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.
On this day in 1969 Mariner 6 was launched on a Mars flyby mission
Aimed at the Martian southern cratered highlands because that region was thought to exhibit seasonal changes, the images instead showed a lifeless and cratered Mars, much like the Moon, a very mistaken impression.
One of the biggest challenges facing astronomers for more than four centuries has been the detection of a star prior to its going supernova. Until very recently, no such detection had ever happened, and so astronomers could only guess at the kind of stars or binary systems that might result in these gigantic stellar explosions.
In recent years the improvement in telescopes, both in orbit and on the ground, has produced some successes, whereby the progenitor star was imaged in archival imagery and found after the explosion. The sample however has been small, and the data limited to only a few wavelengths.
Now, the Webb Space Telescope has made its first detection of a supernova progenitor, in the infrared. That image is to the right, showing the star prior to the June 2025 supernova explosion.
By carefully aligning Hubble and Webb images taken of NGC 1637, the team was able to identify the progenitor star in images taken by Webb’s MIRI (Mid-Infrared Instrument) and NIRCam (Near-Infrared Camera) in 2024. They found that the star appeared surprisingly red – an indication that it was surrounded by dust that blocked shorter, bluer wavelengths of light. “It’s the reddest, most dusty red supergiant that we’ve seen explode as a supernova,” said graduate student and co-author Aswin Suresh of Northwestern University.
This excess of dust could help explain a long-standing problem in astronomy that could be described as the case of the missing red supergiants. Astronomers expect the most massive stars that explode as supernovas to also be the brightest and most luminous. So, they should be easy to identify in pre-supernova images. However, that hasn’t been the case.
One potential explanation is that the most massive aging stars are also the dustiest. If they’re surrounded by large quantities of dust, their light could be dimmed to the point of undetectability. The Webb observations of supernova 2025pht support that hypothesis.
Using both the Hubble Space Telescope and the Chandra X-ray Observatory, astronomers have made the first visual detection of another star’s heliosphere, in both X-rays and in the infrared.
The image to the right, cropped to post here.
Astronomers have nicknamed the HD 61005 star system the “Moth” because it is surrounded by large amounts of dust patterned similarly to the shape of a moth’s wings when viewed through infrared telescopes. The wings are formed from material left behind after the formation of the star, similar to the Kuiper Belt in our own solar system. Observations of these wings with NASA’s Hubble Space Telescope showed that the interstellar matter surrounding HD 61005 is about a thousand times denser than that around the Sun.
The wings are the points to the left and right. The star’s young heliosphere, which they dub an “astrosphere,” is the purple glow above and below. From the caption:
In this composite image of HD 61005 in the inset, X-rays from Chandra (purple and white) have been combined with infrared data from Hubble (blue and white). Chandra reveals a bright source of X-rays in the center of the image, which is the star itself surrounded by the star’s astrosphere. The wing-like structure sweeping away from the star in the infrared image is dusty material that remained behind after the formation of the star. These wings have been swept backwards as they fly through space.
As this star and its solar system are very young, what we have is a very dusty accretion disk interacting with a very temperamental baby star.
The uncertainty of science: Using ground-based and orbiting telescopes, astronomers think they have identified what might be the dimmest galaxy yet discovered, revealed almost entirely not from its stars but from the four globular clusters that reside within or near it.
The image to the right, cropped and sharpened to post here, shows that galaxy, dubbed CDG-2, along with those four globular clusters. From the press release:
To confirm one of the dark galaxy candidates, astronomers employed a trio of observatories: the NASA/ESA Hubble Space Telescope, ESA’s Euclid space observatory, and the ground-based NAOJ Subaru Telescope in Hawaii. Hubble’s high-resolution imaging revealed a close collection of four globular clusters in the Perseus galaxy cluster, 300 million light-years away. Follow-up studies using Hubble, Euclid, and Subaru data then revealed a faint, diffuse glow surrounding the star clusters – strong evidence of an underlying galaxy.
“This is the first galaxy detected solely through its globular cluster population,” said David. “Under conservative assumptions, the four clusters represent the entire globular cluster population of CDG-2.”
Preliminary analysis suggests CDG-2 has the luminosity of roughly 1 million Sun-like stars, with the globular clusters accounting for 16% of its visible content.
The scientists next claim that 99% of the galaxy’s mass is made up of dark matter, a material no one has yet detected except for the gravitational influence its invisible mass imposes on visible objects. It appears the astronomers don’t believe the mass that has been detected is sufficient to hold this galaxy together, and thus they need dark matter to explain its existence.
