Image Archive: Stars

The forest for the trees, the galaxy for the stars

Mon, 05 Feb 2024 06:00:00 +0100

This image shows a densely packed field of stars, laid on top of a background of dust, gas, and light from more distant celestial objects. The stars take up so much of the field of view in this image that it is a little tricky to discern that you are in fact looking at most of a galaxy, known as ESO 245-5. This galaxy is a relatively close neighbour of the Milky Way, lying at the fairly modest distance of 15 million light-years from Earth in the constellation Phoenix.

Another reason that it is perhaps a little tricky to spot that ESO 245-5 is a galaxy is its apparent lack of structure. We frequently enjoy Hubble’s spectacular images of spiral galaxies, which are so interesting to look at in part because of their seemingly extraordinarily ordered arms of stars, gas and dust. ESO 245-5, in contrast, is classified as an IB(s)m type galaxy under the system of galaxy classification known as the De Vaucouleurs system. The IB(s)m designation specifically means that the galaxy is irregular (I), barred (B), has a slight spiral structure ((s)), and is of the Magellanic type (m).

Irregular in this context is quite intuitive: the galaxy does not appear to have a regular, ordered structure. In fact, essentially the entire view here is covered by the stars of this galaxy. The second term means that the galaxy has a barred shape at its centre: this is the dense stretch of stars that crosses through the centre of this image. The third term says that there are hints of a spiral structure, but nothing clear or definitive (hence the ‘s’ is bracketed). Finally, the last term indicates ESO 245-5’s similarity to the Magellanic clouds, the two dwarf galaxies that are close neighbours of the Milky Way.

[Image Description: An irregular galaxy: a cloud of tiny, point-like stars on a dark background. The cloud is densest along a broad, curved band across the centre of the image, coloured a faint blue with glowing purplish patches, and the stars grow more dense out to the edges but don’t fully vanish. A few distant background galaxies appear among the stars as glowing spots.]

Rho Ophiuchi cloud complex

Fri, 15 Dec 2023 10:00:00 +0100

The first anniversary image from the NASA/ESA/CSA James Webb Space Telescope displays star birth like it’s never been seen before, full of detailed, impressionistic texture. The subject is the Rho Ophiuchi cloud complex, the closest star-forming region to Earth. It is a relatively small, quiet stellar nursery, but you’d never know it from Webb’s chaotic close-up. Jets bursting from young stars crisscross the image, impacting the surrounding interstellar gas and lighting up molecular hydrogen, shown in red. Some stars display the telltale shadow of a circumstellar disc, the makings of future planetary systems.

The young stars at the centre of many of these discs are similar in mass to the Sun or smaller. The heftiest in this image is the star S1, which appears amid a glowing cave it is carving out with its stellar winds in the lower half of the image. The lighter-coloured gas surrounding S1 consists of polycyclic aromatic hydrocarbons, a family of carbon-based molecules that are among the most common compounds found in space.

[Image description: Red dual opposing jets coming from young stars fill the darker top half of the image, while a glowing pale-yellow, cave-like structure is bottom centre, tilted toward two o’clock, with a bright star at its centre. The dust of the cave structure becomes wispy toward eight o’clock. Above the arched top of the dust cave three groupings of stars with diffraction spikes are arranged. A dark cloud sits at the top of the arch of the glowing dust cave, with one streamer curling down the right-hand side. The dark shadow of the cloud appears pinched in the centre, with light emerging in a triangle shape above and below the pinch, revealing the presence of a star inside the dark cloud. The image’s largest jets of red material emanate from within this dark cloud, thick and displaying structure like the rough face of a cliff, glowing brighter at the edges. At the top centre of the image, a star displays another, larger pinched dark shadow, this time vertically. To the left of this star is a more wispy, indistinct region.]

Stellar cradle

Mon, 28 Aug 2023 06:00:00 +0200

The protostellar object OH 339.88-1.26, which lies 8 900 light-years from Earth in the constellation Ara, lurks in this dust-filled image from the NASA/ESA Hubble Space Telescope. Winding lanes of dark dust thread through this image, which is also studded with bright stars crowned with criss-crossing diffraction spikes.

