Image Archive: Nebulae

Little Dumbbell Nebula (M76, annotated)

Tue, 23 Apr 2024 16:00:00 +0200

In celebration of the 34th anniversary of the launch of the legendary NASA/ESA Hubble Space Telescope, astronomers took a snapshot of the Little Dumbbell Nebula (also known as Messier 76, M76, or NGC 650/651) located 3400 light-years away in the northern circumpolar constellation Perseus. The photogenic nebula is a favourite target of amateur astronomers.

M76 is classified as a planetary nebula. This is a misnomer because it is unrelated to planets. But its round shape suggested it was a planet to astronomers who first viewed it through low-power telescopes. In reality, a planetary nebula is an expanding shell of glowing gases that were ejected from a dying red giant star. The star eventually collapses to an ultra-dense, hot white dwarf.

M76 is composed of a ring, seen edge-on as the central bar structure, and two lobes on either opening of the ring. Before the star burned out, it ejected the ring of gas and dust. The ring was probably sculpted by the effects of the star that once had a binary companion star. This sloughed-off material created a thick disc of dust and gas along the plane of the companion’s orbit. The hypothetical companion star isn’t seen in the Hubble image, and so it could have been later swallowed by the central star. The disc would be forensic evidence for that stellar cannibalism.

The primary star is collapsing to form a white dwarf. It is one of the hottest stellar remnants known at a scorching 120 000 degrees Celsius, 24 times our Sun’s surface temperature.  The sizzling white dwarf can be seen as a pinpoint in the centre of the nebula. A star visible in projection beneath it is not part of the nebula.  

Pinched off by the disc, two lobes of hot gas are escaping from the top and bottom of the ‘belt’ along the star’s rotation axis that is perpendicular to the disc. They are being propelled by the hurricane-like outflow of material from the dying star, tearing across space at two million miles per hour. That’s fast enough to travel from Earth to the Moon in a little over seven minutes! This torrential ‘stellar wind’ is ploughing into cooler, slower-moving gas that was ejected at an earlier stage in the star’s life, when it was a red giant. Ferocious ultraviolet radiation from the super-hot star is causing the gases to glow. The red colour is from nitrogen, and blue is from oxygen. 

The entire nebula is a flash in the pan by cosmological timekeeping. It will vanish in about 15 000 years.

[Image description: Annotated image labeled “Little Dumbbell Nebula, M76, HST WFC3/UVIS” against the black background of space. Near top left, a color key consisting of five lines reads: “F475W SDSS g’” in light blue; “F502N OIII” in dark blue; “F656N Ha” in green; “F658N NIII” in red; and “F814W I” in orange. The nebula is located 3,400 light-years away in the northern circumpolar constellation Perseus. The name ‘Little Dumbbell’ comes from its shape that is a two-lobed structure of colorful, mottled, glowing gases resembling a balloon that’s been pinched around a middle waist. Like an inflating balloon, the lobes are expanding into space from a dying star seen as a white dot in the centre. Blistering ultraviolet radiation from the super-hot star is causing the gases to glow. The red color is from nitrogen, and blue is from oxygen. At bottom left corner is a scale bar labeled “1 light-year.” At bottom right corner, the “E” compass arrow points towards the 10 o’clock position. The “N” arrow points towards the 1 o’clock position.] 

Little Dumbbell Nebula (M76)

Tue, 23 Apr 2024 16:00:00 +0200

The primary star is collapsing to form a white dwarf. It is one of the hottest stellar remnants known at a scorching 120 000 degrees Celsius, 24 times our Sun’s surface temperature. The sizzling white dwarf can be seen as a pinpoint in the centre of the nebula. A star visible in projection beneath it is not part of the nebula.

The entire nebula is a flash in the pan by cosmological timekeeping. It will vanish in about 15 000 years.

[Image description: A Hubble image of the Little Dumbbell Nebula. The name comes from its shape, which is a two-lobed structure of colourful, mottled glowing gases that resemble a balloon that has been pinched around a middle waist. Like an inflating balloon, the lobes are expanding into space from a dying star seen as a white dot in the centre. Blistering ultraviolet radiation from the super-hot star is causing the gases to glow. The red colour is from nitrogen, and blue is from oxygen.] 

