Globular Star Clusters

Ancient and giant, globular star clusters are stellar "dinosaurs" scattered throughout the universe. They can survive for billions of years, holding some of the oldest stars in the universe.

Globular star clusters contain anywhere from tens of thousands to millions of stars, packed tightly together in dense clumps ranging from 50 to 450 light-years across, and they can be found throughout the halo, or outer regions, of our own Milky Way galaxy. These stars formed within massive clouds of gas anywhere from about 8 to 13 billion years ago. Once formed, these roughly spherical star clusters were left without gas and dust to feed new star formation. There is, however, some evidence that some globular clusters can produce multiple generations of stars early in the cluster’s life.

Globular star clusters are associated with all types of galaxies. The Milky Way holds about 150 known globular clusters, many of which are in retrograde orbits, meaning they are orbiting the center of the galaxy in the opposite direction of most of the objects in the Milky Way. This indicates that our galaxy could have captured these clusters during an interaction with another galaxy. These clusters are born so dense and massive that they can remain a cluster even after being pulled apart by gravity over time.

Because they contain so many stars, globular clusters are often the most visibly obvious clusters. Sky watchers can see many of them with the unaided eye. The largest and brightest globular cluster in the Milky Way galaxy, Omega Centauri (NGC 5139), is one of the clusters visible without a telescope.

"Due to their strong compression of mass, they can also be used for gravitational lensing. https://defcon.social/@grobi/114653568101686376"

* Text excerpt from https://science.nasa.gov/universe/star-clusters-inside-the-universes-stellar-collections/

CREDIT
* Chelsea Gohd
NASA Universe Web Team

Please see ALT-Text for more information about Messier 2 (image below)

#space #cluster #astrophotography #photography #science #physics #nature #NASA

Open Clusters

Smaller than globular clusters, open clusters are more loosely bound groups that typically contain anywhere from tens to thousands of stars. Open star clusters have a core that typically measures a few light-years across that is surrounded by a corona, or the outermost part of a star’s atmosphere, that can stretch about tens of light-years out from the center.

Found in irregular galaxies and spiral galaxies like the Milky Way, open clusters contain both old and young stars and are generally much younger than globular clusters – typically they are less than a billion years old. Stars in open clusters are also more spread out, so these clusters are not very stable and the stars have a tendency to disperse after a few million years.

More plentiful in our galaxy than globular clusters, there are thousands of open clusters in the Milky Way, though it's thought that there could be many, many more. In the Milky Way, these clusters can be spotted in our galaxy's disk, both in and between its spiral arms.

* Text excerpt from https://science.nasa.gov/universe/star-clusters-inside-the-universes-stellar-collections/

CREDIT

* Chelsea Gohd
NASA Universe Web Team

Please see ALT-Text for more information about Messier 2 (image below)

#space #cluster #astrophotography #photography #science #physics #nature #NASA

Stellar Associations

While globular and open clusters are generally referred to as the two main types of star clusters, there is a third variety of stellar groupings, called stellar associations, which are the most dispersed of the bunch. In fact, the vast majority of stars are born as members of a stellar association before they move apart.

In the Milky Way, the highest concentration of stellar associations is in the galaxy's spiral arms. Stellar associations are very loose clusters of 10 to upwards of 10,000 stars. While they might hold fewer stars than other types of clusters, because the stars are so spread out, stellar associations can be very large, averaging 700 light-years across.

Stellar associations are categorized based on the types of stars they contain. OB associations are made up of O and B-type stars that are young and massive (B-type stars are typically 2 to 15 times more massive than the Sun and O-type stars are usually 15 to 90 times as massive); R associations have young, bright stars with a medium mass between 3 to 10 times the mass of the Sun; and T associations contain mostly T Tauri stars that are fairly cool, young stars with low mass similar to the mass of our Sun.
[...]
Please see the reply for more Information about Stellar Associations

* Text excerpt from https://science.nasa.gov/universe/star-clusters-inside-the-universes-stellar-collections/

CREDIT

* Chelsea Gohd
NASA Universe Web Team

Please see ALT-Text for more information about NGC 206
(image below)

#space #cluster #astrophotography #photography #science #physics #nature #NASA

[...]
The stars in stellar associations are so spread out that they defy the image of a "cluster." Visually, the stars in these clusters might not look bound together at all. This is because, while the stars in stellar associations formed together and continue to move together through space, they have become gravitationally unbound. As a result, stellar associations are the least stable variety of star cluster. However, many of the brightest stars in constellations like Scorpius, Lupus, Centaurus, and Crux as well as the bright star Antares are all a part of a stellar association located about 400 light-years away.

