• Messier Object List

Messier Objects

Messier Objects: Guide to the Bright Galaxies, Nebulae and Clusters Listed in the Messier Catalogue

Messier 12: Gumball Globular

March 11, 2015 by admin

Messier 12 (M12), also known as the Gumball Globular, is a globular star cluster located in the constellation Ophiuchus. The Gumball Globular has an apparent magnitude of 7.68 and lies at a distance of 15,700 light years from Earth. It has the designation NGC 6218 in the New General Catalogue.

Messier 12 is invisible to the naked eye, but can be seen with binoculars in good conditions, with clear dark skies and no light pollution. Stars in the cluster can be resolved with an 8-inch or larger telescope. A 10-inch instrument reveals the core with a diameter of 3 arc minutes and a halo of stars stretching across an area of 10 arc minutes.



Messier 12 has a diameter of 75 light years and lies about 3 degrees in the sky from Messier 10, a slightly brighter globular cluster in Ophiuchus. M12 can be found 2 degrees north and 2 degrees west of Messier 10, 2 degrees north and 8.5 degrees east of the star Delta Ophiuchi, or 5.6 degrees from Lambda Ophiuchi. The cluster is approaching us at a velocity of 16 km/s.

The Gumball Globular appears as a fuzzy ball of light in a small 3-inch telescope, while 8-inch instruments reveal the cluster’s brightest stars. Larger telescopes show stars across the entire area of the cluster.

m12,gumball globular,ngc 6218

The high concentration of stars within globular clusters, like Messier 12, shown here in an image from the NASA/ESA Hubble Space Telescope, makes them beautiful photographic targets. But the cramped living quarters in these clusters also makes them home to exotic binary star systems where two stars are locked in tight orbits around each other and matter from one is gobbled up by its companion, releasing X-rays. It is thought that such X-ray binaries form from very close encounters between stars in crowded regions, such as globular clusters, and even though Messier 12 is fairly diffuse by globular cluster standards, such X-ray sources have been spotted there. Astronomers have also discovered that Messier 12 is home to far fewer low-mass stars than was previously expected. In a recent study, astronomers used the European Southern Observatory’s Very Large Telescope at Cerro Paranal, Chile, to measure the brightness and colours of more than 16 000 of the globular’s 200 000 stars. They speculate that nearly one million low-mass stars have been ripped away from Messier 12 as the globular has passed through the densest regions of the Milky Way during its orbit around the galactic centre. It seems that the serenity of this view of Messier 12 is misleading and the object has had a violent and disturbed past.
Messier 12 lies about 23 000 light-years away in the constellation of Ophiuchus (The Serpent Bearer). This image was taken using the Wide Field Channel of Hubble’s Advanced Camera for Surveys. The colour image was created from exposures through a blue filter (F435W, coloured blue), a red filter (F625W, coloured green) and a filter that passes near-infrared light (F814W coloured red). The total exposure times were 1360 s, 200 s and 364 s, respectively. The field of view is about 3.2 x 3.1 arcminutes. Image: ESA/Hubble & NASA

Messier 12 has a Shapley-Sawyer classification of IX, which means that its member stars are concentrated relatively loosely toward the centre for a globular cluster. Compared to its neighbour Messier 10 (class VII), M12 is notably less dense toward the central region.

The cluster was discovered by Charles Messier on May 30, 1764. Messier added the object to his catalogue, describing it as a “nebula without stars.”  His entry read, “Nebula discovered in the Serpent, between the arm and the left side of Ophiuchus: this nebula contains no star, it is round & its light is faint; near this nebula there is a star of 9th magnitude.” (Serpens constellation, which Messier mentions in his entry, is divided into two parts: Serpens Caput and Serpens Cauda, representing the head and tail of the snake. Ophiuchus, also known as Serpentarius, represents Asclepius in Greek mythology and is the celestial figure holding the serpent, standing between the two parts of Serpens constellation.)



messier 12,m12,ngc 6218,globular cluster

Messier 12. Image: Hewholooks at wikipedia.org

Messier provided a slightly more detailed observation of the cluster in 1771:

In the same night of [May] 30 to 31, 1764, I have discovered a nebula in Serpens, between the arm & left side of Ophiuchus, according to the charts of Flamsteed: That nebula doesn’t contain any star; it is round, its diameter can be 3 minutes of arc, its light is faint; on sees it very well with an ordinary [non-achromatic] refractor of 3 feet [FL]. I have determined its position, by comparing with the star Delta Ophiuchi; its right ascension has been concluded at 248d 42′ 10″, & its declination at 1d 30′ 28″ south. I have marked it in the chart of the apparent path of the Comet which I have observed last year [the comet of 1769].

