Image Archive: Cosmology

A Spiral Amongst Thousands

Tue, 02 May 2023 10:00:00 +0200

A crowded field of galaxies throngs this ESA/Webb Picture of the Month from the NASA/ESA/CSA James Webb Space Telescope, along with bright stars crowned with Webb’s signature six-pointed diffraction spikes. The large spiral galaxy at the base of this image is accompanied by a profusion of smaller, more distant galaxies which range from fully-fledged spirals to mere bright smudges. Named LEDA 2046648, it is situated a little over a billion light-years from Earth, in the constellation Hercules.

One of Webb’s principle science goals is to observe distant galaxies in the early universe to understand the details of their formation, evolution, and composition. Webb’s keen infrared vision helps the telescope peer back in time, as the light from these distant galaxies is redshifted towards infrared wavelengths. Comparing these systems with galaxies in the local Universe will help astronomers understand how galaxies grew to form the structure we see today. Webb will also probe the chemical composition of thousands of galaxies to shed light on how heavy elements were formed and built up as galaxies evolved.

To take full advantage of Webb’s potential for galaxy archeology, astronomers and engineers must first calibrate the telescope’s instruments and systems. Each of Webb’s instruments contains a labyrinthine array of mirrors and other optical elements that redirect and focus starlight gathered by Webb’s main mirror. This particular observation was part of the commissioning campaign for Webb’s Near-InfraRed Imager and Slitless Spectrograph (NIRISS). As well as performing science in its own right, NIRISS supports parallel observations with Webb’s Near-InfraRed Camera (NIRCam). NIRCam captured this galaxy-studded image while NIRISS was observing the white dwarf WD1657+343, a well-studied star. This allows astronomers to interpret and compare data from the two different instruments, and to characterise the performance of NIRISS.

[Image description: Many stars and galaxies lie on a dark background, in a variety of colours but mostly shades of orange. Some galaxies are large enough to make out spiral arms. Along the bottom of the frame is a large, detailed spiral galaxy seen at an oblique angle, with another galaxy about one-quarter the size just beneath it. Both have a brightly glowing core, and areas of star formation which light up their spiral arms.]

Hubble Uses Microlensing To Measure the Mass of a White Dwarf

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

This graphic shows how microlensing was used to measure the mass of a white dwarf star.

The dwarf, called LAWD 37, is a burned-out star in the centre of this 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 inset box plots how the dwarf passed in front of a background star in 2019. The wavy blue line traces the dwarf’s apparent motion across the sky as seen from Earth. Though the dwarf is following a straight trajectory, the motion of Earth as it orbits the Sun imparts an apparent sinusoidal offset due to parallax. (The star is only 15 light-years away. Therefore, it is moving at a faster rate against the stellar background.)

As it passed by the fainter background star, the dwarf’s gravitational field warped space (as Einstein’s general theory of relativity predicted a century ago). And this deflection was precisely measured by Hubble’s extraordinary resolution. The amount of deflection yields a mass for the white dwarf of 56 percent our Sun’s mass and provides insights into theories of the structure and composition of white dwarfs. This is the first time astronomers have directly measured the mass of a single, isolated star other than our Sun.

Hubble Measures Deflection of Starlight by a Foreground Object

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

This illustration shows how the gravity of a foreground white dwarf star warps space and bends the light from a distant star behind it. Astronomers using the NASA/ESA Hubble Space Telescope have for the first time directly measured the mass of a single, isolated star other than our Sun — thanks to this optical trick of nature. The target was a white dwarf — the surviving core of a burned-out Sun-like star. The greater the temporary, infinitesimal deflection of the background star’s image, the more massive the foreground star is. Researchers found that the dwarf is 56 percent the mass of our Sun.

This effect, called gravitational lensing, was predicted as a consequence of Einstein’s general theory of relativity from a century ago. Observations of a solar eclipse in 1919 provided the first experimental proof for general relativity. But Einstein didn’t think the same experiment could be done for stars beyond our Sun because of the extraordinary precision required.

