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Mars (left) near the globular cluster M22 in Sagittarius, November 8, 2014. This is a stack of 8 x 1.5 and 2 minute exposures, with the Canon 6D and the TMB 92mm refractor at f/4.4. Taken from my winter home near Silver City, New Mexico.
This is one of the great globular clusters catalog by French astronomer Charles Messier; it is an elliptical cluster in the constellation of Sagittarius near the Milky Way’s galactic center. It is approximately 10,600 light years distant from Earth and of 5.1 magnitude. An interesting feature about this globular cluster is that it is one of the few known clusters to have a planetary nebula.
Image Profile:
Lee, IL
Type: LRGB
Frames: L 10x180 1x1; RGB 10x180 2x2
Imaging Date: 20140709
Hardware:
-Main scope: AT8RC
-Guiding Scope: Orion 80mm Short Tube
-CCD: QHY9M with filter wheel with LRGB Ha
-Orion Atlas Mount
Imaging Applications:
-Acquiring: Nebulosity Ver. 3.0.2
-Guiding: PHD Ver. 1.11.3
Processing Applications:
-CCD Stack
-Photoshop cs3
Comments: The moon was more than 80% full, it set at 3:43 leaving only less than an hour of the darkness since the sunrise twilight started around 4:30am. Temp 62F. Fairly clear skies otherwise.
This image from the Hubble Space Telescope reveals an ancient, glimmering ball of stars called NGC 1466. It is a globular cluster — a gathering of stars all held together by gravity — that is slowly moving through space on the outskirts of the Large Magellanic Cloud, one of our closest galactic neighbors.
Like batches of cookies, stars are born together in groups. These star clusters, containing as many as 1 million members, evolve over time largely through a gravitational pinball where more massive stars are segregated from lower mass stars. Heavy stars tend to progressively sink toward the central region of the star cluster, while low-mass stars can escape from the system.
For more information, visit: hubblesite.org/contents/news-releases/2019/news-2019-42
Credit: ESA and NASA
This globular cluster seems to lie right on the border of where the Milky Way starts to get really busy in the Summer Triangle. Just east of it is where you get to the bright star clouds in Cygnus. This cluster can be found about halfway between Albireo and Sulafat. At about 13 kpc distant (Pietrukowicz, et al, arxiv:0806:1515), it is farther from Earth than the center of the Milky Way is. The stars in it have an especially low content of elements heavier than hydrogen and helium.
This image is from a stack of 17 60 s exposures under Bortle 3 skies with a one-shot color Atik 314L+ on a Celestron Edge HD 925 at f/2.3 with Hyperstar. Preprocessing in Nebulosity; registration, stacking, and initial processing in PixInsight; final processing in Photoshop.
North is at the top in this image. The brighter red star in the upper right is HD 180450.
Comet Lemmon (C/2012 F6) passing close to 47 Tucanae globular cluster and the Small Magellanic Cloud
galaxy in the southern hemisphere.
Single exposure, ISO 3200, 60secs with Canon 135mm f/2.0L lens at f/2.0 on an Olympus E-M5 camera.
No cropping, minor tonal adjustments and purple defringing
Recipe:
Cabbage and Barley Broth with Tahini
1 small onion, thinly sliced
1 clove of garlic
4 oz / 125g cabbage, finely shredded or sliced
1/2 table spoon Tahini
1 table spoon olive oil
1 bay leaf
Vegetable stock or water and Vecon
Salt and pepper and Tahini to taste
Soak and cook the barley and keep the cooking water.
Fry the onion and garlic gently for about 5 minutes without browning.
Add the cabbage and the barley with the cooking water and make it up to 2 pints/1 litre with vegetable stock or water and Vecon.
Bring to the boil, add the bay leaf and simmer for 3-5 minutes until the cabbage is just cooked but still crunchy.
Remove from the heat and stir in the tahini to taste.
fun facts:
The cabbage is a herbaceous, globular cluster flowering leafy plant vegetable of the species Brassicaceae (or Cruciferae).
Labor Day Observing marathon. BTW, I've been controlling the mount directly from Stellarium using the ASCOM standard leading to 100% pointing accuracy on the camera sensor....Awesome! More time shooting, less time hunting. The Orion SynScan was always hit and miss.
This image was first a test of the new QHY600 OSC camera using only 15mins of exposure using a Takahashi FSQ106 EDX3.
I was surprised by the result for only 15 minutes of exposure...
Main objects visible:
MESSIER 8, NGC 6523, NGC 6530 - LAGOON NEBULA AND CLUSTER
The Lagoon Nebula, Messier 8 (NGC 6523) is one of the finest star-forming regions in the sky, and is faintly visible to the naked eye. It is a giant glowing cloud of interstellar gas, divided by a dark lane of dust, containing a cluster of young stars (NGC 6530) that have formed from it.
The brightest parts of the Lagoon Nebula contain a feature known as the "Hourglass Nebula", discovered and named by John Herschel. This is in a region where vivid star formation is taking place, and its bright emission is caused by heavy excitation from very hot, young stars.
The nebula also contains a number of dark globules which represent collapsing clouds of protostellar material. The most prominent of these dark patches were catalogued by E. E. Barnard: B 88, a comet-shaped globule extended North-to-South in the nebula's eastern half; B 89, a smaller dark nebula near the cluster NGC 6530; and B 296, a long, narrow black patch at the nebula's south edge.
Properties and Cluster
The Lagoon Nebula lies in the heart of the galaxy's Sagittarius-Carina spiral arm, but its distance is a bit uncertain. Estimates range from 4,800 to 6,500 light years, with 5,200 quoted by many sources. A 2006 study found a distance of 4,100 light years, which would make its true size about 110 x 50 light years. The nebula probably has a depth comparable to its linear dimensions. The dark "Bok" globules of collapsing protostellar material have diameters of about 10,000 AU.
Hubble Space Telescope image of the "hourglass" structure at the center of M 8.