The dark vertical streak at the centre of this image hides OH 339.88-1.26, which is an astrophysical maser. A maser — which is an acronym for “microwave amplification by stimulated emission of radiation” — is essentially a laser that produces coherent light at microwave wavelengths. Such objects can occur naturally in astrophysical situations, in environments ranging from the north pole of Jupiter to star-forming regions such as the one pictured here.

This image comes from a set of Hubble observations that peer into the hearts of regions where massive stars are born to constrain the nature of massive protostars and test theories of their formation. Astronomers turned to Hubble’s Wide Field Camera 3 to explore the massive protostar G339.88-1.26, which is estimated to be about 20 times the mass of the Sun and is lurking in the dusty clouds in the center of the image. The Hubble observations were supported by other state-of-the-art observatories including ALMA, the Atacama Large Millimeter/submillimeter Array. ALMA is composed of 66 moveable high-precision antennas which can be arranged over distances of up to 16 kilometres on a plateau perched high in the Chilean Andes. Further data were contributed by the Stratospheric Observatory For Infrared Astronomy (SOFIA), which is a telescope that — until recently — operated out of a converted 747 aircraft.

[Image Description: The field is filled with hundreds of bright stars. They are primarily blue in colour, with scattered smaller stars visible in yellow/orange. The background is dominated by cloudy grey dust, with permeating regions of dark black and orange.]

Hubble sees evaporating planet getting the hiccups

Thu, 27 Jul 2023 16:00:00 +0200

A young planet whirling around a petulant red dwarf star is changing in unpredictable ways orbit-by-orbit. It is so close to its parent star that it experiences a consistent, torrential blast of energy, which evaporates its hydrogen atmosphere — causing it to puff off the planet.

Located 32 light-years from Earth, the parent star AU Microscopii (AU Mic) hosts one of the youngest planetary systems ever observed. The star is less than 100 million years old (a tiny fraction of the age of our Sun, which is 4.6 billion years old). The innermost planet, AU Mic b, has an orbital period of 8.46 days and is just 6 million miles from the star (about 1/10th the planet Mercury's distance from our Sun). The bloated, gaseous world is about four times Earth's diameter.

During one orbit observed with the NASA/ESA Hubble Space Telescope, AU Mic b looked like it wasn't losing any material at all, while an orbit observed with Hubble a year and a half later showed clear signs of atmospheric loss. This extreme variability between orbits shocked astronomers. They were equally puzzled to see, when it was detectable, the planet's atmosphere puffing out in front of the planet, like a headlight on a fast-bound train.

The never-before-seen changes in atmospheric outflow from AU Mic b may indicate swift and extreme variability in the host red dwarf's outbursts. One possible explanation for the missing hydrogen is that a powerful stellar flare, seen seven hours prior, may have photoionized the escaping hydrogen to the point where it became transparent to light. Another explanation is that AU Mic’s stellar wind is shaping the planetary outflow, making it observable at some times and not observable at other times, even causing some of the outflow to "hiccup" ahead of the planet itself.

Hubble follow-up observations of more AU Mic b transits should offer additional clues to the star and planet's odd variability, further testing scientific models of exoplanetary atmospheric escape and evolution.

These results are featured in the paper published on 27th July 2023 in The Astronomical Journal.

[Image description: An illustration depicts a planet, shown in silhouette as a small dark circle, passing in front of a much larger red star on a black starry background. Heat from the star is evaporating the planet’s atmosphere, which stretches out linearly along the planet’s orbital path as dark purple gas.]

Webb Inspects NGC 346 (NIRCam Image)

Mon, 24 Jul 2023 10:00:00 +0200

This image features NGC 346, one of the most dynamic star-forming regions in nearby galaxies, as seen by the NASA/ESA/CSA James Webb Space Telescope.

NCG 346 is located in the Small Magellanic Cloud (SMC), a dwarf galaxy close to our Milky Way.