Hubble Uses Microlensing To Measure the Mass of a White Dwarf (Clean)

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

This graphic shows how microlensing was used to measure the mass of a white dwarf star.

The inset boxes at right plot how the dwarf passed in front of a background star in 2019. The wavy blue line traces the dwarf’s apparent motion across the sky as seen from Earth. Though the dwarf is following a straight trajectory, the motion of Earth as it orbits the Sun imparts an apparent sinusoidal offset due to parallax. (The star is only 15 light-years away, and therefore is moving at a faster rate against the stellar background.)

The amount of deflection yields a mass for the white dwarf of 56 percent our Sun’s mass, and this provides insights into theories of the structure and composition of white dwarfs. This is the first time that astronomers have directly measured the mass of a single, isolated star other than our Sun.

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.

Hubble Uses Microlensing To Measure the Mass of a White Dwarf (Annotated)

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

This graphic shows how microlensing was used to measure the mass of a white dwarf star.

The compass graphic points to the object’s orientation on the celestial sphere. North points to the north celestial pole which is not a fixed point in the sky, but it currently lies near the star Polaris, in the circumpolar constellation Ursa Minor. Celestial coordinates are analogous to a terrestrial map, though east and west are transposed because we are looking up rather than down.

Hubble Finds Hungry Black Hole Twisting Captured Star Into Donut Shape

Thu, 12 Jan 2023 23:15:00 +0100

This sequence of artist illustrations shows how a black hole can devour a bypassing star:

A normal star passes near a supermassive black hole in the center of a galaxy.
The star’s outer gasses are pulled into the black hole’s gravitational field.
The star is shredded as tidal forces pull it apart.
The stellar remnants are pulled into a donut-shaped ring around the black hole, and will eventually fall into the black hole, unleashing a tremendous amount of light and high-energy radiation.

Astronomers using the NASA/ESA Hubble Space Telescope have recorded a star’s final moments in detail as it gets gobbled up by a black hole.

These are termed “tidal disruption events.” But the wording belies the complex, raw violence of a black hole encounter. There is a balance between the black hole’s gravity pulling in star stuff, and radiation blowing material out. In other words, black holes are messy eaters. Astronomers are using Hubble to find out the details of what happens when a wayward star plunges into the gravitational abyss.

Hubble can’t photograph the AT2022dsb tidal event’s mayhem up close, since the munched-up star is nearly 300 million light-years away at the core of the galaxy ESO 583-G004. But astronomers used Hubble’s powerful ultraviolet sensitivity to study the light from the shredded star, which includes hydrogen, carbon, and more. The spectroscopy provides forensic clues to the black hole homicide.

For any given galaxy with a quiescent supermassive black hole at the center, it’s estimated that the stellar shredding happens only a few times in every 100,000 years.

This AT2022dsb stellar snacking event was first caught on 1 March 2022 by the All-Sky Automated Survey for Supernovae (ASAS-SN or “Assassin”), a network of ground-based telescopes that surveys the extragalactic sky roughly once a week for violent, variable, and transient events that are shaping our universe. This energetic collision was close enough to Earth and bright enough for the Hubble astronomers to do ultraviolet spectroscopy over a longer than normal period of time. The Hubble spectroscopic data are interpreted as coming from a very bright, hot, donut-shaped area of gas that was once the star. This area, known as a torus, is the size of the solar system and is swirling around a black hole in the middle.

The results were reported at the 241st meeting of the American Astronomical Society in Seattle, Washington.

[Image Description: Four-panel illustration titled “Black Hole Devours Bypassing Star” showing four stages of a star being shredded by a black hole.]