Colouring what human eyes can’t see

Mon, 12 Feb 2024 06:00:00 +0100

If the Hubble Picture of the Week from two weeks ago was somewhat dim and subtle in appearance, then this week’s image is a veritable riot of colour and activity! It features a relatively close-by star-forming region known as IRAS 16562-3959 that lies within the Milky Way in the constellation Scorpius, about 5900 light-years from Earth.

This image was compiled using observations from Hubble’s Wide Field Camera 3 (WFC 3). The detailed nuances of colour are possible because of the four separate filters that were used to collect the data. Filters are thin slivers of highly specialised material that only allow very specific wavelengths of light through. They can be slid in front of the part of the telescope that is sensitive to light, letting astronomers control which wavelengths of light the telescope collects with each observation. This is useful not only for specific scientific research, but also for the creation of images like this one.

Raw telescope observations are always monochrome, regardless of which filter was used. However, specially trained artists and image specialists can select colours that match the wavelength range covered by individual filters. Or, in the case where a direct match is not possible — such as for the data used in this image, which are all in the infrared regime, which human eyes are not sensitive to — the artist can select a colour that sensibly represents what is taking place. For example, they might assign bluer colours to shorter wavelengths and redder colours to longer wavelengths, as is the case in the visible light range. Then, data from multiple filters can be combined to build up a multi-colour image, that both looks beautiful and has scientific meaning.

At the centre of the image, IRAS 16562-3959 is thought to host a massive star — about 30 times the mass of our Sun — that is still in the process of forming. At the near-infrared wavelengths to which Hubble is sensitive, the central region appears dark because there is so much obscuring dust in the way. However near-infrared light leaks out mainly on two sides — upper left and lower right — where a powerful jet from the massive protostar has cleared away the dust. Multi-wavelength images including this incredible Hubble scene will help us gain a better understanding of how the most massive, brightest stars in our galaxy are born.

[Image Description: A nebula with stars. The centre of the image from top-left to bottom-right glows brightly with light from where new stars are being formed, and is partially covered by dark dust. Coloured layers of gas and dust billow out across the rest of the image. The nebula is speckled with foreground stars with large diffraction spikes.]

Webb’s View of the Molecular Cloud Chameleon I

Wed, 26 Apr 2023 15:49:31 +0200

This image by the NASA/ESA/CSA James Webb Space Telescope’s Near-InfraRed Camera (NIRCam) features the central region of the Chameleon I dark molecular cloud, which resides 630 light years away. The cold, wispy cloud material (blue, centre) is illuminated in the infrared by the glow of the young, outflowing protostar Ced 110 IRS 4 (orange, upper left). The light from numerous background stars, seen as orange dots behind the cloud, can be used to detect ices in the cloud, which absorb the starlight passing through them. An international team of astronomers has reported the discovery of diverse ices in the darkest, coldest regions of a molecular cloud measured to date by studying this region. This result allows astronomers to examine the simple icy molecules that will be incorporated into future exoplanets, while opening a new window on the origin of more complex molecules that are the first step in the creation of the building blocks of life. [Image Description: A large, dark cloud is contained within the frame. In its top half it is textured like smoke and has wispy gaps, while at the bottom and at the sides it fades gradually out of view. On the left are several orange stars: three each with six large spikes, and one behind the cloud which colours it pale blue and orange. Many tiny stars are visible, and the background is black.]

Hubble celebrates its 33rd anniversary with NGC 1333 (annotated)

Thu, 20 Apr 2023 16:00:00 +0200

Astronomers are celebrating the NASA/ESA Hubble Space Telescope’s 33rd launch anniversary with an ethereal photo of a nearby star-forming region, NGC 1333. The nebula is in the Perseus molecular cloud, and is located approximately 960 light-years away.

Hubble’s colourful view, showcasing its unique capability to obtain images in light from ultraviolet to near-infrared, unveils an effervescent cauldron of glowing gases and pitch-black dust stirred up and blown around by several hundred newly forming stars embedded within the dark cloud. Even then, Hubble just scratches the surface; most of the star-birthing firestorm is hidden behind clouds of fine dust — essentially soot — that are thicker toward the bottom of the image. The black areas of the image are not empty space, but are filled with obscuring dust.