I simply wonder if the distances involved simply make the matter hard to see.
No matter. This is a cool discovery, because it tells us there is much out there hidden in the darkness we will always find difficult if not impossible to detect.
This image of dark galaxy CDG-2 was captured by the Hubble Space Telescope’s ACS (Advanced Camera for Surveys) with additional data from the European Space Agency’s Euclid space mission. The image shows a scale bar, compass arrows, and colour key for reference. The scale bar is labeled in light-years along the top, which is the distance that light travels in one Earth-year. (It takes about 36,000 years for light to travel a distance equal to the length of the scale bar.) One light-year is equal to about 9.46 trillion kilometers. The scale bar is also labeled in arcseconds, which is a measure of angular distance on the sky. One arcsecond is equal to an angular measurement of 1/3600 of one degree. There are 60 arcminutes in a degree and 60 arcseconds in an arcminute. (The full Moon has an angular diameter of about 30 arcminutes.) The actual size of an object that covers one arcsecond on the sky depends on its distance from the telescope. The north and east compass arrows show the orientation of the image on the sky. Note that the relationship between north and east on the sky (as seen from below) is flipped relative to direction arrows on a map of the ground (as seen from above). The colour key shows which ACS filters were used when collecting the light. The colour of each filter name is the visible-light colour used to represent the light that passes through that filter. [Image description: Image labeled “CDG 2 near Perseus Cluster, HST ACS WFC”. At left, a field of space with a dozen white foreground stars and a number of small, yellow background galaxies. An unremarkable area at center is outlined with a dashed red circle surrounded by a white box. Lines extend from the box to a pullout at right containing faint, grainy white light surrounded by a red circle labeled “Candidate dark galaxy – diffuse emission.” Four white dots are circled in blue and labeled globular clusters. Compass arrows at lower left show east pointing to 1 o’clock and north pointing to 4 o’clock. A scale bar is labeled 36,000 light-years and 30 arcseconds. It extends about one-eighth of the way across the image. A colour key shows F475W in blue, F814W in orange, and Euclid in gray.]
Cool image time! The picture to the right, reduced to post here, was taken by the Hubble Space Telescope as part of a study of “preplanetary nebula,” the initial stages of a planetary nebula that forms as some star types begin dying. From the caption:
Many preplanetary nebulae are relatively dim and hard to spot. They are made of layers of gas ejected by the star, but that star is not yet hot enough to ionise the gas and cause it to glow. The Egg Nebula is relatively unique, easily visible as a sparkling jewelled egg in space. Powerful beams of starlight blast out of the inner cloud, two a-side, giving a breathtaking illumination to this cosmic structure. Fast-moving outflows of hot molecular hydrogen also emerge from within the dust cloud, visible just at the base of the searchlight beams. These outflows glow with infrared light, which is shown in this image by orange highlights.
The central cloud of dust is surrounded by concentric rings, themselves made up from thin, faint arcs of gas. These were created by successive outbursts from the central star, which ejected a little more material from its outer surface every few hundred years. The beams of starlight are reflected by these layers of gas, creating an appearance like ripples on the surface of water. The way that gas molecules reflect and scatter light gives a bluish colour to the arcs. The reflected starlight reveals important details about the central star, which is impossible to view directly in its dusty shell.
Many planetary nebula get their spectacular shapes because they have a binary star system in their center, that act like the blades in a blender as they circle each other, mixing the materials the stars’ eject to form those shapes. Because of those surrounding shells, it is often impossible to determine with the nebula has a single central star, or a binary system.