Revisiting a Celestial Fireworks Display

Mon, 28 Nov 2022 06:00:00 +0100

Shreds of the luridly coloured supernova remnant DEM L 190 seem to billow across the screen in this image from the NASA/ESA Hubble Space Telescope. The delicate sheets and intricate filaments are debris from the cataclysmic death of a massive star that once lived in the Large Magellanic Cloud, a small satellite galaxy of the Milky Way. DEM L 190 — also known as LMC N49 — is the brightest supernova remnant in the Large Magellanic Cloud and lies approximately 160 000 light-years away from Earth in the constellation Dorado.

This striking image was created with data from two different astronomical investigations, using one of Hubble’s retired instruments, the Wide Field Planetary Camera 2 (WFPC2). This instrument has since been replaced by the more powerful Wide Field Camera 3, but during its operational lifetime it contributed to cutting-edge science and produced a series of stunning public outreach images. The first of the two WFPC2 investigations used DEM L 190 as a natural laboratory in which to study the interaction of supernova remnants and the interstellar medium, the tenuous mixture of gas and dust that lies between stars. In the second project, astronomers turned to Hubble to pinpoint the origin of a Soft Gamma-ray Repeater, an enigmatic object lurking in DEM L 190 which repeatedly emits high-energy bursts of gamma rays.

This is not the first image of DEM L 190 to be released to the public — a previous Hubble portrait of this supernova remnant was published in 2003. This new image incorporates additional data and improved image processing techniques, making this spectacular celestial fireworks display even more striking!

[Image description: A supernova remnant, in the shape of a flame, occupies the centre and top. It is made of many long strands and thin layers of gas, that brightly glow orange and blue. Faint gas clouds outline its edges. It is surrounded by several scattered blue and red stars, and the background is black and filled with small red stars.]

Multiple Light Paths of Single, Lensed Supernova

Wed, 09 Nov 2022 17:00:00 +0100

Through the phenomenon of gravitational lensing, the NASA/ESA Hubble Space Telescope captured three different moments in the explosion of a very far-off supernova—all in one picture! In this case, the immense gravity of the galaxy cluster Abell 370 acted as a cosmic lens, bending and magnifying the light from the more distant supernova located behind the cluster. The warping also produced multiple images of the explosion over different time periods that all arrived at Hubble simultaneously.

The top box shows a portion of Abell 370. The box-within-the-box marks the area where the distant supernova was multiply lensed. The bottom image is a magnified version of this area with the light paths marked for the three images of the supernova. The right side of the bottom image shows the distant galaxy in which the supernova exploded. The lines show how the light travelled through the gravitational lens, with some of the light taking longer routes across "valleys" of warped space. The warping produced three images of the explosion over different time periods that all arrived at Hubble simultaneously.

Three Faces of Evolving Supernova (Clean)

Wed, 09 Nov 2022 17:00:00 +0100

As a result of a phenomenon called gravitational lensing, three different moments in a far-off supernova explosion were captured in a single snapshot by the NASA/ESA Hubble Space Telescope. The light from the supernova, which was located behind the galaxy cluster Abell 370, was multiply lensed by the cluster’s immense gravity. This light took three different paths through the cosmic lens of the massive cluster. The three paths were three different lengths, so when the light arrived at Hubble (on the same day in December 2010), the supernova appeared at three different stages of evolution.

The left panel shows the portion of Abell 370 where the multiple images of the supernova appeared. In the top centre is a composite of Hubble observations from 2011 to 2016, showing the locations of the multiply imaged host galaxy after the supernova faded. The top right panel shows a Hubble picture from December 2010, illustrating the three images of the host galaxy and the supernova at different phases in its evolution. The panel in the bottom centre subtracts the image in the panel in the top right from that in the top centre, and shows three different faces of the evolving supernova. Using a similar image subtraction process for multiple filters of data, the panel in the bottom right shows the different colours of the cooling supernova at three different stages in its evolution.

