globularcluster photos on Flickr

Omega Centauri by Allen Versfeld

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Single frame

10 seconds

1600 iso

Celestron C8 f/10 2000mm focal length

Canon EOS 1100d

Processed in Iris:

deconvolved to correct tracking errors

correct colour balance

gaussian noise reduction

reduced colour saturation

Globular Star Cluster by Joseph Knight

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Image of a globular star cluster. This image was taken with Kodak 3200 color print film which increased film grain but allowed for a much shorter exposure.

20170529 M92 annotated by mpusatera

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Discovered by Johann Elert Bode in 1777, this 6th magnitude globular cluster in Hercules is naked eye visible in very dark skies. Messier 92 is located about 26,700 light-years from earth. Extremely old, the cluster exhibits very low metallicity, containing mostly Hydrogen and Helium and is located above the plane of our Milky Way.

There is a nice chain of small galaxies towards the bottom left of the image. NGCs 6323, 6329, 6332 and 6336 all resolved fairly nicely in the field for such a small telescope. I am particularly fond of the structure of NGC6332 and NGC6336. There is a nice article about this chain in a 2006 version of S&T (www.skyandtelescope.com/observing/celestial-objects-to-wa...).

As always, I welcome any suggestions or comments and hope you all enjoy the image!

Acquisition:

Imaged over 6 nights in May & June 2017 from Lake St Louis, MO

Integration: 8 hours (LRGB)

Luminance: 24x600s @ 1x1 (240')

R/G/B: 16/16/16 x 300s @ 1x1 (80'/80'/80')

Equipment:

Scope: William Optics GTF 81 5 element refractor (535mm focal length)

Upgraded with Moonlite CF focuser with motor

Imager: QHY9Ms with Olivon OAG and QHYCFW2-s filter wheel

Guidecam: ASI120MM

Filters: Baader LRGB

Mount: Orion Atlas EQ-G

Processing and Software

Guiding with PHD2

Acquisition using Sequence Generator Pro

Integration and processing with PixInsight 1.8

M92 & Friends: flic.kr/p/23K47Km

Annotated Image: flic.kr/p/23MXq3R

Coma Cluster of Galaxies by Stuart Rankin

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Edited Hubble Space Telescope image of galaxies in the Coma Cluster of galaxies.

Image source: hubblesite.org/image/4269/news_release/2018-44

Original caption: This is a Hubble Space Telescope mosaic of a portion of the immense Coma cluster of over 1,000 galaxies, located 300 million light-years from Earth. Hubble's incredible sharpness was used to do a comprehensive census of the cluster's most diminutive members: a whopping 22,426 globular star clusters. Among the earliest homesteaders of the universe, globular star clusters are snow-globe-shaped islands of several hundred thousand ancient stars. The survey found the globular clusters scattered in the space between the galaxies. They have been orphaned from their home galaxies through galaxy tidal interactions within the bustling cluster. Astronomers will use the globular cluster field for mapping the distribution of matter and dark matter in the Coma galaxy cluster.

Tags

Galaxy Clusters, Globular Clusters, Hubble Telescope, Observations

Credits

NASA, ESA, J. Mack (STScI), and J. Madrid (Australian Telescope National Facility)

M92 (Globular Cluster) by CSky65

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Globular Cluster in the Constellation of Hercules. It contains approximately 300K stars and it’s estimated to be almost as old as the Milky Way. 7.5 Magnitude 27K ly away.

Image Profile:

Location: Lee, IL

Type: Monocrome

Frames: 4x240s (use only 3 frames)

Imaging times: from 20120817 0334 to 0347

Hardware:

-Main scope: Orion EON APO 120mm

-Guiding Scope: Orion 80mm Short Tube

-CCD: QHY9M with filter wheel with LRGB Ha

-Other Filters: Baader UV/IR Cut

Imaging Applications:

-Acquiring: Nebulosity Ver. 3.0.2

-Guiding: PHD Ver. 1.11.3

Processing Applications:

-Maxim DL Essentials Ver. 2.0

-FITS Liberator 3

-Nebulosity Ver. 3.0.2

-Corel PaintShop Pro X4

Comments: Medium Dew Conditions clear otherwise. Object was blocked by a building and could not do more frames.

NGC 1651 by Stuart Rankin

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Edited Hubble Space Telescope image of the globular cluster NGC 1651.