This newly processed image from the NASA/ESA Hubble Space Telescope is the clearest view yet of the Egg Nebula. It is a preplanetary nebula, a structure of gas and dust created as a Sun-like star approaches the end of its life. The Egg that we see now will eventually hatch, revealing a white dwarf at its centre and leaving its shell to become a spectacular planetary nebula. Many preplanetary nebulae are relatively dim and hard to spot. They are made of layers of gas ejected by the star, but that star is not yet hot enough to ionise the gas and cause it to glow. The Egg Nebula is relatively unique, easily visible as a sparkling jewelled egg in space. Powerful beams of starlight blast out of the inner cloud, two a-side, giving a breathtaking illumination to this cosmic structure. Fast-moving outflows of hot molecular hydrogen also emerge from within the dust cloud, visible just at the base of the searchlight beams. These outflows glow with infrared light, which is shown in this image by orange highlights. The central cloud of dust is surrounded by concentric rings, themselves made up from thin, faint arcs of gas. These were created by successive outbursts from the central star, which ejected a little more material from its outer surface every few hundred years. The beams of starlight are reflected by these layers of gas, creating an appearance like ripples on the surface of water. The way that gas molecules reflect and scatter light gives a bluish colour to the arcs. The reflected starlight reveals important details about the central star, which is impossible to view directly in its dusty shell. [Image description: In the centre an opaque cloud of grey gas hides a star. Two strong beams of light from the star emerge from large holes in both sides of the cloud. The central cloud is surrounded by concentric, wispy shells of gas, illuminated by the star’s light. The shells reflect extra light where they’re hit by the twin beams. A crowd of smaller stars with cross-shaped spikes over them surround the nebula on a black background.]
Cool image time! The picture to the right, cropped, reduced, and enhanced to post here, was taken by the Hubble Space Telescope as part of follow-up observations of a now faded supernovae that occurred there two years earlier.
This was on purpose: the aim of the observations was to witness the aftereffects of the supernova and examine its surroundings, which can only be done once the intense light of the explosion is gone.
The galaxy itself, NGC 7722, is 187 million light years away, and is unusual in itself.
A “lenticular”, meaning “lens-shaped”, galaxy is a type that sits in between the more familiar spiral galaxies and elliptical galaxies. It is also less common than these — partly because when a galaxy has an ambiguous appearance, it can be hard to determine if it is actually a spiral, actually an elliptical galaxy, or something in between. Many of the known lenticular galaxies sport features of both spiral and elliptical galaxies. In this case, NGC 7722 lacks the defined arms of a spiral galaxy, while it has an extended, glowing halo and a bright bulge in the center similar to an elliptical galaxy. Unlike elliptical galaxies, it has a visible disc — concentric rings swirl around its bright nucleus. Its most prominent feature, however, is undoubtedly the long lanes of dark red dust coiling around the outer disc and halo.
The streak in the lower left is a very distant background galaxy, seen on edge.
For this Picture of the Month from the NASA/ESA Hubble Space Telescope, we have a sight of an uncommon galaxy with a striking appearance. This is NGC 7722, a lenticular galaxy located about 187 million light-years away in the constellation Pegasus. A “lenticular”, meaning “lens-shaped”, galaxy is a type that sits in between the more familiar spiral galaxies and elliptical galaxies. It is also less common than these — partly because when a galaxy has an ambiguous appearance, it can be hard to determine if it is actually a spiral, actually an elliptical galaxy, or something in between. Many of the known lenticular galaxies sport features of both spiral and elliptical galaxies. In this case, NGC 7722 lacks the defined arms of a spiral galaxy, while it has an extended, glowing halo and a bright bulge in the centre similar to an elliptical galaxy. Unlike elliptical galaxies, it has a visible disc — concentric rings swirl around its bright nucleus. Its most prominent feature, however, is undoubtedly the long lanes of dark red dust coiling around the outer disc and halo. This new Hubble image, the sharpest yet taken of NGC 7722, brings the impressive dust lanes into sharp focus. Bands of dust like this are not uncommon in lenticular galaxies, and they stand out against the broad, smooth halo of light that typically surrounds lenticular galaxies. The distinctive dust lanes of NGC 7722 are thought to result from a merger with another galaxy in the past, similar to other lenticular galaxies. It is not yet fully understood how lenticular galaxies form, but mergers and other gravitational interactions are thought to play an important part, reshaping galaxies and exhausting their supplies of gas while bringing new dust. While it doesn’t host as many new, young stars as a spiral galaxy, there’s still activity in NGC 7722: in 2020 it was host to the explosion of a star that could be detected from Earth. SN 2020SSF was a Type Ia supernova, an event which occurs when a white dwarf star in a binary system siphons enough mass away from its companion star that it grows unstable and explodes. These explosions output a remarkably consistent level of light: by measuring how bright they appear from Earth and comparing against how bright they really are, it’s possible to tell how far away they must be. Type Ia supernovae are one of the best ways to measure distances to galaxies, so understanding exactly how they work is of great importance to astronomers. Taken with Hubble’s Wide Field Camera 3, this Hubble image was obtained as part of an observing programme (#16691, PI: R. J. Foley) that followed up on recent supernovae. SN 2020SSF is not visible in this image, as it was actually taken two years later, when the supernova had long faded. This was on purpose: the aim of the observations was to witness the aftereffects of the supernova and examine its surroundings, which can only be done once the intense light of the explosion is gone. With Hubble’s clear vision, astronomers can search for radioactive material created by the supernova, catalogue its neighbours to see how old the star likely was, and look for the companion star it left behind — all from almost 200 million light-years away. [Image Description: A disc-shaped galaxy. It glows brightly at the centre and shines a faint white light all around it. The disc is made up of tightly-packed rings of dust, some darker and some lighter. Wide, long lanes of dark reddish dust cross the galaxy in front of its edge, blocking out some of its light; the long strands twist and break apart at each side. A couple of nearby stars and distant galaxies are also visible on the black background.] Links Wide view of NGC 7722 Pan Video: NGC 7722 Space Sparks Episode 23 Image on ESA website
In what is a perfect example of the proper use of artificial computer intelligence (AI), astronomers have now used this programming to analyze almost 100 million images taken by the Hubble Space Telescope over the decades to find any galaxies hidden there that have “anomalies” or unusual shapes.
