Search Results for: Hubble

Bright spokes in Saturn’s rings

11:46 am

Bright spokes in Saturn's rings
Click for original image.

Cool image time! The picture to the right, cropped slightly to post here, was taken on December 26, 2008 from a distance of 350,000 miles by the Cassini spacecraft as it orbited Saturn. The resolution is about 37 miles per pixel.

I think sunlight is coming from the upper left, its light bouncing off the rings and thus making the those spokes bright and visible.

In the viewing geometry in which Cassini is looking approximately in the direction of the sun (called high phase), the spokes appear white against the rings because the very small particles comprising the spokes preferentially scatter light forward (in this case, toward Cassini).

At least that’s one theory for explaining the spokes that appear randomly and for only short periods within Saturn’s rings, sometimes bright, sometimes dark, depending on the angle of the Sun. According to a Hubble press release from 2023, the spokes are formed due to an interaction between Saturn’s magnetic field, the solar wind, and the tiny particles in the rings.

“The leading theory is that spokes are tied to Saturn’s powerful magnetic field, with some sort of solar interaction with the magnetic field that gives you the spokes,” said Simon. When it’s near the equinox on Saturn, the planet and its rings are less tilted away from the Sun. In this configuration, the solar wind may more strongly batter Saturn’s immense magnetic field, enhancing spoke formation.

Planetary scientists think that electrostatic forces generated from this interaction levitate dust or ice above the ring to form the spokes, though after several decades no theory perfectly predicts the spokes. [emphasis mine]

Just another strange alien phenomenon in space that remains unsolved. All we really know is that the spokes appear, remain visible for at most a rotation or two of the rings, and then disappear.

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NASA wants its future space telescopes designed to be serviceable, like Hubble

11:04 am

In a briefing at a recent science conference, a NASA official made it clear that it wants its proposed Habitable Worlds Observatory (HWO) — presently undergoing its initial design studies for launch in the 2040s — be designed in a way that it can be maintained, repaired, and upgraded, much like the Hubble Space Telescope.

NASA is planning for HWO to be serviceable, which means that they will need to figure out a way to work on, repair, and maintain the observatory while it operates roughly a million miles (1.5 million kilometers) away. “HWO will have to be serviceable to some extent,” NASA’s astrophysics division director Shawn Domagal-Goldman told Space.com during a session at the American Astronomical Society’s (AAS) 248th meeting in Pasadena, California.

This design decision not only makes sense, NASA should have made it common practice a decade ago. The ability for robots to do this work is becoming increasingly robust, and in the next decade will become commonplace. For NASA to have launched anything in the past decade without this in mind was shameful.

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Webb’s mid-infrared view of the very active galaxy Centaurus A

10:57 am

Centaurus A, as seen by Webb and Hubble
Click for original Webb image. For the original Hubble image, go here.

Cool image time! The false color mid-infrared image above, reduced and annotated to post here, was taken reeently by the mid-infrared instrument on the Webb Space Telescope of the galaxy Centaurus A, 11 million light years away and known for more than a century as an elliptical galaxy crossed by a dark streak of dust, as shown by the inset, an optical Hubble Space Telescope photograph taken in July 2014. More recent research has shown the galaxy is very active, caused by the existence of a supermassive black hole in the center pulling in matter around it.

Webb’s infrared data reveals an entirely different shape. From the press release today:

Webb’s mid-infrared vision highlights the galaxy’s rich dust structures, which glow in intricate shapes that surprise and even perplex astronomers. A warped, parallelogram-like band cuts across the galaxy’s center, while wisps of material stretch outward like cosmic clouds.

An “S” shaped feature, most notable in the image from Webb’s MIRI (Mid-Infrared Instrument), is also unusual and invites questions that need further study to answer. What created this shape? How does the black hole influence it? Is it influenced by merger-induced star formation?

Many of the glowing red points in the MIRI image are dust-rich stars or stellar nurseries, where aging stars are shedding material back into space or new stars are forming. This dust is the raw ingredient for future generations of stars and planets, making it central to the ongoing life cycle of the galaxy.

Once again, this data illustrates the need for astronomers to have telescopes observing in all wavelengths and from space, since a large fraction of the electromagnetic spectrum is blocked by the atmosphere.