Original caption: This image shows a globular cluster known as NGC 1651. Like the object in another recent Picture of the Week, it is located about 162 000 light-years away in the largest and brightest of the Milky Way’s satellite galaxies, the Large Magellanic Cloud (LMC). A notable feature of this image is that the globular cluster almost fills the entire image, even though globular clusters are only about 10 to 300 light-years in diameter (NGC 1651 has a diameter of roughly 120 light-years). In contrast, there are numerous Hubble Pictures of the Week that feature entire galaxies — which can be tens or hundreds of millions of light-years in diameter — that also more or less fill the whole image. A common misconception is that Hubble and other large telescopes manage to observe wildly differently sized celestial objects by zooming in on them, as one would with a specialised camera here on Earth. However, whilst small telescopes might have the option to zoom in and out to a certain extent, large telescopes do not. Each telescope’s instrument has a fixed ‘field of view’ (the size of the region of sky that it can observe in a single observation). For example, the ultraviolet/visible light channel of Hubble’s Wide Field Camera 3 (WFC3), the channel and instrument that were used to collect the data used in this image, has a field of view roughly one twelfth the diameter of the Moon as seen from Earth. Whenever WFC3 makes an observation, that is the size of the region of sky that it can observe. The reason that Hubble can observe objects of such wildly different sizes is two-fold. Firstly, the distance to an object will determine how big it appears to be from Earth, so entire galaxies that are relatively far away might take up the same amount of space in the sky as a globular cluster like NGC 1651 that is relatively close by. In fact, there's a distant spiral galaxy lurking in this image, directly left of the cluster — though undoubtedly much larger than this star cluster, it appears small enough here to blend in with foreground stars! Secondly, multiple images spanning different parts of the sky can be mosaiced together to create single images of objects that are too big for Hubble’s field of view. This is a very complex task and is not typically done for Pictures of the Week, but it has been done for some of Hubble’s most iconic images. [Image Description: A spherical collection of stars, which fills the whole view. The stars merge into a bright, bluish core in the centre, and form a sparse band around that out to the edges of the image. A few stars lie in front of the cluster, with visible diffraction spikes. The background is dark black.]

Trigonometry for NGC 6397, variant by Stuart Rankin

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Edited Hubble Space Telescope image of the globular cluster NGC 6397. Color/processing variant.

Original caption: When you want to know the size of a room, you use a measuring tape to calculate its dimensions.

But you can’t use a tape measure to cover the inconceivably vast distances in space. And, until now, astronomers did not have an equally precise method to accurately measure distances to some of the oldest objects in our universe – ancient swarms of stars outside the disk of our galaxy called globular clusters.

Estimated distances to our Milky Way galaxy’s globular clusters were achieved by comparing the brightness and colors of stars to theoretical models and observations of local stars. But the accuracy of these estimates varies, with uncertainties hovering between 10 percent and 20 percent.

Using NASA’s Hubble Space Telescope, astronomers were able to use the same sort of trigonometry that surveyors use to precisely measure the distance to NGC 6397, one of the closest globular clusters to Earth. The only difference is that the angles measured in Hubble’s camera are infinitesimal by earthly surveyors’ standards.

The new measurement sets the cluster’s distance at 7,800 light-years away, with just a 3 percent margin of error, and provides an independent estimate for the age of the universe. The Hubble astronomers calculated NGC 6397 is 13.4 billion years old and so formed not long after the big bang. The new measurement also will help astronomers improve models of stellar evolution.

M2 by David Davies

A simple RGB image captured on 2 and 8 October 2015 under very hazy conditions; the red channel data, particularly, was very problematic.

40 min each of RGB in 5 min subs.

T: 254mm Newtonian plus Paracorr

Q: QSI 583 plus a Lodestar as off-axis guider

M: NEQ6

Rho Ophiuchus/Antares by Mike Durkin

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Location: Robert Moses State Park, NY

Camera: Hutech Modified Canon Rebel XT

Lens: 70mm zoom lens @ f/4

Exposure: 150x40 seconds (100 minutes)

ISO: 1600

Tracking: AstroTrac

Calibrated with dark and flat frames.

Processed using MaxDSLR and Photoshop.

Weather conditions that night were OK, but less than ideal. A lot of my frames had thin wispy clouds. Despite the clouds, I was happy to have picked up a good bit of the nebulosity in the region.

M4 by Adriano Motta da Silva

15x120";

Canon 1000D Modded;

Sky-Watcher Equinox 80/500 ED;

NEQ6-Pro.