To capture this image, Hubble peered through a veil of dust on the edge of a giant cloud of cold molecular hydrogen — the raw material for fabricating new stars and planets under the relentless pull of gravity. The image underscores the fact that star formation is a messy process in a rambunctious Universe.

Ferocious stellar winds, likely from the bright blue star at the top of the image, are blowing through a curtain of dust. The fine dust scatters the starlight at blue wavelengths.

Farther down, another bright super-hot star shines through filaments of obscuring dust, looking like the Sun shining through scattered clouds. A diagonal string of fainter accompanying stars looks reddish because the dust is filtering their starlight, allowing more of the red light to get through.

The bottom of the picture presents a keyhole peek deep into the dark nebula. Hubble captures the reddish glow of ionised hydrogen. It looks like the finale of a fireworks display, with several overlapping events. This is caused by pencil-thin jets shooting out from newly forming stars outside the frame of view. These stars are surrounded by circumstellar discs, which may eventually produce planetary systems, and powerful magnetic fields that direct two parallel beams of hot gas deep into space, like a double lightsaber from science fiction films. They sculpt patterns on the hydrogen cocoon, like laser lightshow tracings. The jets are a star’s birth announcement.

This view offers an example of the time when our own Sun and planets formed inside such a dusty molecular cloud, 4.6 billion years ago. Our Sun didn’t form in isolation but was instead embedded inside a mosh pit of frantic stellar birth, perhaps even more energetic and massive than NGC 1333.

[Image description: The left half is a color image of NGC 1333 labeled “NGC 1333, HST WFC3/UVIS”. Four filter labels are in blue (F475W), green (F606W), and red (F657N H-alpha plus N-two, and F814W). At bottom a scale bar is labeled 0.2 light-years and 43 arcseconds. The right half shows four black-and-white panels in a two-by-two layout. Each panel is a view of NGC 1333 in an individual filter. ]

Hubble celebrates its 33rd anniversary with NGC 1333

Thu, 20 Apr 2023 16:00:00 +0200

Ferocious stellar winds, likely from the bright blue star at the top of the image, are blowing through a curtain of dust. The fine dust scatters the starlight at blue wavelengths.

[Image description: A vertical image with colors ranging from blue at the top to golden in the middle and red at the bottom. At the top, a bright blue star is illuminating surrounding clouds of gas. At the center of the image, a brighter yellow star illuminates surrounding gas. The bottom of the image is noticeably darker than the rest, with the exception of a dramatic splash of red.]

Exploring a Turbulent Tarantula

Mon, 30 Jan 2023 06:00:00 +0100

A snapshot of the Tarantula Nebula (also known as 30 Doradus) is the most recent Picture of the Week from the NASA/ESA Hubble Space Telescope. The Tarantula Nebula is a large star-forming region of ionised hydrogen gas that lies 161 000 light years from Earth in the Large Magellanic Cloud, and its turbulent clouds of gas and dust can be seen swirling between the region’s bright, newly-formed stars.

The Tarantula Nebula is a familiar site for Hubble. It is the brightest star-forming region in our galactic neighbourhood and home to the hottest, most massive stars known. This makes it a perfect natural laboratory in which to test out theories of star formation and evolution, and a rich variety of Hubble images of this region have been released to the public in recent years. The NASA/ESA/CSA James Webb Space Telescope also recently delved into this region, revealing thousands of never-before-seen young stars.

This new image combines data from two different observing proposals. The first was designed to explore the properties of the dust grains that exist in the void between stars and which make up the dark clouds winding through this image. This proposal, which astronomers named Scylla, complements another Hubble observing proposal called Ulysses and is revealing how interstellar dust interacts with starlight in a variety of environments. This image also incorporates data from an observing programme studying star formation in conditions similar to the early Universe, as well as cataloguing the stars of the Tarantula Nebula for future science with Webb.