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Europe’s Euclid optical space telescope discovers 31 new quasars in the very early universe

9:10 am

The uncertainty of science: The Europe Space Agency’s (ESA) Euclid optical space telescope — with a mirror half the size of Hubble’s — has now identified 31 new quasars in the very early universe, all of which really shouldn’t be there based on present theories as to how long it should take for them to form.

The European Space Agency’s Euclid space telescope has discovered 31 of the most ancient quasars ever found. Two of these giant and dazzling galaxy cores, powered by gargantuan black holes, are the earliest quasars yet observed in cosmic history. They shone with the light of a trillion Suns back when the Universe was 670 million years old – just 5% of its current age.

UPDATE: Astronomers using the Keck telescopes in Hawaii have now confirmed 21 of the 31 one quasars identified by Euclid.

The scientific problem is that, according to most theories on the evolution and formation of galaxies and black holes and quasars, it takes billions of years for such large supermassive black holes to accrete their mass. Yet, these exist less than a billion years after the Big Bang. The numbers do not compute.

Euclid doesn’t get the publicity of Hubble, partly because ESA does not do as good a job of selling its work as NASA, partly because it is a European project and the American propaganda press is thus generally uninterested, and partly because it is simply smaller and a later telescope, thus not ground-breaking. Nonetheless, with a mirror 1.2 meters across, it is capable of truly spectacular optical astronomy, being above the atmosphere as well as above the many satellite constellations now in orbit. It is placed in the Lagrange point 2, a million miles from Earth.

In fact, Euclid is exactly the kind of space telescope the astronomy community should be building, in huge numbers, rather than whining about those satellite constellations blocking its big ground-based telescopes. The future of astronomy is in space, and it is high time astronomers recognized this.

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June 23, 2026 Quick space links

2:55 pm

Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

  • Starliner remains in limbo according to Space News
    Ars Technica claims NASA has a tentative launch date of August 1, 2026, but no one believes it. As I first reported in May, NASA has given all crewed missions to SpaceX through 2030, leaving Boeing and Starliner nothing. It thus appears Boeing no longer wants to spend any money on it.
  • Vast gets a $32.75M tax credit from California
    The company seems proud to stay and even expand in California, which could be a big mistake as long as that state’s government remains decided leftist and hostile to private enterprise.
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A galaxy as seen by Hubble and Webb

9:23 am

A galaxy seen by Hubble and Webb
Click for original image.

Cool image time. The picture to the right, cropped and reduced to post here, was taken on March 20, 2026 in a coordinated observations by both the Hubble and Webb space telescopes.

This March 20, 2026, image of Messier 64, or the Black Eye Galaxy, is a composite view from NASA’s Hubble Space Telescope and James Webb Space Telescope. It shows Messier 64 captured at near- and mid-infrared wavelengths by Webb, while Hubble’s image shows the galaxy in ultraviolet, visible, and near-infrared light.

Messier 64 is characterized by its bizarre internal motion. The gas in the outer regions of this spiral galaxy is rotating in the opposite direction from the gas and stars in its inner regions. This strange behavior may be the result of a merger between M64 and a satellite galaxy over a billion years ago.

The red in this image is dust, as the galaxy gets its nickname from the dark streak that wraps around its nucleus on its left side. In optical that streak is dark. Here Webb’s infrared view sees it in false color red.

READERS: It appears that it is a very slow news day today. Other than SpaceX’s IPO, which is on-going and too soon to post any reports, I can so far find nothing much of great significance on which to report.

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Cosmologists: “We are STILL right! Dark energy does exist!”

12:14 pm

Modern science
The scientific method, according to some cosmologists

The uncertainty of science: In two somewhat self-righteous press releases today from two different academic organizations, scientists who have been for three decades touting the somewhat uncertain evidence that the expansion of the universe is accelerating, thus requiring the ad hoc creation of something they label “dark energy” to explain it, insisted that their theory is still right despite publication of a paper last year that said their evidence was weak and unconvincing.

The headlines of the first press release is especially insulting to the very concept of the scientific method:

Both press releases have an arrogant attitude to those questioning the theory of dark energy, but the first is truly egregious. It is filled with bombastic claims, such as calling it “a crisis” for anyone to dare question the theory. It also uses a reliance on authority to justify its position (“The researchers … include two Nobel Laureates and represent institutions worldwide”). And finally, it demands that such questioning end, so “we can get back to trying to understand what this dark energy actually is, rather than wondering if it exists at all.”