M5 by Matteo Ambrosi

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Italian:

Prosegue l'astrofotografia dal giardino di casa. Questa volta il soggetto è M5, un ammasso globulare nella costellazione del serpente.

Gli ammassi globulari sono un importante oggetto di studio in quanto contengono stelle molto antiche, con una bassa quantità di elementi pesanti,

che si sono formate nelle prime fasi della formazione dell'universo. Questi ammassi non si trovano sul piano galattico come le altre stelle ma nell'alone galattico.

Non subendo le forze mareali dei bracci hanno quindi conservato la loro forma a grappolo.

Si stima che M5 sia formato dalle 100.000 alle 500.000 stelle in un diametro di circa 130 anni luce e che disti 24.500 anni luce dalla terra.

Data acquisizione: 25-26/05/2020

Telescopio: Skywatcher 150/750

Telescopio guida: UltraGuide Artesky 60/240

Montatura: Celestron AVX

Fotocamera: Canon EOS 450d con modifica Baader

Camera guida: Zwo Asi 224 MC

Filtro: Optolong L-Pro

Correttore di coma: Skywatcher coma corrector 2''

Light: 54x150'' a 800 ISO

Dark: 31x150''

Flat: 41

Bias: 41

Software: APT Astro Photography Tool, PixInsight

English:

Astrophotography from my back garden going on. This time the subject is M5, a globular cluster in the snake constellation.

Globular clusters are an important object of study since they contain very ancient stars, with a low amount of heavy elements,

for they were formed in the early stages of the universe formation. These clusters are not on the same galactic plane as the other stars, but in the galactic halo.

Not being subject to the arms tidal forces, they retained their cluster shape.

M5 supposedly contains from 100,000 to 500,000 stars in about 130 light years diameter and is 24,500 light years away from the earth.

Acquisition date: 25-26/05/2020

Telescope: Skywatcher 150/750

Guide scope: UltraGuide Artesky 60/240

Mount: Celestron AVX

Camera: Canon EOS 450d modified with Baader filter

Guide camera: Zwo Asi 224 MC

Filter: Optolong L-Pro

Coma corrector: Skywatcher coma corrector 2''

Lights: 54x150'' 800 ISO

Darks: 31x150''

Flats: 41

Biases: 41

Software: APT Astro Photography Tool, PixInsight

M56 - Globular Cluster in Lyra by Stephen Rahn

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M13 - Globular Cluster by Luca Argalia

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Ammasso Globulare - somma di 22 scatti da 4 minuti a 800 ISO. Strumenti: Canon Eos 350D; Schmidt-Newton Meade 203, focale 812, 7 dark, 25 flat. Località: Mastro (Mercato Saraceno - FC). Data: 18/05/2009

Globular Cluster IC 4499 by Stuart Rankin

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Edited Hubble Space Telescope image of the globular cluster IC 4499. A nice barred spiral galaxy can be seen about 3/5 down the right side.

Original caption: This new NASA/ESA Hubble Space Telescope image shows the globular cluster IC 4499. Globular clusters are big balls of old stars that orbit around their host galaxy. It has long been believed that all the stars within a globular cluster form at the about same time, a property which can be used to determine the cluster's age. For more massive globulars however, detailed observations have shown that this is not entirely true — there is evidence that they instead consist of multiple populations of stars born at different times. One of the driving forces behind this behaviour is thought to be gravity: more massive globulars manage to grab more gas and dust, which can then be transformed into new stars. IC 4499 is a somewhat special case. Its mass lies somewhere between low-mass globulars, which show a single generation build-up, and the more complex and massive globulars which can contain more than one generation of stars. By studying objects like IC 4499 astronomers can therefore explore how mass affects a cluster's contents. Astronomers found no sign of multiple generations of stars in IC 4499 — supporting the idea that less massive clusters in general only consist of a single stellar generation. Hubble observations of IC 4499 have also helped to pinpoint the cluster's age: observations of this cluster from the 1990s suggested a puzzlingly young age when compared to other globular clusters within the Milky Way. However, since those first estimates new Hubble data been obtained, and it has been found to be much more likely that IC 4499 is actually roughly the same age as other Milky Way clusters at approximately 12 billion years old.