[Image Description: A star forming region sweeps across the scene, dominated by hues of purple. Tones of yellow outline the region's irregular shape. Many bright stars dominate the scne, as well as countless smaller stars the scatter the image's background.]

Hubble photographs stellar trail of runaway black hole

Thu, 06 Apr 2023 16:00:00 +0200

This archival image from the NASA/ESA Hubble Space Telescope captures a curious linear feature that is so unusual it was first dismissed as an imaging artifact from Hubble’s cameras. But follow-up spectroscopic observations reveal it is a 200 000-light-year-long chain of young blue stars. A supermassive black hole lies at the tip of the bridge at lower left. The black hole was ejected from the galaxy at upper right. It compressed gas in its wake to leave a long trail of young blue stars. Nothing like this has ever been seen before in the Universe. This unusual event happened when the Universe was approximately half its current age.

This intergalactic skyrocket is likely the result of multiple collisions of supermassive black holes. Astronomers suspect the first two galaxies merged perhaps 50 million years ago. That brought together two supermassive black holes at their centers. They whirled around each other as a binary black hole. When the single black hole took off in one direction, the binary black holes shot off in the opposite direction. There is a feature seen on the opposite side of the host galaxy that might be the runaway binary black hole. Circumstantial evidence for this is that there is no sign of an active black hole remaining at the galaxy’s core. The next step is to do follow-up observations with the NASA/ESA/CSA James Webb Space Telescope and NASA’s Chandra X-ray Observatory to confirm the black hole explanation.

These results are featured in the paper published on 6 April 2023 in the Astrophysical Journal Letters.

[Image description: This image shows a wide field of galaxies and stars against a black background. A callout box is used to highlight a specific linear feature that appears as a streak of small blue stars.]

LAWD 37

Thu, 02 Feb 2023 16:00:00 +0100

Hubble has used microlensing to measure the mass of a white dwarf star.

The dwarf, called LAWD 37, is a burned-out star in the centre of this NASA/ESA Hubble Space Telescope image. Though its nuclear fusion furnace has shut down, trapped heat is sizzling on the surface at roughly 100 000 degrees Celsius, causing the stellar remnant to glow fiercely.

The white dwarf has a ‘spike’ because it is so bright that the light ‘bled’ into the Hubble camera’s CCD detector. This interfered with one of the observing dates for measuring that background star’s position on the sky.

[Image Description: A single bright blue star dominates the scene against a dark background with many small stars visible in the distance.]

Stargazing in NGC 6355

Mon, 02 Jan 2023 06:00:00 +0100

The scattered stars of the globular cluster NGC 6355 are strewn across this image from the NASA/ESA Hubble Space Telescope. This globular cluster lies less than 50,000 light-years from Earth in the Ophiuchus constellation. NGC 6355 is a galactic globular cluster that resides in our Milky Way galaxy's inner regions.

Globular clusters are stable, tightly bound clusters of tens of thousands to millions of stars, and can be found in all types of galaxies. Their dense populations of stars and mutual gravitational attraction give these clusters a roughly spherical shape, with a bright concentration of stars surrounded by an increasingly sparse sprinkling of stars. The dense, bright core of NGC 6355 was picked out in crystal-clear detail by Hubble in this image, and is the crowded area of stars towards the centre of this image.

With its vantage point above the distortions of the atmosphere, Hubble has revolutionised the study of globular clusters. It is almost impossible to distinguish the stars in globular clusters from one another with ground-based telescopes, but astronomers have been able to use Hubble to study the constituent stars of globular clusters in detail. This Hubble image of NGC 6355 contains data from both the Advanced Camera for Surveys and Wide Field Camera 3.

[Image description: A dense collection of stars covers the view. Towards the centre the stars become even more dense in a circular region, and also more blue. Around the edges there are some redder foreground stars, and many small stars in the background.]