The 2025 study that questioned the existence of dark energy — claiming the universe’s expansion rate was not accelerating — was actually part of a string of similar results. It did not occur in a vacuum, and actually stemmed from the overall uncertainty of the original supernova data.

Scientists in the 1990s had begun by assuming the brightness of a certain type of supernova is always the same, no matter when or where it happened. They then measured such supernovae in the early universe and found their brightness suggested the universe was expanding faster than predicted.

Since then, multiple studies have noted the weakness of that basic assumption. We don’t know enough about these supernovae, nor do we know enough about the environment in which they occur in the early universe.

The bottom line: The theory of dark energy might fit the facts as we have them now, but those facts remain uncertain and open to doubt. It is perfectly reasonable to question those facts, and to try to stifle that questioning violates the very fundamentals of the scientific method, which demands you question everything, that you search for truth wherever it may lead.

Sadly, this pattern of arrogance by cosmologists is not new. It has grated on my nerves since my first interview with a cosmologist in 1995, when she got insulted and huffy because I dared ask her some tough questions. This arrogance has gotten so bad that in 2022 24 scientists signed a petition protesting the censorship of their work for questioning the Big Bang theory.

Meanwhile, the data remains uncertain and actually contradictory. One set of data says the Hubble constant (the expansion rate) is one number, while another equally trustworthy data set says the constant is another number. And almost a decade of intense research has failed to resolve the conflict.

This new work might have proven the dark energy theory is still viable, but the press releases do little to convince anyone.

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June 10, 2026 Quick space links

2:40 pm

Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

2 comments

SETI confirms through extensive radio observations: Comet 3I/Atlas has no alien technology

9:28 am

New Hubble image of 3I/Atlas
Comet 3I/Atlas as seen by Hubble
in November 2025. Click for original.

Hardly a surprise: In order to put an end to the stupid clickbait speculations of some hack scientists, the SETI Institute has just completed seven hours of detailed radio observations of interstellar comet 3I/Atlas, and has confirmed that it has no alien technology and is nothing more than a comet, albeit unusual because it comes from outside our solar system.

The team identified nearly 74 million narrowband signals. After removing human interference and filtering for signals matching 3I/ATLAS’s movement, only about 200 remained for review. All traced back to technology on the surface of the Earth or our own Earth-orbiting satellites.

While no technosignatures were found, the study sets new constraints reinforcing that 3I/ATLAS is a natural object. The observations place upper limits on the power of any radio transmitter on or near 3I/ATLAS, ruling out signals stronger than about 10–110 watts, approximately the power of a household appliance, over the detected frequencies.

In other words, the comet is a comet. This research also demonstrated new astronomical capabilities that can quickly do similar observations when new interstellar objects show up.

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Scientists: Europa’s theorized plumes of water vapor might simply be statistical noise

8:56 am

Europa in true color
Europa in true color, taken by Juno September 2022.
Click for full image.

The uncertainty of science: Based on a re-analysis of data from the Hubble Space Telescope, scientists now say that the plumes of water vapor that Hubble had supposedly detected erupting from the surface of the Jupiter moon Europa might not exist, and could instead simply be statistical noise in the data.

The new paper looks at the last 14 years of data from the Hubble Space Telescope’s Space Telescope Imaging Spectrograph (HST/STIS) focused on Europa’s Lyman-alpha emissions. Lyman-alpha is a specific wavelength of ultraviolet light emitted and scattered by hydrogen atoms. From 2012-2014, the team was pushing the limits of the Hubble telescope’s capabilities.

“One of the difficulties in interpreting the data back then was determining where to place Europa within its context,” Retherford said. “The way Hubble works left some uncertainty in terms of placement relative to the center of the image. If Europa’s placement was off even just by a pixel or two, it could affect how the data gets interpreted.”

As a result, what they thought could be evidence of a water vapor plume could also just be statistical noise. “Our reanalysis took our original 99.9% confidence in the plumes’ existence and reduced it to less than 90% confidence,” said Dr. Lorenz Roth (KTH Royal Institute of Technology, Sweden), the paper’s lead author. “That’s simply not enough evidence to support the certainty of claims we made at the time.”

