ESAHubble Picture Of The Week

A sideways spiral galaxy shines in today’s ESA/Hubble Picture of the Week. Located about 60 million light-years away in the constellation Virgo (The Maiden), NGC 4388 is a resident of the Virgo galaxy cluster. The Virgo cluster contains more than a thousand galaxies and is the nearest large galaxy cluster to the Milky Way.

NGC 4388 is tilted at an extreme angle relative to our point of view, giving us a nearly edge-on vantage point. This perspective reveals a curious feature that wasn’t visible in a previous Hubble image of this galaxy released in 2016: a plume of gas from the galaxy’s nucleus, here seen billowing out from the galaxy’s disc towards the lower-right corner of the image. But where did this outflow come from, and why does it glow?

The answer likely lies in vast stretches that separate the galaxies of the Virgo cluster. Though the space between the galaxies appears to be empty, this space is actually occupied by hot wisps of gas called the intracluster medium. As NGC 4388 journeys within the cluster, it plunges through the intracluster medium. The pressure from the hot intracluster gas whisks away the gas from within NGC 4388’s disc, causing it to trail behind as NGC 4388 moves.

The source of the energy that ionises this gas cloud and causes it to glow is more uncertain. Researchers suspect that some of the energy comes from the centre of the galaxy, where a supermassive black hole has spun the gas around it into a superheated disc. The blazing radiation from this disc might ionise the gas closest to the galaxy, while shock waves might be responsible for ionising the filaments of gas farther out.

This image incorporates new data including several additional wavelengths of light to bring the ionised gas cloud into view. The data used to create this image come from several observing programmes that aim to illuminate galaxies with active black holes at their centres.

[Image Description: A spiral galaxy seen nearly edge-on. Its disk is filled with red and blue lights from star-forming nebulae and clusters of hot stars, respectively, as well as thick dark clouds of dust that block the strong white light from its centre. A faint, glowing halo of gas surrounds the disc, fading into the black background. A bluish plume of gas also extends from the galaxy’s core to the lower-right of the image.]

This glittering blue galaxy and subject of today’s ESA/Hubble Picture of the Week is a blue compact dwarf galaxy called Markarian 178 (Mrk 178). This galaxy, which is substantially smaller than our own Milky Way, lies 13 million light-years away in the constellation Ursa Major (The Great Bear).

Mrk 178 is one of more than 1500 Markarian galaxies. These galaxies get their name from the Armenian astrophysicist Benjamin Markarian, who compiled a list of galaxies that were surprisingly bright in ultraviolet light.

While the bulk of the galaxy is blue owing to an abundance of young, hot stars with little dust shrouding them, Mrk 178 gets a red hue from a collection of massive stars, which are especially concentrated in the brightest, reddish region near the galaxy’s edge. This azure cloud is home to a large number of rare objects called Wolf–Rayet stars. Wolf–Rayet stars are massive stars that are casting off their atmospheres through powerful winds. Because Mrk 178 contains so many Wolf–Rayet stars, the bright emission lines from these stars’ hot stellar winds are etched upon the galaxy’s spectrum. Particularly ionised hydrogen and oxygen appear as a red colour to Mrk 178 in this photo, observed using some of Hubble’s specialised light filters.

Massive stars enter the Wolf–Rayet phase just before they collapse into black holes or neutron stars. Because Wolf–Rayet stars last for only a few million years, researchers know that something must have triggered a recent burst of star formation in Mrk 178. At first glance, it’s not clear what could be the cause — Mrk 178 doesn’t seem to have any close galactic neighbours that could have stirred up its gas to form new stars. Astronomers believe that it was triggered by the interaction with a smaller satellite, as revealed by the presence of low surface brightness tidal features detected around Mrk178 in deep imaging acquired with the Large Binocular Telescope. Future high resolution Hubble data will be crucial to study the detailed star formation history of Mrk 178.

[Image Description: A pale blue dwarf galaxy seen on the black backdrop of space with some faraway galaxies. The galaxy itself resembles a fuzzy cloud of tightly-packed stars, with a broad halo of stars dispersed around it. Several small, glowing patches of gas are spread across the galaxy’s core, where very hot stars are concentrated.]

The subject of the latest Hubble Picture of the Week is a stormy and highly active spiral galaxy named NGC 1792. Located over 50 million light-years from Earth in the constellation Columba (the Dove), the bright glow of the galaxy’s centre is offset by the flocculent and sparkling spiral arms swirling around it.

NGC 1792 is just as fascinating to astronomers as its chaotic look might imply. Classified as a starburst galaxy, it is a powerhouse of star formation, with spiral arms rich in star-forming regions. In fact, it is surprisingly luminous for its mass. The galaxy is close to a larger neighbour, NGC 1808, and the strong gravitational interaction between the two is believed to be what has stirred up the reserves of gas in this galaxy. The result is a torrent of star formation, concentrated on the side where gravity has a stronger effect. It’s a perfect target for astronomers seeking to understand the complex interactions between gas, star clusters and supernovae in galaxies.

Hubble has shown off this galaxy before, in 2020. This week’s new image includes additional data collected throughout 2025, providing a deeper view of the tumultuous astrophysical activity taking place in the galaxy. Blossoming red lights in the arms mark out so-called H-alpha emission from dense clouds of hydrogen molecules. Stars form within these clouds and shine powerfully with ultraviolet radiation. They ionise the gas around them, causing the gas to emit a very particular red wavelength of light — a tell-tale sign of new stars.

