Irregular Galaxy Arp 263 as seen by Webb

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The latest Webb picture is a new, infrared look into the strange final phase of a galactic merger. Arp 263, an irregular galaxy, lies in the constellation Leo at a relatively nearby distance of around 25 million light-years.

Originally discovered in 1784 and also catalogued as NGC 3239, this galaxy was included in American astronomer Halton Arp's Atlas of Peculiar Galaxies in 1966, as possibly one of the most remarkable and strange galaxies in the sample. Arp categorised it with the galaxies featuring "irregular clumps". In 2023, the galaxy was featured in an image from the Hubble Space Telescope, where these clumps are revealed to be bright nebulae between the galaxy's dense clouds of gas, where stars are forming.

Arp 263 is believed to result from a past galactic merger. Apart from its unusual distorted shape, astronomers have noticed a few features that point to this. It has two short, curved tails of stars, beyond the field of view of this Webb image, which are a feature that's associated with gravitational interactions. However, there are no nearby galaxies that Arp 263 could be interacting with now. The stars in the galaxy are oriented differently to its hydrogen gas, where they would normally be symmetric, and parts of that gas are moving at different velocities to each other. And, of course, the widespread formation of new stars across Arp 263 is typical of a galaxy whose gas has been seriously shaken up.

Although Arp 263 clearly hasn't yet settled into a more regular shape after its gravitational tug-of-war, its former companion galaxy is now nowhere to be found. It’s possible that this was a dwarf galaxy small enough to have been already completely dissolved into the larger Arp 263 – or that its companion was simply much more heavy than it was bright, making it difficult to spot as a remnant.

This new image from Webb's Near-Infrared Camera (NIRCam) reveals an entirely different view of Arp 263, taking us inside the thick gas crowding the galaxy to see the many stars scattered there. These old stars contrast with the several areas of star birth, where multitudes of new stars are forming in numerous clusters. Dust spread throughout the galaxy glows with the light, here shown in red, emitted by complex molecules; around the star-forming regions we also see – in blue colours – hydrogen gas, ionised by starlight and emitting its own light in turn. The most intense area of star formation features a curved chain of compact star clusters, leading to the largest and brightest star-forming nebula. Webb allows us to peek into this stellar nursery and see the stars that have formed within.

The brightest of the bright spots in Arp 263 is a shining star, named BD+17 2217. It appears so large and bright, with long diffraction spikes created by the telescope's optics, because it is part of our own galaxy. The galaxies that appear in the background are much more distant, most hundreds of millions of light-years away from both us and Arp 263. A few of these galaxies are identifiable as spiral galaxies, but Webb's NIRCam reveals the hundreds of much more distant galaxies lurking in the background as orange dots.

This image was made with data from a survey of the nearby, large, star-forming galaxies in the southern sky. These galaxies are close enough that Webb's sharp vision can deliver a detailed picture of the stars, star clusters and interstellar dust within the galaxy. The observations will be used to better understand the cycle of star formation and how it plays out across galaxies; Arp 263, with its disturbed disc of gas and its chaotic star formation, presents a unique and fascinating target for these investigations.

Image Credit: ESA/Webb, NASA and CSA, A. Leroy

Image enhancement: Jean-Baptiste Faure

Spiral Galaxy NGC 4698

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Though the spiral galaxy in this Hubble picture seems serene, it hides a chaotic secret. This galaxy is NGC 4698, and it lies about 55 million light-years away in the constellation Virgo. It's one of over one thousand galaxies in the Virgo Cluster, the nearest large cluster of galaxies bound together by gravity.

As a spiral galaxy similar to our own Milky Way galaxy, NGC 4698 has spiral arms that curl around within a thin disc of stars, gas and dust. These arms are marked by opaque clumps of brown dust and dotted with small collections of bright blue stars. Unlike many other spiral galaxies, like this one recently photographed by Hubble, NGC 4698's delicate spiral arms are only prominent in the outer reaches of the disc; spiral arms often wind down to the very centre of a galaxy, but NGC 4698's spiral arms appear to shy away from its glowing center. The arms instead hover in a ring-like structure around the perimeter of the galaxy.

NGC 4698's center is dominated by a galactic bulge. The diffuse off-white glow of the galaxy's bulge comes from stars smaller, older, and cooler than the massive blue stars that dot the galaxy's outer disc. These tightly packed stars orbit a supermassive black hole containing millions of times the Sun's mass. Scientists have found signs that this black hole is actively growing, drawing gas inward with its gravitational pull.

