Image of the Week

22 February 2023: Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab, is shown here at dusk. In the foreground is the WIYN 0.9-meter Telescope while standing prominently on the far left hilltop is the Nicholas U. Mayall 4-meter Telescope. The pinkish band near the horizon is known as the Belt of Venus, an atmospheric phenomenon created by sunlight scattered in Earth’s atmosphere shortly after sunset, right above the Earth Shadow. NOIRLab operates the Mayall telescope on behalf of the US Department of Energy's Dark Energy Spectroscopic Instrument (DESI) survey. NOIRLab also hosts facilities belonging to a number of consortia that operate more than a dozen optical telescopes and two radio telescopes between them. KPNO is located 90 kilometers (56 miles) southwest of Tucson, Arizona, at an altitude of 2096 meters (6877 feet) in the Schuk Toak District on the Tohono O'odham Nation. This image was taken before the 2022 Contreras Fire, …

15 February 2023: Gemini North, one half of the International Gemini Observatory, operated by NSF’s NOIRLab, looks distinctly peculiar in this week’s Image of the Week. Photographs of the telescopes are often taken during the day, and so the telescope domes are closed in a lot of images. Even when the dome is open, only part of the dome is ajar. However, in this image, we see the entire top of the telescope directed at an object in the night sky! The photographer created this curious image by capturing a dozen images of the observatory as the dome turned a full 180 degrees and then stacking the images together. With this photographic trick, it appears the dome has become mysteriously transparent. The odd, brightly lit appearance of Gemini North is juxtaposed with the sprawling brilliance of the Milky Way overhead.

8 February 2023: The smudge in the center of this image from the Dark Energy Camera (DECam), built by the US Department of Energy, is the elusive dwarf galaxy Donatiello II. It is one of six dwarf galaxies discovered by Italian amateur astronomer Giuseppe Donatiello. Three of them — Donatiello II, III and IV — were tucked away in the DECam images, and are now known to be satellites of the Sculptor Galaxy (NGC 253) (outside the field, to the far right). DECam is an instrument on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF’s NOIRLab. It combines a wide field of view with high sensitivity, meaning that it can scan large swathes of the night sky and also pick out the faint stars making up neighboring dwarf galaxies such as this one. The Milky Way shares its patch of the Universe with a whole …

1 February 2023: The beauty of the night sky is often a subtle one, but from the right location the Universe’s radiance truly emerges. Wide, clear skies perfect for exploration are luckily commonplace for Gemini South, the southern twin of the International Gemini Observatory, operated by NSF’s NOIRLab. This photo shows a brilliantly colored menagerie above and below Gemini South on Cerro Pachón. The telescope’s laser guide star system beams a column of light at the Milky Way. Our galaxy stretches like a belt across this photo, above the plethora of other objects. The most obvious of these are the Large and Small Magellanic Clouds at the bottom left of the center of the image. These galaxies are most conspicuous in the southern hemisphere and are easy to spot from Chile. Further to the left, near the horizon, is light generated from the nearby town of Andacollo. To the right of the …

25 January 2023: Maunakea, one of the volcanoes constituting the island of Hawai‘i, is an inactive shield volcano and one of the tallest mountains on Earth at an elevation of 4205 meters (13,786 feet). It’s home to Gemini North, one half of the International Gemini Observatory, operated by NSF’s NOIRLab. The summit of Maunakea makes for a fantastic astronomical observing location thanks to its high altitude, low humidity, and position far from and above most city lights. It’s also located above the tropical cloud cover that can obscure the view of the night sky around much of the rest of the island. The barren slopes of the volcano are clearly visible and if you zoom in you can see several telescopes, including Gemini North, on the snowy summit.

18 January 2023: As the Sun sets and its light scatters through Earth’s atmosphere, the Arizona sky glows in wondrous shades of vivid color. Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab, is the perfect location to enjoy these spectacular sunsets. Arid deserts, like the Arizona-Sonoran Desert where KPNO is located, display a clearer array of colors than areas where rain and humid weather are almost daily features. When heavy particles are present in the atmosphere, like water vapor, they absorb some of the sunlight and desaturate the colors. Through dry desert air, however, sunlight can pass unobstructed as it reaches our eyes. These natural conditions are helped by the clean air and low air pollution that are due to Arizona’s sparse population. For astronomers, the torrid, cleaner air enhances their ability to capture sharper data of the visible sky once the dark sets in. This photo was taken as part …

11 January 2023: The extent of our visual field is limited, and can process little information compared to its actual environment. But what would the night sky look like with a much wider field of view, like with a camera? In this panorama, the Milky Way sets the night ablaze in a bright glowing pillar, dividing the sky in two. On the right, the Gemini South telescope — one half of the International Gemini Observatory, operated by NSF’s NOIRLab — projects its laser guide star into the atmosphere. In the sky above the telescope, from left to right, lie the Small and Large Magellanic Clouds and the star Canopus. On the other end of the image is the SOAR Telescope — part of Cerro Tololo Inter-American Observatory, a Program of NOIRLab — with three stars above it forming the semblance of a triangle. The top left vertex is Denebola, the bottom Arcturus, …