[Image description: Wispy, nebulous clouds extend from the lower-left of the image. At the top and right the dark background of space can be seen through the sparse nebula. Along the left and in the corner are many layers of brightly-coloured gas and dark, obscuring dust. A cluster of small, bright blue stars in the same corner expands out across the image. Many much smaller stars cover the background.]

Tempestuous Young Stars in Orion

Mon, 23 Jan 2023 06:00:00 +0100

The bright variable star V 372 Orionis takes centre stage in this image from the NASA/ESA Hubble Space Telescope, which has also captured a smaller companion star in the upper left of this image. Both stars lie in the Orion Nebula, a colossal region of star formation roughly 1450 light years from Earth.

V 372 Orionis is a particular type of variable star known as an Orion Variable. These young stars experience some tempestuous moods and growing pains, which are visible to astronomers as irregular variations in luminosity. Orion Variables are often associated with diffuse nebulae, and V 372 Orionis is no exception; the patchy gas and dust of the Orion Nebula pervade this scene.

This image overlays data from two of Hubble’s instruments. Data from the Advanced Camera for Surveys and Wide Field Camera 3 at infrared and visible wavelengths were layered to reveal rich details of this corner of the Orion Nebula. Hubble also left its own subtle signature on this astronomical portrait in the form of the diffraction spikes surrounding the bright stars. These prominent artefacts are created by starlight interacting with Hubble’s inner workings, and as a result they reveal hints of Hubble’s structure. The four spikes surrounding the stars in this image are created by four vanes inside Hubble supporting the telescope’s secondary mirror. The diffraction spikes of the NASA/ESA/CSA James Webb Space Telescope, on the other hand, are six-pointed as a result of Webb’s hexagonal mirror segments and 3-legged support structure for the secondary mirror.

[Image description: Two very bright stars with cross-shaped diffraction spikes are prominent: the larger is slightly lower-right of centre, the smaller lies towards the upper-left corner. Small red stars with short diffraction spikes are scattered around them. The background is covered nearly completely by gas: smoky, bright blue gas around the larger star in the centre and lower-right, and wispier red gas elsewhere.]

Festive and Free-Floating

Mon, 19 Dec 2022 06:00:00 +0100

Just in time for the festive season, this new Picture of the Week from the NASA/ESA Hubble Space Telescope features a glistening scene in holiday red. This image shows a small region of the well-known nebula Westerhout 5, which lies about 7000 light-years from Earth. Suffused with bright red light, this luminous image hosts a variety of interesting features, including a free-floating Evaporating Gaseous Globule (frEGG). The frEGG in this image is the small tadpole-shaped dark region in the upper centre-left. This buoyant-looking bubble is lumbered with two rather uninspiring names — [KAG2008] globule 13 and J025838.6+604259.

FrEGGs are a particular class of Evaporating Gaseous Globules (EGGs). Both frEGGs and EGGs are regions of gas that are sufficiently dense that they photoevaporate less easily than the less compact gas surrounding them. Photoevaporation occurs when gas is ionised and dispersed away by an intense source of radiation — typically young, hot stars releasing vast amounts of ultraviolet light. EGGs were only identified fairly recently, most notably at the tips of the Pillars of Creation, which were captured by Hubble in iconic images released in 1995. FrEGGs were classified even more recently, and are distinguished from EGGs by being detached and having a distinct ‘head-tail’ shape. FrEGGs and EGGs are of particular interest because their density makes it more difficult for intense UV radiation, found in regions rich in young stars, to penetrate them. Their relative opacity means that the gas within them is protected from ionisation and photoevaporation. This is thought to be important for the formation of protostars, and it is predicted that many FrEGGs and EGGs will play host to the birth of new stars.

The frEGG in this image is a dark spot in the sea of red light. The red colour is caused by a particular type of light emission known as H-alpha emission. This occurs when a very energetic electron within a hydrogen atom loses a set amount of its energy, causing the electron to become less energetic and this distinctive red light to be released.

[Image description: The background is filled with bright orange-red clouds of varying density. Towards the top-left several large, pale blue stars with prominent cross-shaped spikes are scattered. A small, tadpole-shaped dark patch floats near one of these stars. More of the same dark, dense gas fills the lower-right, resembling black smoke. A bright yellow star and a smaller blue star shine in front of this.]