With a flat, starry disc and diffusely glowing center, NGC 4698 looks a lot like a typical spiral galaxy – but this galaxy is far from normal. NGC 4698 is one of only a few known spiral galaxies with a bulge that extends out from the disc at a right angle. The elongation is faintly visible in this Hubble image, which shows the ghostly glow of the starry bulge peeking above and below the dusty disc. What's more, the stars and gas nearest the galaxy's center rotate perpendicular to the rest of the disc!

What could cause a galaxy to be so out of sync? Astronomers have found that the culprit likely lies outside the galaxy. If NGC 4698 funneled in gas from an outside source, the newly collected gas could have formed a disc of gas and stars in the galaxy's center, at an angle relative to the rest of the disc. Some observations suggest that this galaxy once experienced a minor galactic merger, as evidenced by a short "tail" of hydrogen streaming from one side of the galaxy.

The data used to create this image come from an observing programme focusing on galaxies in the Virgo Cluster. This programme zooms in on the details of these relatively nearby galaxies, such as individual star clusters and nebulae. At the same time, researchers will use these data to take stock of the larger picture, learning how a galaxy's journey through a cluster affects the galaxy's evolution and ability to form new stars.

Image Credit: ESA/Hubble and NASA, D. Thilker, the MAUVE-HST Team

Image enhancement: Jean-Baptiste Faure

Spiral Galaxy M77 as seen by Subaru

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M77 aka NGC 1068 is a spiral galaxy located relatively close to our Milky Way. At its center lies a supermassive black hole about 10 million times the mass of the Sun. As enormous amounts of energy are released around the black hole, M77 is known as an active galaxy.

Because of its proximity, M77 has been extensively studied across the electromagnetic spectrum, from X-rays to radio waves, using various telescopes, including the Subaru Telescope and ALMA. Recently, observations with the Subaru Telescope's Hyper Suprime-Cam (HSC) have revealed evidence that M77 experienced a previously hidden minor merger with a low-mass satellite galaxy billions of years ago.

Image Credit: NAOJ/SDSS/David Hogg/Michael Blanton

Image Processing: Ichi Tanaka

Image enhancement: Jean-Baptiste Faure

The Milky Way Galaxy's center as seen by Webb

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A dense star field fills the entire image, with countless stars scattered across a backdrop of glowing clouds in shades of red, orange, pink, white, and blue. At the center, a brilliant concentration of stars creates a bright, almost white core surrounded by intricate filaments and wisps of illuminated gas and dust that radiate outward. Dark, irregular patches of opaque dust interrupt the glowing clouds, particularly toward the left side of the image, where they appear as silhouetted shapes against the brighter background. The surrounding stellar population varies in brightness and colour, with cool blue stars and warmer orange and red stars distributed throughout the scene.

This image features data from Webb's NIRCam (Near Infrared Camera) and MIRI (Mid Infrared Instrument) to capture the most detailed mid-infrared view yet of the field that hosts the highly evolved star IRS 3, which is located just 0.55 light-years from Sagittarius A, the Milky Way galaxy's central supermassive black hole.

An international team of astronomers have discovered that dust and water can form and survive surprisingly close to this supermassive black hole. The observations reveal that the evolved star IRS 3 continues to enrich its surroundings with newly formed material despite the intense radiation environment around Sagittarius A.

Image Credit: ESA/Webb, NASA and CSA, F. Peißker, J. Lu, F. Yusef-Zadeh, N. B. Sabha, C. Chan

Image enhancement: Jean-Baptiste Faure

Planetary Nebula NGC 1514 by Gemini North

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NGC 1514, nicknamed the Crystal Ball Nebula, is showcased in this enchanting image captured by Gemini Multi-Object Spectrograph (GMOS) on the Gemini North telescope, located on Maunakea in Hawai'i. Gemini North is one half of the International Gemini Observatory, partly funded by the U.S. National Science Foundation (NSF) and operated by NSF NOIRLab.

German–British astronomer William Herschel discovered the Crystal Ball Nebula in 1790. It's located in the constellation Taurus, near the border of Perseus. While, culturally, crystal balls are known for divining the future, the Crystal Ball Nebula provides us with a snapshot of the final stages of a star's life from long ago. It sits around 1500 light-years from Earth. This means the light captured in this image left its source around 1500 years ago, traveling across the Universe before finally reaching Gemini North.

The Crystal Ball Nebula is categorized as a planetary nebula, a nomenclature first presented by the nebula's discoverer, William Herschel. He coined the term in the 1700s after spotting the spherical shape of these objects, which reminded him of planets. In reality, planets and planetary nebulae are unrelated.

Planetary nebulae form when a low- or intermediate-mass star ejects its outer layers near the end of its life, forming a somewhat spherical cloud of gas. They typically have smoother, spherical shapes, making the Crystal Ball Nebula unique for its bumpy shells of gas. As the central star casts away this gas, its inner core is exposed. Radiation from the core energizes the gas, giving it a scorching temperature and chromatic glow. The Crystal Ball Nebula, for example, has an estimated temperature of 15,000 K.