Messier 3 by Link Observatory Space Science Institute

Messier 3 (also known as M3 or NGC 5272) is a globular cluster of stars in the northern constellation of Canes Venatici. It was discovered by Charles Messier on May 3, 1764,[7] and resolved into stars by William Herschel around 1784. Since then, it has become one of the best-studied globular clusters. Identification of the cluster's unusually large variable star population was begun in 1913 by American astronomer Solon Irving Bailey and new variable members continue to be identified up through 2004.

Many amateur astronomers consider it one of the finest northern globular clusters, following only Messier 13.[1] M3 has an apparent magnitude of 6.2,[4] making it a difficult naked eye target even with dark conditions. With a moderate-sized telescope, the cluster is fully defined. It can be a challenge to locate through the technique of star hopping, but can be found by looking almost exactly halfway along an imaginary line connecting the bright star Arcturus to Cor Caroli. Using a telescope with a 25 cm (9.8 in) aperture, the cluster has a bright core with a diameter of about 6 arcminutes and spans a total of 12 arcminutes.[1]

This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is estimated to be 8 billion years old. It is located at a distance of about 33,900 light-years away from Earth.[citation needed]

Messier 3 is located 31.6 kly (9.7 kpc) above the Galactic plane and roughly 38.8 kly (11.9 kpc) from the center of the Milky Way. It contains 274 known variable stars; by far the highest number found in any globular cluster. These include 133 RR Lyrae variables, of which about a third display the Blazhko effect of long-period modulation. The overall abundance of elements other than hydrogen and helium, what astronomers term the metallicity, is in the range of –1.34 to –1.50 dex. This value gives the logarithm of the abundance relative to the Sun; the actual proportion is 3.2–4.6% of the solar abundance. Messier 3 is the prototype for the Oosterhoff type I cluster, which is considered "metal-rich". That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements.

M4 region by s58y

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Subject: M4, NGC6144, IC4605, SH2-9, etc.

(M4 is the large GC, NCG6144 is the smaller GC, IC4605 is the blue nebula, and SH2-9 is the red nebula, Antares is the bright star near the bottom)

Image FOV = 3.33 degrees by 2.25 degrees (200 min by 135 min)

Image Scale = 12 arc-second/pixel

Date: RGB: 2008/05/11, H-alpha: 2008/05/29

Location: near Halcottsville, NY

Exposure: RGB: 9 x 10 minutes, H-alpha 8 x 10 minutes, = 2h50m total exposure, ISO800, f/4.8

Filter: RGB: IDAS LPS, H-alpha: Baader 7nm H-alpha

Camera: Hutech-modified Canon 30D

Telescope: SV80S 80mm f/6 + TV TRF-2008 0.8X reducer/flattener = 384mm FL, f/4.8

Mount: AP900

Guiding: ST-402 autoguider and SV66 guidescope. MaximDL autoguiding software using 6-second guide exposures

Processing: Raw conversion and calibration with ImagesPlus (dark frames and bias only, no flat frames); Aligning and combing with Registar; Red channel = max(RGB-red, H-alpha-red), Green channel = max(RGB-green, 0.33*H-alpha-red), Blue channel = max(RGB-blue, 0.25*H-alpha-red). Levels, curves, cropping, JPEG conversion with Photoshop CS.

Remarks: Temperature at end: 35F (RGB), 42F (H-alpha). SQM readings (RGB) 21.36 at start, 21.62 at end (however, target lies in a light dome to the south). SQM readings (H-alpha) 21.63 at start, 21.68 at end.

Globular Cluster M13 by Zolt Levay

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The great globular cluster in Herculer, Messier 13 (M13.

The Dark Doodad in Musca (77mm 5DII) by Alan Dyer

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The Dark Doodad dark nebula in Musca the Fly, near the globular cluster NGC 4372 at lower right. The other globular cluster at upper left is NGC 4833.

This is a stack of 5 x 8 minute exposures at f/4.3 with the Borg 77mm astrograph (330mm focal length) and Canon 5D MkII at ISO 800. Taken from Coonabarabran, Australia, March 2014.

Globular Cluster Messier 22 M22 by Tom Wildoner

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Messier 22 - Globular Cluster in the constellation Sagittarius. Photographed on September 4th, 2013 using a Canon T4i and 300mm lens mounted on a iOptron SkyTracker. Two 25 second images, ISO1600, f/5.6, stacked in ImagesPlus and processed in Paintshop Pro X5.

