Image of the Week

22 January 2025: This Image of the Week showcases the stunning Milky Way gracefully arcing over the NSF Víctor M. Blanco 4-meter Telescope at the U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab in Chile. CTIO is located at an altitude of 2200 meters (7200 feet) in the remote mountains of Chile. This location, high in the sky and far from city light pollution, allows telescopes like the Blanco Telescope to study the sky in breathtaking clarity. This image encapsulates the beauty of the cosmos and the sophisticated efforts undertaken by astronomers to unravel its mysteries. One such effort in which this telescope has played a major role is the Dark Energy Survey (DES). The survey examined the origin of the accelerating Universe to uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion. Over a six-year period, this telescope, armed with the …

15 January 2025: NSF–DOE Vera C. Rubin Observatory, jointly funded by the U.S. National Science Foundation (NSF) and the U.S. Department of Energy (DOE) Office of Science, is seen here on the low ridge of Cerro Pachón in Chile with snow-dusted mountains in the background. With an altitude of more than 2600 meters (8600 feet) at Rubin Observatory, Cerro Pachón is an ideal location for astronomical research with its dry, stable air. The 8.4-meter Simonyi Survey Telescope at Rubin Observatory, equipped with the LSST Camera — the largest digital camera in the world — will survey the entire southern hemisphere every few nights for a decade to create an ultra-wide ultra-high-definition time-lapse record of our Universe. This unique ‘movie’ will bring the night sky to life, yielding a treasure trove of discoveries. Rubin is positioned near two other observatories in the foothills of the Chilean Andes: the Gemini South telescope, seen at upper-right, …

8 January 2025: A pivotal hub for astronomy sits in the Sonoran Desert, surrounded by the mountains of southern Arizona. Southwest of Tucson, the Quinlan Mountains majestically rise to an altitude of 2100 meters (7000 feet) in the Schuk Toak District of the Tohono O’odham Nation. Atop the central peak in this image sits the U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a Program of NSF NOIRLab and the largest collection of optical and radio telescopes in the northern hemisphere. Kitt Peak’s ideal vantage point, combined with the dark, dry environment of the desert, allows astronomers to make discoveries in many areas of astronomy including exoplanets, galaxies, and dark energy. KPNO is just one of several observatories in the area, including the Mount Graham international Observatory and the Mount Lemmon Observatory, operated by the University of Arizona. In addition, Pima County, in which Tucson resides, is also a hub for space …

1 January 2025: On top of observing astronomical events in the northern skies, Gemini North — one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab— is also set in an environment of gorgeous sunsets near the summit of Maunakea, Hawai‘i. Every so often, though, Gemini North is the site of something special. Upon closer inspection, a stream of shadow can be seen streaking across the right side of the image, outlined by parallel beams of light known as anticrepuscular rays. These rays are caused by clouds obscuring the dim, backscattered sunlight and appear to converge on a point directly opposite the Sun, known as the antisolar point. If these rays originated directly from the Sun, they would be called crepuscular rays. Anticrepuscular rays require the right environment to be created so they are difficult to glimpse.

25 December 2024: The Milky Way, looking like a river of stars and dust, stretches between the Víctor M. Blanco 4-meter Telescope (left) and the SMARTS–GSU 1.5-meter Telescope (right) over the U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. And, like a vast river, the Milky Way can be hard to navigate without some stellar guides: constellations. Among them, Sagittarius (left of center) is particularly important as it has an iconic asterism, called the Teapot, that points toward the center of our galaxy, where the supermassive black hole known as Sagittarius A* resides. Nearby, Scorpius (right of center) is a standout feature in the sky with its bright red supergiant star Antares. Often called the ‘heart’ of the scorpion, Antares can point the way to the Galactic core as well. This image is part of a fulldome photo. You can also see it as a panorama. This …

18 December 2024: The magnificent spiral galaxy NGC 7331, located approximately 40 million light-years away in the constellation Pegasus, is the brightest and closest galaxy in the visual galaxy group that bears its name, the NGC 7331 Group. Revealed in the details of this image are populations of hot stars and dark dust lanes winding throughout the spiral arms. Also known as Caldwell 30, this galaxy is often thought of as a twin to the Milky Way owing to its similar size and spiral structure. However, there are a couple of features of its core that set it apart from our home galaxy. For instance, astronomers have found evidence that the Milky Way has a central bar of stars and dust cutting through its center, a feature common to many spiral galaxies. But NGC 7331 lacks this feature. Additionally, NGC 7331’s central bulge rotates in the opposite direction to its galactic disk — …

11 December 2024: We at NOIRLab, funded by the U.S. National Science Foundation (NSF), would like to wish you the best this holiday season, and a successful and prosperous 2025! This background image reveals the bright, young stars surrounded by billowing clouds of dust and gas inside the star-forming nebula NGC 6357, known as the Lobster Nebula, located in the constellation Scorpius. It was captured by the U.S. Department of Energy-built Dark Energy Camera (DECam) on the Víctor M. Blanco 4-meter Telescope at NSF Cerro Tololo Inter-American Observatory, a Program of NSF NOIRLab. You can print and share your own copy of this card to wish others a happy holiday season. Check out our animated holiday card here and download the image without text here. Happy Holidays, Felices Fiestas, and Mele Kalikimaka and Hau‘oli Makahiki Hou!