Cosmic Smokescreen

Mon, 12 Dec 2022 06:00:00 +0100

A portion of the open cluster NGC 6530 appears as a roiling wall of smoke studded with stars in this image from the NASA/ESA Hubble Space Telescope. NGC 6530 is a collection of several thousand stars lying around 4350 light-years from Earth in the constellation Sagittarius. The cluster is set within the larger Lagoon Nebula, a gigantic interstellar cloud of gas and dust. It is the nebula that gives this image its distinctly smokey appearance; clouds of interstellar gas and dust stretch from one side of this image to the other.

Astronomers investigated NGC 6530 using Hubble’s Advanced Camera for Surveys and Wide Field Planetary Camera 2. They scoured the region in the hope of finding new examples of proplyds, a particular class of illuminated protoplanetary discs surrounding newborn stars. The vast majority of proplyds have been found in only one region, the nearby Orion Nebula. This makes understanding their origin and lifetimes in other astronomical environments challenging.

Hubble’s ability to observe at infrared wavelengths — particularly with Wide Field Camera 3— have made it an indispensable tool for understanding starbirth and the origin of exoplanetary systems. In particular, Hubble was crucial to investigations of the proplyds around newly born stars in the Orion Nebula. The new NASA/ESA/CSA James Webb Space Telescope’s unprecedented observational capabilities at infrared wavelengths will complement Hubble observations by allowing astronomers to peer through the dusty envelopes around newly born stars and investigate the faintest, earliest stages of starbirth.

[Image description: Clouds of gas cover the entire view, in a variety of bold colours. In the centre the gas is brighter and very textured, resembling dense smoke. Around the edges it is more sparse and faint. Several small, bright blue stars are scattered over the nebula.]

Pillars of Creation (NIRCam and MIRI Composite Image)

Wed, 30 Nov 2022 18:00:00 +0100

By combining images of the iconic Pillars of Creation from two cameras aboard the NASA/ESA/CSA 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.

Revisit Webb’s near-infrared image and its its mid-infrared image. The Pillars of Creation was made famous by the NASA/ESA Hubble Space Telescope in 1995, and again in 2014.

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 Description: Semi-opaque layers of blue, purple, and grey gas and dust start at the bottom left and rise toward the top right. There are three prominent pillars. The left pillar is the largest and widest. The background is orange near the top and dark blue and purple near the bottom. Some blue and white stars dot the overall scene.]

Clouded Vision

Mon, 14 Nov 2022 06:00:00 +0100

A small, dense cloud of gas and dust called CB 130-3 blots out the centre of this image from the NASA/ESA Hubble Space Telescope. CB 130-3 is an object known as a dense core, a compact agglomeration of gas and dust. This particular dense core is in the constellation Serpens, and seems to billow across a field of background stars.

Dense cores like CB 130-3 are the birthplaces of stars, and as such are of particular interest to astronomers. During the collapse of these cores enough mass can accumulate in one place to reach the temperatures and densities required to ignite hydrogen fusion, marking the birth of a new star. While it may not be obvious from this image, a compact object teetering on the brink of becoming a fully fledged star is embedded deep within CB 130-3.

Astronomers used Hubble’s Wide Field Camera 3 to better understand the environment surrounding this fledgling star. As this image shows, the density of CB 130-3 isn’t constant; the outer edges of the cloud consist of only tenuous wisps, whereas at its core CB 130-3 blots out background light entirely. The gas and dust making up CB 130-3 affect not only the brightness but also the colour of background stars, with stars towards the centre the cloud appearing redder than their counterparts at the outskirts of this image. Astronomers used Hubble to measure this reddening effect and chart out the density of CB 130-3, providing insights into the inner structure of this stellar nursery.

[Image description: The image shows an irregularly-shaped bright orange object composed of dense gas and dust, which appears darker and more compact at the centre. This dense cloud, called CB 130-3, is outlined by thinner gas and dust in light shades of blue. The background shows a multitude of bright stars against a black background.]