Messier 92, variant by Stuart Rankin

Edited Hubble Space Telescope image of the globular cluster M92. Color/processing variant.

Original caption: This striking new NASA/ESA Hubble Space Telescope image shows a glittering bauble named Messier 92. Located in the northern constellation of Hercules, this globular cluster — a ball of stars that orbits a galactic core like a satellite — was first discovered by astronomer Johann Elert Bode in 1777. Messier 92 is one of the brightest globular clusters in the Milky Way, and is visible to the naked eye under good observing conditions. It is very tightly packed with stars, containing some 330 000 stars in total. As is characteristic of globular clusters, the predominant elements within Messier 92 are hydrogen and helium, with only traces of others. It is actually what is known as an Oosterhoff type II (OoII) globular cluster, meaning that it belongs to a group of metal-poor clusters — to astronomers, metals are all elements heavier than hydrogen and helium. By exploring the composition of globulars like Messier 92, astronomers can figure out how old these clusters are. As well as being bright, Messier 92 is also old, being one of the oldest star clusters in the Milky Way, with an age almost the same as the age of the Universe. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Gilles Chapdelaine. Links Gilles Chapdelaine’s Hidden Treasures entry on Flickr

Globular Cluster NGC 1866 by Stuart Rankin

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Edited Hubble Space Telescope image of the globular cluster NGC 1866.

Original caption: Star clusters are common structures throughout the Universe, each made up of hundreds of thousands of stars all bound together by gravity. This star-filled image, taken with the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 (WFC3), shows one of them: NGC 1866. NGC 1866 is found at the very edges of the Large Magellanic Cloud, a small galaxy located near to the Milky Way. The cluster was discovered in 1826 by Scottish astronomer James Dunlop, who catalogued thousands of stars and deep-sky objects during his career. However, NGC 1866 is no ordinary cluster. It is a surprisingly young globular cluster situated close enough to us that its stars can be studied individually — no mean feat given the mammoth distances involved in studying the cosmos! There is still debate over how globular clusters form, but observations such as this have revealed that most of their stars are old and have a low metallicity. In astronomy, ‘metals’ are any elements other than hydrogen and helium; since stars form heavier elements within their core as they carry out nuclear fusion throughout their lifetimes, a low metallicity indicates that a star is very old, as the material from which it formed was not enriched with many heavy elements. It’s possible that the stars within globular clusters are so old that they were actually some of the very first to form after the Big Bang. In the case of NGC 1866, though, not all stars are the same. Different populations, or generations, of stars are thought to coexist within the cluster. Once the first generation of stars formed, the cluster may have encountered a giant gas cloud that sparked a new wave of star formation and gave rise to a second, younger, generation of stars — explaining why it seems surprisingly youthful.

Hubble Sees the Globular Cluster M22, processed 1 by Stuart Rankin

Edited Hubble Space Telescope image of the globular cluster M22. Color/processing variant.

Original caption: This image shows the centre of the globular cluster Messier 22, also known as M22, as observed by the NASA/ESA Hubble Space Telescope. Globular clusters are spherical collections of densely packed stars, relics of the early years of the Universe, with ages of typically 12 to 13 billion years. This is very old considering that the Universe is only 13.8 billion years old. Messier 22 is one of about 150 globular clusters in the Milky Way and at just 10 000 Â light-years away it is also one of the closest to Earth. It was discovered in 1665 by Abraham Ihle, making it one of the first globulars ever to be discovered. This is not so surprising as it is one of the brightest globular clusters visible from the northern hemisphere, located in the constellation of Sagittarius, close to the Galactic Bulge â the dense mass of stars at the centre of the Milky Way. The cluster has a diameter of about 70 light-years and, when looking from Earth, appears to take up a patch of sky the size of the full Moon. Despite its relative proximity to us, the light from the stars in the cluster is not as bright as it should be as it is dimmed by dust and gas located between us and the cluster. As they are leftovers from the early Universe, globular clusters are popular study objects for astronomers. M22 in particular has fascinating additional features: six planet-sized objects that are not orbiting a star have been detected in the cluster, it seems to host two black holes, and the cluster is one of only three ever found to host a planetary nebula â a short-lived gaseous shells ejected by massive stars at the ends of their lives.