Multiwavelength View of a Turbulent Stellar Nursery

Mon, 17 Oct 2022 06:00:00 +0200

The lives of newborn stars are tempestuous, as this image of the Herbig–Haro objects HH 1 and HH 2 from the NASA/ESA Hubble Space Telescope depicts. Both objects are in the constellation Orion and lie around 1250 light-years from Earth. HH 1 is the luminous cloud above the bright star in the upper right of this image, and HH 2 is the cloud in the bottom left. While both Herbig–Haro objects are visible, the young star system responsible for their creation is lurking out of sight, swaddled in the thick clouds of dust at the centre of this image. However, an outflow of gas from one of these stars can be seen streaming out from the central dark cloud as a bright jet. Meanwhile, the bright star between that jet and the HH 1 cloud was once thought to be the source of these jets, but it is now known to be an unrelated double star that formed nearby.

Herbig–Haro objects are glowing clumps found around some newborn stars, and are created when jets of gas thrown outwards from these young stars collide with surrounding gas and dust at incredibly high speeds. In 2002 Hubble observations revealed that parts of HH 1 are moving at more than 400 kilometres per second!

This scene from a turbulent stellar nursery was captured with Hubble’s Wide Field Camera 3 using 11 different filters at infrared, visible, and ultraviolet wavelengths. Each of these filters is sensitive to just a small slice of the electromagnetic spectrum, and they allow astronomers to pinpoint interesting processes that emit light at specific wavelengths.

In the case of HH 1/2, two groups of astronomers requested Hubble observations for two different studies. The first delved into the structure and motion of the Herbig–Haro objects visible in this image, giving astronomers a better understanding of the physical processes occurring when outflows from young stars collide with surrounding gas and dust. The second study instead investigated the outflows themselves to lay the groundwork for future observations with the NASA/ESA/CSA James Webb Space Telescope. Webb, with its ability to peer past the clouds of dust enveloping young stars, will revolutionise the study of outflows from young stars.

[Image description: Two wispy, gaseous clouds occupy the corners of this image, HH 1 in the upper right, and HH 2 in the lower left. Both are light blue and surrounded by dimmer multi-coloured clouds, while the background is dark black due to dense gas. A very bright orange star lies just to the lower left of HH 1, and beyond that star is a narrow jet, emerging from the dark centre of the field.]

Starstruck in Terzan 4

Mon, 12 Sep 2022 06:00:00 +0200

A glittering multitude of stars in the globular cluster Terzan 4 fill this image from the NASA/ESA Hubble Space Telescope. Globular clusters are collections of stars bound together by their mutual gravitational attraction, and can contain millions of individual stars. As this image shows, the heart of a globular cluster such as Terzan 4 is a densely packed, crowded field of stars — which makes for spectacular images!

The launch of Hubble in 1990 revolutionised the study of globular clusters. The individual stars in these dense crowds are almost impossible to distinguish from one another with ground-based telescopes, but can be picked apart using space telescopes. Astronomers have taken advantage of Hubble’s crystal-clear vision to study the stars making up globular clusters, as well as how these systems change over time.

This particular observation comes from astronomers using Hubble to explore Terzan 4 and other globular clusters to understand the shape, density, age, and structure of globular clusters close to the centre of the Milky Way. Unlike globular clusters elsewhere in the sky, these globular clusters have evaded detailed observation because of the clouds of gas and dust swirling around the galactic core. These clouds blot out starlight in a process that astronomers refer to as ‘extinction’, and complicate astronomical observations.

Astronomers took advantage of the sensitivity of two of Hubble’s instruments — the Advanced Camera for Surveys and Wide Field Camera 3 — to overcome the impact of extinction on Terzan 4. By combining Hubble imagery with sophisticated data processing, astronomers were able to determine the ages of galactic globular clusters to within a billion years — a relatively accurate measurement in astronomical terms!

NGC 346

Thu, 08 Sep 2022 16:00:00 +0200

Astronomers have been bemused to find young stars spiralling into the centre of a massive cluster of stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way. The outer arm of the spiral in this huge, oddly shaped stellar nursery — called NGC 346 — may be feeding star formation in a river-like motion of gas and stars. This is an efficient way to fuel star birth, researchers say.

