Picture of the Month

27 August 2024
This stunning new mosaic of images from the NASA/ESA/CSA James Webb Space Telescope showcases the nearby star-forming cluster, NGC 1333. The nebula is in the Perseus molecular cloud, and located approximately 960 light-years away. Webb’s superb sensitivity allows astronomers to investigate young objects with extremely low masses. Some of the faintest ‘stars’ in the picture are in fact newly born free-floating brown dwarfs with masses comparable to those of giant planets. The same cluster was featured as the 33rd anniversary image of the NASA/ESA Hubble Space Telescope in April of 2023. Hubble’s image just scratched the surface of this region, because clouds of dust obscure much of the star formation process. Observing with a larger aperture and in the infrared part of the spectrum, Webb is capable of peering through the dusty veil to reveal newborn stars, brown dwarfs and planetary mass objects. The centre of the image presents a …

9 August 2024
Featured in this new image from the NASA/ESA/CSA James Webb Space Telescope is Messier 106, also known as NGC 4258. This is a nearby spiral galaxy that resides roughly 23 million light-years away in the constellation Canes Venatici, practically a neighbour by cosmic standards. Messier 106 is one of the brightest and nearest spiral galaxies to our own and two supernovae have been observed in this galaxy in 1981 and 2014. At its heart, as in most spiral galaxies, is a supermassive black hole, but this one is particularly active. Unlike the black hole at the centre of the Milky Way, which pulls in wisps of gas only occasionally, Messier 106’s black hole is actively gobbling up material. As the gas spirals towards the black hole, it heats up and emits powerful radiation. This image was captured with Webb’s Near-InfraRed Camera (NIRCam). This observation was taken as part of a …

5 July 2024
This new ESA/Webb Picture of the Month features the gravitational lensing of the quasar known as RX J1131-1231, located roughly 6 billion light-years from Earth in the constellation Crater. It is considered one of the best lensed quasars discovered to date, as the foreground galaxy smears the image of the background quasar into a bright arc and creates four images of the object. Gravitational lensing, first predicted by Einstein, offers a rare opportunity to study regions close to the black hole in distant quasars, by acting as a natural telescope and magnifying the light from these sources. All matter in the Universe warps the space around itself, with larger masses producing a more pronounced effect. Around very massive objects, such as galaxies, light that passes close by follows this warped space, appearing to bend away from its original path by a clearly visible amount. One of the consequential effects of …

29 May 2024
Featured in this new image from the NASA/ESA/CSA James Webb Space Telescope is the dwarf galaxy NGC 4449. This galaxy, also known as Caldwell 21, resides roughly 12.5 million light-years away in the constellation Canes Venatici. It is part of the M94 galaxy group, which lies close to the Local Group that hosts our Milky Way.NGC 4449 has been forming stars for several billion years, but it is currently experiencing a period of star formation at a much higher rate than in the past. Such unusually explosive and intense star formation activity is called a starburst and for that reason NGC 4449 is known as a starburst galaxy. In fact, at the current rate of star formation, the gas supply that feeds the production of stars would only last for another billion years or so. Starbursts usually occur in the central regions of galaxies, but NGC 4449 displays more widespread …

1 May 2024
This new image from the NASA/ESA/CSA James Webb Space Telescope features NGC 6440, a globular cluster that resides roughly 28 000 light-years from Earth in the constellation Sagittarius. The object was first discovered by William Herschel in May of 1786. Globular clusters like NGC 6440 are roughly spherical, tightly packed, collections of old stars bound together by gravity. They can be found throughout galaxies, but often live on the outskirts. They hold hundreds of thousands to millions of stars that are on average about one light-year apart, but they can be as close together as the size of our Solar System. NGC 6440 is known to be a high-mass and metal-rich cluster that formed and is orbiting within the Galactic bulge, which is a dense, near-spherical region of old stars in the inner part of the Milky Way. This image was obtained with 2023 data from Webb’s Near-InfraRed Camera (NIRCam) …