4 January 2023: This observation captures the variable star HP Tau, which lies more than 550 light-years from Earth in the constellation Taurus. This image was created using data from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab. HP Tau is a T Tauri star, a young and chaotic type of star that is settling into a more sedate phase of stellar life known as the main sequence. The length of time that a star spends on the main sequence will depend on its mass. Our Sun, for example, is about halfway through its roughly 10-billion-year main-sequence lifetime. HP Tau is part of a triple star system — the three separate stars are visible at the center of this image — surrounded by a large arcing reflection nebula. These nebulae, as the name suggests, reflect the light from nearby stars rather than glowing like …

28 December 2022: The Gemini North telescope, part of the International Gemini Observatory, operated by NSF’s NOIRLab, is located near the summit of Maunakea in Hawai‘i. This timelapse image captures Gemini North (second from the left) along with five other telescopes located near the summit. Maunakea is one of the five volcanoes that constitutes the island of Hawai‘i. The summit of Maunakea lies 4.2 kilometers (2.6 miles) above sea level, placing it above most of the tropical clouds and humidity of Hawai‘i. In contrast to the general climate of the island, the local environment near the summit can become snowy from time to time. Generally, little rain falls in the area and the soil is not suitable for most plant life. Low oxygen levels also make it a somewhat hazardous place to be for long periods of time. However, the unique conditions at Maunakea’s summit are also precisely what make its environment suitable …

21 December 2022: We at NSF's NOIRLab would like to wish you the best this holiday season, and a peaceful and successful 2023! Check out our animated holiday card here. Happy Holidays, Felices Fiestas and Mele Kalikimaka and Hau‘oli Makahiki Hou!

14 December 2022: A full Moon is arguably the worst time to do any optical astronomy, whether it’s with a backyard telescope or at Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab, near Tucson, Arizona. But the full Moon does make for a spectacular view to the naked eye and in this shot beautifully illuminates the surrounding desert landscape. Taken from the west of KPNO, this image appears to show the Nicholas U. Mayall 4-meter Telescope eclipsing nearly half the diameter of the Moon after moonrise. The Mayall telescope is home to the Dark Energy Spectroscopic Instrument (DESI). DESI, led by the US Department of Energy, is acquiring the spectra of tens of millions of galaxies and quasars to construct a 3D map that will reveal the effects of dark energy in the Universe. This image was taken before the 2022 Contreras Fire, which affected KPNO. Read more here.

7 December 2022: Looking past Earth’s brightly lit atmosphere, incredibly brilliant and colorful celestial objects exist in the vast expanse of space. The Milky Way is the most conspicuous of these nighttime objects, captured here near Cerro Pachón in Chile, home to several facilities operated by NSF's NOIRLab, including half of the International Gemini Observatory, the SOAR Telescope and Vera C. Rubin Observatory. The Milky Way’s luminous disk is partially obscured by the interstellar clouds of dust known as the Great Rift. Some of the rift’s dark nebulae fragments appear to stretch into the nearby neighborhood of nebulae. The small grouping of colors is known as the Rho Ophiuchi cloud complex, a dynamic bunch made of reflection nebulae, scattering bright blue and yellow hues from nearby stars, and emission nebulae, diffusing the reddish glow of hot hydrogen gas. Hidden among this interstellar complex are the stars Rho Ophiuchi itself and the ‘heart’ of …

30 November 2022: This Image of the Week shows the lava flows from Mauna Loa caught by one of the International Gemini Observatory’s Cloudcams, which operates 24/7 near the snow-covered summit of Maunakea (the highest point in the image). Mauna Loa, on the island of Hawaiʻi, began erupting on 27 November 2022, when lava emerged from fissures in Moku‘āweoweo, Mauna Loa's caldera at the summit. The reddish glow from the flows can be seen across the island. Mauna Loa is the world's largest active volcano and has not erupted in nearly 40 years. The image was taken in the early morning at 02:15 am local time on 29 November. This eruption is being watched closely by all inhabitants of the island of Hawaiʻi. Staff at Gemini North, operated by NSF's NOIRLab, and the other Maunakea Observatories are monitoring with bated breath as the flows move down the flank of Mauna Loa towards the …

23 November 2022: A quartet of interacting galaxies is captured in this observation from Gemini South, which is one of the twin telescopes of the International Gemini Observatory, operated by NSF’s NOIRLab. The four galaxies in this image are collectively known as NGC 6845, and lie roughly 270 million light-years from Earth in a constellation named, appropriately, Telescopium. This constellation is one of a handful named after scientific instruments rather than animals or mythological figures. The galaxies in NGC 6845 come in two varieties: the pair of galaxies at the top of this image are well-defined spiral galaxies whereas the two below them are disk-shaped lenticular galaxies. Connecting the galaxies is evidence of star-forming regions and filaments made of stars detached from their original galaxies. Being relatively close neighbors, the galaxies in NGC 6845 are interacting. These gravitational interactions are subtly distorting the galaxies in NGC 6845, and astronomers believe that the two …