Herschel found this object fascinating, amazed by its faintly illuminated shell. Prior to its discovery, he believed that nebulae were collections of stars that were too far away to individually resolve. The distinct bright point at the heart of the gaseous shell shattered this theory. He wrote in 1791, "Our judgment I may venture to say, will be, that the nebulosity about the star is not of a starry nature." He believed the illumination of the Crystal Ball Nebula came from a single star, not a far-off grouping.

While it may appear in this image as if there is a single shining light source at the heart of the Crystal Ball Nebula, as Herschel saw, it actually contains two stars. These two stars orbit each other with a period of around nine years – the longest known for any binary pair within a planetary nebula. Scientists believe that one of these stars, which was once several times more massive than our Sun, released its outer layers while in the throes of death. As the progenitor star and its binary companion orbit each other, they mold the expanding shell of gas with their strong, asymmetrical winds, forming the lumpy layers we see today.

Image Credit: International Gemini Observatory/NOIRLab/NSF/AURA

Image Processing: J. Miller and M. Rodriguez (International Gemini Observatory/NSF NOIRLab), T.A. Rector (University of Alaska Anchorage/NSF NOIRLab), D. de Martin and M. Zamani (NSF NOIRLab)

Image enhancement: Jean-Baptiste Faure

The Pillars of Creation as seen by Webb

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By combining images of the iconic Pillars of Creation from two cameras aboard the James Webb Space Telescope, the Universe has been framed in its infrared glory. Webb's near-infrared image was fused with its mid-infrared image, setting this star-forming region ablaze with new details.

Myriad stars are spread throughout the scene. The stars primarily show up in near-infrared light, marking a contribution of Webb's Near-Infrared Camera (NIRCam). Near-infrared light also reveals thousands of newly formed stars – look for bright orange spheres that lie just outside the dusty pillars.

In mid-infrared light, the dust is on full display. The contributions from Webb's Mid-Infrared Instrument (MIRI) are most apparent in the layers of diffuse, orange dust that drape the top of the image, relaxing into a V. The densest regions of dust are cast in deep indigo hues, obscuring our view of the activities inside the dense pillars.

Dust also makes up the spire-like pillars that extend from the bottom left to the top right. This is one of the reasons why the region is overflowing with stars – dust is a major ingredient of star formation. When knots of gas and dust with sufficient mass form in the pillars, they begin to collapse under their own gravitational attraction, slowly heat up, and eventually form new stars. Newly formed stars are especially apparent at the edges of the top two pillars – they are practically bursting onto the scene.

At the top edge of the second pillar, undulating detail in red hints at even more embedded stars. These are even younger, and are quite active as they form. The lava-like regions capture their periodic ejections. As stars form, they periodically send out supersonic jets that can interact within clouds of material, like these thick pillars of gas and dust. These young stars are estimated to be only a few hundred thousand years old, and will continue to form for millions of years.

Almost everything you see in this scene is local. The distant universe is largely blocked from our view both by the interstellar medium, which is made up of sparse gas and dust located between the stars, and a thick dust lane in our Milky Way galaxy. As a result, the stars take center stage in Webb’s view of the Pillars of Creation.

The Pillars of Creation is a small region within the vast Eagle Nebula, which lies 6,500 light-years away.

MIRI was contributed by ESA and NASA, with the instrument designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.

Webb's NIRCam was built by a team at the University of Arizona and Lockheed Martin's Advanced Technology Center.

Image Credit: NASA, ESA, CSA, STScI, J. DePasquale (STScI), A. Pagan (STScI), A. M. Koekemoer (STScI)

Image enhancement: Jean-Baptiste Faure

Deep Field in the Constellation Lupus by Rubin

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This 1.7-gigapixel image of a field of stars in the constellation Lupus showcases the unprecedented view of the Universe that NSF–DOE Vera C. Rubin Observatory gives us. Equipped with the LSST Camera – the largest digital camera in the world – Rubin combines a wide view of the sky with the ability to detect extremely faint objects. With this capability, Rubin can reveal details of the cosmos across an enormous range of scales, from distant galaxies, to individual stars, to the wispy clouds of dust spread throughout our galaxy.

The faint, glowing clouds spread across this image are galactic cirrus: clouds of interstellar gas and dust that can be seen in the foreground of the Milky Way. Rubin's ability to capture scenes like this in unmatched detail will open new windows into the structure of our galaxy and the Universe beyond it.

Imaqge Credit: NSF–DOE Vera C. Rubin Observatory/NOIRLab/SLAC/AURA

Image enhancement: Jean-Baptiste Faure