[Image Description: A spiral galaxy, seen partly from the side, with a messy, turbulent appearance. Its disc is made of multiple patchy arms that contain numerous sparkling blue and glowing red regions — star clusters and star-forming nebulae. Thick clumps of dark reddish dust swirl through the disc. The glow of the disc extends out into the dark background, where both distant and nearby stars can be seen.]

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• Pan: NGC 1792

Today’s ESA/Hubble Picture of the Week brings a distant stellar birthplace into focus. This gigantic cloud of cold hydrogen gas is called N159, and it’s located about 160 000 light-years away in the constellation Dorado. N159 is one of the most massive star-forming clouds in the Large Magellanic Cloud, a dwarf galaxy that is the largest of the small galaxies that orbit the Milky Way.

This image shows just a portion of the N159 star-forming complex. The entire complex stretches over 150 light-years across. To put that into perspective, 150 light-years is nearly 10 million times the distance between Earth and the Sun!

In the subzero interior of this gas cloud, subjected to the crushing pressure of gravity, young stars begin to gleam in the darkness. Particularly hot and high-mass stars illuminate their birthplaces with red light. This red glow is characteristic of excited hydrogen atoms, to which Hubble is exquisitely sensitive.

Though some of the bright stars in the cloud appear to be blanketed with reddish gas, others seem to lie at the centre of a reddish bubble, through which the dark backdrop of space is visible. These bubbles are evidence of stellar feedback, in which young stars fry their habitats with high-energy radiation and blow bubbles with their intense stellar winds.

A previous Hubble image of the full N159 star-forming cloud was released in 2016. This version incorporates an additional wavelength of light to highlight the hot gas that surrounds newborn stars.

[Image Description: A field filled with stars and covered by clouds of gas and dust. The centre and left side are totally blanketed with billowing, bright red clouds. They are opaque some places — showing clusters of stars forming within — and transparent others. Small patches are dark black in colour, while a large cloud below the centre is mostly pale blue. The right side of the view, mostly gas-free, glitters with stars near and far.]

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• Pan: N159

Today’s ESA/Hubble Picture of the Week features the spiral galaxy NGC 4535, which is situated about 50 million light-years away in the constellation Virgo (The Maiden). This galaxy has been nicknamed the ‘Lost Galaxy’ because it’s extremely faint when viewed through a small telescope. With a mirror spanning 2.4 metres across, Hubble is well equipped to observe dim galaxies like NGC 4535 and pick out features like its massive spiral arms and central bar of stars.

On full display in this Hubble image are NGC 4535’s young star clusters, which dot the galaxy’s spiral arms. Many of the groupings of bright blue stars are enclosed by glowing pink clouds. These clouds, called H II (‘H-two’) regions, are a sign that the galaxy is home to especially young, hot, and massive stars that are blazing with high-energy radiation. By heating the clouds in which they were born, shooting out powerful stellar winds, and eventually exploding as supernovae, massive stars certainly shake up their surroundings. 

This Hubble image incorporates data from an observing programme that will catalogue roughly 50 000 H II regions in nearby star-forming galaxies like NGC 4535. A previous image of NGC 4535 was released in 2021. Both the 2021 image and today’s image incorporate observations from the PHANGS programme, which seeks to understand the connections between young stars and cold gas. Today’s image adds a new dimension to our understanding of NGC 4535 by capturing the brilliant red glow of the nebulae that encircle massive stars in their first few million years of life.

[Image Description: A close-in view of a spiral galaxy that faces the viewer. Brightly lit spiral arms swing outwards through the galaxy’s disc, starting from an elliptical region in the centre. Thick strands of dark reddish dust are spread across the disc, mostly following the spiral arms. The arms also contain many glowing pink-red spots where stars form. The galaxy is a bit fainter beyond the arms, but speckled with blue stars.]

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• Pan: NGC 4535

Though interesting to look at, NGC 1511 is one galaxy you might not want for a neighbour. Seen in this ESA/Hubble Picture of the Week, NGC 1511 is a peculiar spiral galaxy located roughly 50 million light-years away in the constellation Hydrus.

Like many galaxies, NGC 1511 doesn’t travel through space alone. Instead, it does so with a pair of small galactic companions called NGC 1511A and NGC 1511B, both of which lie outside the frame of this Hubble image. NGC 1511B is situated closest to NGC 1511, and the two galaxies have apparently clashed in the past; a narrow strand of hydrogen gas connects them, and NGC 1511B has been stretched and distorted by the encounter. Researchers have even found evidence that NGC 1511 once had another small companion galaxy that it has disrupted entirely!

These disruptions have an impact on NGC 1511, too. The galaxy is experiencing a burst of star formation, and its disc features strange loops and plumes that could point to past interactions with its neighbouring galaxies. Researchers will use Hubble’s keen observations of NGC 1511 to study star clusters embedded within its dusty gas, seeking to understand how matter is cycled from interstellar clouds to stars and back to clouds once again.

[Image Description: A spiral galaxy, tilted away so that it is seen mostly from the edge. The disc of the galaxy glows blue from its centre, due to younger stars in the spiral arms. There are large and small patches of gas, glowing in red and pink colours, where new stars are forming. Webs of dark dust are spread over the disc. The glow of the disc fades into a dark background, with a couple of stars.]