The western half of M 8 is primarily illuminated by the magnitude 5.97 star 9 Sagittarii, an extremely hot O5 star which radiates 44 times more high-energy ultraviolet than visual light. At visual wavelengths, 9 Sagittarii is 23,000 times brighter than our Sun! The illuminator of the "Hourglass" feature is the hot star Herschel 36 (mag 9.5, spectral class O7). In 2006, four Herbig-Haro objects were detected within the Hourglass, providing the first direct evidence of active star formation by accretion within it.
The hot O-type stars of the young open cluster NGC 6530 are fluorescing the eastern part of the nebula. As their light shows little reddening by interstellar matter, this cluster is probably situated just in front of the Lagoon Nebula. Its brightest star is a hot, mag 6.9 class O5 star, with an age around 2 million years. The cluster also contains one extremely hot, peculiar star of spectral type Of, with spectral lines of ionized Helium and Nitrogen.
MESSIER 20, NGC 6514 - TRIFID NEBULA
Messier 20 (NGC 6514) is also known as the Trifid Nebula. Named for its three-lobed appearance, it is one of the most famous objects in the sky. This object is an unusual combination of an open cluster of stars, an emission nebula, a reflection nebula, and a dark nebula that divides the emission nebula into three parts.
The Trifid is nearly the size of the full moon, and contains both reddish emission and bluish reflection nebulosity. The red emission nebula, and young star cluster near its center, is surrounded by a blue reflection nebula which is particularly conspicuous at the northern end. The emission nebula spans a diameter of 15' around the central star. The fainter reflection nebula to the north, surrounding a yellowish magnitude 7.5 star, appears about half this size. Both sections of the nebula are enveloped by a faint outer haze that reaches a diameter of 30', and is more extensive to the east.
The relatively high surface brightness of M 20 provides a good contrast to its three dark, radial dust lanes. The three sections into which the dark lanes divide the nebula are unequal in area; the northern is largest, and the SW the smallest. The dark lanes themselves are unequal in length and width: the NE lane is longest and most distinct; the west lane is broad and short; and the south lane is thin and short. The lanes do not converge directly, but lead to a circular, mottled central area. High power reveals a short and very thin lane headed straight north from the inner half of the west lane.
Properties and Evolution
M 20 is estimated to lie about 5,200 light years away, on the far side of the same complex of nebulosity that includes the Lagoon Nebula, M 8. The Trifid's exact distance is rather uncertain, with estimates ranging from 2,200 to 9,000 light years. At the value of 5,200 light years adopted here, the Trifid spans a diameter about 10 light years across.
M 20 is only about 300,000 years old, making it among the youngest emission nebulae known. All of its bright central stars are extremely hot, of spectral type O5 to O7. They illuminate a dense pillar of gas and dust, producing a bright rim on the side facing them. Star formation is no longer occurring in the immediate vicinity of the central star cluster, because its intense radiation has blown away the gas and dust from which new stars are made.
RA: 18h 04m 53.5s
DEC: -24° 29’ 02.0“
Location: Sagittarius
Distance: 4,100 ly
Magnitude: 6.0
Captured July 17 2020
Fiel Of view: 3d 53' 50.7" x 2d 36' 26.0"
Total acquisition time of 15 mins.
Technical Details
Data acquisition: Martin PUGH
Processing: Nicolas ROLLAND
Location: Yass, New South Whales, Australia
RGB: 1 x 900sec
Optics: FSQ106 EDX3 @F/D 5.0
Mount: Paramount ME II
CCD: QHY600 OSC
Pre Processing: CCDstack & Pixinsight
Post Processing: Photoshop CC
Objects visible in the plate solved version:
NGC 6553 -- Globular cluster
NGC 6554 -- Open Cluster
NGC 6559 -- Star-forming region
IC 4685 -- Emission/reflection nebulae
IC 1274 -- HII (ionized) region
NGC 6530 -- Open cluster
Text source : Livesky.com
I am almost at the end of my UKMON Fireball Challenge, where I've been creating an astronomy sketch of piece of art every day for 2 months.
This is my sketch from day 58 and it's another globular cluster sketch, this time Messier 92. Sketched with pencil on white paper from one of my own photos. This is the digitally inverted version
Equipment used:
RASA 8", QHY128C, & EQ-8
That night my guider camera died so - short unguided exposures only, sum of 37 x 20 sec.
Crop 2K x 2K from the full frame.
One thing to notice here: image is obviously undersampled with QHY128C's 5.97μm pixel size, you have to choose camera with smaller pixel ~3μm to get the best out of RASA. 8' resolution
Messier 3
Credit: ESO/Dss2, Giuseppe Donatiello
FoV: 45'x45'
Colorized plate with RGB information taken with DSLR.
Another Messier object to check off the list, and the only one in Capricornus. The star to the left (east) is 41 Cap. If you look closely, you will see some tiny (very distant) galaxies that share the view with this globular cluster.
This image is a stack of 23 guided 90s exposures made with a Celestron Edge HD 925 at f/2.3 with HyperStar and an Atik 314L+ color CCD. Preprocessing in Nebulosity; stacking and initial processing in PixInsight; final touches in PS CS 5.1.
The image center (J2000) is at
RA 21h 40m 50s
DEC -23° 12' 6"
This image of globular star cluster Caldwell 81 combines visible and infrared observations taken with Hubble's Advanced Camera for Surveys.
Caldwell 81 is located roughly 20,000 light-years from Earth. The cluster is located in the constellation Ara and was discovered in 1826 by Scottish astronomer James Dunlop while he lived in Australia.
Credit: NASA, ESA, A. Sarajedini (Florida Atlantic University); Processing: Gladys Kober (NASA/Catholic University of America)
For Hubble's Caldwell catalog website and information on how to find these objects in the night sky, visit:
Took another crack at globular cluster M13 last night, before the clouds came. One of my first astro images a few years back, this one's big improvement. However, must add "comma corrector" to kit. Also, that slight smudge to the upper left corner is galaxy NGC 6207, a very dim 11th magnitude galaxy way beyond the current capabilities of my current kit. It's nice when the camera picks up details that I'll never see in an eye piece.