[Image Description: Five panels are shown. The larger left panel shows the portion of the galaxy cluster Abell 370 where the multiple images of the supernova appeared, which is shown in four panels on the right. These panels show the locations of the multiply imaged host galaxy after a supernova faded and the different colours of the cooling supernova at three different stages in its evolution.]

Three Faces of Evolving Supernova (Annotated)

Fri, 04 Nov 2022 15:38:23 +0100

As a result of a phenomenon called gravitational lensing, three different moments in a far-off supernova explosion were captured in a single snapshot by the NASA/ESA Hubble Space Telescope. The light from the supernova, which was located behind the galaxy cluster Abell 370, was multiply lensed by the cluster’s immense gravity. This light took three different paths through the cosmic lens of the massive cluster. The three paths were of three different lengths, so when the light arrived at Hubble (on the same day in December 2010), the supernova appeared at three different stages of evolution.

The left panel shows the portion of Abell 370 where the multiple images of the supernova appeared. Panel A, a composite of Hubble observations from 2011 to 2016, shows the locations of the multiply imaged host galaxy after the supernova faded. Panel B, a Hubble picture from December 2010, shows the three images of the host galaxy and the supernova at different phases in its evolution. Panel C, which subtracts the image in Panel B from that in Panel A, shows three different faces of the evolving supernova. Using a similar image subtraction process for multiple filters of data, Panel D shows the different colours of the cooling supernova at three different stages in its evolution.

[Image Description: Five panels are shown. The larger left panel shows the portion of the galaxy cluster Abell 370 where the multiple images of the supernova appeared, which is shown in four panels labelled A through D on the right. These panels show the locations of the multiply imaged host galaxy after a supernova faded and the different colours of the cooling supernova at three different stages in its evolution.]

Twin Tail Revealed in New Hubble Image of Didymos-Dimorphos System Following DART Impact

Thu, 20 Oct 2022 17:00:00 +0200

Two tails of dust ejected from the Didymos-Dimorphos asteroid system are seen in new images from the NASA/ESA Hubble Space Telescope, documenting the lingering aftermath of the NASA’s Double Asteroid Redirection Test (DART) impact on 27 September 2022 at 01:14 CEST. Current data show that DART shortened Dimorphos’ original 11 hour and 55 minute orbit around Didymos by about 32 minutes.

Repeated observations from Hubble over the last several weeks have allowed scientists to present a more complete picture of how the system’s debris cloud has evolved over time. The observations show that the ejected material, or “ejecta,” has expanded and faded in brightness as time went on after impact, largely as expected. The twin tail is an unexpected development, although similar behavior is commonly seen in comets and active asteroids. The Hubble observations provide the best-quality image of the double-tail to date.

Following impact, Hubble made 18 observations of the system. Imagery indicates the second tail formed between 2-8 October 2022.

In this image, DART impacted the Didymos-Dimorphos system from the 10 o’clock direction.

The relationship between the comet-like tail and other ejecta features seen at various times in images from Hubble and other telescopes is still unclear, and is something the Investigation Team is currently working to understand. The northern tail is newly developed. In the coming months, scientists will be taking a closer look at the data from Hubble to determine how the second tail developed. There are a number of possible scenarios the team will investigate.

[Image Description: A bright blue spot is at the center of the image, which has a black background. The center bright spot has 3 diffraction spikes extending from its core at the 1 o’clock, 7 o’clock, and 10 o’clock positions. Two tails of ejecta that appear as white streams of material extend out from the center at the 2 o’clock and 3 o’clock positions.]

Webb Captures DART Debris (27 September 2022)

Thu, 29 Sep 2022 15:30:00 +0200

This image from the NASA/ESA/CSA James Webb Space Telescope’s Near-Infrared Camera (NIRCam) instrument shows Dimorphos, the asteroid moonlet in the double-asteroid system of Didymos, about 4 hours after NASA’s Double Asteroid Redirection Test (DART) made impact. A tight, compact core and plumes of material appearing as wisps streaming away from the centre of where the impact took place, are visible in the image. Those sharp points are Webb’s distinctive eight diffraction spikes, an artefact of the telescope’s structure.