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• Pan: NGC 1511

What lies at the heart of this unusual-looking spiral galaxy? The galaxy NGC 4102, featured in this ESA/Hubble Picture of the Week, is home to what astronomers call an active galactic nucleus. Active galactic nuclei are luminous galactic centres powered by supermassive black holes that contain millions to billion times the mass of our Sun. As these black holes ensnare gas from their surroundings and draw it close with their intense gravitational pull, the gas becomes so hot that it begins to glow and emits light from X-ray to radio wavelengths.

At a distance of just 56 million light-years away in the constellation Ursa Major (The Great Bear), NGC 4102 provides an ideal opportunity to study the ways in which active galactic nuclei interact with their home galaxies. Active galactic nuclei come in many different flavours, from extremely powerful types that consume massive amounts of matter and shoot out jets of charged particles, to calmer types that sip gas from their surroundings and glow more faintly.

NGC 4102 likely falls into the latter category. It’s classified as Compton-thick — a way of saying that its nucleus is obscured by a thick layer of gas — and a LINER, or low-ionisation nuclear emission-line region. LINER galaxies are identified by emission lines from certain weakly ionised elements, and they can be powered by a supermassive black hole that is lazily collecting gas from around it. 

A previous image of this galaxy, made from data taken with Hubble’s Wide Field Planetary Camera 2 (WFPC2), was released in 2014. This new version presents an upgraded view of the galaxy, using data from the Wide Field Camera 3, which replaced WFPC2 in 2009 and improved upon its resolution and field of view. The new observations come from a programme that will combine visible-light images from Hubble with X-ray information from the Chandra X-ray Observatory to study the relationship between NGC 4102 and its active galactic nucleus.

[Image Description: A spiral galaxy. The inner region immediately around the bright centre is golden in colour. A gap separates this region from a bright ring, itself surrounded by a glowing halo. Strands of dark brown dust swirl around the centre and the outer ring, joined in one spot by a curved arm. Bright, blue and pink specks of light dot the ring, showing where stars are concentrated or have recently formed.]

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• Pan: NGC 4102

A star-studded spiral galaxy shines in this NASA/ESA Hubble Space Telescope Picture of the Week. This galaxy is called NGC 4571, and it’s situated about 60 million light-years away in the constellation Coma Berenices. NGC 4571 dominates the scene with its feathery spiral structure and sparkling star clusters.

The galaxy’s dusty spiral arms are dotted with brilliant pink nebulae that contain massive young stars. Though the star-forming clouds that are seen here are heated to roughly 10 000 degrees by searing ultraviolet light from the young stars at their cores, stars get their start in much chillier environments. The sites of star birth are giant molecular clouds tens to hundreds of light-years across, in which the temperature hovers just a few tens of degrees above absolute zero.

The dramatic transformation from freezing gas cloud to fiery young star happens thanks to the immense pull of gravity, which collects gas into dense clumps within a star-forming cloud. As these clumps yield to gravity’s pull and collapse inward, they eventually become hot and dense enough to spark nuclear fusion in their centres and begin to shine. The glowing clouds in this image surround particularly massive stars that are hot enough to ionise the gas of their birthplaces.

A Hubble image of NGC 4571 was previously released in 2022, using data from an observing programme the combines data from leading observatories like Hubble, the NASA/ESA/CSA James Webb Space Telescope, and the Atacama Large Millimeter/submillimeter Array to study star formation in nearby spiral galaxies like NGC 4571. The new image released today adds data from a programme that seeks to understand how dust affects our observations of young stars deeply embedded within their natal clouds.

[Image Description: A spiral galaxy, seen face-on, fills the view. Swirling, patchy and broken spiral arms surround a softly glowing centre. The arms are filled with blue, speckled patches showing star clusters, shining pink and red dots where young stars are lighting up gas clouds, and a web of thin, dark red dust lanes. The glow of the galaxy’s arms extends out into the dark background. Individual tiny stars appear throughout.]

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• Pan: NGC 4571

Today’s ESA/Hubble Picture of the Week features a galaxy that Hubble has captured multiple times over more than 20 years. The galaxy is called NGC 3370, and it is a spiral galaxy located nearly 90 million light-years away in the constellation Leo (The Lion).

What is it about this galaxy that makes it a popular target for researchers? NGC 3370 is home to two kinds of objects that astronomers prize for their usefulness in determining distances to faraway galaxies: Cepheid variable stars and Type Ia supernovae.

Cepheid variable stars change in both size and temperature as they pulsate. As a result, the luminosity of these stars varies over a period of days to months. It does so in a way that reveals something important: the more luminous a Cepheid variable star is, the more slowly it pulsates. By measuring how long a Cepheid variable’s brightness takes to complete one cycle, astronomers can determine how bright the star actually is. Paired with how bright the star appears from Earth, this information gives the distance to the star and its home galaxy.

Type Ia supernovae provide a way to measure distances in a single explosive burst rather than through regular brightness variations. Type Ia supernovae happen when the dead core of a star ignites in a sudden flare of nuclear fusion. These explosions peak at very similar luminosities, and much like for a Cepheid variable star, knowing the intrinsic brightness of a supernova explosion allows for its distance to be measured. Observations of Cepheid variable stars and Type Ia supernovae are both critical for precisely measuring how fast our Universe is expanding. 

A previous Hubble image of NGC 3370 was released in 2003. The image released today zooms in on the galaxy, presenting a richly detailed view that incorporates wavelengths of light that were not included in the previous version. NGC 3370 is a member of the NGC 3370 group of galaxies along with other Hubble targets NGC 3447 and NGC 3455.