Because they are not as obvious as their counterparts, stellar associations can be hard to spot. But scientists can still determine if stars are part of the same cluster or have common origins based on key factors like the stars’ age, movement, and sometimes even their chemical composition.

* Text excerpt from https://science.nasa.gov/universe/star-clusters-inside-the-universes-stellar-collections/

CREDIT

* Chelsea Gohd
NASA Universe Web Team

Please see ALT-Text for more information
(image below)

#space #cluster #astrophotography #photography #science #physics #nature #NASA

2025 July 26

Globular Cluster Omega Centauri
* Image Credit & Copyright: Data acquisition - SkyFlux Team, Processing - Leo Shatz
https://app.astrobin.com/u/spinlock#gallery

Explanation:
Globular star cluster Omega Centauri packs about 10 million stars much older than the Sun into a volume some 150 light-years in diameter. Also known as NGC 5139, at a distance of 15,000 light-years it's the largest and brightest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence of different stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way. With a yellowish hue, Omega Centauri's red giant stars are easy to pick out in this sharp telescopic view. A two-decade-long exploration of the dense star cluster with the Hubble Space Telescope has revealed evidence for a massive black hole near the center of Omega Centauri.
https://app.astrobin.com/i/7na4mz
https://ui.adsabs.harvard.edu/abs/2021A%26A...653L...8L/abstract
https://en.wikipedia.org/wiki/Globular_cluster
https://earthsky.org/clusters-nebulae-galaxies/omega-centauri-milky-ways-prize-star-cluster/
https://esahubble.org/news/heic0809/

https://apod.nasa.gov/apod/ap250726.html

About Intermediate-Mass Black Hole in Omega Centauri:
https://defcon.social/@grobi/114918173169808417

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA

2025 August 7

The Double Cluster in Perseus
* Image Credit & Copyright: Ron Brecher
https://astrodoc.ca/about-me/

Explanation:
This stunning starfield spans about three full moons (1.5 degrees) across the heroic northern constellation of Perseus. It holds the famous pair of open star clusters, h and Chi Persei. Also cataloged as NGC 869 (right) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. Separated by only a few hundred light-years, the clusters are both 13 million years young based on the ages of their individual stars, evidence that both clusters were likely a product of the same star-forming region. Always a rewarding sight in binoculars or small telescopes, the Double Cluster is even visible to the unaided eye from dark locations.
https://astrodoc.ca/double-cluster-2025/
https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-caldwell-catalog/caldwell-14/
http://www.messier.seds.org/xtra/ngc/n0869.html
https://arxiv.org/abs/astro-ph/0205130

https://astrobackyard.com/double-cluster-in-perseus/
https://en.wikipedia.org/wiki/Perseus_(constellation)
http://www.messier.seds.org/open.html

https://apod.nasa.gov/apod/ap250807.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA

2025 August 14

M13: The Great Globular Cluster in Hercules
* Image Credit & Copyright: R. Jay Gabany
https://www.cosmotography.com/index.html

Explanation:
In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent." Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Sharp telescopic views like this one reveal the spectacular cluster's hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter. Approaching the cluster core, upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison with our neighborhood of the Milky Way, the closest star to the Sun is over 4 light-years away. Early telescopic observers of the great globular cluster also noted a curious convergence of three dark lanes with a spacing of about 120 degrees, seen here just below the cluster center. Known as the propeller in M13, the shape is likely a chance optical effect of the distribution of stars viewed from our perspective against the dense cluster core.
http://www.messier.seds.org/m/m013.html
https://science.nasa.gov/missions/hubble/a-celestial-snow-globe-of-stars/
https://www.cosmotography.com/images/small_ngc6205.html

https://en.wikipedia.org/wiki/Globular_cluster
http://www.messier.seds.org/xtra/similar/halley_pt.html
https://www.bbc.co.uk/history/historic_figures/halley_edmond.shtml
https://skyandtelescope.org/observing/gobs-of-globs-guide-to-16-spring-globular-clusters/

https://apod.nasa.gov/apod/ap250814.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA

2025 September 5

47 Tucanae: Globular Star Cluster
* Image Credit & Copyright: Carlos Taylor
https://app.astrobin.com/u/CAPastrophotography#gallery