These observations, when combined with data from the NASA/ESA Hubble Space Telescope, will allow scientists to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, and how fast it was ejected.

In the coming months, scientists will use Webb’s Mid-Infrared Instrument (MIRI) and Near-Infrared Spectrograph (NIRSpec) to observe Dimorphos further. Spectroscopic data will also provide researchers with insight into the asteroid’s chemical composition.

The observations shown here were conducted in the filter F070W (0.7 microns) and assigned the colour red.

An Enigmatic Astronomical Explosion

Mon, 19 Sep 2022 06:00:00 +0200

A bright young star is surrounded by a shroud of thick gas and dust in this image from the NASA/ESA Hubble Space Telescope. Hubble’s Wide Field Camera 3 inspected a young stellar object, over 9000 light years away in the constellation Taurus, to help astronomers understand the earliest stages in the lives of massive stars. This object — which is known to astronomers as IRAS 05506+2414 — is thought to be an example of an explosive event caused by the disruption of a massive young star system. If so, it would only be the second such example known.

Usually the swirling discs of material surrounding a young star are funnelled into twin outflows of gas and dust from the star. In the case of IRAS 05506+2414, however, a fan-like spray of material travelling at velocities of up to 350 kilometres per second is spreading outwards from the centre of this image.

Astronomers turned to Hubble’s Wide Field Camera 3 to measure the distance to IRAS 05506+2414. While it is possible to measure the velocity of material speeding outwards from the star, astronomers cannot tell how far from Earth the star actually is from a single observation. However, by measuring the distance that the outflow travels between successive images, they will be able to infer the distance to IRAS 05506+2414. This will allow astronomers to determine how bright the star is and how much energy it is emitting, and hence to estimate its mass — all vital information that will help to understand the origin of this bright young star’s unusual outflow.

Star-Studded Skyfield

Mon, 01 Aug 2022 06:00:00 +0200

This star-studded image from the NASA/ESA Hubble Space Telescope shows the heart of the globular cluster NGC 6638 in the constellation Sagittarius. The star-strewn observation highlights the density of stars at the heart of globular clusters, which are stable, tightly bound clusters of tens of thousands to millions of stars. To capture the data in this image, Hubble used two of its cutting-edge astronomical instruments: Wide Field Camera 3 and the Advanced Camera for Surveys.

Hubble revolutionised the study of globular clusters, as it is almost impossible to clearly distinguish the stars in globular clusters with ground-based telescopes. The blurring caused by Earth’s atmosphere makes it impossible to tell one star from another, but from Hubble’s location in low Earth orbit the atmosphere no longer poses a problem. As a result, Hubble has been used to study what kind of stars globular clusters are made up of, how they evolve, and the role of gravity in these dense systems.

The NASA/ESA/CSA James Webb Space Telescope will further our understanding of globular clusters by peering into those globular clusters that are currently obscured by dust. Webb will predominantly observe at infrared wavelengths, which are less affected by the gas and dust surrounding newborn stars. This will allow astronomers to inspect star clusters that are freshly formed, providing insights into stellar populations before they have a chance to evolve.

Microlensing Black Hole

Fri, 10 Jun 2022 16:00:00 +0200

The star-filled sky in this NASA/ESA Hubble Space Telescope photo lies in the direction of the Galactic centre. The light from stars is monitored to see if any change in their apparent brightness is caused by a foreground object drifting in front of them. The warping of space by the interloper would momentarily brighten the appearance of a background star, an effect called gravitational lensing. One such event is shown in the four close-up frames at the bottom. The arrow points to a star that momentarily brightened, as first captured by Hubble in August 2011. This was caused by a foreground black hole drifting in front of the star, along our line of sight. The star brightened and then subsequently faded back to its normal brightness as the black hole passed by. Because a black hole doesn't emit or reflect light, it cannot be directly observed. But its unique thumbprint on the fabric of space can be measured through these so-called microlensing events. Though an estimated 100 million isolated black holes roam our galaxy, finding the telltale signature of one is a needle-in-a-haystack search for Hubble astronomers.

