (ERIS) instrument, the researchers say they may have found their prime suspect. The team spotted the planet candidate right at the base of one of the disc’s spiral arms, exactly where theory had predicted they might find the planet responsible for carving such a pattern.

The newly detected object however might be a brown dwarf and not an exoplanet. More observations are required to reduce the uncertainty.

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Have astronomers observed a black hole twice gobble from the same star?

9:23 am

Astronomers have now observed identical flares 700 days apart and coming from the same supermassive black hole, suggesting that a star was partially disrupted both times as it orbited the black hole.

Both flares produced less energy than predicted, based on calculations that assumed the complete destruction of a star. From the paper’s [pdf] abstract:

Here we present the optical-ultraviolet tidal disruption event AT 2022dbl, which showed a nearly identical repetition 700 days after the first flare. Ruling out gravitational lensing and two chance unrelated disruptions, we conclude that at least the first flare represents the partial disruption of a star.

…Since both flares are typical of the optical-ultraviolet class of tidal disruptions in terms of their radiated energy, temperature, luminosity, and spectral features, it follows that either the entire class are partial rather than full stellar disruptions, contrary to the prevalent assumption, or some members of the class are partial disruptions, having nearly the same observational characteristics as full disruptions. Whichever option is true, these findings could require revised models for the emission mechanisms of optical-ultraviolet tidal disruption flares and a reassessment of their expected rates.

Assuming the star wasn’t completely destroyed during the second flare, a third flare should occur about two years from now, as the star swings around and makes its next close approach. If so it will confirm this theory. If not, we will be left with the simple uncertainty of science.

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A galaxy surrounded by galaxies

11:12 am

A galaxy surrounded by 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 of galaxies where Type 1a supernovae have occurred, in order to better refine the precise brightness of these explosions.

What makes this galaxy most interesting are the hundreds of other galaxies that appear to surround it. And that ain’t an illusion.

NGC 3285B is a member of the Hydra I cluster, one of the largest galaxy clusters in the nearby Universe. Galaxy clusters are collections of hundreds to thousands of galaxies that are bound to one another by gravity. The Hydra I cluster is anchored by two giant elliptical galaxies at its centre. Each of these galaxies is about 150,000 light-years across, making them about 50% larger than our home galaxy, the Milky Way. NGC 3285B sits on the outskirts of its home cluster, far from the massive galaxies at the centre.

As for the survey program, Type 1a supernovae are the measure cosmologists have used to discover the unexpected acceleration of the universe’s expansion rate at the largest scales, something they dub “dark energy” because they really don’t understand what they have discovered. That discovery however hinges entirely on the assumed intrinsic brightness of Type 1a supernovae. Astronomers have assumed these supernovae all have the same approximate brightness, and extrapolate their distance by that brightness.

The problem are the assumptions. We really don’t know if all Type 1a supernovae are approximately the same brightness. And even if they are equally bright, we also do not have a firm grasp of what that brightness should be.

This survey is an attempt to narrow or eliminate these uncertainties.

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Astronomers detect first evidence of gas condensing to molecular solids in baby solar system

11:39 am

Baby star with jets of new material
Click for original image.

Using a combination of ground- and space-based telescopes, astronomers have detected the first evidence of the gas and dust surrounding a young star condensing to molecular solids, thus beginning the initial stages of planet formation.

This newborn planetary system is emerging around HOPS-315, a ‘proto’ or baby star that sits some 1300 light-years away from us and is an analogue of the nascent Sun. Around such baby stars, astronomers often see discs of gas and dust known as ‘protoplanetary discs’, which are the birthplaces of new planets. … Their results show that SiO [silicon monoxide] is present around the baby star in its gaseous state, as well as within these crystalline minerals, suggesting it is only just beginning to solidify. “This process has never been seen before in a protoplanetary disc — or anywhere outside our Solar System,” says co-author Edwin Bergin, a professor at the University of Michigan, USA.

…With these data, the team determined that the chemical signals were coming from a small region of the disc around the star equivalent to the orbit of the asteroid belt around the Sun.

The false-color picture to the right, cropped, reduced, and sharpened to post here, was taken by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile. It shows jets blowing out from the central baby star. Orange indicates carbon monoxide, while blue is the silicon monoxide. Initially the astronomers detected these molecules using spectroscopy from the Webb Space Telescope. This ALMA image was then used to identify where these molecules were located in the system.

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First good image released of interstellar object 3I/Atlas as it plunges through the solar system

3:25 pm

First good image of instellator object 3I/Atlas
Click for original image of 3I/Atlas.

Astronomers using the Gemini North Telescope in Hawaii have obtained the first good image of the interstellar object 3I/Atlas, as it plunges within the orbit of Jupiter on its way through the solar system.

That picture is to the right, cropped to post here and overlaid on top of a map showing the interstellar object’s calculated path through the solar system.

The picture clearly shows this is a comet, with central nucleus surrounded by a cloud of dust and gas. The data also suggests its nucleus has a diameter of about twelve miles. That it resembles a comet also suggests it is a dirty snowball, made up of ice and rocky material mixed together.

Because it will never get closer to the Sun then just inside the orbit of Mars, it is not likely it will ever get bright enough for naked eye observations. At the same time, it is large enough and will be close enough to make possible some excellent observations as it zips by and leaves the solar system sometime in the fall. The previous two identified interstellar objects, Oumuamua and Comet 21/Borisov, were either too small or too far away as they flew past to get this kind of good data.

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Webb spots aftermath of collision of two galaxies

10:06 am

colliding galaxies
Click for source.

Using the Webb Space Telescope, astronomers have discovered the collision of two spiral galaxies that appears to have caused a supermassive black hole to collapse in its wake.