Spiralling Stars in NGC 346

Thu, 08 Sep 2022 16:00:00 +0200

The red spiral superimposed on NGC 346 traces the movement of stars and gas toward the center. Scientists say this spiraling motion is the most efficient way to feed star formation from the outside toward the center of the cluster.

Hubble Sees Red Supergiant Star Betelgeuse Slowly Recovering After Blowing Its Top

Thu, 11 Aug 2022 16:00:00 +0200

This illustration plots changes in the brightness of the red supergiant star Betelgeuse, following the titanic mass ejection of a large piece of its visible surface. The escaping material cooled to form a cloud of dust that temporarily made the star look dimmer, as seen from Earth. This unprecedented stellar convulsion disrupted the monster star’s 400-day-long oscillation period that astronomers had measured for more than 200 years. The interior may now be jiggling like a plate of gelatin dessert.

The star Betelgeuse appears as a brilliant, ruby-red, twinkling spot of light in the upper right shoulder of the winter constellation Orion the Hunter. This ageing star is classified as a supergiant because it has swelled up to an astonishing diameter of approximately 1 billion miles. If placed at the centre of our Solar System it would reach out to the orbit of Jupiter.

The star's ultimate fate is to explode as a supernova. When that eventually happens it will be briefly visible in the daytime sky from Earth. But there are a lot of fireworks going on now before the final detonation. Astronomers using Hubble and other telescopes have deduced that the star blew off a huge piece of its visible surface in 2019. This has never before been seen on a star. Our Sun routinely goes through mass ejections of its outer atmosphere, the corona. But those events are orders of magnitude weaker than what was seen on Betelgeuse.

The first clue came when the star mysteriously darkened in late 2019. An immense cloud of obscuring dust formed from the ejected surface as it cooled. Astronomers have now pieced together a scenario for the upheaval. And the star is still slowly recovering; the photosphere is rebuilding itself. And the interior is reverberating like a bell that has been hit with a sledgehammer, disrupting the star’s normal cycle. This doesn't mean the monster star is going to explode any time soon, but the late-life convulsions may continue to amaze astronomers.

Hubble Spies a Glittering Gathering of Stars

Mon, 16 May 2022 06:00:00 +0200

This glittering gathering of stars is the globular cluster NGC 6558, and it was captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys. NGC 6558 is closer to the centre of the Milky Way than Earth is, and lies about 23 000 light years away in the constellation Sagittarius.

Globular clusters like NGC 6558 are tightly bound collections of tens of thousands to millions of stars, and they can be found in a wide range of galaxies. As this observation shows, the stars in globular clusters can be densely packed; this image is thronged with stars in a rich variety of hues. Some of the brightest inhabitants of this globular cluster are surrounded by prominent diffraction spikes, which are imaging artefacts caused by starlight interacting with the inner workings of Hubble.

Globular clusters equip astronomers with interesting natural laboratories in which to test their theories, as all the stars in a globular cluster formed at approximately the same time with similar initial composition. These stellar clusters therefore provide unique insights into how different stars evolve under similar conditions. This image comes from a set of observations investigating globular clusters in the inner Milky Way. Astronomers were interested in studying these globular clusters to gain greater insight into how globular clusters in the inner Milky Way form and evolve.

Wide-Field View of the Hickson Compact Group 40

Tue, 19 Apr 2022 16:00:00 +0200

This image shows a wide-field view centred on the Hickson Compact Group 40.

Crop of the GNz7q in the Hubble GOODS-North field

Wed, 13 Apr 2022 17:00:00 +0200

An international team of astronomers using archival data from the NASA/ESA Hubble Space Telescope and other space- and ground-based observatories have discovered a unique object in the distant, early Universe that is a crucial link between young star-forming galaxies and the earliest supermassive black holes. This object is the first of its kind to be discovered so early in the Universe’s history, and had been lurking unnoticed in one of the best-studied areas of the night sky.

The object, which is referred to as GNz7q, is shown here in the centre of the image of the Hubble GOODS-North field.