26 March 2024
The NASA/ESA/CSA James Webb Space Telescope has captured a spectacular view of the galaxy I Zwicky 18 (I Zw 18) in this new image. The galaxy was first identified by Swiss astronomer Fritz Zwicky in the 1930’s and resides roughly 59 million light-years from Earth. This galaxy has gone through several sudden bursts of star formation. This galaxy is typical of the kinds of galaxies that inhabited the early Universe and it is classified as a dwarf irregular galaxy (much smaller than our Milky Way). Two major starburst regions are embedded in the heart of the galaxy. The wispy brown filaments surrounding the central starburst region are bubbles of gas that have been heated by stellar winds and intense ultraviolet radiation unleashed by hot, young stars. A companion galaxy resides nearby to the dwarf galaxy, which can be seen at the bottom of the wider-field image. The companion may be …

27 February 2024
This image features the barred spiral galaxy galaxy NGC 1559 as seen by the NASA/ESA/CSA James Webb Space Telescope. The galaxy hosts a visible central region with a distinct open pattern in the loosely-wound spiral arms. NGC 1559 resides approximately 35 million light-years away in the little-observed southern constellation Reticulum (The Reticule). The data featured in this portrait make use of two of Webb’s instruments: the Mid-InfraRed Instrument (MIRI) and Near-InfraRed Camera (NIRCam). Here MIRI captures the glow of interstellar dust grains, which trace out the interstellar medium, the fuel for future star formation. NIRCam shows the light from stars, even young stars hidden behind prodigious amounts of dust. NIRCam also captures emission from ionised nebulae around young stars. The data were collected by the PHANGS team as part of an observing programme in which Webb will observe 55 galaxies that have also been mapped by the Atacama Large Millimeter/submillimeter …

23 January 2024
This image from the NASA/ESA/CSA James Webb Space Telescope features an H II region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. This nebula, known as N79, is a region of interstellar atomic hydrogen that is ionised, captured here by Webb’s Mid-InfraRed Instrument (MIRI). N79 is a massive star-forming complex spanning roughly 1630 light-years in the generally unexplored southwest region of the LMC. N79 is typically regarded as a younger version of 30 Doradus (also known as the Tarantula Nebula), another of Webb’s recent targets. Research suggests that N79 has a star formation efficiency exceeding that of 30 Doradus by a factor of two over the past 500 000 years. This particular image centres on one of the three giant molecular cloud complexes, dubbed N79 South (S1 for short). The distinct ‘starburst’ pattern surrounding this bright object is a series of diffraction spikes. All telescopes …

19 December 2023
The vast galaxy cluster SDSS J1226+2152 in the constellation Coma Berenices is distorting the images of distant background galaxies into streaks and smears of light in this image from the NASA/ESA/CSA James Webb Space Telescope. This is a spectacular example of gravitational lensing, a phenomenon which occurs when a massive celestial object such as a galaxy cluster deforms spacetime and causes the path of light from more distant galaxies to be deflected, almost as if a monumental lens was redirecting it. This image is from a set of early science observations with Webb. One of the most notable lensed galaxies in this rich field is named SGAS J12265.3+215220. In this image, it's the innermost lensed galaxy, just above and to the right of the central galaxy. This lies far beyond the foreground cluster in distance, giving us a view into the galaxy roughly two billion years after the big bang. …

28 November 2023
This new Picture of the Month from the NASA/ESA/CSA James Webb Space Telescope reveals intricate details of the Herbig Haro object number 797 (HH 797). Herbig-Haro objects are luminous regions surrounding newborn stars (known as protostars), 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. HH 797, which dominates the lower half of this image, is located close to the young open star cluster IC 348, near the eastern edge of the Perseus dark cloud complex. The bright infrared objects in the upper portion of the image are thought to host two further protostars. This image was captured with Webb’s Near-InfraRed Camera (NIRCam). Infrared imaging is a powerful way to study newborn stars and their outflows, because the youngest stars are invariably still embedded within the gas and dust from which they are …