The Webb false-color infrared image to the right shows the two galaxies as the red dots, both surrounded by a ring, with the supermassive black hole the bluish spot in between but offset somewhat to the left. Follow-up radio observations suggested that this bluish spot was a supermassive black hole, having a mass of a million suns and sucking up matter from the giant gas cloud that surrounds it.

The team proposes that the black hole formed there via the direct collapse of a gas cloud – a process that may explain some of the incredibly massive black holes Webb has found in the early universe.

This hypothesis however has enormous uncertainties, and requires a lot more observations to confirm. The black hole could simply exist unrelated to the galaxy collision, having come there from elsewhere. Or it could be from a third galaxy in this group that these initial observations have not yet detected.

The image however is quite cool.

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A distant globular cluster

10:03 am

A distant globular cluster
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 research project to study globular clusters in galaxies other than the Milky Way.

The data for this image comes from an observing programme comparing old globular clusters in nearby dwarf galaxies — the LMC [Large Magellanic Cloud], the Small Magellanic Cloud and the Fornax dwarf spheroidal galaxy — to the globular clusters in the Milky Way galaxy. Our galaxy contains over 150 of these old, spherical collections of tightly-bound stars, which have been studied in depth — especially with Hubble Space Telescope images like this one, which show them in previously-unattainable detail. Being very stable and long-lived, they act as galactic time capsules, preserving stars from the earliest stages of a galaxy’s formation.

Astronomers once thought that the stars in a globular cluster all formed together at about the same time, but study of the old globular clusters in our galaxy has uncovered multiple populations of stars with different ages. In order to use globular clusters as historical markers, we must understand how they form and where these stars of varying ages come from. This observing programme examined old globular clusters like NGC 1786 [pictured] in these external galaxies to see if they, too, contain multiple populations of stars. This research can tell us more not only about how the LMC was originally formed, but the Milky Way Galaxy, too.

This cluster, discovered in 1835 by John Herschel, is about 160,000 light years away.

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LIGO detects gravitational waves of largest black hole merger yet

9:22 am

The LIGO gravitational wave detector, spread across several continents, successfully detected the largest black hole merger yet on November 23, 2023.

The two black holes that merged were approximately 100 and 140 times the mass of the Sun. In addition to their high masses they are also rapidly spinning, making this a uniquely challenging signal to interpret and suggesting the possibility of a complex formation history. “This is the most massive black hole binary we’ve observed through gravitational waves, and it presents a real challenge to our understanding of black hole formation,” says Professor Mark Hannam, from Cardiff University and a member of the LIGO Scientific Collaboration. “Black holes this massive are forbidden through standard stellar evolution models. One possibility is that the two black holes in this binary formed through earlier mergers of smaller black holes.”

To date, approximately 300 black-hole mergers have been observed through gravitational waves, including candidates identified in the ongoing O4 run. Until now the most massive confirmed black-hole binary was the source of GW190521, with a much smaller total mass of “only” 140 times that of the sun.

As noted by the press release as well as this news article, present theories of stellar evolution say that these black holes could not have come from single stars, which are predicted to never be this massive. It is posited that each black hole might have formed from earlier mergers, but there is also a lot of uncertainty in the data. To quote the release again: “Extracting accurate information from the signal required the use of theoretical models that account for the complex dynamics of highly spinning black holes.”

That this detection was almost two years ago and only announced now makes me wonder if the timing of the announcement has more to do with lobbying and less to do with science. Trump’s proposed budget eliminates the U.S. funding portion for this project, and it is standard operating procedure for such projects to suddenly announce big discoveries timed to correspond to when Congress is considering the budget.

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Astronomers link fast X-ray bursts with gamma ray bursts and supernovae

1:17 pm

Using observations of a fast X-ray burst (FXT) 2.8 billion light years away by a plethora of space- and ground-based telescopes, astronomers now think the burst was caused by a massive star’s supernova explosion that would normally result in a gamma ray burst (GRB), but does not because the star’s outer layers trap the gamma rays from escaping.

Through analysis of EP 250108a’s rapidly evolving signal over the first six days following initial detection, the team found that this FXT is likely a ‘failed’ variation of a gamma-ray burst (GRB). GRBs are the most powerful explosions in the Universe and have been observed preceding supernovae. During these events, violent geysers of high-energy particles burst through a star’s outer layers as it collapses in on itself. These jets flow at nearly the speed of light and are detectable by their gamma-ray emission.

EP 250108a appears similar to a jet-driven explosion, but one in which the jets do not break through the outer layers of the dying star and instead remain trapped inside. As the stifled jets interact with the star’s outer layers, they decelerate and their kinetic energy is converted to the X-rays detected by Einstein Probe.

As always, there are many uncertainties with this conclusion.

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Another interstellar object identified entering the solar system

11:44 am

A11pl3Z's path through the solar system

Astronomers think they have identified another interstellar object that is now entering the solar system.

The dim space rock is currently at about magnitude 18.8. Our new visitor, A11pl3Z, will get its closest to the sun – at about 2 astronomical units (AU), or twice as far as Earth is from the sun – in October. As it reaches perihelion – its closest point to the sun – it should be moving at about 68 km/s relative to the sun, or at about 152,000 miles per hour.

The object’s calculated path through the solar system, shown by the blue line in the graphic to the right, as well as the object’s high speed, are why the astronomers think it is interstellar in origin. Both facts suggest it is coming from beyond the Oort cloud.

This is the third such object discovered, after Oumuamua (whose nature remains somewhat unknown), followed by Comet 21/Borisov.

UPDATE: The object has now been renamed 3I/Atlas. The “3I” indicates it is the third interstellar object discovered, and “Atlas” refers to the discovering telescope survey.

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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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