Hubble Finds the Most Distant Star Ever Seen

Wed, 30 Mar 2022 17:00:00 +0200

With this observation, the NASA/ESA Hubble Space Telescope has established an extraordinary new benchmark: detecting the light of a star that existed within the first billion years after the Universe’s birth in the Big Bang (at a redshift of 6.2) — the most distant individual star ever seen. This sets up a major target for the NASA/ESA/CSA James Webb Space Telescope in its first year.

Hubble Snaps a Jet Set

Mon, 07 Mar 2022 06:00:00 +0100

An energetic outburst from an infant star streaks across this image from the NASA/ESA Hubble Space Telescope. This stellar tantrum — produced by an extremely young star in the earliest phase of formation — consists of an incandescent jet of gas travelling at supersonic speeds. As the jet collides with material surrounding the still-forming star, the shock heats this material and causes it to glow. The result is the colourfully wispy structures, which astronomers refer to as Herbig–Haro objects, billowing across the lower left of this image.

Herbig–Haro objects are seen to evolve and change significantly over just a few years. This particular object, called HH34, was previously captured by Hubble between 1994 and 2007, and again in glorious detail in 2015. HH34 resides approximately 1250 light-years from Earth in the Orion Nebula, a large region of star formation visible to the unaided eye. The Orion Nebula is one of the closest sites of widespread star formation to Earth, and as such has been pored over by astronomers in search of insights into how stars and planetary systems are born.

The data in this image are from a set of Hubble observations of four nearby bright jets with the Wide Field Camera 3 taken to help pave the way for future science with the NASA/ESA/CSA James Webb Space Telescope. Webb — which will observe at predominantly infrared wavelengths — will be able to peer into the dusty envelopes surrounding still-forming protostars, revolutionising the study of jets from these young stars. Hubble’s high-resolution images of HH34 and other jets will help astronomers interpret future observations with Webb.

One Galaxy, Three Times

Mon, 22 Nov 2021 06:00:00 +0100

This star- and galaxy-studded image was captured by Hubble’s Wide Field Camera 3 (WFC3), using data that were collected for scientific purposes. The object of interest was a galaxy that is visible in the bottom right corner of the image, named SGAS 0033+02. What makes this particular galaxy interesting is a little unusual — it appears not just once in this image, but three times. The thrice-visible galaxy is a little difficult to spot: it appears once as a curved arc and twice more as small round dots around the star.

SGAS 0033+02’s multiple appearances in the same image are not the result of an error, but instead are due to a remarkable phenomenon known as gravitational lensing. Gravitational lensing occurs when the light from a very distant galaxy — such as SGAS 0033+02 — is curved (or ‘lensed’) by the gravity of a massive celestial object that lies in the foreground, between the distant galaxy and the Earth. SGAS 0033+02 was discovered by its namesake, the Sloan Giant Arcs Survey (SGAS), which aimed to identify highly magnified galaxies that were gravitationally lensed by foreground galaxy clusters. SGAS 0033+02 is of special interest because of its highly unusual proximity in the sky to a very bright star. The star is useful, because it can be used to calibrate and correct observations of the lensed SGAS 0033+02.

CW Leonis

Thu, 28 Oct 2021 17:00:00 +0200

The NASA/ESA Hubble Space Telescope celebrates Halloween this year with a striking observation of the carbon star CW Leonis, which resembles a baleful orange eye glaring from behind a shroud of smoke.

CW Leonis glowers from deep within a thick shroud of dust in this image from the NASA/ESA Hubble Space Telescope. Lying roughly 400 light-years from Earth in the constellation Leo, CW Leonis is a carbon star — a luminous type of red giant star with a carbon-rich atmosphere. The dense clouds of sooty gas and dust engulfing this dying star were created as the outer layers of CW Leonis itself were thrown out into the void.

Wide-Field View of CW Leonis

Thu, 28 Oct 2021 17:00:00 +0200

This image shows a wide field view of CW Leonis.