Cosmic Keyhole

Mon, 24 Oct 2022 06:00:00 +0200

This peculiar portrait from the NASA/ESA Hubble Space Telescope showcases NGC 1999, a reflection nebula in the constellation Orion. NGC 1999 is around 1350 light-years from Earth and lies near to the Orion Nebula, the closest region of massive star formation to Earth. NGC 1999 itself is a relic of recent star formation — it is composed of detritus left over from the formation of a newborn star.

Just like fog curling around a street lamp, reflection nebulae like NGC 1999 only shine because of the light from an embedded source. In the case of NGC 1999, this source is the aforementioned newborn star V380 Orionis which is visible at the centre of this image. The most notable aspect of NGC 1999’s appearance, however, is the conspicuous hole in its centre, which resembles an inky-black keyhole of cosmic proportions.

This image was created from archival Wide Field Planetary Camera 2 observations that date from shortly after Servicing Mission 3A in 1999. At the time, astronomers believed that the dark patch in NGC 1999 was something called a Bok globule — a dense, cold cloud of gas, molecules, and cosmic dust that blots out background light. However, follow-up observations using a collection of telescopes including ESA’s Herschel Space Observatory revealed that the dark patch is actually an empty region of space. The origin of this unexplained rift in the heart of NGC 1999 remains unknown.

Celestial Cloudscape in the Orion Nebula

Mon, 08 Aug 2022 06:00:00 +0200

This celestial cloudscape from the NASA/ESA Hubble Space Telescope captures the colourful region surrounding the Herbig-Haro object HH 505. Herbig-Haro objects are luminous regions surrounding newborn stars, and are formed when stellar winds or jets of gas spewing from these newborn stars form shockwaves colliding with nearby gas and dust at high speeds. In the case of HH 505, these outflows originate from the star IX Ori, which lies on the outskirts of the Orion Nebula around 1000 light-years from Earth. The outflows themselves are visible as gracefully curving structures at the top and bottom of this image, and are distorted into sinuous curves by their interaction with the large-scale flow of gas and dust from the core of the Orion Nebula.

This observation was captured with Hubble’s Advanced Camera for Surveys (ACS) by astronomers studying the properties of outflows and protoplanetary discs. The Orion Nebula is awash in intense ultraviolet radiation from bright young stars. The shockwaves formed by the outflows are brightly visible to Hubble, but the slower-moving currents of stellar material are also highlighted by this radiation. That allows astronomers to directly observe jets and outflows and learn more about their structures.

The Orion Nebula is a dynamic region of dust and gas where thousands of stars are forming, and is the closest region of massive star formation to Earth. As a result, it is one of the most scrutinised areas of the night sky and has often been a target for Hubble. This observation was also part of a spellbinding Hubble mosaic of the Orion Nebula, which combined 520 ACS images in five different colours to create the sharpest view ever taken of the region.

Aftermath of a Cosmic Cataclysm

Mon, 09 May 2022 06:00:00 +0200

This image from the NASA/ESA Hubble Space Telescope shows the tattered remnant of a supernova — a titanic explosion marking the end of the life of a dying star. This object — known as DEM L249 — is thought to have been created by a Type 1a supernova during the death throes of a white dwarf. While white dwarfs are usually stable, they can slowly accrue matter if they are part of a binary star system. This accretion of matter continues until the white dwarf reaches a critical mass and undergoes a catastrophic supernova explosion, ejecting a vast amount of material into space in the process.

DEM L249 lies in the constellation Mensa and is within the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way only 160 000 light-years from Earth. The LMC is an ideal natural laboratory where astronomers can study the births, lives, and deaths of stars, as this region is nearby, oriented towards Earth, and contains relatively little light-absorbing interstellar dust. The data in this image were gathered by Hubble’s Wide Field Camera 3 instrument, and were obtained during a systematic search of the LMC for the surviving companions of white dwarf stars which have gone supernova.

Screenshot of ESA/Hubble Outreach Image on the ESASky Platform

Wed, 20 Oct 2021 10:00:00 +0200

This image is a screenshot of the ESA/Hubble outreach image of the Crab Nebula in the ESASky platform. The ESA/Hubble and ESASky teams have collaboratively developed an application programming interface that connects the outreach images on the ESA/Hubble website with the ESASky application, which allows users to visualise and download public astronomical data.