Explanation:
Also known as NGC 104, 47 Tucanae is a jewel of the southern sky. Not a star but a dense cluster of stars, it roams the halo of our Milky Way Galaxy along with some 200 other globular star clusters. The second brightest globular cluster (after Omega Centauri) as seen from planet Earth, 47 Tuc lies about 13,000 light-years away. It can be spotted with the naked eye close on the sky to the Small Magellanic Cloud in the constellation of the Toucan. The dense cluster is made up of hundreds of thousands of stars in a volume only about 120 light-years across. Red giant stars on the outskirts of the cluster are easy to pick out as yellowish stars in this sharp telescopic portrait. Tightly packed globular star cluster 47 Tuc is also home to a star with the closest known orbit around a black hole.
http://www.messier.seds.org/xtra/ngc/n0104.html
http://www.messier.seds.org/xtra/ngc/n0104.html
http://www.ianridpath.com/startales/tucana.html
https://app.astrobin.com/u/CAPastrophotography?i=y6g3ax#gallery

https://apod.nasa.gov/apod/ap250905.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA

2025 October 3

Pandora's Cluster of Galaxies
* Image Credit: NASA, ESA, CSA, Ivo Labbe (Swinburne), Rachel Bezanson (University of Pittsburgh)
https://www.nasa.gov/
https://www.esa.int/
https://www.asc-csa.gc.ca/eng/
* Processing: Alyssa Pagan (STScI)
https://www.stsci.edu/

Explanation:
This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 recorded by the James Webb Space Telescope's NIRCam. Also dubbed Pandora's Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters. It lies some 3.5 billion light-years away, toward the constellation Sculptor. Dominated by dark matter, the mega-cluster warps and distorts the fabric of spacetime, gravitationally lensing even more distant objects. Redder than the Pandora cluster galaxies, many of the lensed sources are very distant galaxies in the early Universe, their lensed images stretched and distorted into arcs. Of course, distinctive diffraction spikes mark foreground Milky Way stars. At the Pandora Cluster's estimated distance, this cosmic box spans about 6 million light-years. But don't panic. You can explore the tantalizing region in a 2 minute video tour.
https://science.nasa.gov/missions/webb/nasas-webb-uncovers-new-details-in-pandoras-cluster/
FYI in Gravitational Lensing you might want to see:
https://defcon.social/@grobi/114374350096488478

https://apod.nasa.gov/apod/fap/ap220319.html

https://apod.nasa.gov/apod/ap251003.html <- Due to the lapse in federal government funding, NASA is not updating this website.

#NASA #inofficial #space #cluster #astrophotography #photography #science #astronomy #physics #nature

Take a Tour of Pandora’s Cluster

This video tours Pandora’s Cluster (Abell 2744), a region where multiple clusters of galaxies are in the process of merging to form a megacluster. Astronomers estimate 50,000 sources of near-infrared light are represented in this image from NASA’s James Webb Space Telescope.

The concentration of mass in Pandora’s Cluster is so great that the fabric of spacetime is warped by gravity, creating an effect that makes the region of special interest to astronomers: a natural, super-magnifying glass called a “gravitational lens” that they can use to see very distant sources of light beyond the cluster that would otherwise be undetectable, even to Webb. These lensed sources, which are particularly prominent in the lower right area, appear red in the image, and often as elongated arcs distorted by the gravitational lens.

The video also highlights a mysterious object that appears to be no more than a red dot. One theory is that this source of infrared light is a glowing disk of gas surrounding a supermassive black hole in the early universe.

Credit
Video: STScI, Danielle Kirshenblat; Music: PremiumBeat Music, Klaus Hergersheimer; Science: Ivo Labbe (Swinburne), Rachel Bezanson (University of Pittsburgh); Image Processing: STScI, Alyssa Pagan

https://science.nasa.gov/asset/webb/take-a-tour-of-pandoras-cluster/ <- Due to the lapse in federal government funding, NASA is not updating this website.

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA

Abell 2744: Pandora's Cluster Revealed

X-ray, Optical & Lensing Map Images of Abell 2744

One of the most complicated and dramatic collisions between galaxy clusters ever seen is captured in this new composite image. This collision site, known officially as Abell 2744, has been dubbed "Pandora's Cluster" because of the wide variety of different structures seen. Data from NASA's Chandra X-ray Observatory are colored red, showing gas with temperatures of millions of degrees. In blue is a map showing the total mass concentration (mostly dark matter) based on data from the Hubble Space Telescope (HST), the European Southern Observatory's Very Large Telescope (VLT), and the Japanese Subaru telescope. Optical data from HST and VLT also show the constituent galaxies of the clusters.