[Image Description: A spiral galaxy occupies most of the image. It is a slightly tilted disc of stars, yellow-white in the centre and blue in the outskirts, showing light from different stars in the galaxy. Its spiral arms curl outwards from the centre, speckled with blue star clusters. Dark reddish threads of dust swirl around the galaxy’s centre. The backdrop is two medium-sized and many small, distant galaxies on a black background.]

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• Wider view around NGC 3370
• Pan: NGC 3370

The celestial object that is displayed in this NASA/ESA Hubble Space Telescope Picture of the Week is NGC 7496, a galaxy located over 24 million light-years away in the constellation Grus (The Crane). NGC 7496 is a dusty spiral galaxy with a bar of stars stretching across its centre. Adding to its intrigue is an active galactic nucleus: a supermassive black hole that feasts on gas at the very heart of the galaxy.

Astronomers have observed NGC 7496 at wavelengths from radio to ultraviolet in order to study the galaxy’s active galactic nucleus, dust clouds, and star formation. Hubble first observed this galaxy as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) programme. This programme has enlisted the abilities of several powerful astronomical observatories, including the Atacama Large Millimetre/submillimetre Array (ALMA), the Very Large Telescope, and the NASA/ESA/CSA James Webb Space Telescope, in addition to Hubble. NGC 7496 was the first galaxy in the PHANGS sample that Webb observed.

Each of these observatories offers a different perspective on this well-studied galaxy. With its unique ultraviolet capabilities and fine resolution, Hubble’s view reveals young star clusters bursting with high-energy radiation. Hubble’s observations of NGC 7496 help to reveal the ages and masses of these young stars, as well as the extent to which their starlight is blocked by dust.

A previous Hubble image of NGC 7496 was released in 2022. Today’s image incorporates new data that highlight the galaxy’s star clusters, which are surrounded by glowing red clouds of hydrogen gas. Astronomers collected these data in order to study nebulae like those that massive stars leave behind when they explode as supernovae and those from which newborn stars are made.

[Image Description: A spiral galaxy featuring a bright, glowing core that is crossed by a horizontal bar of yellowish light. Spiral arms emerge from each end of this bar and wrap around it, creating a disc that is stretched out to the right. Some areas, mostly along the arms, glow pink where stars are forming in nebulae. Webs of dark reddish dust also follow the arms. A star in our galaxy shines prominently, off to the right.]

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• Pan: NGC 7496

The glittering galaxy in this NASA/ESA Hubble Space Telescope Picture of the Week is NGC 6951, which resides about 70 million light-years away in the constellation Cepheus.

As this Hubble image shows, NGC 6951 is a spiral galaxy with plenty of intriguing structures. Most eye-catching are its spiral arms, which are dotted with brilliant red nebulae, bright blue stars and filamentary dust clouds. The spiral arms loop around the galactic centre, which has a golden glow that comes from a population of older stars. The centre of the galaxy is also distinctly elongated, revealing the presence of a slowly rotating bar of stars.

NGC 6951’s bar may be responsible for another remarkable feature: a white-blue ring that encloses the very heart of the galaxy. This is called a circumnuclear starburst ring — essentially, a circle of enhanced star formation around the nucleus of a galaxy. The bar funnels gas toward the centre of the galaxy, where it collects in a ring about 3800 light-years across. Two dark dust lanes that run parallel to the bar mark the points where gas from the bar enters the ring.

The dense gas of a circumnuclear starburst ring is the perfect environment to churn out an impressive number of stars. Using data from Hubble, astronomers have identified more than 80 potential star clusters within NGC 6951’s ring. Many of the stars formed less than 100 million years ago, but the ring itself is longer-lived, potentially having existed for 1–1.5 billion years.

Astronomers have imaged NGC 6951 with Hubble for a wide variety of reasons, including mapping the dust in nearby galaxies, studying the centres of disc galaxies and keeping tabs on recent supernovae (of which NGC 6951 has hosted five or six).

[Image Description: A spiral galaxy with large, open arms. A bar of yellow light, where old stars are gathered, crosses the middle of the disk. The very centre is a white point surrounded by a small, shining ring of star clusters. Thin lanes of dust swirl around this ring, reaching out to follow the spiral arms; also visible across the arms are red, glowing spots where stars are forming. To the right a star shines large and bright.]

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• Pan: NGC 6951

Stars of all ages are on display in today’s NASA/ESA Hubble Space Telescope Picture of the Week. This sparkling spiral galaxy is called NGC 6000 and it is located 102 million light-years away in the constellation Scorpius. 

This galaxy has a glowing yellow centre and glittering blue outskirts. The colours reflect differences in the average ages, masses and temperatures of the galaxy’s stars. In the heart of the galaxy, the stars tend to be older and smaller. Less massive stars are cooler than more massive stars, and somewhat counterintuitively, cooler stars are redder, while hotter stars are bluer. Farther out along NGC 6000’s spiral arms, brilliant star clusters host young, massive stars that appear distinctly blue.

Hubble collected the data for this image while surveying the sites of recent supernova explosions in nearby galaxies. NGC 6000 has hosted two recent supernovae: SN 2007ch in 2007 and SN 2010as in 2010. Using Hubble’s sensitive detectors, researchers are able to discern the faint glow of supernovae years after the initial explosion. These observations help to constrain the masses of supernova progenitor stars and can indicate if they had any stellar companions. 

