Image of the Week

26 August 2020: This stunning image features NGC 3198, a galaxy that lies about 47 million light-years away in the constellation Ursa Major. This image was taken with the Mosaic instrument on the 4-meter Nicholas U. Mayall Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, and shows the full extent of the galaxy, from the bright central bulge to the tenuous outer reaches of the tightly-wound spiral arms. Almost all the objects lurking in the background are galaxies or galaxy clusters — a sea of distant galaxies of all shapes, sizes, and orientations. Accurately measuring the distance to an astronomical object — everything from our own Sun to galaxies such as NGC 3198 — is an age-old challenge for astronomers, and requires a combination of measurements and methods. The galaxy at the heart of this image has played a part in this astronomical undertaking by allowing astronomers to calibrate astronomical …

19 August 2020: The Milky Way appears to be trapped in a crystal ball in this fisheye image taken at the Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab. Thanks to its remote location atop Cerro Tololo in northern Chile, CTIO enjoys a breathtaking panoramic view of the southern hemisphere’s night sky, and a spectacular perspective on the heart of the Milky Way. Though the dusty band of our Milky Way dominates this image, several of CTIO’s telescopes can also be seen along the edges. With more than 20 telescopes operating at the site, CTIO is fully equipped to take advantage of the pristine Chilean skies.

12 August 2020: Although this appears to be a daytime scene, star trails circle and illuminate the night sky in this long-exposure photo of Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab. The telescope visible at the highest peak is the Nicholas U. Mayall 4-meter Telescope and almost directly above it, at the center of the concentric star trails, sits the North Star, Polaris. As the Earth turns and the stars appear to move through the sky, Polaris remains stationary at the north celestial pole, our planet’s axis of rotation. The lights of Tucson, Arizona, glow yellow on the horizon about 89 kilometers (55 miles) to the northeast. The NOIRLab citizen science campaign Globe at Night enables stargazers of all ages to help monitor their city’s light pollution no matter where they are in the world.

5 August 2020: Pictured here is Gemini South, sitting on the summit of Cerro Pachón in Chile. It is the southern member of the pair of 8.1-meter telescopes, which together comprise the international Gemini Observatory, a Program of NSF's NOIRLab. Gemini North saw its first light in 1999, and — appropriately for twin telescopes — Gemini South followed quickly behind with its first light in 2000. Since then, the united Gemini twins have provided a wealth of scientific observations. In this image, Gemini South is framed by the spectacular Milky Way, which — thanks to the photographic technique used — appears as a celestial arch, curving across the sky.

29 July 2020: This image shows an immersive view from inside the dome of the Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab. The rotating dome is an impressive feat of engineering — designed to protect the delicate telescope from the elements. It weighs in at 430 tonnes (475 tons) and was built to withstand Chilean earthquakes. In addition to the Blanco’s dome, this photograph shows some of the equipment needed to run an astronomical observatory, ranging from calibration targets to good old-fashioned ladders! Glimpses of the mountains surrounding CTIO can be seen through the openings on the side of the dome, and a star-studded sky is visible overhead.

22 July 2020: The spiral galaxy NGC 2541 is shown in extravagant detail in this astronomical snapshot from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. Astronomers recognize a variety of galaxy types, and NGC 2541 is classified as an unbarred spiral galaxy. These galaxies possess spectacular spiral arms like the ones shown here, but lack the central bar-shaped structure displayed by galaxies such as the Milky Way. NGC 2541 lies 37 million light-years from Earth in the constellation of Lynx (The Lynx). Sandwiched between the constellations of Ursa Major, Gemini, and Leo, Lynx is one of 10 new constellations established by the 17th century astronomer Johannes Hevelius. The constellation is composed of very faint stars, leading Hevelius to claim that only the lynx-eyed — people with exceptionally keen eyesight — would be able to spot this unobtrusive constellation.