Word Bank: Nebula

Mon, 02 Aug 2021 14:34:26 +0200

Word Bank: Planetary Nebula

Mon, 02 Aug 2021 14:34:26 +0200

Cosmic Silver Lining

Mon, 10 May 2021 06:00:00 +0200

This Picture of the Week showcases the emission nebula NGC 2313. The bright star V565 — surrounded by four prominent diffraction spikes — illuminates a silvery, fan-shaped veil of gas and dust, while the right half of this image is obscured by a dense cloud of dust. Nebulae with similar shapes — a star accompanied by a bright fan of gas — were once referred to as cometary nebulae, though the name is no longer used.

The language that astronomers use changes as we become better acquainted with the Universe, and astronomical history is littered with now-obsolete phrases to describe objects in the night sky, such as “spiral nebulae” for spiral galaxies or “inferior planets” for Mercury and Venus.

In the Sky with Diamonds

Mon, 26 Apr 2021 06:00:00 +0200

The interaction of two doomed stars has created this spectacular ring adorned with bright clumps of gas — a diamond necklace of cosmic proportions. Fittingly known as the Necklace Nebula, this planetary nebula is located 15 000 light-years away from Earth in the small, dim constellation of Sagitta (The Arrow).

The Necklace Nebula — which also goes by the less glamorous name of PN G054.2-03.4 — was produced by a pair of tightly orbiting Sun-like stars. Roughly 25 000 years ago, one of the aging stars expanded and engulfed its smaller companion, creating something astronomers call a “common envelope”. The smaller star continued to orbit inside its larger companion, increasing the bloated giant’s rotation rate until large parts of it spun outwards into space. This escaping ring of debris formed the Necklace Nebula, with particularly dense clumps of gas forming the bright “diamonds” around the ring.

The pair of stars which created the Necklace Nebula remain so close together — separated by only a few million kilometres — that they appear as a single bright dot in the centre of this image. Despite their close encounter the stars are still furiously whirling around each other, completing an orbit in just over a day.

The Necklace Nebula was featured in a previously released Hubble image, but now this new image has been created by applying advanced processing techniques, making for a new and improved view of this intriguing object. The composite image includes several exposures from Hubble’s Wide Field Camera 3.

Editor's note (March 2024): The figure "25 000 years ago" was corrected from 10 000 years.

Return to the Veil Nebula

Mon, 29 Mar 2021 06:00:00 +0200

This Picture of the Week revisits the Veil Nebula, a popular subject for Hubble images! This object was featured in a previous Hubble photo release, but now new processing techniques have been applied, bringing out fine details of the nebula’s delicate threads and filaments of ionised gas.

To create this colourful image, observations taken by Hubble's Wide Field Camera 3 instrument through 5 different filters were used. The new post-processing methods have further enhanced details of emissions from doubly ionised oxygen (seen here in blues), ionised hydrogen and ionised nitrogen (seen here in reds).

The Veil Nebula lies around 2100 light-years from Earth in the constellation of Cygnus (The Swan), making it a relatively close neighbour in astronomical terms. Only a small portion of the nebula was captured in this image.

The Veil Nebula is the visible portion of the nearby Cygnus Loop, a supernova remnant formed roughly 10 000 years ago by the death of a massive star. The Veil Nebula’s progenitor star — which was 20 times the mass of the Sun — lived fast and died young, ending its life in a cataclysmic release of energy. Despite this stellar violence, the shockwaves and debris from the supernova sculpted the Veil Nebula’s delicate tracery of ionised gas — creating a scene of surprising astronomical beauty.

Cosmic Ripples — image created with FITS Liberator

Thu, 18 Mar 2021 21:00:00 +0100

This image was “liberated” with the FITS Liberator from the FITS file from the Gemini North telescope. It captures the heart of Messier 1, the Crab Nebula. Formed by a colossal supernova explosion in the year 1054, the Crab Nebula consists of the outer layers of a now-dead massive star strewn across a region of space roughly 10 light-years across. The ripple-like structures visible in this image emanate from the heart of the nebula, where a pulsar — the dense, quickly rotating remains of the supernova’s progenitor star — is unleashing a hail of charged particles into the surrounding gas. The boundary where these charged particles slow down and pile up creates the bright ripples shown here. These ripples then expand outward over the course of months, causing the Crab Nebula to resemble a pool of disturbed water on an unimaginably vast scale.

