Picture of the Month 2023

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 …