By zooming in to the right side of the galaxy’s disc in this image, you may see something else yellow and blue: a set of four thin lines. These are an asteroid in our Solar System, which was drifting across Hubble’s field of view as it gazed at NGC 6000. The four streaks are due to different exposures that were recorded one after another with slight pauses in between. These were combined to create this final image. The colours appear this way because each exposure used a filter to collect only very specific wavelengths of light, in this case around red and blue. Having these separate exposures is important to study and compare stars by their colours — but it also makes asteroid interlopers very obvious!

[Image Description: An oval-shaped spiral galaxy, of which only the centre and lower half is in frame. Its centre is mainly golden in colour with a white glowing core, while its thick spiral arms are mostly blue, particularly at the outskirts; the colours merge in between. Dark lanes of dust swirl through the centre, blocking some of its light. Stars and distant galaxies can be seen around the edges on a black background.]

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• Pan: NGC 6000

Today’s NASA/ESA Hubble Space Telescope Picture of the Week features a galaxy that’s hard to categorise. The galaxy in question is NGC 2775, which lies 67 million light-years away in the constellation Cancer (The Crab). NGC 2775 sports a smooth, featureless centre that is devoid of gas, resembling an elliptical galaxy. It also has a dusty ring with patchy star clusters, like a spiral galaxy. Which is it, then: spiral or elliptical — or neither?

Because we can only view NGC 2775 from one angle, it’s difficult to say for sure. Some researchers have classified NGC 2775 as a spiral galaxy because of its feathery ring of stars and dust, while others have classified it as a lenticular galaxy. Lenticular galaxies have features common to both spiral and elliptical galaxies.

It’s not yet known exactly how lenticular galaxies come to be, and they might form in a variety of ways. Lenticular galaxies might be spiral galaxies that have merged with other galaxies, or that have mostly run out of star-forming gas and lost their prominent spiral arms. They also might have started out more similar to elliptical galaxies, then collected gas into a disk around them.

Some evidence suggests that NGC 2775 has merged with other galaxies in the past. Invisible in this Hubble image, NGC 2775 has a tail of hydrogen gas that stretches almost 100 000 light-years around the galaxy. This faint tail could be the remnant of one or more galaxies that wandered too close to NGC 2775 before being stretched apart and absorbed. If NGC 2775 merged with other galaxies in the past, it could explain the galaxy’s strange appearance today.

A Hubble image of NGC 2775 was previously released in 2020. The new version adds observations of a specific wavelength of red light that is emitted by clouds of hydrogen gas surrounding massive young stars.

[Image Description: A galaxy seen face-on, with a slightly elliptical disc that appears to have a hole in the centre like a doughnut. In the hole, the core is a brightly glowing point that shines light out beyond the edge of the disc. Around the hole is an inner ring of dust, and at the galaxy’s edge is a thicker outer ring of dust, with a swirling web of dust strands in between. Blue stars and red nebulae are visible behind the dust.]

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• Pan: NGC 2775

What lurks behind the dense, dusty clouds of this galactic neighbour? There lies the star-powered heart of the galaxy Messier 82 (M82), also known as the Cigar Galaxy. Located just 12 million light-years away in the constellation Ursa Major (The Great Bear), the Cigar Galaxy is considered a nearby galaxy. As this NASA/ESA Hubble Space Telescope Picture of the Week shows in great detail, it’s home to brilliant stars whose light is shaded by sculptural clouds, clumps and streaks of dust and gas.

It’s no surprise that the Cigar Galaxy is so packed with stars, obscured though they might be by the distinctive clouds pictured here. Forming stars 10 times faster than the Milky Way, the Cigar Galaxy is what astronomers call a starburst galaxy. The intense starburst period that grips this galaxy has given rise to super star clusters in the galaxy’s heart. Each of these super star clusters contains hundreds of thousands of stars and is more luminous than a typical star cluster. Researchers used Hubble to home in on these massive clusters and reveal how they form and evolve.

Hubble’s views of the Cigar Galaxy have been featured before, both as a previous Picture of the Week in 2012 and as an image released in celebration of Hubble’s 16th birthday. The NASA/ESA/CSA James Webb Space Telescope has also turned toward the Cigar Galaxy, producing infrared images in 2024 and earlier this year. 

This image features something not seen in previously released Hubble images of the galaxy: data from the High Resolution Channel of the Advanced Camera for Surveys (ACS). The High Resolution Channel is one of three sub-instruments of ACS, which was installed in 2002. In five years of operation, the High Resolution Channel returned fantastically detailed observations of crowded, starry environments like the centres of starburst galaxies. An electronics fault in 2007 unfortunately left the High Resolution Channel disabled.

[Image Description: A close-in view of the centre of galaxy M82. Bright, bluish light radiating from the centre is due to stars actively forming there. A thick lane of gas, black in the centre and red around the edges, crosses the centre and blocks much of the light. Thinner strands and clumps of reddish dust cover much of the rest of the view.]

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• Location of galaxy centre in Messier 82
• Pan: Messier 82

This new NASA/ESA Hubble Space Telescope Picture of the Week features a cloudy starscape from an impressive star cluster. This scene is located in the Large Magellanic Cloud, a dwarf galaxy situated about 160 000 light-years away in the constellations Dorado and Mensa. With a mass equal to 10–20% of the mass of the Milky Way, the Large Magellanic Cloud is the largest of the dozens of small galaxies that orbit our galaxy.

The Large Magellanic Cloud is home to several massive stellar nurseries where gas clouds, like those strewn across this image, coalesce into new stars. Today’s image depicts a portion of the galaxy’s second-largest star-forming region, which is called N11. (The most massive and prolific star-forming region in the Large Magellanic Cloud, the Tarantula Nebula, is a frequent target for Hubble.) We see bright, young stars lighting up the gas clouds and sculpting clumps of dust with powerful ultraviolet radiation.