15 July 2020: Comet NEOWISE — technically known as C/2020 F3 (NEOWISE) — is visible in this spectacular image of the pre-dawn sky to the right (East) of the Gemini North telescope on Maunakea in Hawai‘i, one of the pair of telescopes of the international Gemini Observatory, a Program of NSF’s NOIRLab. First discovered by the NEOWISE project using the Wide-field Infrared Survey Explorer space telescope in March 2020, the comet is a dirty snowball of gas, dust and ice roughly 5 km (3 miles) across. The curving golden tail of C/2020 F3 visible in this image is composed of gas and dust left behind as the comet swept through the inner Solar System. While creating a spectacle for stargazers, the comet’s passage close to the Sun will not happen again for another 6,800 years. Fortunately, there is still a chance to enjoy the show — Comet NEOWISE should be visible in the …

8 July 2020: Cameras allow us to see things which our eyes cannot! This atmospheric light painting was captured at Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab. The composition is framed by an inky sky and the spectacular arch of the McMath-Pierce Solar Telescope serves as a backdrop. Light painting — where a moving light source is captured with a long camera exposure — has been practiced for well over a century. It has both scientific and artistic applications. NOIRLab’s Colors of Nature Summer Academy explores the science of color and the role color plays in art and nature. Colors of Nature students learned about light painting and had the opportunity to practice the art on a trip to Kitt Peak with their families.

1 July 2020: The Milky Way spills across the night sky above the Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab. Commissioned in 1974, the telescope was once the largest optical telescope south of the equator and remains an astronomical powerhouse to this day. This photograph captures the open dome of the telescope as it gazes upwards at the luminous band of stars and dust lanes making up our galaxy. Like all telescopes at CTIO, the Blanco benefits from the crystal-clear observing conditions in northern Chile — as you can see from this star-filled image!

24 June 2020: This image of the Gemini South telescope is so full of light that it is difficult to believe that it was captured at night. Gemini South is the southern half of the international Gemini Observatory, a Program of NSF’s NOIRLab. The wedge-shaped light on the right side of the photo is not from an artificial source (although there are city lights below it), but is a natural phenomenon known as zodiacal light. This occurs when sunlight is scattered off dust particles in the plane of our Solar System, causing part of the sky to become illuminated either after Sun-down or before Sun-up. The zodiac itself is a belt-shaped region on the sky, as seen from Earth, and is the apparent path of the planets in the sky. Gemini Observatory is named after one section of the zodiacal belt: Gemini, the constellation of the Twins.

17 June 2020: These whirling lines in the sky are the trails of stars after an hour-long exposure above Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab. The trails are shortest around the North Star, Polaris, a star that happens to coincide almost directly with the celestial north pole. The different colors in the trails reflect the different temperatures of the stars, with blue being the hottest stars and yellow/red the coolest. The telescope visible above the horizon is the Nicholas U. Mayall 4-meter Telescope, and the red glow on the mountain is caused by red lights used to ensure the eyes of visitors and staff remain dark adapted at night. The yellow glow on the horizon comes from Tucson, AZ, about 89 kilometers (55 miles) to the northeast. Over the past decade, light pollution like this has increased by 2% a year from many medium-sized and larger cities. To help …

10 June 2020: A shooting star streaks above Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab. Silhouetted against the night sky and the faint glow of Earth’s atmosphere are (from left to right) the Víctor M. Blanco 4-meter Telescope, the SMARTS 1.0-meter Telescope, the former University of Chile telescope, Las Cumbres Observatory 1-meter Telescope, and the KMTNet 1.6-meter Telescope. This image also features scattered boulders and desert plants (left) of Cerro Tololo. Before being purchased in 1967 to create an astronomical observatory, the land upon which CTIO stands supported a handful of subsistence farmers and goat herders. As the site’s old inhabitants voluntarily left for better prospects in nearby towns, much of the desert surrounding Cerro Tololo slowly returned to its natural state. Native species of desert plants and animals once in danger of extinction have returned to the area, and CTIO now hosts not only cutting-edge astronomical telescopes but also …

3 June 2020: The Silver Sliver Galaxy — more formally known as NGC 891 — is shown in this striking image from the Mosaic instrument on the 4-meter Nicholas U. Mayall Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. NGC 891 is a spiral galaxy that lies almost perfectly edge-on to us, leading to its elongated appearance and its striking resemblance to our home galaxy, the Milky Way, as seen from the Earth. Since NGC 891 is oriented edge-on, it’s great for investigating the galactic fountain model. When stellar winds and supernovae from the disk of a galaxy eject gas into the surrounding medium, it can create condensation that rains back down onto the disk. The condensed gas then provides new fuel for star formation. In addition to the portrait of NGC 891, this image is littered with astronomical objects near and far — bright foreground stars from our own …

27 May 2020: We are so accustomed to skies full of light pollution that this photograph of the Milky Way appears almost unreal in its vividness. It was taken at the site of the KPNO 2.1-meter Telescope of the Kitt Peak National Observatory, a Program of NSF’s NOIRLab. The locations for advanced telescopes are chosen based on several key criteria: the lack of artificial light sources nearby, an arid environment, and clear skies. Not only do these conditions facilitate science-quality telescopic observations, but they make for extraordinary astrophotography.