4 December 2024: Two world-class astronomical sites are seen in this aerial sunset image captured in northern Chile. In the foreground is NSF–DOE Vera C. Rubin Observatory, jointly funded by the U.S. National Science Foundation (NSF) and the U.S. Department of Energy (DOE) Office of Science. Rubin Observatory is located on Cerro Pachón at an altitude of 2600 meters (8600 feet). In the distance to the right of Rubin Observatory is the mountaintop Cerro Tololo, home to the NSF Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. The structure at the top of Cerro Tololo is the Víctor M. Blanco 4-meter Telescope, located at an altitude of approximately 2200 meters (7200 feet). Together Cerro Pachón and Cerro Tololo form a major astronomical observation hub. Their high-altitude locations provide astronomers with an abundance of cloud-free nights with dry, stable air — when the occasional clouds do form, they contribute to beautiful sunsets …

27 November 2024: Star trails streak across the sky above the summit of Maunakea in this image, which shows the surroundings of the Gemini North telescope, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. The long exposure time of this photograph, coupled with the rotation of Earth, has caused the stars to streak into a multitude of graceful arcs. To the right of the image a much more earthly trail is visible; hikers with head torches have illuminated the final stretch of the Humuʻula Trail which winds up to the summit of Maunakea. One of the streaks of light in the skies above Maunakea didn’t originate from a distant star, but rather from something much closer to home. A passing airplane has left a dashed trail at the lower left of this image, pointing the way to the glowing patch …

20 November 2024: The Milky Way dominates the sky as it stretches over U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab, which is located high in the mountains of Chile, at an altitude of 2200 meters (7200 feet). CTIO is a complex of astronomical telescopes and instruments that has long served as the principal platform for American astronomical investigation of the southern skies. In addition to the many telescopes it operates, CTIO provides space for others to access the southern sky — almost a dozen tenant observatories are hosted at the site. Pictured here are telescopes operated by Las Cumbres Observatory (LCO). LCO operates a network of telescopes spread out longitudinally across the northern and southern hemispheres. The strategic positioning of its telescopes means that LCO always has a telescope in darkness and it can coordinate its telescopes to quickly collect data that would be missed by …

13 November 2024: Gemini South, one half of the International Gemini Observatory which is supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab, sits high atop Cerro Pachón in Chile, surrounded by gems of the southern night sky. One of these gems, the center of our Milky Way, is also the center of this image. The heart of our galaxy, densely packed with stars, is home to a supermassive black hole, known as Sagittarius A*, surrounded by the colossal clouds of cosmic dust of the Great Rift. While difficult to see in this image, these dark clouds house many interesting and beautiful deep-sky objects, like Ptolemy’s Cluster (Messier 7) and the Cat’s Paw Nebula (NGC 6334). Below the densest part of the Milky Way in this image is the constellation Scorpius (the Scorpion), which is best seen from southern latitudes. Its three-pronged ‘head’ and ‘claws’ stretch out from …

6 November 2024: The starry band of the Milky Way hangs overhead in this panorama taken from Maunakea, the home of Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. Down on the mountain at the center of the image, a snaking band of light marks the location of an access road. In the distance, the large cities on the Island of Hawai‘i light up spots under the clouds while the active volcano Mauna Loa rises above them. Just like Mauna Loa, Maunakea is a shield volcano — though thankfully a dormant one. However, the volcanic past of Maunakea continues to be an asset to astronomers. The mountain’s smoothly sloping sides and high elevation are two of the factors that contribute to the exceptional observing conditions at the summit.

30 October 2024: The Milky Way is a disk-shaped spiral galaxy with many arms, each holding countless stars and celestial objects. Often, the most common view of the Milky Way is of the brightest and most concentrated region of the galaxy in the direction of the constellation Sagittarius. This photographer instead looked toward Orion — identifiable by the distinct three-star ‘belt’ — for this Image of the Week to capture the Orion-Cygnus Arm. The bright stars, clusters, and nebulae, such as the red giant Aldebaran (center) and the Orion Nebula (center right), that lie within the arm hold significance for cultures across the globe and are areas ripe for exploring many astrophysical processes. This section of the Milky Way is also where our Solar System is located. Pictured beneath this fascinating patch of sky is the Visitor Center Roll Off Roof Observatory at U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a …

23 October 2024: Breathtaking views of astronomical events are a never-ending source of great excitement for the staff at Gemini North, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. One such example is the lunar eclipse taking place in the distance on the right side of this image, captured in 2019. It is seemingly encased in the dark blue band above the horizon. Lunar eclipses occur when Earth moves between the Sun and the Moon. The Moon, which is only visible by the sunlight reflected off it, is darkened by the Earth’s shadow. An eclipse like this one can be viewed from anywhere on Earth where the Moon is visible, though the extent of the eclipse depends on how aligned the Moon is to Earth’s shadow and one’s viewing location. In 2022, for example, the two lunar eclipses, both total …