Diagram of the Atmospheres of Uranus and Neptune

Tue, 31 May 2022 17:00:00 +0200

This diagram shows three layers of aerosols in the atmospheres of Uranus and Neptune, as modelled by a team of scientists. The height scale on the diagram represents the pressure above 10 bar.

The deepest layer (the Aerosol-1 layer) is thick and composed of a mixture of hydrogen sulphide ice and particles produced by the interaction of the planets’ atmospheres with sunlight.

The key layer that affects the colours is the middle layer, which is a layer of haze particles (referred to in the paper as the Aerosol-2 layer) that is thicker on Uranus than on Neptune. The team suspects that, on both planets, methane ice condenses onto the particles in this layer, pulling the particles deeper into the atmosphere in a shower of methane snow. Because Neptune has a more active, turbulent atmosphere than Uranus does, the team believes Neptune’s atmosphere is more efficient at churning up methane particles into the haze layer and producing this snow. This removes more of the haze and keeps Neptune’s haze layer thinner than it is on Uranus, meaning the blue colour of Neptune looks stronger.

Above both of these layers is an extended layer of haze (the Aerosol-3 layer) similar to the layer below it but more tenuous. On Neptune, large methane ice particles also form above this layer.

Abell 370 Parallel Field with Asteroids

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

Some asteroids from within our Solar System have photobombed deep images of the Universe taken by the NASA/ESA Hubble Space Telescope. These asteroids reside, on average, only about 260 million kilometres from Earth — right around the corner in astronomical terms. Yet they've horned their way into this picture of thousands of galaxies scattered across space and time at inconceivably farther distances.

This Hubble photo of a random patch of sky is part of the Frontier Fields survey. The colourful image contains thousands of galaxies, including massive yellowish ellipticals and majestic blue spirals. Much smaller, fragmentary blue galaxies are sprinkled throughout the field. The reddest objects are most likely the farthest galaxies, whose light has been stretched into the red part of the spectrum by the expansion of space.

Intruding across the picture are asteroid trails that appear as curved or S-shaped streaks. Rather than leaving one long trail, the asteroids appear in multiple Hubble exposures that have been combined into one image. Of the 20 total asteroid sightings for this field, seven are unique objects. Of these seven asteroids, only two were earlier identified. The others were too faint to be seen previously.

The trails look curved due to an observational effect called parallax. As Hubble orbits around Earth, an asteroid will appear to move along an arc with respect to the vastly more distant background stars and galaxies. The motion of Earth around the Sun, and the motion of the asteroids along their orbits, are other contributing factors to the apparent skewing of asteroid paths.

All the asteroids were found manually, the majority by "blinking" consecutive exposures to capture apparent asteroid motion. Astronomers found a unique asteroid for every 10 to 20 hours of exposure time.

The Frontier Fields program is a collaboration among several space telescopes and ground-based observatories to study six massive galaxy clusters and their effects. Using a different camera, pointing in a slightly different direction, Hubble photographed six so-called "parallel fields" at the same time it photographed the massive galaxy clusters. This maximised Hubble's observational efficiency in doing deep space exposures. These parallel fields are similar in depth to the famous Hubble Deep Field, and include galaxies about four-billion times fainter than can be seen by the human eye.

This picture is of the parallel field for the galaxy cluster Abell 370. It was assembled from images taken in visible and infrared light. The field's position on the sky is near the ecliptic, the plane of our Solar System. This is the zone in which most asteroids reside, which is why Hubble astronomers saw so many crossings. Hubble deep-sky observations taken along a line-of-sight near the plane of our Solar System commonly record asteroid trails.