The team analyzed nearly 100 million image cutouts from the Hubble Legacy Archive, each measuring just a few dozen pixels (7 to 8 arcseconds) on a side. They identified more than 1,300 objects with an odd appearance in just two and a half days — more than 800 of which had never been documented in scientific literature.
The six galaxies to the right are just a small sample. All six were previously unidentified, and include “three lenses with arcs distorted by gravity, one galactic merger, one ring galaxy, and one galaxy that defied classification” (the galaxy at the top left). From the European Space Agency’s (ESA) press release:
The strange, bi-polar galaxy seen here is certainly anomalous, with its compact, swirling core and two open lobes at the sides. Exactly what kind of galaxy it is is unclear, and it was not previously known to astronomers.
As noted in the first link, the volume of data that astronomers are now collecting from ground-based and orbiting telescopes — many of which are survey telescopes that photograph the entire sky repeatedly — has actually become a problem. They have great data, but don’t have the time or human resources to study it sufficiently. Even employing large numbers of ordinary citizens, working at home with their own computers, can’t get the job done.
This is the kind of grunt work that AI is ideally made for. It can quickly review the data and identify objects that don’t fit normal expectations. Humans then can do the real work, finding the most interesting of these strange objects, such as the top left galaxy, and devote human creativity to studying it.
Schmidt Sciences, a foundation created by one of Google’s founders, announced yesterday it is financing the construction of four new research telescopes, one of which will be an orbiting optical telescope with a mirror 3.1 meters in diameter, larger than the 2.4 meter primary mirror on the Hubble Space Telescope.
Today at a meeting of the American Astronomical Society, Schmidt Sciences, a foundation backed by billionaires Eric and Wendy Schmidt, announced one of the largest ever private investments in astronomy: funding for an orbiting observatory larger than NASA’s Hubble Space Telescope, along with funds to build three novel ground-based observatories. The project aims to have all four components up and running by the end of the decade.
“We’re providing a new set of windows into the universe,” says Stuart Feldman, president of Schmidt Sciences, which will manage the observatory system. Time on the telescopes will be open to scientists worldwide, and data harvested by them will be available in linked databases. Schmidt Sciences declined to say how much it is investing but Feldman says the space telescope, called Lazuli, alone will cost hundreds of millions of dollars.
Eric Schmidt was once CEO of Google, and in recent years has been spending his large fortune (estimated to exceed $50 billion) on space ventures. For example, in March 2025 he acquired control of the rocket startup Relativity.
While the three new ground-based telescopes will do important work, the Lazuli space telescope is by far the most important, not only scientifically but culturally. » Read more
Astronomers believe they have detected evidence of the wake created by Betelgeuse’s companion star as it plows through the primary star’s vast atmosphere.
You can read their paper here [pdf]. The cartoon to the right, annotated by me to post here, is figure 5 of the paper, looking down at Betelgeuse’s pole. It is not to scale. The scientists have nicknamed the companion Siwarha.
The team detected Siwarha’s wake by carefully tracking changes in the star’s light over nearly eight years. These changes show the effects of the previously unconfirmed companion as it plows through the outer atmosphere of Betelgeuse. This discovery resolves one of the biggest mysteries about the giant star, helping scientists to explain how it behaves and evolves while opening new doors to understanding other massive stars nearing the end of their lives.