NGC 5466 is a class XII (Shapley–Sawyer - almost no concentration towards the center) globular cluster in the constellation Boötes. Located 51,800 light years from Earth and 52,800 light years from the Galactic Center. (ref: Wikipedia)
Observation data (J2000 epoch)
Class: XII
Constellation: Boötes
Right ascension: 14h 05m 27.29s
Declination: +28° 32′ 04.0″
Distance: 51.9 kly
Apparent magnitude (V): 10.5
Apparent dimensions (V): 11
Tech Specs: Orion 8” RC Telescope, ZWO ASI2600MC camera running at -10F, 139 x 60 seconds, Celestron CGEM-DX pier mounted, ZWO EAF and ASIAir Pro, processed in PixInsight. Image Date: February 6, 2024. Location: The Dark Side Observatory (W59), Weatherly, PA, USA (Bortle Class 4).
NGC 6934 is a globular cluster of stars in the constellation Delphinus. It's located about 52,000 light-years from the Sun and is home to some of the most distant stars in the Milky Way galaxy.
NGC 6934 is located close to the celestial equator, so it's visible from both hemispheres at certain times of the year. Backyard scopes show a fuzzy disk of nebulosity, about 5 arc minutes in diameter with a brighter core. The cluster stars are estimated to be some 10 billion years old.
Observation data (J2000 epoch)
Class: VIII
Constellation: Delphinus
Right ascension: 20h 34m 11.37s
Declination: +07° 24′ 16.1″
Distance: 52 kly
Apparent magnitude (V): 8.83
Apparent dimensions (V): 1.20′
Tech Specs: Sky-Watcher Esprit 120ED Telescope, ZWO ASI2600MC camera running at 0F, 81x60 seconds guided exposures, Sky-Watcher EQ6R-Pro pier mounted, ZWO EAF and ASIAir Pro, processed in DSS and PixInsight. Image Date: July 11, 2023. Location: The Dark Side Observatory (W59), Weatherly, PA, USA (Bortle Class 4).
Almost like snowflakes, the stars of the globular cluster NGC 6441 sparkle peacefully in the night sky, about 13,000 light-years from the Milky Way’s galactic center. Like snowflakes, the exact number of stars in such a cluster is difficult to discern. It is estimated that together the stars have 1.6 million times the mass of the Sun, making NGC 6441 one of the most massive and luminous globular clusters in the Milky Way.
NGC 6441 is host to four pulsars that each complete a single rotation in a few milliseconds. Also hidden within this cluster is JaFu 2, a planetary nebula. Despite their name, planetary nebulas have little to do with planets. A phase in the evolution of intermediate-mass stars, planetary nebulas last for only a few tens of thousands of years, the blink of an eye on astronomical timescales.
There are about 150 known globular clusters in the Milky Way. Globular clusters contain some of the first stars to be produced in a galaxy, but the details of their origins and evolution still elude astronomers.
For more information: www.nasa.gov/image-feature/goddard/2020/hubble-catches-co...
Text credit: ESA (European Space Agency)
Image credit: ESA/Hubble & NASA, G. Piotto
Omega Centauri is at the focal point of another edition of Deep Space LIVE with astrophotographer Dietmar Hager at at the Ars Electronica Center’s Deep Space 8K.
credit: Ars Electronica / Robert Bauernhansl
A best of Ars Electronica photos can be found here.
Ars Electronica Center Linz
Ars-Electronica-Straße 1
4040 Linz
Austria
After reading a few articles on the globular cluster and the difficulties many amateur astronomers have had with this (at least on visual observations), I was curious if I could capture any data at all. NGC 6749 is nestled a dusty region of the constellation Aquila and has a magnitude of roughly 12.4. It is very faint and has a low surface brightness. Some references state that this is one of the faintest globular clusters in the entire NGC catalog.
The image shown is 21-minutes of collected data and you can clearly see the reddish glow in both images caused by looking “through” the Milky Way’s dust and gas. The cropped and zoomed image was further processed to boost the signal and clearly resolves some of the stars in this glob.
Tech Specs: Sky-Watcher Esprit 120mm ED Triplet APO Refractor, Canon 6D, ISO 3200, 21 x 60 seconds (with darks and bias frames), guided using a ZWO ASI290MC and 60mm guide scope. Stacked with DSS and processed in ImagesPlus. Image date: 29 July 2019. Location: The Dark Side Observatory in Weatherly, PA, USA.
My UKMON Fireball Challenge is to create an astronomy sketch or piece of astronomy inspired art every day for 2 months. This is my day 52 sketch, and I chose the Great Globular Cluster in Hercules, M13. I've never attempted to sketch a globular cluster before because I find them very intimidating to draw! I created this in layers, using one of my own photos from 2013 as a reference.
Sketched with graphite pencils on white paper. The finished sketch was scanned and a digitally inverted version was created as well as the original. I'm really pleased with how the centre of this sketch looks in this inverted version. The scale probably isn't perfect, but I like the overall effect.
ESA's star-surveying Gaia mission has released a treasure trove of new data as part of its ‘focused product release’. As part of this data release Gaia explored Omega Centauri, the largest globular cluster that can be seen from Earth and a great example of a ‘typical’ cluster.
The team has revealed 526 587 stars that Gaia had not seen before, detecting stars that lie too close together to be measured in the telescope’s regular pipeline and those in the cluster core that are up to 15 times fainter than previously seen. The new data reveal 10 times more stars in Omega Centauri; this new knowledge will enable researchers to study the cluster’s structure, how the constituent stars are distributed, how they’re moving, and more.
This image is from Gaia’s Data Release 3 in 2022. It is contrasted in a new slider with an image from today’s data release, to highlight just how many new sources have been imaged in the cluster’s centre. Only faint stars within Omega Centauri are plotted here.
Alt-text: This image shows a star cluster, which appears as a collection of bright stars against a dark background. The roughly circular cluster appears like a doughnut with an empty centre.
Acknowledgments: Michele Trabucchi, Nami Mowlavi and Thomas Lebzelter
Credits: ESA/Gaia/DPAC, CC BY-SA 3.0 IGO
The complete mosaic with this globular cluster and its surroundings can be viewed at flic.kr/p/2m84gRJ
Globular cluster M4 is the closest globular cluster to the Earth. It is situated in a very colorful part of the sky known as the Rho Ophiuchi dust complex. You can get a hint of the colors in the background of this image. This is part of the larger mosaic I am working on constructing around Antares. This is proving to be a good bit more challenging than the one near Sadr ( flic.kr/p/tYxubt ), mostly due to so many bright stars in the region. The gradients from the colors of interstellar dust and gas is also a challenge to work with.