16 November 2022: This still image combines hundreds of time-lapse exposures that capture the entirety of the 8 November 2022 total lunar eclipse above the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab. Lunar eclipses occur when the Moon passes through the shadow of Earth. During a total lunar eclipse, when the whole Moon enters Earth’s shadow, our natural satellite is drenched in red. The period of totality is evident in this image by the red at the center of the lunar light ‘string.’ The other long streaks of light in the night sky are stars. These star trails form in the camera image as Earth turns. Polaris, the North Star, is the smallest trail in the top right corner of the image. On the ground, an observer drives down the hill, as revealed by the streak of their red tail lights, from the Mayall telescope. …

9 November 2022: Next to the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, a Program of NSF’s NOIRLab, a total lunar eclipse crawls across the desert sky in the early morning hours of yesterday in this week’s Image of the Week. The Milky Way, dotted by star-forming regions, arches over the telescope (explore in the zoomable image). This year, the typical two annual lunar eclipses were both total, something which hasn’t happened since 2018. You can see the other 2022 total lunar eclipse above Cerro Tololo International Observatory, another Program of NSF’s NOIRLab, in the Image of the Week here and in comparison shots here and a compilation of all 2022 lunar and solar eclipses here. For a total lunar eclipse to occur, the Moon must enter the innermost part of the Earth’s shadow, the umbra. The Moon doesn’t align within the shadow every time it is full, but the …

2 November 2022: Kitt Peak National Observatory (KPNO), a Program of NSF’s NOIRLab, is seen in this daytime aerial panorama of the Arizona-Sonoran Desert on the Tohono O'odham Nation in Arizona. The two largest telescopes, towards the center of the image, are the Nicholas U. Mayall 4-meter Telescope (center) and the UArizona Bok 2.3-meter Telescope (right). The Mayall telescope is currently fitted with the Dark Energy Spectroscopic Instrument (DESI), led by the US Department of Energy. The DESI Survey will measure the effect of dark energy. This mysterious energy is causing the expansion of the Universe to accelerate, instead of being slowed by the effects of gravity as initially expected by researchers before observations of distant objects were possible. By collecting the optical spectra of tens of millions of galaxies and quasars, researchers will use the DESI Survey to construct a 3D map of the nearby Universe and measure its expansion. This image …

26 October 2022: This long-exposure image, taken shortly before sunrise, shows stars appearing to “trail” around the south celestial pole (at the center of the circles) above the Southern Astrophysical Research Telescope (SOAR Telescope). The SOAR Telescope is part of Cerro Tololo Inter-American Observatory, a Program of NSF’s NOIRLab. These trails are caused by the rotation of Earth, which makes stars appear to streak over a long exposure. A few airplanes, shooting stars and satellite trails are also faintly visible. To produce clear, sharp images of stars, planets, and galaxies without the trails seen in this image, astronomical research telescopes like SOAR use sophisticated tracking and guiding systems to precisely follow their targets for hours at a time. Combined with their adaptive optics systems, modern telescopes are able to generate clear images of all types of celestial objects.

19 October 2022: This panorama shows a menagerie of telescopes — including Gemini North (right), one half of the International Gemini Observatory, operated by NSF’s NOIRLab — basking in a glorious snowy sunset near the summit of Maunakea in Hawai‘i. The 8-meter-diameter Gemini North is visible at the right hand edge of this image, and the 3.8-meter-diameter United Kingdom Infrared Telescope is the leftmost telescope in view. Other telescopes are dotted along the ridge in the background, including the Subaru Telescope and the W. M. Keck Observatory. The Maunakea Observatories study phenomena across the electromagnetic spectrum, from radio to ultraviolet, and they all benefit from the dark, dry, still skies at the site. Gemini North — like its twin telescope Gemini South in the southern hemisphere — has silver-coated mirrors optimized for observing at mid-infrared wavelengths. Infrared observations from ground-based observatories are usually limited by water vapor in the atmosphere, which absorbs …

12 October 2022: The constellation Coma Berenices hosts the galaxy NGC 4495 among myriad other astronomical objects. This galaxy has a tumultuous history: several supernovae have been recorded over the years, including the three named 1994S, 2010lo, and 2011ca. This last burst of energy from a dying star can be triggered by a number of different processes. 1994S, for example, was triggered by interactions between a white dwarf and another star, which reignited the core of the stellar remnant — a Type Ia supernova. 2011ca on the other hand is a Type Ic supernova, triggered by the core collapse of a single massive star. This image was captured by the DOE-built Dark Energy Camera (DECam) on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO) as part of the DESI Legacy Imaging Surveys. The DESI Legacy Imaging Surveys were conducted to identify targets for the Dark Energy Spectroscopic Instrument (DESI) …