Located roughly 650 light-years away from Earth in the constellation Orion, Betelgeuse is a red supergiant star so large that more than 400 million Suns could fit inside. Because of its enormous size and proximity, Betelgeuse is one of the few stars whose surface and surrounding atmosphere can be directly observed by astronomers, making it an important and accessible laboratory for studying how giant stars age, lose mass, and eventually explode as supernovae.
Using NASA’s Hubble and ground-based telescopes at the Fred Lawrence Whipple Observatory and Roque de Los Muchachos Observatory, the team was able to see a pattern of changes in Betelgeuse, which provided clear evidence of a long-suspected companion star and its impact on the red supergiant’s outer atmosphere. Those include changes in the star’s spectrum, or the specific colors of light given off by different elements, and the speed and direction of gases in the outer atmosphere due to a trail of denser material, or wake. This trail appears just after the companion crosses in front of Betelgeuse every six years, or about 2,100 days, confirming theoretical models.
Betelgeuse is essentially a giant blob that undulates like a blob of water floating in weightlessness on ISS. Knowing the location and orbit of this companion will help astronomers better understand the central star’s periodic inexplicable changes.
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.
Astronomers detect a three-galaxy merger, the third ever discovered
The headline at the link is utter garbage, designed as clickbait. The headline I have given you describes the story’s text accurately. One other detail: All three galaxies also appear to have active nuclei, suggesting the presence of supermassive black holes.
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.
Sidus Space wins contract from Missile Defense Agency
The press release is very vague, par for the course for these kind of defense contract awards. It appears the program could be worth up to $151 billion, but I doubt that is all going to Sidus.
Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken by the Hubble Space Telescope on February 8, 2025, and shows what scientists believe is the largest protoplanetary disk so far measured.
Located roughly 1,000 light-years from Earth, IRAS 23077+6707, nicknamed “Dracula’s Chivito,” spans nearly 400 billion miles — 40 times the diameter of our solar system to the outer edge of the Kuiper Belt of cometary bodies. The disk obscures the young star within it, which scientists believe may be either a hot, massive star, or a pair of stars. And the enormous disk is not only the largest known planet-forming disk; it’s also shaping up to be one of the most unusual.
…The impressive height of these features wasn’t the only thing that captured the attention of scientists. The new images revealed that vertically imposing filament-like features appear on just one side of the disk, while the other side appears to have a sharp edge and no visible filaments. This peculiar, lopsided structure suggests that dynamic processes, like the recent infall of dust and gas, or interactions with its surroundings, are shaping the disk.
You can read the peer-reviewed paper here [pdf]. The structure of this system has left them with more questions than answers. They can’t see the central star due to the dust. They don’t know if any planets exist as yet in the system. They don’t really understand the structural details that they can see.
Cool image time! The picture to the right, reduced and sharpened to post here, was released today as the Hubble picture of the week. From the caption:
The trick is that these galaxies are not actually very close. The large blue galaxy MCG-02-05-050 is located 65 million light-years from Earth; its brighter smaller companion MCG-02-05-050a, at 675 million light-years away, is over ten times the distance! Owing to this, MCG-02-05-050a is likely the larger galaxy of the two, and MCG-02-05-050 comparatively small. Their pairing in this image is simply an unlikely visual coincidence.
The smaller blue galaxy, also called Arp 4, has an active nucleus that emits a lot of energy, suggesting the presence of a supermassive black hole. Less is known about the more distant orange galaxy.