Hubble Reveals Surviving Companion Star In Aftermath Of Supernova

Thu, 05 May 2022 16:00:00 +0200

Hubble has uncovered a witness at the scene of a star's explosive death: a companion star previously hidden in the glare of its partner's supernova. The discovery is a first for a particular type of supernova—one in which the star was stripped of its entire outer gas envelope before exploding. The finding provides crucial insight into the binary nature of massive stars, as well as the potential prequel to the ultimate merger of the companion stars that would rattle across the universe as gravitational waves, ripples in the fabric of spacetime itself.

This visual presents Hubble images of galaxy NGC 3287 and the supernova 2013ge fading over time, revealing the steady source of ultraviolet light astronomers have identified as its binary companion star.

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 cutout from the Hubble GOODS-North field.

Hubble Confirms Largest Comet Nucleus Ever Seen

Tue, 12 Apr 2022 16:00:00 +0200

The NASA/ESA Hubble Space Telescope has determined the size of the largest icy comet nucleus ever seen by astronomers.

This image sequence shows how the nucleus of Comet C/2014 UN271 (Bernardinelli-Bernstein) was isolated from a vast shell of dust and gas surrounding the solid icy nucleus. On the left is a photo of the comet taken by the NASA/ESA Hubble Space Telescope's Wide Field Camera 3 on 8 January 2022. A model of the coma (middle panel) was obtained by means of fitting the surface brightness profile assembled from the observed image on the left. This allowed for the coma to be subtracted, unveiling the point-like glow from the nucleus. Combined with radio telescope data, astronomers arrived at a precise measurement of the nucleus size. That's no small feat from something roughly 4.8 billion kilometres away. Though the nucleus is estimated to be as large as 135 kilometres across, it is so far away it cannot be resolved by Hubble. Its size is derived from its reflectivity as measured by Hubble. The nucleus is estimated to be as black as charcoal. The nucleus area is gleaned from radio observations.

Spiral Snapshot

Mon, 11 Apr 2022 06:00:00 +0200

The spiral galaxy M91 fills the frame of this Wide Field Camera 3 observation from the NASA/ESA Hubble Space Telescope. M91 lies approximately 55 million light-years from Earth in the constellation Coma Berenices and — as is evident in this image — is a barred spiral galaxy. While M91’s prominent bar makes for a spectacular galactic portrait, it also hides an astronomical monstrosity. Like our own galaxy, M91 contains a supermassive black hole at its centre. A 2009 study using archival Hubble data found that this central black hole weighs somewhere between 9.6 and 38 million times as much as the Sun.

Whilst archival Hubble data allowed astronomers to weigh M91’s central black hole, more recent observations have had other scientific aims. This observation is part of an effort to build a treasure trove of astronomical data exploring the connections between young stars and the clouds of cold gas in which they form. To do this, astronomers used Hubble to obtain ultraviolet and visible observations of galaxies already seen at radio wavelengths by the ground-based Atacama Large Millimeter/submillimeter Array (ALMA).

Observing time with Hubble is a highly valued, and much sought-after, resource for astronomers. To obtain data from the telescope, astronomers first have to write a proposal detailing what they want to observe and highlighting the scientific importance of their observations. These proposals are then anonymised and judged on their scientific merit by a variety of astronomical experts. This process is incredibly competitive: following Hubble’s latest call for proposals, only around 13% of the proposals were awarded observing time.

Are you interested in finding out what Hubble is observing right now? You can follow the space telescope’s observations in real time at this link.

Hubble Spies a Serpentine Spiral Galaxy

Mon, 04 Apr 2022 06:00:00 +0200

The lazily winding spiral arms of the galaxy NGC 5921 snake across this image from the NASA/ESA Hubble Space Telescope. This galaxy lies approximately 80 million light-years from Earth, and much like our own galaxy, the Milky Way, contains a prominent bar. Roughly half of all spiral galaxies are thought to contain bars, and these bars affect their parent galaxies by fuelling star formation and affecting the motion of stars and interstellar gas.