The plumes might still exist, but the data used here is simply more uncertain that previously thought. It is hoped that when Europa Clipper and Juice both enter Jupiter orbit in a few years they will be able to settle this issue more definitively.

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May 14, 2026 Quick space links

2:44 pm

Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

  • Video of the launch of Venera 10 on May 14, 1975
    The lander operated for 65 minutes on the surface of Venus, taking the second picture ever of that surface. It worked in conjunction with Venera-9, which launched a week earlier and took the first picture ever of Venus’s surface.
17 comments

May 12, 2026 Quick space links

2:45 pm

Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

3 comments

April 27, 2026 Quick space links

2:45 pm

Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.

16 comments

Hubble looks at the Trifid Nebula again

9:59 am

Trifid Nebula as seen by Hubble
Click for original image.

Cool image time! The picture to the right, cropped to post here, was taken by the Hubble Space Telescope and released today. It shows a small section of the Trifid Nebula, located about 5,000 light years away.

This location has been imaged numerous times in the past by Hubble. The area shown illustrates some fundamental aspects of stellar and nebula formation. The dark area in the lower right is a thick dust cloud. Several energetic O and B supermassive stars are out of view at the top. The radiation from these stars (indicated by the blue), is hitting that dust cloud and literally destroying it. It appears that the foreground “horn” exists because a larger object is blocking the radiation, allowing dust to survive in the background.

I have no explanation for the background “horn”.

This new image was taken in parallel with an image of the entire Trifid Nebula, taken by the new Rubin Telescope in Chile. Though Rubin cannot see with the same resolution as Hubble, its image is quite worthwhile viewing.

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heic2608acropped

The colours in this image from the NASA/ESA Hubble Space Telescope tell a story about density in the Trifid Nebula, a star-forming region about 5000 light-years from Earth. The top left, where it is bright blue, has the smallest amount of dust. Here, powerful ultraviolet light stripped electrons from nearby gas, creating a glow, with winds creating a bubble by clearing out surrounding dust. An example of active cloud destruction is toward the top of the head-shaped area with two “horns.” Bright yellow gas streams upward where gas and dust are being destroyed. Thicker dust appears dark brown, like mud. In the far-right corner, which is nearly pitch black, the dust is the densest. Fully formed stars (bright orange orbs) are scattered across the scene. Their light and stellar winds have also cleared the immediate areas around them. Over millions of years, the gas and dust that make up this nebula (also known as Messier 20 or M20) will disappear and only stars will remain. [Image description: A tightly cropped Hubble view of a vast star-forming region known as the Trifid Nebula. The top left is bright blue. Brown and amber colours run from top right through the center in irregular, overlapping lines to the bottom-center. At bottom right, the view is almost black. Tiny, amber-coloured stars appear throughout the scene. Toward the left there is a prominent brown shape that looks like a head with two horns. The left horn points left and is wavy. The right horn is triangular and points up. The brown dust continues, flowing down, as if along a back, and up toward the top right. A prominent line, about the same length as the left horn, appears below the middle of the body, and changes from orange to red. A small, separate semi-transparent pillar is left of the head. A few slightly larger, blue foreground stars with four diffraction spikes appear in the bottom half.]

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New data from Webb suggests two of Uranus’ outer rings are starkly different

11:03 am

The outer two rings of Uranus as seen by Webb in the infrared
Click for original image.

Using new infrared data obtained by the Webb Space Telescope in February 2025 and combined with optical data previously obtained by the ground-based Keck Observatory in 2007 and the Hubble Space Telescope in 2003 and 2013, astronomers now think that two adjacent outer rings of Uranus are completely different from each other, with one ring largely created by icy material thrown off the moon Mab.

The infrared image to the right was taken by Webb, and shows the two subject rings, dubbed v and μ.

Though they orbit the same planet, Uranus’s μ and ν rings are fundamentally different. Prior observations with the combined Keck Observatory and HST showed that the μ ring appeared blue, a signature of extremely small particles, while the ν ring’s reddish hue points to a more typical dusty ring. Why the rings were so different remained a mystery, though.