The panels of the mosaic are stacks of 90 s shots. This portion includes 3 panels. There are 4 in the i Sco mosaic posted earlier (available at flic.kr/p/2gbsUqJ ). The 90 s shots were taken with a guided Celestron Edge HD 925 at f/2.3 with HyperStar and an Atik 314L+ one shot color camera. Preprocessing in Nebulosity with flats, darks, and bias frames; stacking, compiling the mosaic, and initial processing in PixInsight; final touches in PS CS 5.1.
Image center (J2000) is at
RA 16h 22m 57s
DEC -26° 23' 1"
The image spans about 1.5° x 1.0°.
Terzan 2 is a globular cluster in the constellation Scorpio. Globular clusters are stable, tightly gravitationally bound clusters of tens of thousands to millions of stars found in a wide variety of galaxies. The intense gravitational attraction between the closely packed stars gives globular clusters a regular, spherical shape. As a result, images of the hearts of globular clusters, such as this Hubble Space Telescope observation of Terzan 2, are crowded with a multitude of glittering stars.
Credit: ESA/Hubble & NASA, R. Cohen
For more information, visit: esahubble.org/images/potw2228a/
Noisy, but with more vivid colors. I reprocessed my image of M5.
99x180"
QHY8L
SW 200/1000 reflector
SW NEQ6-Pro
Optolong L-Pro filter
Description: The clusters, Arches (upper right), Quintuplet (upper center), and the GC cluster (bottom center), contain massive stars that appear as very bright, point-like X-ray sources when winds from their surfaces collide with those from an orbiting companion. Vast amounts of energy are also released when these stars explode as supernovas, heating the surrounding material. Stellar corpses in this image also emit X-rays as either neutron stars or black holes in binary systems. Collisions between the clusters themselves and cooler molecular clouds of gas contribute to the diffuse X-rays seen in this image.
Creator/Photographer: Chandra X-ray Observatory
NASA's Chandra X-ray Observatory, which was launched and deployed by Space Shuttle Columbia on July 23, 1999, is the most sophisticated X-ray observatory built to date. The mirrors on Chandra are the largest, most precisely shaped and aligned, and smoothest mirrors ever constructed. Chandra is helping scientists better understand the hot, turbulent regions of space and answer fundamental questions about origin, evolution, and destiny of the Universe. The images Chandra makes are twenty-five times sharper than the best previous X-ray telescope. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra science and flight operations from the Chandra X-ray Center in Cambridge, Massachusetts.
Medium: Chandra telescope x-ray
Date: 2004
Persistent URL: chandra.harvard.edu/photo/2006/gcenter/
Repository: Smithsonian Astrophysical Observatory
Collection: Milky Way Collection
Gift line: NASA/CXC/UMass Amherst/Q.D.Wang et al.
Accession number: gcenter
Globular star cluster NGC 2203, contains lots of astronomical treats that have helped astronomers puzzle together the lifetimes of stars. A "main sequence star" is the term used for a star during the longest period of its life, when it burns fuel steadily. Astronomers studying NGC 2203, which contains stars that are roughly twice as massive as our Sun, found that their rotation might be a factor as to why some of the stars stay longer than usual in this main-sequence phase of their life.
Credit: ESA/Hubble & NASA, L. Girardi
For more information, visit: www.spacetelescope.org/images/potw2030a/
Many colorful stars are packed close together in this Hubble Space Telescope image of the globular cluster NGC 1805. This tight grouping of thousands of stars is located near the edge of the Large Magellanic Cloud, a satellite galaxy of our own Milky Way. The stars orbit close to one another, like bees swarming around a hive. In the dense center of one of these clusters, stars are 100 to 1,000 times closer together than the nearest stars are to our Sun.
The striking difference in star colors shows in this image: blue stars, shining brightest in near-ultraviolet light, and red stars, illuminated in red and near-infrared.
Usually, globular clusters contain stars that are born at the same time; however, NGC 1805 is unusual as it appears to host two different populations of stars with ages millions of years apart. Observing such clusters of stars can help astronomers understand how stars evolve, and what factors determine whether they end their lives as white dwarfs, or explode as supernovae.
Credit: ESA/Hubble & NASA, J. Kalirai
For more information, visit: esahubble.org/images/potw2036a/
Neutron stars, the ultra-dense cores left behind after massive stars collapse, contain the densest matter known in the Universe outside of a black hole. New results from Chandra and other X-ray telescopes have provided one of the most reliable determinations yet of the relation between the radius of a neutron star and its mass. These results constrain how nuclear matter – protons and neutrons, and their constituent quarks – interact under the extreme conditions found in neutron stars.
Three telescopes -- Chandra, ESA's XMM-Newton, and NASA's Rossi X-ray Timing Explorer (RXTE) -- were used to observe 8 different neutron stars, including one in 47 Tucanae, a globular cluster located about 15,000 light years away in the outskirts of the Milky Way. The image shown here was constructed from a long Chandra observation of 47 Tucanae. Lower-energy X-rays are red, X-rays with intermediate energies are green, and the highest-energy X-rays are shown in blue.
In the image, the double, or binary, star system labeled as X7 contains a neutron star slowly pulling gas away from a companion star with a mass much lower than the Sun. In 2006, researchers used observations of the amount of X-rays from X7 at different energies together with theoretical models to determine a relationship between the mass and the radius of the neutron star. A similar procedure was used for Chandra observations of a neutron star in another globular cluster, NGC 6397, and for two other neutron stars in clusters observed by ESA’s XMM-Newton.
Four other neutron stars were observed with RXTE to undergo bursts of X-rays that cause the atmosphere of the neutron star to expand. By following the cooling of the star, its surface area can be calculated. Then, by folding in independent estimates of the distance to the neutron star, scientists were able to gather more information on the relationships between the masses and radii of these neutron stars.