Appropriately, given NGC 5921’s serpentine spiral arms, this galaxy resides in the constellation Serpens in the northern celestial hemisphere. Serpens is the only one of the 88 modern constellations to consist of two unconnected regions — Serpens Caput and Serpens Cauda. These two regions — whose names mean the Serpent’s Head and the Serpent’s Tail, respectively — are separated by Ophiuchus, the Serpent Bearer.

The scientific study behind this image was also split into two parts — observations from Hubble’s Wide Field Camera 3 and observations from the ground-based Gemini Observatory. These two observatories joined forces to better understand the relationship between galaxies like NGC 5921 and the supermassive black holes they contain. Hubble’s contribution to the study was to determine the masses of stars in the galaxies and also to take measurements that help calibrate the observations from Gemini. Together, the Hubble and Gemini observations provided astronomers with a census of nearby supermassive black holes in a diverse variety of galaxies.

Hubble Looks Through Cosmic Zoom Lens

Mon, 07 Mar 2022 16:00:00 +0100

The Advanced Camera for Surveys (ACS) aboard the NASA/ESA Hubble Space Telescope has used a natural 'zoom lens' in space to boost its view of the distant universe. Besides offering an unprecedented and dramatic new view of the cosmos, the results promise to shed light on galaxy evolution and dark matter in space. Hubble peered straight through the center of one of the most massive galaxy clusters known, called Abell 1689.

For this observation, Hubble had to gaze at the distant cluster, located 2.2 billion light-years away, for more than 13 hours. The gravity of the cluster's trillion stars " plus dark matter " acts as a 2-million-light-year-wide 'lens' in space. This 'gravitational lens' bends and magnifies the light of galaxies located far behind it, distorting their shapes and creating multiple images of individual galaxies.

Hubble Finds a Black Hole Igniting Star Formation in a Dwarf Galaxy

Wed, 19 Jan 2022 20:20:38 +0100

Black holes are often described as the monsters of the universe—tearing apart stars, consuming anything that comes too close, and holding light captive. Detailed evidence from the NASA/ESA Hubble Space Telescope, however, shows a black hole in a new light: fostering, rather than suppressing, star formation. Hubble imaging and spectroscopy of the dwarf starburst galaxy Henize 2-10 clearly show a gas outflow stretching from the black hole to a bright star birth region like an umbilical cord, triggering the already dense cloud into forming clusters of stars. Astronomers have previously debated that a dwarf galaxy could have a black hole analogous to the supermassive black holes in larger galaxies. Further study of dwarf galaxies, which have remained small over cosmic time, may shed light on the question of how the first seeds of supermassive black holes formed and evolved over the history of the universe.

This dwarf starburst galaxy Henize 2-10 sparkles with young stars in this Hubble visible-light image. The bright region at the center, surrounded by pink clouds and dark dust lanes, indicates the location of the galaxy's massive black hole and active stellar nurseries.

Hubble's View of Beta Pictoris in 2012

Wed, 13 Oct 2021 16:07:39 +0200

Astronomers have used the NASA/ESA Hubble Space Telescope to take the most detailed picture to date of a large, edge-on, gas-and-dust disc encircling the 20-million-year-old star Beta Pictoris. Beta Pictoris remains the only directly imaged debris disc that has a giant planet (discovered in 2009). Because the orbital period is comparatively short (estimated to be between 18 and 22 years), astronomers can see large motion in just a few years. This allows scientists to study how the Beta Pictoris disc is distorted by the presence of a massive planet embedded within the disc. This 2012 visible-light Hubble image traces the disc to within about 1050 million kilometres of the star (which is inside the radius of Saturn's orbit about the Sun).

Image Archive: Cosmology

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Hubble's View of Beta Pictoris in 2012