The "core" region shows a bullet-shaped structure in the X-ray emitting hot gas and a separation between the hot gas and the dark matter. (As a guide, local peaks in the distribution of hot gas and overall matter in the different regions are shown with red and blue circles respectively). This separation occurs because electric forces between colliding particles in the clouds of hot gas create a friction that slows them down, while dark matter is unaffected by such forces.

In the Northwest ("NW") region, a much larger separation is seen between the hot gas and the dark matter. Surprisingly, the hot gas leads the "dark" clump (mostly dark matter) by about 500,000 light years. [...]

https://chandra.harvard.edu/photo/2011/a2744/

CREDIT
X-ray: NASA/CXC/ITA/INAF/J.Merten et al
Lensing: NASA/STScI; NAOJ/Subaru; ESO/VLT
Optical: NASA/STScI/R.Dupke)

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA #education

2022 May 12

Young Stars of NGC 346
* Image Credit: NASA, ESA -
https://www.nasa.gov/
https://www.esa.int/
* acknowledgement: Antonella Nota (ESA/STScI) et al.
https://www.stsci.edu/

Explanation:
The massive stars of NGC 346 are short lived, but very energetic. The star cluster is embedded in the largest star forming region in the Small Magellanic Cloud, some 210,000 light-years distant. Their winds and radiation sweep out an interstellar cavern in the gas and dust cloud about 200 light-years across, triggering star formation and sculpting the region's dense inner edge. Cataloged as N66, the star forming region also appears to contain a large population of infant stars. A mere 3 to 5 million years old and not yet burning hydrogen in their cores, the infant stars are strewn about the embedded star cluster. In this false-color Hubble Space Telescope image, visible and near-infrared light are seen as blue and green, while light from atomic hydrogen emission is red.
https://science.nasa.gov/asset/hubble/young-stars-sculpt-gas-with-powerful-outflows-in-the-small-magellanic-cloud/
https://chandra.harvard.edu/edu/formal/stellar_ev/story/index2.html

https://apod.nasa.gov/apod/ap220512.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA

2025 November 26

Globular Cluster M15 Deep Field
* Image Credit & Copyright: Alvaro Ibanez Perez
https://aipastroimaging.com/sobre-mi/

Explanation:
Stars, like bees, swarm around the center of bright globular cluster M15. The central ball of over 100,000 stars is a relic from the early years of our Galaxy, and continues to orbit the Milky Way's center. M15, one of about 150 globular clusters remaining, is noted for being easily visible with only binoculars, having at its center one of the densest concentrations of stars known, and containing a high abundance of variable stars and pulsars. The featured image of M15 was taken by combining very long exposures -- 122 hours in all -- and so brings up faint wisps of gas and dust in front of the giant ball of stars. M15 lies about 35,000 light years away toward the constellation of the Winged Horse (Pegasus).
https://science.nasa.gov/universe/stars/
https://apod.nasa.gov/apod/ap980719.html
https://science.nasa.gov/resource/the-milky-way-galaxy/
https://apod.nasa.gov/apod/ap241124.html
https://www.youtube.com/watch?v=hmN7Rj2ns3M
https://en.wikipedia.org/wiki/Globular_cluster
https://apod.nasa.gov/apod/ap000804.html
https://apod.nasa.gov/apod/ap070415.html
https://svs.gsfc.nasa.gov/10144
https://en.wikipedia.org/wiki/Integrated_Flux_Nebula
https://apod.nasa.gov/apod/ap190328.html
https://spaceplace.nasa.gov/constellations/en/
https://en.wikipedia.org/wiki/Pegasus_(constellation)

https://apod.nasa.gov/apod/ap251126.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA #apod

2025 December 4

Galaxies in the Furnace
* Image Credit & Copyright: Simone Curzi and the ShaRA Team
https://app.astrobin.com/u/MRWSKYLOVER?i=0ym89c#gallery
https://astrotrex.wordpress.com/2024/12/16/shara11-fornax-a-and-a-potential-discovery/

