Starship Asterisk*

A large number of bright stars, each with a cross-shape extending from its centre. In the centre there is a dense collection of foreground stars. Five are orange and the rest are blue. The black background is filled with small stars — most of them, however, larger than a single point.

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Image Credit: ESA/Hubble & NASA, A. Nota, G. De Marchi

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A small portion of the Small Magellanic Cloud (SMC) is pictured in this image from the NASA/ESA Hubble Space Telescope. The SMC is a dwarf galaxy and one of the Milky Way’s nearest neighbours, lying only about 200 000 light-years from Earth. It makes a pair with the Large Magellanic Cloud (LMC), and both objects can be seen from the southern hemisphere, as well as from some northern latitudes.

The Small Magellanic Cloud contains hundreds of millions of stars, but this image focuses on just a small fraction of them. These stars comprise the open cluster NGC 376, which has a total mass only about 3400 times that of the Sun. Open clusters, as the name suggests, are loosely bound and sparsely populated. This distinguishes open clusters from globular clusters, which are often so thronged with stars that they have a continuous blur of starlight at their centres. In the case of NGC 376, individual stars can be picked out clearly even in the most densely populated parts of this image.

The data in this image come from two different astronomical investigations which relied on two of Hubble’s instruments: the Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS). The first investigation used the ACS to explore a handful of star clusters in the Small Magellanic Cloud and help astronomers explore topics including the abundance of low- and high-mass stars in different environments. The second investigation used both the WFC3 and ACS, and aimed to answer fundamental questions about the lives of stars and help astronomers understand precisely where, when, why and how stars form.

Image Credit: NASA, ESA and G. Gilmore (University of Cambridge); Processing: Gladys Kober (NASA/Catholic University of America)

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A twinkling group of stars dominates the center of this image. NGC 2002 is an open star cluster that resides roughly 160,000 light-years away from Earth in the Large Magellanic Cloud, a satellite galaxy of our Milky Way containing numerous star-forming regions. NGC 2002 is about 30 light-years in diameter and is a relatively young cluster at 18 million years old.

The Large and Small Magellanic Clouds (LMC, SMC) are rich in young star clusters, making them ideal laboratories for studying stellar formation and evolution. In fact, the LMC and SMC are the only systems that contain star clusters at all stages of evolution while also being near enough to Earth to be fully resolved, meaning that one can make out and study individual stars.

NGC 2002 is more spherical than a typical open cluster, which is a type of star cluster that has low star density and an irregular shape due to the weak mutual gravitational attraction of its constituent stars. Individual stars in an open cluster can generally be observed, while the stars in a globular cluster – the other main type of cluster – are often too dense to make out even with powerful telescopes. Researchers used Hubble’s high resolution and sensitivity at discerning individual stars to study NGC 2002.

NGC 2002 contains about 1,100 stars. The more massive stars in the cluster tend to sink inwards towards the center, while the lighter stars move away from the center as the cluster evolves. Visible in the center of the cluster are five red supergiants, which are physically massive but cooler stars that are fusing helium after exhausting their hydrogen fuel.

Image Credit: NASA, ESA, and L. Bianchi (Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America)

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Open cluster KMHK 1231 is a group of stars loosely bound by gravity. Seen in the upper right of this Hubble Space Telescope image, this cluster in the Large Magellanic Cloud is surrounded by a crimson nebula of gas and dust extending across the image, where new stars may someday form. Orange and red in this image indicates visible and near-infrared light, respectively.

Open clusters are found in spiral and irregular galaxies, where star formation is common. They tend to form from the same cloud of gas and dust, so their stars share characteristics like age and chemical composition, providing excellent laboratories for studying how stars form and evolve. After a few million years, they may disperse into their galaxies. Hubble observed this particular cluster as part of a program to examine how ultraviolet light is absorbed by the material that exists in space between Earth and the Large Magellanic Cloud. This information helps astronomers discover how much light objects in the satellite galaxy to the Milky Way truly emanate, critical to determining the characteristics of these objects.

Image Credit: NOIRLab/NSF/AURA/Petr Horálek (Institute of Physics in Opava)

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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 Scorpius, Antares. ‘Above’ this vibrant group is a much larger deep red emission nebula known as Sh2-27, surrounding the star Zeta Ophiuchi.

The diffuse light to the right of the center is the gegenschein, which is caused by sunlight that is scattered back from dust particles in the outer Solar System. The dust that produces the zodiacal light and Gegenschein comes from a variety of sources, including comet tails and asteroid collisions.

This 170-megapixel photo was taken as part of the recent NOIRLab 2022 Photo Expedition to all the NOIRLab sites. Explore the details of the image with the zoom feature.

Image Credit: ESO/PHANGS

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The NGC 3627 galaxy, also known as Messier 66, appears to be expelling flames out of its majestic spiral arms in this Picture of the Week. The “fire” actually marks clouds of cold molecular gas, which is the material out of which stars form, and has been captured using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, of which ESO is a partner. The bluish regions in the background reveal the pattern of older, already formed stars, imaged by the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope (VLT) also in Chile.

Located approximately 31 million light-years from Earth in the constellation Leo, NGC 3627 is one of the many galaxies observed as part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) project. PHANGS is making high-resolution observations of nearby galaxies with telescopes operating across all colours or wavelengths of the electromagnetic spectrum. Different wavelengths can reveal a multitude of secrets about a galaxy, and by comparing them astronomers are able to study what triggers, boosts or hinders the birth of new stars.

Clouds of gas cover the entire view, in a variety of bold colours. In the centre the gas is brighter and very textured, resembling dense smoke. Around the edges it is more sparse and faint. Several small, bright blue stars are scattered over the nebula.

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Image Credit: ESA/Hubble & NASA, ESO, O. De Marco
Acknowledgement: M. H. Özsaraç

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A portion of the open cluster NGC 6530 appears as a roiling wall of smoke studded with stars in this image from the NASA/ESA Hubble Space Telescope. NGC 6530 is a collection of several thousand stars lying around 4350 light-years from Earth in the constellation Sagittarius. The cluster is set within the larger Lagoon Nebula, a gigantic interstellar cloud of gas and dust. It is the nebula that gives this image its distinctly smokey appearance; clouds of interstellar gas and dust stretch from one side of this image to the other.

Astronomers investigated NGC 6530 using Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Planetary Camera 2 (WFPC2). They scoured the region in the hope of finding new examples of proplyds, a particular class of illuminated protoplanetary discs surrounding newborn stars. The vast majority of proplyds have been found in only one region, the nearby Orion Nebula. This makes understanding their origin and lifetimes in other astronomical environments challenging.

Hubble’s ability to observe at infrared wavelengths — particularly with Wide Field Camera 3 (WFC3) — have made it an indispensable tool for understanding starbirth and the origin of exoplanetary systems. In particular, Hubble was crucial to investigations of the proplyds around newly born stars in the Orion Nebula. The new NASA/ESA/CSA James Webb Space Telescope’s (JWST) unprecedented observational capabilities at infrared wavelengths will complement Hubble observations by allowing astronomers to peer through the dusty envelopes around newly born stars and investigate the faintest, earliest stages of starbirth.

Image Credit: M. Hunt/KPNO/NOIRLab/NSF/AURA

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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 close to Tucson, several tens of miles/kilometers from KPNO, this image appears to show the Nicholas U. Mayall 4-meter Telescope (Mayall 4m) 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.