Hubble Sees the Globular Cluster M22 by Stuart Rankin

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This image shows the centre of the globular cluster Messier 22, also known as M22, as observed by the NASA/ESA Hubble Space Telescope. Globular clusters are spherical collections of densely packed stars, relics of the early years of the Universe, with ages of typically 12 to 13 billion years. This is very old considering that the Universe is only 13.8 billion years old. Messier 22 is one of about 150 globular clusters in the Milky Way and at just 10 000 light-years away it is also one of the closest to Earth. It was discovered in 1665 by Abraham Ihle, making it one of the first globulars ever to be discovered. This is not so surprising as it is one of the brightest globular clusters visible from the northern hemisphere, located in the constellation of Sagittarius, close to the Galactic Bulge — the dense mass of stars at the centre of the Milky Way. The cluster has a diameter of about 70 light-years and, when looking from Earth, appears to take up a patch of sky the size of the full Moon. Despite its relative proximity to us, the light from the stars in the cluster is not as bright as it should be as it is dimmed by dust and gas located between us and the cluster. As they are leftovers from the early Universe, globular clusters are popular study objects for astronomers. M22 in particular has fascinating additional features: six planet-sized objects that are not orbiting a star have been detected in the cluster, it seems to host two black holes, and the cluster is one of only three ever found to host a planetary nebula — a short-lived gaseous shells ejected by massive stars at the ends of their lives.

M13 June 2014 Annotated by S Migol

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This is a shot of the globular cluster Messier 13, in Hercules. Taken over two nights in the backyard for testing prior to GSSP 2014.

Was challenged to fix some problems with camera and mount prior to the star party. The mount part was easy - I re routed some cables so that they didn't snag. The camera part was not easy. During waiting fo rthe skies to clear, I ran the camera to capture a series of dark frames. Unfortunately, during these sequences a piece of flocking paper fell down into the camera body and blocked the movement of the shutter. The shutter electronics a dead and now it will not open. I've had to hot glue the shutter open and now rely on the motion of the mirror plus the electronics of the CCD to time the exposures. Biggest follow up to the shutter issue has been taking flats. Because short duration flats allow over exposure as the mirror flaps up and down, long duration flats are better. I'm now recording flats with a duration of .7 seconds vs 1/60 second. I may consider building a strobe box to further experiment.

This image is a sum of 18 exposures at 1200 seconds each at 100 ISO.

Standard setup: Stellarvue SV4, Pentax K10D (modified and cooled - and broken shutter), SSF6 flattener

Filter: IDAS HEUIB II

Mount: Losmandy G11 with Gemini 2

Guiding scope: Stellarvue SV70ED with Orion SSAG

Guiding: Maxim 5.24

Exposure control: Star Labs DSLR Shutter and Pentax tethering software

Calibrated in Maxim with 10 darks, 21 flats, and 260 bias

Stacked in DSS 3.3.3 beta 51

Processed in PixInsight 1.8 with Crop, DBE, Masked Stretch, Histogram Stretch to reset black point, TGVDenoise, masked curves to boost saturation and reduce muddy sky glow, and unsharp mask on bright stars to tighten.

Passed through LR5 for export to web

Here's the platesolve from PI

Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]):

-8.66381e-007 -0.000530417 +0.680789

+0.00053032 -9.15332e-007 -1.0261

+0 +0 +1

Projection origin.. [1937.076485 1280.333772]pix -> [RA:+16 41 52.45 Dec:+36 29 51.55]

Resolution ........ 1.909 arcsec/pix

Rotation .......... 89.898 deg

Focal ............. 653.58 mm

Pixel size ........ 6.05 um

Field of view ..... 2d 3' 16.7" x 1d 21' 29.8"

Image center ...... RA: 16 41 52.423 Dec: +36 29 51.40

Image bounds:

top-left ....... RA: 16 45 13.027 Dec: +35 28 07.62

top-right ...... RA: 16 45 17.404 Dec: +37 31 22.18

bottom-left .... RA: 16 38 32.813 Dec: +35 27 59.29

bottom-right ... RA: 16 38 26.431 Dec: +37 31 13.63

M13 by S Migol

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Another view of this target - 12 hours of integration using 77 lights of 10 minutes at 400 ISO.

I reworked my original set of data with the addition of a lot of much better darks and more lights with improved tracking. I found that with the high resolution available on this target, I was pushing my mount to its limits with the settings I was using. I've found improved methods of handling tracking and these are the results.