Because the mass and radius of a neutron star is directly related to interactions between the particles in the interior of the star, the latest results give scientists new information about the inner workings of neutron stars.
The researchers used a wide range of different models for the structure of these collapsed objects and determined that the radius of a neutron star with a mass that is 1.4 times the mass of the Sun is between 10.4 and 12.9 km (6.5 to 8.0 miles). They also estimated the density at the center of a neutron star was about 8 times that of nuclear matter found in Earth-like conditions. This translates into a pressure that is over ten trillion trillion times the pressure required for diamonds to form inside the Earth.
The results apply whether the entire set of bursting sources, or the most extreme of the other sources, are removed from the sample. Previous studies have used smaller samples of neutron stars or have not accounted for as many uncertainties in using the models.
The new values for the neutron star's structure should hold true even if matter composed of free quarks exists in the core of the star. Quarks are fundamental particles that combine to form protons and neutrons and are not usually found in isolation. It has been postulated that free quarks may exist inside the centers of neutron stars, but no firm evidence for this has ever been found.
The researchers also made an estimate of the distances between neutrons and protons in atomic nuclei here on earth. A larger neutron star radius naturally implies that, on average, neutrons and protons in a heavy nucleus are farther apart. Their estimate is being compared with values from terrestrial experiments.
The neutron star observations also provided new information about the so-called "symmetry energy" for nuclear matter, which is the energy cost required to create a system with a different number of protons than neutrons. The symmetry energy is important for neutron stars because they contain almost ten times as many neutrons as protons. It is also important for heavy atoms on Earth, like Uranium, because they often have more neutrons than protons. The results show that the symmetry energy does not change much with density.
These results will be published in a paper in the March 1st, 2013 issue of The Astrophysical Journal Letters. The authors are Andrew Steiner, from the Institute for Nuclear Theory at the University of Washington, James Lattimer from Stony Brook University in New York and Edward Brown from Michigan State University.
NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.
Read entire caption/view more images: chandra.harvard.edu/photo/2013/47tuc/
Image credit: NASA/CXC/Michigan State/A.Steiner et al
Caption credit: Harvard-Smithsonian Center for Astrophysics
Read more about Chandra:
p.s. You can see all of our Chandra photos in the Chandra Group in Flickr at: www.flickr.com/groups/chandranasa/ We'd love to have you as a member!
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These official NASA photographs are being made available for publication by news organizations and/or for personal use printing by the subject(s) of the photographs. The photographs may not be used in materials, advertisements, products, or promotions that in any way suggest approval or endorsement by NASA. All Images used must be credited. For information on usage rights please visit: www.nasa.gov/audience/formedia/features/MP_Photo_Guidelin...
While choosing a photo to post today, I spent possibly too much time deciding if I should select this one. I had a feeling that I’d featured these fluffy, floating orbs–the Magellanic Clouds–too many times throughout 2020, and didn’t want to bore anyone. After a quick flick through my published images for the year, I found that this will be only the third time since January that I’ve brought them to you, and I hope that you’ll enjoy another look.
Despite their names, you’re not looking at clouds but two dwarf galaxies that are travelling through space with our Milky Way galaxy, at the relatively close distances of 163,000 light-years and 206,000 light-years from us, respectively. My photo managed to capture them both in the same frame, but that gap between the two irregular dwarf galaxies has been measured at around 75,000 light-years. Southern Hemisphere observers–and some from the lower northern latitudes–can see the Clouds in the night sky, even in light-polluted cities such as the one I live in, Sydney, Australia.
To create this photo, I shot eleven individual images of this part of the sky, then combined (stacked) those in software so that I could reduce the amount of digital signal noise in the scene. For each one of the eleven frames, I used a Canon EOS 6D Mk II camera, a Yongnuo 50mm f/1.4 lens @ f/2.0 using an exposure time of 8.0 seconds @ ISO 6400.
Hubble’s Wide Field Camera 3 captured this image in ultraviolet and visible light showing 100,000 stars in the core of Caldwell 80 (Omega Centauri) soon after the camera was installed in 2009. The stars’ colors give us information about them. Bright blue stars are old, hot stars that are fusing helium in their cores. Bright red stars are cool giants that are heading into old age. Dimmer red stars are cool dwarfs destined to live for a long time. White stars are typically middle-aged, average stars.
Credit: NASA, ESA, and the Hubble SM4 ERO Team
For Hubble's Caldwell catalog website and information on how to find these objects in the night sky, visit:
Messier 3 (ook M3 of NGC 5272) is een bolvormige sterrenhoop in het sterrenbeeld Jachthonden (Canes Venatici). Deze bolhoop is een van de grootste en helderste aan de hemel en bestaat uit ongeveer 500 000 sterren. Hij is net niet met het blote oog te zien, op magnitude 6.2. Vanuit mijn achtertuin in de stad lukt dat sowiesio niet.
Met mijn 15cm refractor kun je al veel individuele sterren in de kern zien, omgeven door een wazige vlek aan onopgeloste sterren. Door te fotograferen kom je een stuk dieper en zie je zeer veel sterren.
Opname : ruim 20 minuten met een "normale" Canon EOS90D - gecombineerd in Deep Sky Stacker en nabewerkt in Photoshop.
Kijker: APM 152ED f/7.9 refractor op AZ/EQ6 Montering.
Globular Cluster M3 - Messier 3
Messier 3 (M3; also NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici. This cluster is one of the largest and brightest clusters, and is made up of around 500,000 stars
M3 has an apparent magnitude of 6.2 making it a difficult naked eye target even with dark conditions with averted vision.
After more that 30 years of visually looking at the stars through telescopes this is one of my first images taken with my refractor :-)
More then 20 minutes exposure, stacked in Deep Sky Stacker. and processed with Photoshop.
Canon EOS90D on an APM 152ED refractor on AZ-EQ6 mount.
From SpaceTelescope.org, “NGC 7006 resides in the outskirts of the Milky Way. It is about 135,000 light-years away, five times the distance between the Sun and the center of the galaxy, and it is part of the galactic halo. This roughly spherical region of the Milky Way is made up of dark matter, gas and sparsely distributed stellar clusters.”