31 October 2023
This month, Webb presents a spectacular treat… for the eyes. The barred spiral galaxy M83 is revealed in detail by the NASA/ESA/CSA James Webb Space Telescope. M83, which is also known as NGC 5236, was observed by Webb as part of a series of observations collectively titled Feedback in Emerging extrAgalactic Star clusTers, or FEAST. Another target of the FEAST observations, M51, was the subject of a previous Webb Picture of the Month. As with all six galaxies that comprise the FEAST sample, M83 and M51 were observed with both NIRCam and MIRI, two of the four instruments that are mounted on Webb. MIRI, or the Mid-InfraRed Instrument, makes observations in the mid-infrared, which spans wavelengths of light very different from optical wavelengths. Optical wavelengths in astronomy roughly correspond to the range of light waves that human eyes are sensitive to, and extend from about 0.38 to 0.75 micrometres (a …

27 September 2023
This image shows the irregular galaxy NGC 6822, as observed by the Near-InfraRed Camera (NIRCam) mounted on the NASA/ESA/CSA James Webb Space Telescope. NIRCam probes the near-infrared, which in this case makes it suitable for observing the densely packed star field. Webb’s near-infrared NIRCam image shows the galaxy’s countless stars in incredible detail. Here, the dust and gas that pervade the galaxy are reduced to translucent red wisps, laying the stars bare for astronomical study. The power of Webb’s ice-cold infrared instruments and the incredible resolution of its primary mirror is necessary to examine stars hidden in dusty environments, and the results as shown here are spectacular. The brightest stars appear in pale blue and cyan colours in this image, colours which are assigned to the shortest wavelengths of light that NIRCam can detect: red and nearest infrared. The amount of light emitted by any star decreases at longer and …

29 August 2023
The graceful winding arms of the grand-design spiral galaxy M51 stretch across this image from the NASA/ESA/CSA James Webb Space Telescope. Unlike the menagerie of weird and wonderful spiral galaxies with ragged or disrupted spiral arms, grand-design spiral galaxies boast prominent, well-developed spiral arms like the ones showcased in this image. This galactic portrait is a composite image that integrates data from Webb’s Near-InfraRed Camera (NIRCam) and Mid-InfraRed Instrument (MIRI).In this image the dark red regions trace the filamentary warm dust permeating the medium of the galaxy. The red regions show the reprocessed light from complex molecules forming on dust grains, while colours of orange and yellow reveal the regions of ionised gas by the recently formed star clusters. Stellar feedback has a dramatic effect on the medium of the galaxy and create complex network of bright knots as well as cavernous black bubbles. M51 — also known as NGC …

31 July 2023
This image shows the irregular galaxy NGC 6822, which was observed by the Near-InfraRed Camera (NIRCam) and Mid-InfraRed Instrument (MIRI) mounted on the NASA/ESA/CSA James Webb Space Telescope. As their names suggest, NIRCam and MIRI probe different parts of the electromagnetic spectrum. This allows the instruments to observe different components of the same galaxy, with MIRI especially sensitive to its gas-rich regions (the yellow swirls in this image) and NIRCam suitable for observing its densely packed field of stars. NGC 6822 lies about 1.5 million light-years away, and is the Milky Way’s nearest galactic neighbour that is not one of its satellites. It has a low metallicity, meaning that it contains low proportions of elements that are not hydrogen and helium. Metallicity is an absolutely key concept in astronomy, in part because elements other than hydrogen and helium are largely produced by stars over their lifetimes. Therefore, in the very …