Used PEC at .2 x sideral tracking -- actually closed loop or King tracking seems to offer better results. With normal sideral tracking, the RA was wobbling and thus there was streaking. All along I was thinking that the issue was solely in DEC and so I was concentrating on reducing the error on that axis. Once the RMS on that axis was under .5 arc seconds I was able to see clearly that RA was the source of the rest of the problem. Additionally, I have found that each session must begin with a new upload of the PEC file as the stored one doesn't reproduce properly.

Because of the changes to tracking, the resolution has improved and the core of the cluster is better resolved.

Processed in DSS 3.3.3. beta 47 from a stack of 96 lights over the course of a week from June 19 to June 28 2012.

Since these were taken in a suburban backyard, there's quite a bit of brown skyglow which hinders the display of faint objects.

At this point, I'm going to just test a couple more settings to see if King or closed loop is better for the high magnification and then I'll move on to other targets.

The center of globular cluster NGC 6397 by Ángel R. López Sánchez

En español, ver la historia del blog: angelrls.blogalia.com/historias/72252

Image obtained using the FPI camera of 2dF at the 3.9m Anglo-Australian Telescope (Siding Spring Observatory, Australia) on 13 Aug 2012 - 08:30 UT.

32 x 5 second frames obtained during the twilight

Frames reduced (bias, flatfield corrected) and aligned using IRAF.

This was the first field to be observed using 2dF at the beginning of the night.

False colour given using Photoshop.

Astronomers: Anna Sippel, Emma Ryan-Weber & Brian Keeney. Night Assistant: Kristin Fiegert.

Image credit: Ángel R. López-Sánchez (AAO/MQ)

Stars through the pine trees by Gene Spesard

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Taken with my old OM 1:1.8 50mm lens at f1.8. Given that the lens is 36 years old and the sensor is 6 years out of date I'm fairly pleased with the result, althought it is noisy and not too sharp.

RAW file processed with Olympus Viewer 3.

(_A011804.orf)

See where this picture was taken. [?]

NGC 6544 by NASA Hubble Space Telescope

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The teeming stars of the globular cluster NGC 6544 glisten in this image from the NASA/ESA Hubble Space Telescope. This cluster of tightly bound stars lies more than 8,000 light-years away from Earth and is, like all globular clusters, a densely populated region of tens of thousands of stars.

This image of NGC 6544 combines data from two of Hubble’s instruments, the Advanced Camera for Surveys and Wide Field Camera 3, as well as two separate astronomical observations. The first observation was designed to find a visible counterpart to the radio pulsar discovered in NGC 6544. A pulsar is the rapidly spinning remnant of a dead star, emitting twin beams of electromagnetic radiation like a vast astronomical lighthouse. This pulsar rotates particularly quickly, and astronomers turned to Hubble to help determine how this object evolved in NGC 6544.

The second observation which contributed data to this image was also designed to find the visible counterparts of objects detected at other electromagnetic wavelengths. Instead of matching up sources to a pulsar, however, astronomers used Hubble to search for the counterparts of faint X-ray sources. Their observations could help explain how clusters like NGC 6544 change over time.

Credit: ESA/Hubble & NASA, W. Lewin, F. R. Ferraro

For more information, visit: science.nasa.gov/missions/hubble/hubble-glimpses-a-gliste...

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M107 by Serge Meunier

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M107

Globular cluster in Ophiuchus

Source: Hubble Legacy Archive

HST_10775_33_ACS_WFC_F606W

HST_10775_33_ACS_WFC_F814W

M13 22 Oct 2012 by Grant Ritchie

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M13 with a Celestron NexStar 5se and Nikon D7000 at prime foucs. 78x8s exposures and 25 darks stacked in DSS.

M13 by Don McCrady

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M13, the great Hercules globular cluster. This was first light with my STL-4020M, and Astrodon LRGB filters.

M2 - Globular Cluster in Aquarius by Stephen Rahn

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20150814 NGC6441 Names by mpusatera

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NGC6441 is a globular cluster in Scopius. It is located approximately 38,000 light years from Earth. It was discovered in 1826 by James Dunlop.

3rd magnitude G Scorpius is just to the right.

This cluster is a DSO in the Astronomical League Universe Sampler program.

Imaged from New Florence, MO on August 14, 2015.

Celestron Nexstar 8SE

Orion EQ6

Canon T2i (modified)

12x300s

#NGC6441 #GScorpii #Globular #Space #Astronomy #Astrophotography

M92 GlobularCluster Hercules by Nightsky NL

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Picture saved with settings applied.