Observation data (J2000 epoch)
Class: I
Constellation: Delphinus
Right ascension: 21h 1m 29.4s
Declination: +16° 11′ 14.4″
Apparent magnitude (V): 10.6
Apparent dimensions (V): 2.8′
Tech Specs: Orion 8” RC Telescope, ZWO ASI2600MC camera running at 0F, 120 x 60 second exposures, Celestron CGEM-DX pier mounted, ZWO EAF and ASIAir Pro, processed in PixInsight. Image Date: June 12, 2024. Location: The Dark Side Observatory (W59), Weatherly, PA, USA (Bortle Class 4).
In the top left corner of this starry sight, the globular cluster NGC 2031 shines brilliantly. This dense group of thousands of stars is held together in a spherical shape by its stars’ mutual gravitational attraction. The cluster is located in the constellation Mensa in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way with many star-forming regions. It is visible from Earth’s southern hemisphere.
NGC 2031 contains a sizable population of Cepheid variable stars (at least 14), which are stars that brighten and dim periodically. A Cepheid’s period between peak brightness, combined with measurements of brightness and some observations taken from Earth, can help astronomers determine the star’s distance from us. Using these measurements, scientists estimate the distance of NGC 2031 as roughly 150,000 light-years from Earth.
The NGC 2031 cluster lives in an extremely dense and starry region of the LMC. Its location in this crowded area results in “stellar contamination,” a phenomenon where the atmospheres and surface features of nearby stars affect the measurements of objects under study.
Stellar contamination is one theory that could explain observations of bright blue stars in the cluster center. Stars like these typically burn very hot and have short lifespans, but globular clusters are known for housing only ancient stars. Another theory is that these bright blue stars are in fact blue stragglers, a type of star that forms later than its neighbors, enabling astronomers to observe them in older globular clusters such as NGC 2031. Blue stragglers are thought to form from the merging of two old, red stars, resulting in a star with greater mass and therefore bluer color – a theory developed with Hubble’s help from imaging another globular cluster, 47 Tucanae.
NGC 2031 is estimated to be 140 million years old and has a mass more than 3,000 times that of our Sun. Astronomers studied this cluster using Hubble’s ultraviolet capabilities.
Credit: NASA, ESA and L. Bianchi (The Johns Hopkins University); Processing: Gladys Kober (NASA/Catholic University of America)
This glittering gathering of stars is the globular cluster NGC 6558. NGC 6558 is closer to the center of the Milky Way than Earth is, and lies about 23,000 light years away in the constellation Sagittarius. Globular clusters like NGC 6558 are tightly bound collections of tens of thousands to millions of stars, and they can be found in a wide range of galaxies. As this Hubble Space Telescope observation shows, the stars in globular clusters can be densely packed; this image is thronged with stars in a rich variety of hues.
Some of the brightest inhabitants of this globular cluster are surrounded by prominent diffraction spikes, which are imaging artefacts caused by starlight interacting with the inner workings of Hubble.
Globular clusters equip astronomers with interesting natural laboratories in which to test their theories, as all the stars in a globular cluster formed at approximately the same time with similar initial composition. These stellar clusters therefore provide unique insights into how different stars evolve under similar conditions.
This image comes from a set of observations investigating globular clusters in the inner Milky Way. Astronomers were studying these globular clusters to gain greater insight into how globular clusters in the inner Milky Way form and evolve.
Credit: ESA/Hubble & NASA, R. Cohen
For more information, visit: esahubble.org/images/potw2220a/
Here is a shot I snapped of the Messier 92 globular cluster this past week at Frosty Drew Observatory in Charlestown, Rhode Island, USA. M92 is found in the constellation Hercules and is one of the brighter globular star clusters visible in the Northern Hemisphere making it, at times, just barely naked eye visible. M96 residing at near 26,700 light years distant and has a diameter of 109 light years.
Photo Details:
Camera: Canon 60D MagicLantern
1370mm
f/9
ISO: 2500
Exposure: 60 seconds * 14 images
This is a median composite of 14 frames to reduce noise.
-Scott
This image from the Hubble Space Telescope captures the sparkling globular cluster NGC 6569 in the constellation Sagittarius. Hubble explored the heart of this cluster, revealing a glittering hoard of stars in this astronomical treasure trove.
Globular clusters are stable, tightly bound clusters containing tens of thousands to millions of stars, and are associated with all types of galaxies. The intense gravitational attraction of these closely packed clusters of stars means that globular clusters have a regular spherical shape with a densely populated center — as can be seen in this image.
This observation comes from an investigation of globular clusters which lie close to the center of the Milky Way. The astronomers who proposed these observations combined data from Hubble with data from astronomical archives, allowing them to measure the ages of globular clusters, including NGC 6569. Their research also provided insights into the structure and density of globular clusters towards the center of our galaxy.
Credit: ESA/Hubble & NASA, R. Cohen
For more information, visit: esahubble.org/images/potw2226a/
A globular cluster of stars in the constellation Canis Venatici
Telescope: WO ZenithStar 81 Refractor
Mount: Losmandy GM811G
Imaging Camera: ZWO ASI 2600MC Pro
Filter: Optolong L-Pro Filter
Site: Elk Grove, California, USA
Calibration Files: None
Guiding: ZWO ASI 174mm mini/Orion 60mm Guidescope/PHD2
Integration Time: 2h 6m
No of Frames: 42
Sub Exposure Time: 180 seconds
Bortle Zone: Class 6
Date Taken: April 22, 2021
M13, a globular star cluster in the constellation Hercules. Nikon Z 6, 200-500mm f/5.6 @500mm, 30 frames, each 90 sec., f/8, ISO 1000, combined using Starry Sky Stacker.
This is the 8th magnitude globular cluster NGC 6712 (at right) next to the 12th magnitude green planetary nebula IC 1295, both in Scutum the Shield and in a rich starfield. The globular appears yellowed by interstellar dust? They form a visual duo that is obvious even through the eyepiece of a telescope of modest aperture.
Technical:
This is a stack of 16 x 6 minute exposures with the Askar APO120 refractor at f/7 and with the Canon Ra at ISO 800. Taken from the Quailway Cottage in southeast Arizona on October 8, 2024 with the waxing Moon up and below the field.