These galaxies look to be close companions — a small, bright spiral galaxy flitting around the edge of a much larger spiral with a dark and disturbed countenance. But looks can be deceiving — how close are they really? The celestial pair featured in this week’s Hubble Picture of the Week is known by the name Arp 4, and lies in the constellation Cetus (the Whale). The designation Arp 4 comes from the Atlas of Peculiar Galaxies, compiled in the 1960s by astronomer Halton Arp. “Unusual galaxies” were selected and photographed to provide examples of weird and non-standard shapes, the better to study how galaxies evolve into these forms. Throughout its mission the Hubble Space Telescope has revolutionised the study of galaxies and shown us some fantastically unusual examples from Arp’s atlas. In that catalogue, the first few galaxies like Arp 4 are “low surface brightness” galaxies, a type of galaxy that is unexpectedly faint and hard to detect. The large galaxy here — also catalogued as MCG-02-05-050 — fits this description well, with its fragmentary arms and dim disc. Its smaller companion, MCG-02-05-050a, is a much more bright and active spiral. The trick is that these galaxies are not actually very close. The large blue galaxy MCG-02-05-050 is located 65 million light-years from Earth; its brighter smaller companion MCG-02-05-050a, at 675 million light-years away, is over ten times the distance! Owing to this, MCG-02-05-050a is likely the larger galaxy of the two, and MCG-02-05-050 comparatively small. Their pairing in this image is simply an unlikely visual coincidence. Despite this lack of a physical relation between them, our point of view on Earth allows us to enjoy the sight of Arp 4 as an odd couple in the sky. [Image Description: This image shows two galaxies side by side. The galaxy on the top left is smaller in size, and appears as a bright glowing spiral with clearly-defined arms. A larger blue galaxy dominates the full right field of the image. This galaxy is more irregularly shaped, with a glowing central bar, and varying regions of concentrated hues of blue. The background is black with various stars and galaxies in the distance.] Links Pan: Arp 4
Blue Skies is in the process of commissioning the Mauve and plans to start delivering data to scientists in early 2026. Customers include Boston University, Columbia University, INAF’s Osservatorio Astrofisico di Arcetri, Konkoly Observatory, Kyoto University, Maynooth University, the National Astronomical Observatory of Japan, Rice University, Vanderbilt University, and Western University.
The spacecraft’s three-year mission is to study flares from stars and their impact on the habitability of planets around them. From low Earth orbit, it hosts a telescope that can collect data in the ultraviolet to visual light range (200-700 nm spectrum).
With such a small mirror Mauve is not going to be able to do a lot of ground-breaking work, though there are definitely observations of value it can accomplish, such as those listed above. Its main purpose is as a demonstration project to attract a bigger round of new investment capital, from universities like the ones listed above, for launching a larger private telescope with greater capabilities.
This is how all telescopes were funded in the U.S. until World War II, through private funds privately built. Blue Skies effort here suggests we are heading back to that model, with government budgets increasingly constrained. The company is already working on a second and larger space telescope, dubbed Twinkle with a 18-inch primary mirror. It hopes over time to continue to scale up its orbital telescopes until it is matching Hubble and Webb, and doing so faster and at far less cost.
Using the Hubble Space Telescope, astronomers have detected a bright object in the debris disk that surrounds the nearby star Fomalhaut that wasn’t there previously, suggesting it is a glowing cloud of material left over from the collision of two asteroids.
You can read the published paper here [pdf]. Fomalhaut is a young star about 25 light years away, and has one of the best-mapped debris disks known.
The image to the right, reduced to post here, shows this new object, labeled CS2 and detected in 2023. CS1 is a similar detection from 2012 that was initially thought to be an exoplanet. When CS1 faded over time that theory was dismissed, replaced instead with the hypothesis that it was a cloud produced by an asteroid collision.
The recent appearance of CS2 strengthens this hypothesis, which will be further confirmed by future observations that show CS2 fading in the same manner. It also provides scientists a chance to measure the rate of such collisions within Fomalhaut’s debris disk, which scientists believe is essentially a baby solar system in formation. While very uncertain due to the short time scale, this data will help them begin to figure out the rate in which planets will form in such a disk.
Cool image time! The picture to the right, reduced and sharpened to post here, was taken by the Hubble Space Telescope back in 2017 but released this week by NASA’s PR department. It shows what astronomers have nicknamed the Calabash Nebula. From the Wikipedia page:
The Calabash Nebula, also known as the Rotten Egg Nebula or by its technical name OH 231.84 +4.22, is a protoplanetary nebula (PPN) 1.4 light years (13 Pm) long and located some 5,000 light years (47 Em) from Earth in the constellation Puppis. The name “Calabash Nebula” was first proposed in 1989 in an early paper on its expected nebular dynamics, based on the nebula’s appearance.[5] The Calabash is almost certainly a member of the open cluster Messier 46, as it has the same distance, radial velocity, and proper motion.[6] The central star is QX Puppis, a binary composed of a very cool Mira variable and an A-type main-sequence star.
The star in the center is an ancient red giant that is in the initial stages of dying. As it does so it periodically erupts, sending out jets of material from its poles. The result is this elongated shape. According to the release, “the gas shown in yellow is moving close to a million kilometers an hour.”
Over the next few thousand years these eruptions will shape the planetary nebula. Since the central star is actually a binary, those two stars will likely act like the blades in a mixer, adding more interesting forms to the material as it is shot out to form this nebula.