This image marries observations made roughly 20 years apart, a testament to Hubble’s longevity. The first set of observations, which were carried out in 2002–2003, capitalised on the exquisite sensitivity and resolution of the then-newly-installed Advanced Camera for Surveys. Astronomers turned Hubble toward the N11 star cluster to do something that had never been done before at the time: catalogue all the stars in a young cluster with masses between 10% of the Sun’s mass and 100 times the Sun’s mass. 

The second set of observations came from Hubble’s newest camera, the Wide Field Camera 3. These images focused on the dusty clouds that suffuse the cluster, bringing a new perspective on cosmic dust.

[Image Description: Stars in a star cluster shine brightly blue, with four-pointed spikes radiating from them. The centre shows a small, crowded group of stars while a larger group lies out of view on the left. The nebula is mostly thick, smoky clouds of gas, lit up in blue tones by the stars. Clumps of dust hover before and around the stars; they are mostly dark, but lit around their edges where the starlight erodes them.]

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• Pan: LMC N44C

While it may appear unassuming at first glance, just another spiral galaxy among thousands in the Universe, this subject of the ESA/Hubble Picture of the Week has plenty to study. NGC 7456 is its name, located over 51 million light-years away in the constellation Grus (the Crane).

In this image we see in fine detail the patchy spiral arms of this galaxy, followed by clumps of dark, obscuring dust. Blossoms of glowing pink are rich reservoirs of gas where new stars are forming, illuminating the clouds around them and causing the gas to emit this tell-tale red light. The Hubble programme which collected this data is focused on stellar activity just like this, tracking new stars, clouds of hydrogen and star clusters to learn how the galaxy has evolved through time.

Hubble, with its ability to capture visible, ultraviolet and some infrared light, is not the only observatory focused on NGC 7456. ESA’s XMM-Newton satellite has imaged X-rays from the galaxy on multiple occasions, discovering a number of so-called ultraluminous X-ray sources. These small, compact objects emit terrifically powerful X-rays, much more than would be expected for their size. Astronomers are still trying to pin down what powers these extreme objects, and NGC 7456 contributes a few more examples.

On top of that, the region around the galaxy’s supermassive black hole is spectacularly bright and energetic, making NGC 7456 an active galaxy. Whether looking at its core or its outskirts, at visible light or X-rays, this galaxy has something interesting to show!

[Image Description: A spiral galaxy. It shines brightly at the centre, and most of its disc also glows in warm colours. Its two spiral arms, which wind outwards from the centre, are made up mostly of large patches of bright blue specks. They also contain thin, reddish clouds of dust, and bright pink bubbles of glowing gas, where stars are forming. Distant galaxies can be seen around the galaxy as small orange spots, on a dark background.]

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• Pan: NGC 7456

Today’s NASA/ESA Hubble Space Telescope Picture of the Week features a galaxy whose asymmetric appearance may be the result of a galactic tug of war. Located 35 million light-years away in the constellation Leo, the spiral galaxy Messier 96 is the brightest of the galaxies in its group. The gravitational pull of its galactic neighbours may be responsible for Messier 96’s uneven distribution of gas and dust, asymmetric spiral arms, and off-centre galactic core. 

This asymmetric appearance is on full display in a new Hubble image, which incorporates observations made in ultraviolet and optical light. Hubble images of Messier 96 have been released previously in 2015 and 2018. Each successive image has added new data, building up a beautiful and scientifically valuable view of the galaxy.

This third version gives an entirely new perspective on Messier 96’s star formation. The bubbles of pink gas in this image surround hot, young, massive stars, illuminating a ring of star formation in the outskirts of the galaxy. These young stars are still embedded within the clouds of gas from which they were born. The new data included for the first time in this image will be used to study how stars are born within giant dusty gas clouds, how dust filters starlight, and how stars affect their environments.

[Image Description: A spiral galaxy, tilted nearly face-on to us, with a slightly unusual shape. Its spiral arms form an oval-shaped ring around the galaxy’s disc, filled with blue light from stars, as well as pink glowing gas bubbles where new stars are forming. Threads of dark red dust swirl around the brightly glowing core, blocking some of its light. The dust lanes extend into and follow the spiral arms.]

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• Pan: Messier 96

Today’s NASA/ESA Hubble Space Telescope Picture of the Week offers a closeup of a nearby spiral galaxy. The subject is NGC 2835, which lies 35 million light-years away in the constellation Hydra (The Water Snake).

A previous Hubble image of this galaxy was released in 2020, and the NASA/ESA/CSA James Webb Space Telescope turned its gaze toward NGC 2835 in recent years as well. Do you see anything different between today’s image of NGC 2835 and the previously released versions? Overall, NGC 2835 looks quite similar in all of these images, with spiral arms dotted with young blue stars sweeping around an oval-shaped centre, where older stars reside.

This image differs from previously released images because it incorporates new data from Hubble that captures a specific wavelength of red light called H-alpha. The regions that are bright in H-alpha emission can be seen along NGC 2835’s spiral arms, where dozens of bright pink nebulae appear like flowers in bloom. Astronomers are interested in H-alpha light because it signals the presence of several different types of nebulae that arise during different stages of a star’s life. Newborn massive stars create nebulae called H II regions that are particularly brilliant sources of H-alpha light, while dying stars can leave behind supernova remnants or planetary nebulae that can also be identified by their H-alpha emission.