A glittering multitude of stars in the globular cluster Terzan 4 fill this image from the Hubble Space Telescope. Globular clusters are collections of stars bound together by their mutual gravitational attraction, and can contain millions of individual stars. As this image shows, the heart of a globular cluster such as Terzan 4 is a densely packed, crowded field of stars.
The launch of Hubble in 1990 revolutionized the study of globular clusters. The individual stars in these dense crowds are almost impossible to distinguish from one another with ground-based telescopes, but can be picked apart using space telescopes. Astronomers have taken advantage of Hubble’s crystal-clear vision to study the stars making up globular clusters, as well as how these systems change over time.
This particular observation comes from astronomers using Hubble to explore Terzan 4 and other globular clusters to understand the shape, density, age, and structure of globular clusters close to the center of the Milky Way.
Credit: ESA/Hubble & NASA, R. Cohen
For more information, visit: esahubble.org/images/potw2237a/
Fairly faint and hardly visually spectacular, Messier 71 is one of the nearest globular clusters to us at 13000 LY and is relatively young at about 10 billion years old.
Admiral Smyth described it in 1844 as… “of a very feeble light”.
It lies fairly close to the edge of the Milky Way so the stellar background is quite crowded which reduces contrast.
For many years, astronomers thought it looked more like an small open cluster than a globular until high resolution spectroscopy confirmed it was a globular.
This was my first image since March with my Esprit 120 scope. I had a lot of trouble with it out of the box back then with a faulty mechanical focuser and pinched optics from an overtightened lens unit - it took me most of last season to sort that out.
Given a 68% waning Moon, scudding cloud, a gusty wind and Saharan sand in the atmosphere (!), I thought I should go for something straightforward and its always nice to bag another Messier object!
I'd planned to get 30 x 2 minute subs over an hour but strong gusts of wind and scudding cloud left me with 25 x subs over 2 hours.
I'm just happy that my stars are round instead of hexagonal and the focuser was flawless.
Technical Card
840/120mm f/7 SkyWatcher Esprit 120ED triplet refractor.
SkyWatcher 1.0 x FF with 2 inch IDAS LPS P3 filter
ZWO ASI2600MC; 25 x 120 second subs, Gain 100, Offset 25, Temp = -10c.
EQ6 pro mount with Rowan belt drives. EQMOD control. Pegasus Astro Focus Cube electronic focuser.
Session control; SharpCap 4.0 on laptop with WiFi link to IPad.
Automated plate solving GOTO via ASTAP (4 secs exp at Gain 350)
FWHM multistar focusing - the best FWHM reading I could get was 4.3 - I didn't know it but next morning, the media had lots of pictures of dusty sunsets all over the UK - Saharan sand suspended in the atmosphere.
40 dark frames
60 flat frames (electroluminescent panel, 3000ms exposure at Gain 0).
Post processed in PixInsight 1.8.9.2.
Light Pollution and Weather:
Gusts of wind and scudding cloud. About half of all subs were discarded.
SQM (L) not measured due to waning Moon.
Polar Alignment:
PoleMaster alignment
Error measured by PHD2= 3.1 arc minute.
RA drift + 3.85 arcsec/min
Dec drift + 0.78 arcsec/min
Guiding:
PHD2 guiding with ZWO ASI290mm/Primalucelab
240/60mm guider.
RA RMS error 0.77 arcsec
Dec RMS error 0.74 arcsec
This deteriorated later in the evening as it got windier.
I'm thinking of changing to a 320mm f4 guide scope - I understand guide FL should be about 1/3 of scope FL.
Astrometry:
Focal distance: 862.40 mm
Pixel size: 3.76 um
Resolution: 0.9 arcsec/pxl.
Field of view:55' 34.6" x 34' 45.5"
Image centre: RA: 19 53 44.124 Dec: +18 46 01.89
NGC 7006 is a globular cluster in the constellation Delphinus. NGC 7006 is about 135,000 light-years away.
Observation data (J2000 epoch)
Class: I
Constellation: Delphinus
Right ascension: 21h 1m 29.4s
Declination: +16° 11′ 14.4″
Apparent magnitude (V): 10.6
Apparent dimensions (V): 2.8′
Tech Specs: Sky-Watcher Esprit 120ED Telescope, ZWO ASI2600MC camera running at 0F, 81x60 seconds guided exposures, Sky-Watcher EQ6R-Pro pier mounted, ZWO EAF and ASIAir Pro, processed in DSS and PixInsight. Image Date: July 11, 2023. Location: The Dark Side Observatory (W59), Weatherly, PA, USA (Bortle Class 4).
Questa foto mostra un ricco campo stellare della Via Lattea, la nostra galassia. L’addensamento di stelle al centro è un ammasso globulare, ovvero un raggruppamento sferico di decine di migliaia di stelle posto nella periferia della galassia.
Nel nostro caso si tratta dell’ammasso globulare chiamato M71, perché occupa la posizione 71 nel catalogo di oggetti “nebulosi” compilato dall’astronomo francese Charles Messier alla fine del 1700.
M71 si trova nella costellazione della Freccia ed è visibile sotto cieli bui con un binocolo potente: dista da noi 13000 anni luce.
Dati tecnici dell’immagine:
Telescopio Newton diametro 200mm, focale 1000mm con correttore di coma Baader
Canon EOS 400D modificata Baader
Montatura Losmandy G11 con FS2
Guida con rifrattore 60/600 + Lodestar, PhD Guiding
Somma di 13 pose da 5' per un totale di 65' di posa, Iso 800
5 flat, 15 dark flat, 5 dark
Elaborazione con Iris e Photoshop
----------
This photo shows a rich field of the Milky Way, our galaxy.
The star accumulation in the center is a globular cluster, that is a spherical cluster composed of thousands of star located in the external halo of the galaxy.
In our case, this is the globular cluster called M71, because it is inserted in the place n° 71 of the catalogue of “nebular” objects compiled by the French astronomer Charles Messier at the end of 1700.
M71 can be found in the Sagitta constellation, by using a powerful binocular under dark skies.
It is 13000 light years far away from us.