M3_20200502 by Brandon Ghany / Horizon Productions SFL

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LATEST VERSION: flic.kr/p/2rxcArQ

Messier 3 / M3 / NGC 5272

Messier 3 is one of the brightest globular clusters in the northern sky and it contains about 500,000 stars. It is about 34,000 light-years away, orbiting the Milky Way, and it is estimated to be 11.39 billion years old. It is often overshadowed by M13, a slightly brighter cluster: flic.kr/p/2oKjm3J

Total integration: 8 hours 48 minutes (528 minutes)

02/17/19: 105 x 60 seconds ISO800 [Bortle 6]

03/17/19: 341 x 60 seconds ISO800 [Bortle 6]

05/02/20: 41 x 120 seconds ISO200 [Bortle 7]

Location: Charlottesville, VA and Coral Springs, FL

SQM: 19.22 mag/arcsec^2 and 18.18 mag/arcsec^2 (Bortle 6 and Bortle 8/9)

Camera: Canon T3i (stock/unmodified)

Average camera temperature: 80 F (27 C)

Telescope: Explore Scientific ED80 f/6.0 Apochromatic Refractor (with ES field flattener)

Mount: Orion Sirius EQ-G

Guide scope: Svbony 50mm f/4.0 Guide Scope

Guide camera: Orion StarShoot AutoGuider

Software: N.I.N.A. with PlateSolve2 and PHD2

Pre-processed with PixInsight, processed with PixInsight and Paint.NET

Globular Cluster M2 in Aquarius by Tom Wildoner

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Messier 2 or M2 (also designated NGC 7089) is a globular cluster in the constellation Aquarius, five degrees north of the star Beta Aquarii. It was discovered by Jean-Dominique Maraldi in 1746 and is one of the largest known globular clusters. Messier 13 (M13), also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster, is a globular cluster of about 300,000 stars in the constellation of Hercules. This image taken using a Meade LX-90 12" telescope with a Canon T3i at prime focus.

The M5 globular cluster in Serpens by Francesco Meschia

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7x480s frames

Astro-Tech AT130EDT apo triplet, 0.8x reducer/flattener (f/5.6)

iOptron iEQ45 Pro mount

Lacerta MGEN-II autoguider with Stellarvue 9x50 guidescope

Processed in PixInsight 1.8

M13 - Globular Cluster in Hercules by Stephen Rahn

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M5 Globular Cluster by Doug Spalding

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Messier 5 or M5 is a globular cluster in the constellation Serpens. Distance 25,000 light years

Details:

M5 (Globular Cluster)

Location: ASKC Dark Sky Site near Butler, MO

Date: April 9 and 10, 2010

Telescope: CGE 1100

Camera: Nikon D50

Reducer: Fastar lens (Net F/2)

8 images at 30 sec each (ISO1600 w/noise reduction), stacked in ImagePlus and processed in Photoshop CS2.

M13 in Hercules by chancehatcher

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Meade SN10 on Celestron DX through Canon 90D and Optolong L-Pro filter. Bortle class 5 sky. 20 x 90 second subs using LENR and no calibration frames. Stacked in DSS and processed in PS.

Messier 3 by Danny Flippo

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Messier 3 is a globular star cluster located in the constellation of Canes Venatici

Optics: Celestron C-11 @ f/7.5 (2030mm), Starizona SCT Corrector

Camera: SBIG ST-10XME

Mount: Astro-Physics 900GTO

Processing: CCDStack 2, Photoshop CS5

Messier 10 by Steven Rosenow

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10 millions of stars in Omega Centauri by hsrdtr

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............. to see the colors od the stars: best to be seen larger on black: clic here

..............

OMEGA CENTAURI is the largest known globular cluster of stars in our galaxy (the "Milky Way").

It's one of the few that can alredy be seen with the naked eye in the SOUTHERN SKY as a faint nebulous spot. Most of the 200 known clusters in our galaxy can only be seen by a telescope.

This enormous ball of stars located 15,000 light-years away from Earth spans 150 light years across and contains about 10 MILLION stars. It's age is 12 billion years.

The image has been taken with the use of a telescope with 0.35 m aperture and 3 m focal length and color filters (Blue, Green, Red) from a very dark site in NAMIBIA in southern Africa. The images in the different colors were added to give the color image. Total exposure time was about one hour.

#407 in Flickr EXPLORE May 30, 2007

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