3 July 2023
The peculiar galaxy NGC 3256 dominates this image from the NASA/ESA/CSA James Webb Space Telescope. This Milky Way-sized galaxy lies about 120 million light-years away in the constellation Vela, and is a denizen of the Hydra-Centaurus Supercluster. NGC 3256 may seem peaceful, a swirl of tightly entwined spiral arms set in a hazy cloud of light, but this image shows the aftermath of an ancient cosmic clash. This distorted galaxy is the wreckage of a head-on collision between two equally massive spiral galaxies which astronomers estimate to have met around 500 million years ago. The tumultuous past of NGC 3256 is captured in the long tendrils of shining dust and stars which extend outwards from the main body of the galaxy. The striking red and orange regions spread across the galaxy contain young stars created in the merger that are irradiating small dust grains, which then emit infrared light that …

2 June 2023
A delicate tracery of dust and bright star clusters threads across this image from the NASA/ESA/CSA James Webb Space Telescope. The bright tendrils of gas and stars belong to the barred spiral galaxy NGC 5068, whose bright central bar is visible in the upper left of this image. NGC 5068 lies around 17 million light-years from Earth in the constellation Virgo. This portrait of NGC 5068 is part of a campaign to create an astronomical treasure trove, a repository of observations of star formation in nearby galaxies. Previous gems from this collection can be seen here and here. These observations are particularly valuable to astronomers for two reasons. The first is because star formation underpins so many fields in astronomy, from the physics of the tenuous plasma that lies between stars to the evolution of entire galaxies. By observing the formation of stars in nearby galaxies, astronomers hope to kick-start …

24 April 2023
The seven galaxies highlighted in this image from the NASA/ESA/CSA Telescope have been confirmed to be at a distance that astronomers refer to as redshift 7.9, which correlates to 650 million years after the big bang. This makes them the earliest galaxies yet to be spectroscopically confirmed as part of a developing cluster. The seven galaxies confirmed by Webb were first established as candidates for observation using data from the NASA/ESA Hubble Space Telescope’s Frontier Fields program. The program dedicated Hubble time to observations using gravitational lensing, to observe very distant galaxies in detail. However, because Hubble cannot detect light beyond near-infrared, there is only so much detail it can see. Webb picked up the investigation, focusing on the galaxies scouted by Hubble and gathering detailed spectroscopic data in addition to imagery. Astronomers used Webb's Near-Infrared Spectrograph (NIRSpec) instrument to precisely measure the distances and determine that the galaxies are …

28 March 2023
Streaks of light and bright arcs betray the presence of a vast gravitational lens in this image from the NASA/ESA/CSA James Webb Space Telescope. A galaxy cluster in the foreground has magnified distant galaxies, warping their shapes and creating the bright smears of light spread throughout this image. This effect, referred to by astronomers as gravitational lensing, occurs when a massive celestial object such as a galaxy cluster causes a sufficient curvature of spacetime for light to be visibly bent around it, as if by a gargantuan lens. One of the consequential effects of gravitational lensing is that it can magnify distant astronomical objects, letting astronomers study objects that would otherwise be too faint or far away. This useful quirk of gravitational lensing has also been used to reveal some of the most distant galaxies humanity has ever encountered. The long, bright, and distorted arc spreading out near the core …

28 February 2023
This observation from the NASA/ESA/CSA James Webb Space Telescope features the massive galaxy cluster RX J2129. Due to Gravitational lensing, this observation contains three different images of the same supernova-hosting galaxy, which you can see in closer detail here. Gravitational lensing occurs when a massive celestial body causes a sufficient curvature of spacetime to bend the path of light travelling past or through it, almost like a vast lens. In this case, the lens is the galaxy cluster RX J2129, located around 3.2 billion light-years from Earth in the constellation Aquarius. Gravitational lensing can cause background objects to appear strangely distorted, as can be seen by the concentric arcs of light in the upper right of this image. Astronomers discovered the supernova in the triply-lensed background galaxy using observations from the NASA/ESA Hubble Space Telescope, and they suspected that they had found a very distant Type Ia supernova. These supernovae …

31 January 2023
A crowded field of galaxies throngs this 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 …