Technical data
Telescope Newton diameter 200mm, focal lenght 1000mm with Baader coma corrector
Canon EOS 400D Baader modified
Losmandy G11 mount with FS2
Guide with refractor 60/600 + Lodestar, PhD Guiding
Sum of 13 exposures each one of 5', total exposure 65’, Iso 800
5 flat, 15 dark flat, 5 dark
Elaboration with Iris and Photoshop
Messier 13
As I am waiting for galaxy season to end, looking forward imaging nebula, I wanted to image Messier 13, the Great Globular Cluster in Hercules. I think I have solved my focuser tilt / back focus problem. The stars are looking mostly round out to the corners of the image.
The cluster is 84 light years across, and is 22,200 to 25,000 light years away from us.
1 hour 40 minutes of exposure.
Location: Southern Maryland, USA (Bortle 5-6)
Date: May 13th 2021
==Gear==
Mount: SkyWatcher EQ6-R Pro
Imaging Telescope: William Optics Zenithstar 61 II APO
Field Flattener: William Optics Flat 61A
Imaging Camera: ZWO ASI 2600MC Pro
Guide Scope: ZWO 30 mm f/4 Mini Guide Scope
Guide Camera: ZWO ASI120MM
==Acquisition==
Light Frames: 100x60s (gain: 100.00) -10C
Dark Frames: 1 master frame (30 x 60s) -10C
Bias Frames: 0
Flat Frames: 32
Flat Darks: 32
==Stacking==
DSS stacked(Kappa sigma) 2x drizzled
Channel Align
Background Calibration
==Processing==
StarTools:
Autodev
Crop
Bin 35%
HDR
Contrast
Color
Noise reduction
Affinity Photo:
White balance
Levels
Globular clusters are relatively common in our sky, and generally look similar. However, this image, taken using the NASA/ESA Hubble Space Telescope, shows a unique example of such a cluster — Palomar 2. Palomar 2 is part of a group of 15 globulars known as the Palomar clusters. These clusters, as the name suggests, were discovered in survey plates from the first Palomar Observatory Sky Survey in the 1950s, a project that involved some of the most well-known astronomers of the day, including Edwin Hubble. They were discovered quite late because they are so faint — each is either extremely remote, very heavily hidden behind blankets of dust, or has a very small number of remaining stars. This particular cluster is unique in more than one way. For one, it is the only globular cluster that we see in this part of the sky, the northern constellation of Auriga (The Charioteer). Globular clusters orbit the centre of a galaxy like the Milky Way in the same way that satellites circle around the Earth. This means that they normally lie closer in to the galactic centre than we do, and so we almost always see them in the same region of the sky. Palomar 2 is an exception to this, as it is around five times further away from the centre of the Milky Way than other clusters. It also lies in the opposite direction — further out than Earth — and so it is classed as an “outer halo” globular. It is also unusual due to its brightness. The cluster is veiled by a mask of dust, dampening the apparent brightness of the stars within it and making it appear as a very faint burst of stars. The stunning NASA/ESA Hubble Space Telescope image above shows Palomar 2 in a way that could not be captured from smaller or ground-based telescopes — some amateur astronomers with large telescopes attempt to observe all of the obscure and well-hidden Palomar 15 as a challenge, to see how many they can pick out from the starry sky.
Credits: ESA/Hubble & NASA
Comet Leonard approaching globular cluster M3. Photographed close to the horizon and therefore in difficult light polluted conditions, even in my rural location. Comet Leonard subsequently dipped permanently below the horizon to give a more dramatic show for Southern Hemisphere observers during the Christmas period.
Albeit beautiful, the San Francisco Bay Area is a heavily light polluted urban environment. My astronomy club, the SFAA (San Francisco Amateur Astronomers) as access to Mount Tamalpias State Park, an Island of open space in a heavily urbanized location. Mnt. Tam offers glimpses of the Milky Way which is otherwise invisible here. At a reasonably high elevation, the sky really darkens when the fog rolls in and blocks the light dome of the City of San Francisco, which is about 15 miles to the South. Here in the Northern Hemisphere, the summer sky offers an excellent view of Scorpius and Sagittarius, which are brimming with star clusters and emission nebula and comprise the foot of the Milky Way. Even a good pair of binoculars pointed to the South will yield excellent results if you're inclined to star gazing.
This is the pairing of the bright and large edge-on spiral galaxy NGC 253 with the large and loose globular star cluster NGC 288. The two are just 1.75 degrees apart in the constellation Sculptor, but are actually 12 million light years apart in space, with NGC 288 belonging to our Milky Way Galaxy, while NGC 253 is another galaxy altogether!
They lie close to the South Galactic Pole, so are directly below the plane of the Milky Way, indeed as far from the Milky Way band as you can get!
NGC 253 is one of the brightest galaxies in the sky and belongs to the Sculptor Group, one of the next galaxy groups out from our own Local Group that includes the Andromeda and Triangulum galaxies. NGC 253 is a spiral galaxy, while NGC 288 is a Class X globular, meaning it is loose and easily resolved.
NGC 253 is also known as the Silver Coin Galaxy and is Caldwell 65 in Sir Patrick Moore's list of non-Messier objects.
The field is 3º by 2º.
Technical:
This is a stack of 20 x 3-minute exposures with the Askar APO120 refractor with its 0.8x Reducer for 560mm focal length and f/5.6, and the Canon Ra at ISO 1600. No filter was employed. The mount was the Astro-Physics AP400, autoguided with the MGEN3 autoguider. Taken Oct 2/3, 2024 from the Quailway Cottage in southeastern Arizona, where even from latitude 32º N the objects are still fairly low in the south.
Documentary shot (cropped) of comet Leonard that was taken from a not very good locacion (in terms of light conditions) relatively near the town Lučenec, Slovakia. The comet (in the constellation Boötes) was visually observed throuh small 8x42 binocular and had approx. same brightness and appearance as the globular cluster M3 (up in the center).
camera Pentax K-5II
lens smc Pentax-A 135mm F2.8@3.5
ISO-2000
stack of 51x1,3s, 51x2s and 2x5s using SIRIL
postprocessing done in Darktable