When JWST came on-line and observed Uranus, the research team used all its data, taken at different infrared wavelengths, in combination with Keck Observatory and HST observations to construct a complete spectrum from the visible through to infrared. By analyzing how sunlight reflects off the rings, the team identified a strong absorption feature near a wavelength of 3 microns (3 millionths of a meter) visible in the infrared for both rings. Beyond that shared feature, the differences become clear when simulating the detailed spectra: the μ ring closely matches the spectral signature of water ice, while the ν ring is clearly composed of rocky material, mixed with approximately 10–15% carbon-rich organic compounds commonly found in the outer solar system.

The μ ring seems to be made up of tiny icy grains knocked off the planet’s small (12-km sized) moon, Mab, by micrometeorite impacts. Interestingly, the icy composition of the μ ring also confirms that the moon Mab is composed mostly of water-ice.

According to the paper’s abstract, the v ring is dusty and, “like typical dusty rings, is sourced from collisions between, and micrometeoroid impacts on, larger but as yet unseen parent bodies orbiting within this ring. These bodies must be composed in part of organic materials [molecules with carbon as one component].”

This data really only raises more questions than it answers. For one, what are those larger objects within the v ring? Without a nearby orbiter there is no way to find them. For another, this new data really doesn’t explain why these two adjacent rings are so different. What processes force such a distinct distribution of materials?

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Neptune’s rings, as seen by Voyager-2 in 1989

2:05 pm

The rings of Neptune as seen by Voyager-2
Click for original image.

Cool image time! The picture to the right, cropped, reduced slightly, and sharpened to post here, was taken by Voyager-2 on August 26, 1989 shortly after it had completed its close fly-by of Neptune, looking back at the planet from a distance of about 175,000 miles.

The two main rings are clearly visible and appear complete over the region imaged. … Also visible in this image is the inner faint ring at about 25,000 miles from the center of Neptune, and the faint band which extends smoothly from the 33,000 miles ring to roughly halfway between the two bright rings. Both of these newly discovered rings are broad and much fainter than the two narrow rings.

These long exposure images were taken while the rings were back-lighted by the sun at a phase angle of 135 degrees. This viewing geometry enhances the visibility of dust and allows fainter, dusty parts of the ring to be seen. The bright glare in the center is due to over-exposure of the crescent of Neptune. The two gaps in the upper part of the outer ring in the image on the left are due to blemish removal in the computer processing. Numerous bright stars are evident in the background. Both bright rings have material throughout their entire orbit, and are therefore continuous.

While Voyager-2 took other pictures of these rings (here, here, here, here, and here), I think this picture shows the rings best, if not terrible well. Images using the Hubble and Webb space telescopes as well as others have not been better.

The rings were first confirmed to exist in the mid-1980s, shortly before Voyager-2’s fly-by. We now think there are five rings total, all made of dark material, likely a mix of carbon-based molecules, much of it the equivalent of dust and soot.

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Voyager-2 discovered Neptune to be a planet of quickly changing weather

10:53 am

Neptune's fast changing weather
Click for source.

Cool image time! When Voyager-2 flew past Uranus in 1986, the data showed the gas giant’s weather to be relatively sedate and quiet, with little changing during the fly-by. Scientists expected this: Uranus’s distance from the Sun meant it got little energy to fuel an active climate, with any activity produced by internal heating due to the gravitational pressure of its mass. And Uranus did not produce that much heat internally.

When Voyager-2 passed Neptune three year later, the scientists expected something similar, or even less, due to Neptune’s greater distance from the Sun. Instead, Voyager-2’s data showed Neptune’s weather patterns to be changing constantly and quickly, as illustrated by the three images of the Great Dark Spot to the right, the biggest storm on Neptune at that time and located in the planet’s southern mid-latitudes.

The bright cirrus-like clouds of Neptune change rapidly, often forming and dissipating over periods of several to tens of hours. In this sequence spanning two rotations of Neptune (about 36 hours) Voyager 2 observed cloud evolution in the region around the Great Dark Spot at an effective resolution of about 60 miles per pixel. The surprisingly rapid changes which occur over the 18 hours separating each panel shows that in this region Neptune’s weather is perhaps as dynamic and variable as that of the Earth. However, the scale is immense by our standards — the Earth and the [Great Dark Spot] are of similar size.