By using Hubble’s sensitive instruments to survey 19 nearby galaxies, researchers aim to identify more than 50 000 nebulae. These observations will help to explain how stars affect their birth neighbourhoods through intense starlight and winds.

[Image Description: A spiral galaxy seen face-on. Its centre is a bright glowing yellow. The galaxy’s spiral arms contain sparkling blue stars, pink spots of star formation, and dark threads of dust that follow the arms.]

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• Pan: NGC 2835

This NASA/ESA Hubble Space Telescope Picture of the Week zooms in on the feathery spiral arms of the galaxy NGC 45, which lies just 22 million light-years away in the constellation Cetus (The Whale).

The data used to create this portrait were drawn from two complementary observing programmes. The first took a broad view of 50 nearby galaxies, leveraging Hubble’s ability to observe light from the ultraviolet to the near-infrared in order to study star formation in these galaxies. The second programme examined many of the same nearby galaxies as the first, narrowing in on a particular wavelength of red light called H-alpha. Star-forming nebulae are powerful producers of H-alpha light, and several of these regions can be identified across NGC 45 by their bright pink-red colour.

These observing programmes aimed to study star formation in galaxies of different sizes, structures, and degrees of isolation — and NGC 45 makes for a particularly interesting target. Though it may appear to be a regular spiral galaxy, NGC 45 is actually a remarkable type called a low surface brightness galaxy.

Low surface brightness galaxies are fainter than the night sky itself, making them incredibly difficult to detect. They appear unexpectedly faint because they have relatively few stars for the amount of gas and dark matter they carry. In the decades since the first low surface brightness galaxy was serendipitously discovered in 1986, researchers have learned that 30–60% of all galaxies may fall into this category. Studying these hard-to-detect galaxies is key to understanding how galaxies form and evolve, and Hubble’s sensitive instruments are equal to the task.

[Image Description: This Hubble image features a close-up view of the outer arms of the spiral galaxy NGC 45. These spiral arms are filled with tiny blue dots - stars - and glowing pink clouds - star-forming nebulae. This is shown against a dark background.]

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• Pan: NGC 45

A scene from a star-forming factory shines in this NASA/ESA Hubble Space Telescope Picture of the Week. This Hubble picture captures incredible details in the dusty clouds in a star-forming region called the Tarantula Nebula. What’s possibly the most amazing aspect of this detailed image is that this nebula isn’t even in our galaxy. Instead, it’s in the Large Magellanic Cloud, a dwarf galaxy that is located about 160 000 light-years away in the constellations Dorado and Mensa. 

The Large Magellanic Cloud is the largest of the dozens of small satellite galaxies that orbit the Milky Way. The Tarantula Nebula is the largest and brightest star-forming region not just in the Large Magellanic Cloud, but in the entire group of nearby galaxies to which the Milky Way belongs.

The Tarantula Nebula is home to the most massive stars known, some of which are roughly 200 times as massive as our Sun. The scene pictured here is located away from the centre of the nebula, where there is a super star cluster called R136, but very close to a rare type of star called a Wolf–Rayet star. Wolf–Rayet stars are massive stars that have lost their outer shell of hydrogen and are extremely hot and luminous, powering dense and furious stellar winds.

This nebula is a frequent target for Hubble, whose multiwavelength capabilities are critical for capturing sculptural details in the nebula’s dusty clouds. The data used to create this image come from an observing programme called Scylla, named for a multi-headed sea monster from the Greek myth of Ulysses. The Scylla programme was designed to complement another Hubble observing programme called ULLYSSES (Ultraviolet Legacy Library of Young Stars as Essential Standards). ULLYSSES targets massive young stars in the Small and Large Magellanic Clouds, while Scylla investigates the structures of gas and dust that surround these stars.

[Image Description: A nebula. The top-left is dense with layers of fluffy pink and greenish clouds. Long strands of green clouds stretch out from here; a faint layer of translucent blue dust combines with them to create a three-dimensional scene. A sparse network of dark dust clouds in the foreground adds reddish-black patches atop the nebula. Blue-white and orange stars, from our galaxy and beyond, are spread amongst the clouds.]

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• Pan: Tarantula

Rich with detail, the spiral galaxy NGC 1309 shines in this NASA/ESA Hubble Space Telescope Picture of the Week. NGC 1309 is situated about 100 million light-years away in the constellation Eridanus.

This stunning Hubble image encompasses NGC 1309’s bluish stars, dark brown gas clouds and pearly white centre, as well as hundreds of distant background galaxies. Nearly every smudge, streak and blob of light in this image is an individual galaxy. The only exception to the extragalactic ensemble is a star, which can be identified near the top of the frame by its diffraction spikes. It is positively neighbourly, just a few thousand light-years away in the Milky Way galaxy.

Hubble has turned its attention toward NGC 1309 several times; previous Hubble images of this galaxy were released in 2006 and 2014. Much of NGC 1309’s scientific interest derives from two supernovae, SN 2002fk in 2002 and SN 2012Z in 2012. SN 2002fk was a perfect example of a Type Ia supernova, which happens when the core of a dead star (a white dwarf) explodes.

SN 2012Z, on the other hand, was a bit of a renegade. It was classified as a Type Iax supernova: while its spectrum resembled that of a Type Ia supernova, the explosion wasn’t as bright as expected. Hubble observations showed that in this case, the supernova did not destroy the white dwarf completely, leaving behind a ‘zombie star’ that shone even brighter than it did before the explosion. Hubble observations of NGC 1309 taken across several years also made this the first time the white dwarf progenitor of a supernova has been identified in images taken before the explosion.