A Closer Look at Hubble’s 31st Anniversary Snapshot

Mon, 13 Sep 2021 06:00:00 +0200

This comparison view shows puffing dust bubbles and an erupting gas shell — the final acts of a monster star.You can explore the detail of the nebula surrounding the star AG Carinae by using the slider tool on the image above.

This Picture of the Week showcases new views of the dual nature of the star AG Carinae, which was the target of the NASA/ESA Hubble Space Telescope’s 31st anniversary image in April 2020. This new perspective was developed thanks to Hubble’s observations of the star in 2020 and 2014, along with others captured by the telescope’s WFPC2 instrument in 1994. You can compare these two new versions of AG Carinae by using the slider tool on the image above.

The first image showcases the details of the ionised hydrogen and ionised nitrogen emissions from the nebula (seen here in red). In the second image, the blue demonstrates the contrasting appearance of the distribution of the dust that shines of reflected stellar light. Astronomers believe that the dust bubbles and filaments formed within and were shaped by powerful stellar wind .

This giant star is waging a tug-of-war between gravity and radiation to avoid self-destruction. The star is surrounded by an expanding shell of gas and dust — a nebula — that is shaped by the powerful winds emanating from the star. The nebula is about five light-years wide, equal to the distance from here to our nearest star, Alpha Centauri.

AG Carinae is formally classified as a Luminous Blue Variable because it is hot (blue), very luminous, and variable. Such stars are quite rare because there are not many stars that are so massive. Luminous Blue Variable stars continuously lose mass in the final stages of their life, during which a significant amount of stellar material is ejected into the surrounding interstellar space, until enough mass has been lost that the star has reached a stable state.

AG Carinae is surrounded by a spectacular nebula, formed by material ejected by the star during several of its past outbursts. The nebula is approximately 10 000 years old, and the observed velocity of the gas is approximately 70 kilometres per second. While this nebula looks like a ring, it is in fact a hollow shell rich in gas and dust, the centre of which has been cleared by the powerful stellar wind travelling at roughly 200 kilometres per second. The gas (composed mostly of ionised hydrogen and nitrogen) is visible to us in these images as a thick bright red ring, which appears doubled in places — possibly the result of several outbursts colliding into each other. The dust, here visible in blue, has formed in clumps, bubbles and filaments that are shaped by the stellar wind.

Scientists who observed the star and its surrounding nebula note that the ring is not perfectly spherical; it appears to have a bipolar symmetry, indicating that the mechanism producing the outburst may have been caused by the presence of a disc in the centre, or that the star is not alone but might have a companion (known as a binary star). An alternative and simpler theory is that the star rotates very fast (as many massive stars have been found to do).

A Closer Look at Hubble’s 31st Anniversary Snapshot

Mon, 13 Sep 2021 06:00:00 +0200

Word Bank: Neutron Star

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

Word Bank: Red Giant

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

Image Archive: Stars

The forest for the trees, the galaxy for the stars

Links

Rho Ophiuchi cloud complex

Stellar cradle

Links

Hubble sees evaporating planet getting the hiccups

Webb Inspects NGC 346 (NIRCam Image)

Hubble photographs stellar trail of runaway black hole

LAWD 37

Stargazing in NGC 6355

Links

Multiwavelength View of a Turbulent Stellar Nursery

Links

Starstruck in Terzan 4

NGC 346

Spiralling Stars in NGC 346

Hubble Sees Red Supergiant Star Betelgeuse Slowly Recovering After Blowing Its Top

Hubble Spies a Glittering Gathering of Stars

Links

Wide-Field View of the Hickson Compact Group 40

Crop of the GNz7q in the Hubble GOODS-North field

Hubble Finds the Most Distant Star Ever Seen

Hubble Snaps a Jet Set

One Galaxy, Three Times

Links

CW Leonis

Wide-Field View of CW Leonis

A Closer Look at Hubble’s 31st Anniversary Snapshot

A Closer Look at Hubble’s 31st Anniversary Snapshot

Word Bank: Neutron Star

Word Bank: Red Giant