In Neptune’s frigid atmosphere, where temperatures are as low as 55 degrees Kelvin (-360 F), the cirrus clouds are composed of frozen methane rather than Earth’s crystals of water ice.

Subsequent observations by the Hubble Space Telescope in 1994 found this Great Dark Spot was gone, replaced by a comparable storm in the northern hemisphere. Further Hubble observations found Neptune’s storms tend to last about two years, fading as they drifted towards the equator. Those observations however also detected storms drifting away from the equator. Other research suggested the storms might be influenced by the Sun’s sunspot cycle.

All of the data post-Voyager-2 remains very coarse and uncertain, as we are looking at Neptune at a great distance. Thus, no theory about what is happening carries much weight, especially because we do not know why Neptune produces so much more internal heat than Uranus, fueling this fast-changing weather. For example, Neptune gets 1/20th of the energy received by Jupiter, yet its atmosphere appears even more active and variable.

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Voyager-2’s view of clouds on top of clouds on Neptune

11:45 am

Neptune's upper clouds
Click for original image.

Time to continue our cool image tour this week of the Voyager-2 archive of Neptune, taken during the spacecraft’s August 25, 1989 close fly-by of the gas giant, zipping only 2,700 miles above the cloud-tops. This remains the only mission to visit Neptune so far.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken two hours before Voyager-2’s closest approach. From the caption:

These clouds were observed at a latitude of 29 degrees north near Neptune’s east terminator. The linear cloud forms are stretched approximately along lines of constant latitude and the sun is toward the lower [right]. The bright sides of the clouds which face the sun are brighter than the surrounding cloud deck because they are more directly exposed to the sun. Shadows can be seen on the side opposite the sun.

These shadows are less distinct at short wavelengths (violet filter) and more distinct at long wavelengths (orange filter). This can be understood if the underlying cloud deck on which the shadow is cast is at a relatively great depth, in which case scattering by molecules in the overlying atmosphere will diffuse light into the shadow. Because molecules scatter blue light much more efficiently than red light, the shadows will be darkest at the longest (reddest) wavelengths, and will appear blue under white light illumination.

The resolution of this image is 6.8 miles per pixel and the range is only 98,000 miles. The width of the cloud streaks range from 30 to 125 miles, and their shadow widths range from 18 to 30 miles. Cloud heights appear to be of the order of 31 miles.

Of all the high resolution images taken of Neptune by Voyager-2, this is the only one that clearly shows some dimensionality. Later photographs taken by Hubble and other ground- and space-based telescopes can only show global views that are far less sharp than the global views produced by Voyager-2.

This picture hints at Neptune’s very complex weather patterns, which has no well-defined surface and is made up mostly of gas and liquid. Though scientists have used Hubble to roughly track those weather patterns, they can only glean the most basic facts. For example, its fast-changing weather appears to be driven by high winds, thought to move as fast as 1,300 miles per hour. This fact however is woefully incomplete and very uncertain, as we have no way to track detailed weather patterns at multiple depths.

Our tour will continue tomorrow.

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A soft barred galaxy with an active nucleus

9:56 am

A barred galaxy with an active galactic nucleus
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 two different surveys aimed at studying galaxies with what scientists call active galactic nuclei.

IC 486 lies right on the edge of the constellation Gemini (the Twins), around 380 million light-years from Earth. Classified as a barred spiral galaxy, it features a bright central bar-shaped structure from which its spiral arms unfurl, wrapping around the core in a smooth, almost ring-like pattern.

…At the galaxy’s center a noticeable white glow outshines the starlight around it. This is light given off by IC 486’s active galactic nucleus (AGN), powered by a supermassive black hole more than 100 million times the mass of the Sun. Every sufficiently large galaxy hosts a supermassive black hole at its center, but some of these black holes are particularly ravenous, marshaling vast amounts of gas and dust into swirling accretion discs from which they feed. The intense heat generated by the orbiting disc of material generates intense radiation up to and including X-rays, which can outshine the entire rest of the galaxy. In these cases, the galaxy is known as an active galaxy, with an AGN at its center.

For comparison, the relatively inactive supermassive black hole at the center of the Milky Way has a mass of about four million Suns, considerably smaller than IC 486’s. Why one is active and the other not however is not yet truly understood, though their different masses might provide part of the explanation.

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