[Image Description: A top-down view of a spiral galaxy, showing its brightly shining centre, its broad spiral arms and the faint halo around its disc, as well as distant galaxies and stars on a dark background. Large blue clouds of gas speckled with small stars and strands of dark dust swirl around the galaxy’s disc. A couple of the background galaxies are large enough that their own swirling spiral arms can be seen.]

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• Pan: NGC 1309

The swirling spiral galaxy in this NASA/ESA Hubble Space Telescope Picture of the Week is NGC 3285B, which resides 137 million light-years away in the constellation Hydra (The Water Snake). Hydra has the largest area of the 88 constellations that cover the entire sky in a celestial patchwork. It’s also the longest constellation, stretching 100 degrees across the sky. It would take nearly 200 full Moons, placed side by side, to reach from one side of the constellation to the other.

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. This galaxy drew Hubble’s attention because it hosted a Type Ia supernova in 2023. Type Ia supernovae happen when a type of condensed stellar core called a white dwarf detonates, igniting a sudden burst of nuclear fusion that briefly shines about 5 billion times brighter than the Sun. The supernova, named SN 2023xqm, is visible here as a blue-ish dot on the left edge of the galaxy’s disc.

Hubble observed NGC 3285B as part of an observing programme that targeted 100 Type Ia supernovae. By viewing each of these supernovae in ultraviolet, optical, and near-infrared light, researchers aim to disentangle the effects of distance and dust, both of which can make a supernova appear redder than it actually is. This programme will help refine cosmic distance measurements that rely on observations of Type Ia supernovae.

[Image Description: A spiral galaxy with a disc made up of several swirling arms. Patchy blue clouds of gas are speckled over the disc, where stars are forming and lighting up the gas around them. The core of the galaxy is large and shines brightly gold, while the spiral arms are a paler and faint reddish colour. Neighbouring galaxies - from small, elongated spots to larger swirling spirals - can be seen across the black background.]

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• Pan: NGC 3285B

For this ESA/Hubble Picture of the Week, we gaze upon the field of stars that is NGC 1786. This object is a globular cluster in the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way Galaxy that is approximately 160 000 light-years away from Earth. NGC 1786 itself is in the constellation Dorado. It was discovered in the year 1835 by John Herschel.

The data for this image comes from an observing programme comparing old globular clusters in nearby dwarf galaxies — the LMC, 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 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.

[Image Description: A cluster of stars in space. It’s bright in the centre, where the stars are densely packed together in the cluster’s core, and grows dimmer and more diffuse out to the edges, as the stars give way to the dark background of space. A few orange stars are spread across the cluster, but most are pale, bluish-white points of light. Three large stars with cross-shaped spikes around them lie between us and the cluster.]

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• Pan: NGC 1786

A massive, spacetime-warping cluster of galaxies is the setting of today’s NASA/ESA Hubble Space Telescope Picture of the Week. The galaxy cluster in question is Abell 209, which is located 2.8 billion light-years away in the constellation Cetus (The Whale).

This Hubble image of Abell 209 shows more than a hundred galaxies, but there’s more to this cluster than even Hubble’s discerning eye can see. Abell 209’s galaxies are separated by millions of light-years, and the seemingly empty space between the galaxies is actually filled with hot, diffuse gas that can be spotted only at X-ray wavelengths. An even more elusive occupant of this galaxy cluster is dark matter: a form of matter that does not interact with light. The Universe is understood to be comprised of 5% normal matter, 25% dark matter, and 70% dark energy.

Hubble observations like the ones used to create this image can help astronomers answer fundamental questions about our Universe, including mysteries surrounding dark matter and dark energy. These investigations leverage the immense mass of a galaxy cluster, which can bend the fabric of spacetime itself and create warped and magnified images of background galaxies and stars in a process called gravitational lensing.

While this image lacks the dramatic rings that gravitational lensing can sometimes create, Abell 209 still shows subtle signs of lensing at work, in the form of streaky, slightly curved galaxies within the cluster’s golden glow. By measuring the distortion of these galaxies, astronomers can map the distribution of mass within the cluster, illuminating the underlying cloud of dark matter. This information, which Hubble’s fine resolution and sensitive instruments help to provide, is critical for testing theories of how our Universe has evolved.

[Image Description: A cluster of distant, mainly elliptical galaxies. They appear as brightly shining points radiating golden light that each take the shape of a smooth, featureless oval. They crowd around one that is extremely large and bright. A few spiral galaxies of comparable size appear too, bluer in colour and with unique shapes. Of the other, more small and distant galaxies covering the scene, a few are warped into long lines.]

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• Pan: Abell 209

The subject of this week's Hubble Picture of the Week is a reflection nebula, identified as GN 04.32.8. Reflection nebulae are clouds of dust in space that don't emit their own light, as other nebulae do. Instead, the light from nearby stars hits and scatters off their dust, lighting them up. Because of the way the light scatters, many reflection nebulae tend to appear blue, GN 04.32.8 included.

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.

[Image Description: A long, smoky, greyish-blue cloud in the centre of the image curves in an arc around three bright stars, each with long cross-shaped diffraction spikes. The cloud is lit more brightly on the inner side facing the stars, and fades into the dark background on the outer side. A few other stars and points of light surround the cloud: one small star below it has a dark band crossing its centre.]

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• Pan: GN 04.32.8