16 October 2024: A stunning view of the Milky Way above the U.S. National Science Foundation Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab, is captured in this Image of the Week. In addition to its largest and best-known telescopes, CTIO hosts around 40 telescopes from 11 tenant observatories and research projects. Shown here are many of the facilities operated by Las Cumbres Observatory (LCO), including the three Las Cumbres Observatory 1-meter Telescopes (left) and the ‘igloo’ for an echelle spectrograph (center). The Planetary Defense 1.3-meter Telescope is on the right. LCO is a global network of telescopes that are spaced out longitudinally around the globe, allowing for night-sky objects to be monitored around the clock. This ability to observe objects continuously is crucial in the field of time-domain astronomy, the study of how astronomical objects change with time. Time-domain astronomy is concerned with objects that change rapidly in brightness or …

9 October 2024: The Milky Way flows across the southern hemisphere’s night sky in this photograph of Gemini South, one half of the International Gemini Observatory. Supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab, Gemini South resides on the summit of Cerro Pachón in Chile, a location well known for its dazzling dark skies. Here it’s operating its constellation of five laser guide stars, which is used by its advanced adaptive optics system to reduce the blurring of images that’s caused by Earth’s atmosphere. Speckled through the Milky Way are some iconic constellations: Centaurus (the centaur), Crux (the Southern Cross), and Canis Major (the Great Dog — which is distinguished by the brightest star in the sky, Sirius). The large red splotch in the Milky Way at the center of the image is the Carina Nebula, one of the largest diffuse nebulae in our skies. To the …

30 September 2024: Comet C/2023 A3 (Tsuchinshan–ATLAS) graces the dawn sky over the U.S. National Science Foundation Kitt Peak National Observatory, a Program of NSF NOIRLab, just outside Tucson, Arizona in this image. It was captured in the morning hours before sunrise on Saturday 28 September 2024 by Rob Sparks from NOIRLab. In the foreground is the McMath-Pierce Solar Telescope, which is in the final stages of being transformed into a must-see location for visitors to Arizona, currently named the Windows Center. Comets are dirty snowballs of gas, dust and ice, often from the far reaches of the Solar System. As a comet approaches the Sun, the solar radiation heats the icy body which then releases streams of dust and gas into space, forming the distinct tail. Comet Tsuchinshan–ATLAS was discovered in 2023 and is named after the two facilities that independently discovered it. From further observations of the comet, astronomers have estimated …

25 September 2024: In the southern constellation of Fornax lies NGC 922, a peculiar galaxy with a structure that has puzzled astronomers for years. Previously, researchers thought its distinctive features — the stellar plume and off-center galactic bar — resulted from a collision with a nearby dwarf galaxy some 330 million years ago. However, new observations have revealed an umbrella-like tidal tail, seen in this image taken with the DOE-built DECam on the U.S. National Science Foundation Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF NOIRLab. These observations contradict the previous collision theory by showing that this newly detected tail doesn’t align with the trajectory of the dwarf galaxy. Moreover, the dwarf galaxy itself shows signs of ongoing star formation and has a well-defined structure, which is inconsistent with the aftermath of a direct collision. So, a new hypothesis has emerged: that these complex features …

18 September 2024: The star-filled Milky Way arches over Cerro Pachón in this Image of the Week, the sky alight with the spectacular green, orange, and purple airglow of Earth's upper atmosphere. On the right is Gemini South, one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab, while on the left atop the structure is the DIMM3 Seeing Monitor. Both Gemini South and the DIMM3 Seeing Monitor are perched at an altitude of 8980 feet (2737 meters) in the mountains of Chile. This high location is known for its dry, stable air, and provides the excellent ‘seeing’ conditions needed to make high-quality observations. However, even in the best conditions, the turbulent atmosphere will still distort the data. That’s where the DIMM3 Seeing Monitor (and the two other DIMM monitors at Cerro Pachón) come in. A Differential Image Motion Monitor (DIMM) is …

11 September 2024: The disc of the Milky Way spreads across the eastern horizon of Hawaiʻi as it rises over the summit of Maunakea. The center of our galaxy silhouettes the Maunakea Observatories, including Gemini North (third from left), one half of the International Gemini Observatory, supported in part by the U.S. National Science Foundation and operated by NSF NOIRLab. At about 19 degrees north of the equator, Maunakea is in one of the most southerly locations in the United States. This makes it an excellent location to view large portions of the southern skies from the northern hemisphere, wonderfully captured in this stunning photograph. At the center of this image is the constellation Scorpius (the Scorpion), including the star Antares, its bright red ‘heart’. To its left is Ophiuchus (the serpent bearer). These two constellations are dotted with a variety of colorful nebulae. A closer look at these nebulae is in our …