20 May 2020: If you took only a quick glance at this image, you might think that the dark patches occulting the stars were smoke, rising from the ground. In fact this dazzling image — taken on Maunakea, Hawai’i at the northern site of the international Gemini Observatory (right), a program of NSF’s NOIRLab — shows the Milky Way in vivid detail, allowing us to see not only the stars, but the dusty regions which block their light. Tiny flecks mostly inorganic matter make up cosmic dust which in turn forms enormous obscuring clouds. The dark, smoke-like trail through the heart of the Milky Way is one such cloud, known as the Great Rift, containing more mass than 1 million suns

13 May 2020: In this time-exposure photo, the center of the Milky Way glows in various colors — an effect invisible to oneʻs eyes — above the Cerro Tololo Inter-American Observatory (CTIO), a program of NSF’s NOIRLab. The heart of our galaxy is best viewed from the southern hemisphere and areas near the equator (such as Hawaiʻi) because of its orientation relative to the Earth. Thanks to its location in the mountains of northern Chile, CTIO makes the southern skies accessible to US astronomers. As well as hosting large research telescopes, CTIO accommodates a variety of smaller tenant observatories. The small domes populating the lower left of this image belong to PROMPT, one such tenant observatory. As the name suggests, these telescopes are built for quick observations which support time-domain astronomy — in particular observing the aftermath of gamma-ray bursts, tremendously powerful and distant explosions which can last only fractions of a second. …

6 May 2020: The two galaxies in this image — NGC 672 (top right) and IC 1727 (bottom left) — appear to be so close that they are almost elbowing each other, like playful children. In fact, the galaxies shown in this beautifully detailed image taken at the Kitt Peak National Observatory, a program of NSF’s NOIRLab, are classified as a galactic pair, and the gravity of each galaxy influences the other. The pair are located around 20 million light-years away from Earth and the space between them spans over 80,000 light-years, a seemingly enormous gap. However, from the perspective of the galaxies themselves, that separation is not so significant, as it is roughly equivalent to the size of the galaxies themselves.

29 April 2020: Take a peek at the inner workings of a world-class observatory in this image of the international Gemini Observatory, a program of NSF’s NOIRLab. Illuminated by the Moon outside this picture, the open structure of silver beams holding the secondary mirror (center) allows cool night air to pass freely between the mirrors. Combined with the open sides of the dome, the entire design ensures a uniform temperature matching the outside environment. Any variations of temperature create local turbulence that blurs astronomical images. Although this is a picture of the Gemini South telescope in Chile, its twin, the Gemini North telescope in Hawai’i is identical in its layout.

22 April 2020: The stars and dust lanes of the Milky Way hang above telescope domes in this richly hued image of Cerro Tololo Inter-American Observatory (CTIO), a program of NSF’s NOIRLab. The two bright, wispy ovals to the right are the Large and Small Magellanic Clouds, dwarf galaxies visible only in the southern hemisphere. The band of color along the horizon is a phenomenon known as airglow, a visible reaction between molecules in Earth’s atmosphere and solar radiation. In this picture are the Curtis Schmidt Telescope (left), the Víctor M. Blanco 4-meter Telescope (middle), and the SMARTS 1.5-meter Telescope (right). These telescopes, alongside 12 others, comprise CTIO, the principal ground-based optical platform for US astronomical investigation of the southern skies.

15 April 2020: The glow behind the 3.5-meter WIYN telescope looks like a celestial aura, but it is really a phenomenon known as the Zodiacal Light. This faint glow, created by the scattering of light by small dust particles left over from the formation of our Solar System, is only visible during evening and morning twilight (in the west and east, respectively) and along the plane of the Solar System or the zodiac (hence the name zodiacal light). The WIYN telescope is part of the Kitt Peak National Observatory (KPNO), a program of NSF’s NOIRLab. Also visible is the brilliant light of the planet Venus just above the telescope’s dome.