Explanation:
An example of violence on a cosmic scale, enormous elliptical galaxy NGC 1316 lies about 75 million light-years away toward Fornax, the southern constellation of the Furnace. Investigating the startling sight, astronomers suspect the giant galaxy of colliding with smaller neighbor NGC 1317 seen just right of the large galaxy's center, causing far flung loops and shells of stars. Light from their close encounter would have reached Earth some 100 million years ago. In the sharp telescopic image, the central regions of NGC 1316 and NGC 1317 appear separated by over 100,000 light-years. Complex dust lanes visible within also indicate that NGC 1316 is itself the result of a merger of galaxies in the distant past. Found on the outskirts of the Fornax galaxy cluster, NGC 1316 is known as Fornax A. One of the visually brightest of the Fornax cluster galaxies it is one of the strongest and largest celestial radio sources with radio emission extending well beyond this one degree wide field-of-view.
https://earthsky.org/constellations/fornax-the-furnace-galaxy-hubble-ultra-deep-field/
https://science.nasa.gov/mission/hubble/multimedia/hubble-images/
https://chandra.harvard.edu/photo/cosmic_lookback.html
https://app.astrobin.com/u/MRWSKYLOVER?i=0ym89c#gallery
http://www.atlasoftheuniverse.com/galgrps/for.html
https://apod.nasa.gov/apod/ap050628.html

https://apod.nasa.gov/apod/ap251204.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA #apod

"According to wikipedia-de , the Fornax cluster has the fourth strongest radio source in the sky at a frequency of 1400 MHz
https://de.wikipedia.org/wiki/Fornax-Galaxienhaufen "

2005 June 28

The Giant Radio Lobes of Fornax A
* Credit: Ed Fomalont (NRAO) et al., VLA, NRAO, AUI, NSF

Explanation:
Together, the radio lobes span over one million light years -- what caused them? In the center is a large but peculiar elliptical galaxy dubbed NGC 1316. Detailed inspection of the NGC 1316 system indicates that it began absorbing a small neighboring galaxy about 100 million years ago. Gas from the galactic collision has fallen inward toward the massive central black hole, with friction heating the gas to 10 million degrees. For reasons not yet well understood, two oppositely pointed fast moving jets of particles then developed, eventually smashing into the ambient material on either side of the giant elliptical galaxy. The result is a huge reservoir of hot gas that emits radio waves, observed as the orange (false-color) radio lobes in the above image. The radio image is superposed on an optical survey image of the same part of the sky. Strange patterns in the radio lobes likely indicate slight changes in the directions of the jets.

https://apod.nasa.gov/apod/ap050628.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA #apod

2025 December 28

NGC 1898: Globular Cluster in the Large Magellanic Cloud
* Image Credit: ESA/Hubble & NASA
https://www.esa.int/
https://science.nasa.gov/mission/hubble/
!>https://www.nasa.gov/

Explanation:
Jewels don't shine this bright -- only stars do. And almost every spot in this jewel-box of an image from the Hubble Space Telescope is a star. Now, some stars are more red than our Sun, and some more blue -- but all of them are much farther away. Although it takes light about 8 minutes to reach Earth from the Sun, NGC 1898 is so far away that it takes light about 160,000 years to get here. This huge ball of stars, NGC 1898, is called a globular cluster and resides in the central bar of the Large Magellanic Cloud (LMC) -- a satellite galaxy of our Milky Way Galaxy. The featured multi-colored image includes light from the infrared to the ultraviolet and was taken to help determine if the stars of NGC 1898 all formed at the same time or at different times. There are increasing indications that most globular clusters formed stars in stages, and that, in particular, stars from NGC 1898 formed shortly after ancient encounters with the Small Magellanic Cloud (SMC) and our Milky Way Galaxy.
https://science.nasa.gov/mission/hubble/overview/about-hubble/
https://science.nasa.gov/sun/
https://apod.nasa.gov/apod/ap220206.html
https://chandra.harvard.edu/photo/cosmic_distance.html
https://esahubble.org/images/potw1840a/zoomable/
https://en.wikipedia.org/wiki/Globular_cluster
https://apod.nasa.gov/apod/ap180516.html
https://apod.nasa.gov/apod/ap180428.html
https://en.wikipedia.org/wiki/Satellite_galaxies_of_the_Milky_Way#List
https://www.atlasoftheuniverse.com/milkyway.html
https://esahubble.org/images/potw1840a/
https://science.nasa.gov/ems/07_infraredwaves/
https://science.nasa.gov/ems/10_ultravioletwaves/
https://archive.stsci.edu/proposal_search.php?mission=hst&id=13435

https://apod.nasa.gov/apod/ap160725.html
https://apod.nasa.gov/apod/ap100903.html

https://apod.nasa.gov/apod/ap251228.html

#space #cluster #astrophotography #photography #science #astronomy #physics #nature #NASA #apod