A Flash of Life

Mon, 15 Mar 2021 06:00:00 +0100

Located around 5000 light-years away in the constellation of Cygnus (The Swan), Abell 78 is an unusual type of planetary nebula.

After exhausting the nuclear fuel in their cores, stars with a mass of around 0.8 to 8 times the mass of our Sun collapse to form dense and hot white dwarf stars. As this process occurs, the dying star will throw off its outer layers of material, forming an elaborate cloud of gas and dust known as a planetary nebula. This phenomenon is not uncommon, and planetary nebulae are a popular focus for astrophotographers because of their often beautiful and complex shapes. However, a few like Abell 78 are the result of a so-called “born again” star.

Although the core of the star has stopped burning hydrogen and helium, a thermonuclear runaway at its surface ejects material at high speeds. This ejecta shocks and sweeps up the material of the old nebula, producing the filaments and irregular shell around the central star seen in this Picture of the Week, which features data from Hubble’s Wide Field Camera 3 and PANSTARSS.

A Cosmic Hourglass

Mon, 08 Feb 2021 06:00:00 +0100

This week’s NASA/ESA Hubble Space Telescope Picture of the Week features an impressive portrait of M1-63, a beautifully captured example of a bipolar planetary nebula located in the constellation of Scutum (the Shield). A nebula like this one is formed when the star at its centre sheds huge quantities of material from its outer layers, leaving behind a spectacular cloud of gas and dust.

It is believed that a binary system of stars at the centre of the bipolar nebula is capable of creating hourglass or butterfly-like shapes like the one in this image. This is because the material from the shedding star is funnelled towards its poles, with the help of the companion, creating the distinctive double-lobed structure seen in nebulae such as M1-63.

An Interstellar Distributor

Mon, 25 Jan 2021 06:00:00 +0100

The lives of planetary nebulae are often chaotic, from the death of their parent star to the scattering of its contents far out into space. Captured here by the NASA/ESA Hubble Space Telescope, ESO 455-10 is one such planetary nebula, located in the constellation of Scorpius (The Scorpion).

The oblate shells of ESO 455-10, previously held tightly together as layers of its central star, not only give this planetary nebula its unique appearance, but also offer information about the nebula. Seen in a field of stars, the distinct asymmetrical arc of material over the north side of the nebula is a clear sign of interactions between ESO 455-10 and the interstellar medium.

The interstellar medium is the material — consisting of matter and radiation — between star systems and galaxies. The star at the centre of ESO 455-10 allows Hubble to see the interaction with the gas and dust of the nebula, the surrounding interstellar medium, and the light from the star itself. Planetary nebulae are thought to be crucial in galactic enrichment as they distribute their elements, particularly the heavier metal elements produced inside a star, into the interstellar medium which will in time form the next generation of stars.

Image Archive: Nebulae

Little Dumbbell Nebula (M76, annotated)

Little Dumbbell Nebula (M76)

Colouring what human eyes can’t see

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Webb’s View of the Molecular Cloud Chameleon I

Hubble celebrates its 33rd anniversary with NGC 1333 (annotated)

Hubble celebrates its 33rd anniversary with NGC 1333

Exploring a Turbulent Tarantula

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Tempestuous Young Stars in Orion

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Festive and Free-Floating

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Cosmic Smokescreen

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Pillars of Creation (NIRCam and MIRI Composite Image)

Clouded Vision

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Cosmic Keyhole

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Celestial Cloudscape in the Orion Nebula

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Aftermath of a Cosmic Cataclysm

Screenshot of ESA/Hubble Outreach Image on the ESASky Platform

Word Bank: Nebula

Word Bank: Planetary Nebula

Cosmic Silver Lining

In the Sky with Diamonds

Return to the Veil Nebula

Cosmic Ripples — image created with FITS Liberator

A Flash of Life

A Cosmic Hourglass

An Interstellar Distributor