German astronomer Johann Elert Bode observed the cluster in 1774 and also described it as a nebula:

On August 14, I discovered in Ophiuchus two new nebulae [M10 and M12] not far from each other. One of them is situated south of 14, 16, 19 and 21 Oph near the western arm, the other below this one and eastward, closely west of 30 Oph. These nebulae appear very pale, and because of this, I found not very reliably the separation to Lambda as 6deg 7′, to the star 14 as 3deg 50′, and to 21 as 3deg 32′. The other one is separated from the 21st star by 5deg 32′, and by 1deg 4′ from the 30th, as shown in the second figure.



messier 12,globular cluster

Centre of the globular cluster Messier 12 as observed with the FORS-1 multi-mode instrument on ESO’s Very Large Telescope (Cerro Paranal, Chile). The picture covers a region of about 3.5 arcmin on a side, corresponding to about 23 light years at the distance of Messier 12. It is based on data in five different filters: U, B, V, R and H-alpha. Here only the short exposures were used while for their scientific analysis, the authors used much longer exposures. Guido De Marchi (ESA) reduced the data and Kristina Boneva and Haennes Heyer (ESO) did the final image processing. The observations were obtained with very good conditions, the image quality (‘seeing’) being around 0.6 arcsec. Image: ESO

William Herschel was the first to resolve the cluster into individual stars. He noted, “1783, 1799, 10 feet telescope. With 120, and an aperture of 4 inches, easily resolvable; with 5 inches, stars become visible; with 6 inches, pretty distinctly visible; and with all open, the lowest power shows the stars.”

Admiral William Henry Smyth observed the cluster in August 1837 and offered the following description:

A fine rich globular cluster, between the right hip and the elbow of Ophiuchus, with a cortège of bright stars, and many minute straggling outliers. This resolvable mass is greatly condensed towards the centre, with several very bright spots; it was discovered by Messier in 1764, but, probably from the imperfection of his means, was registered as “a round nebula, unaccompanied by any star.” Its place was obtained by differentiating with Epsilon Ophiuchi, from which it is 8deg 1/2 distant, on a north-west-by-west line, leading nearly upon Beta.

Sir William Herschel resolved this object in 1783; and in the folowing year his 20-foot reflector made it “a brilliant cluster, 7′ or 8′ in diameter; the most compressed parts about 2′.” By the gauging process, he held its profundity to be of the 186th order.

The Gumball Globular contains about 200,000 stars. The brightest ones are of 12th magnitude and the mean visual magnitude of the 25 brightest stars in M12 is 13.97. American astronomer Allan Sandage found 13 variable stars in the cluster.

In 2006, M12 was discovered to contain a surprisingly low number of low mass stars. Scientists believe that these stars were stripped from M12 by the gravitational pull of the Milky Way Galaxy and that the cluster lost four times as many members as it still has over its lifetime.  In other words, as the cluster’s orbit took it through the denser regions of the Milky Way plane, M12 ejected about a million stars into the galaxy’s halo. This explains why there are hardly any M-class (red) dwarfs in the cluster. It will take another 4.5 billion years before M12 dissociates completely.

Messier 12 is best seen in the months of May, June and July.

FACTS

Object: Cluster
Type: Globular 
Class: IX 
Designations:  Messier 12, M12, NGC 6218, C 1644-018, GCl 46
Constellation: Ophiuchus
Right ascension: 16h 47m 14.18s
Declination: -01°56’54.7”
Distance: 15,700 light years (4,800 parsecs) 
Age: 12.67 billion years 
Number of stars: 200,000    
Apparent magnitude: +7.68 
Apparent dimensions: 16′
Radius: 37.2 light years

LOCATION

gumball globular location,m12 location,where is messier 12

Messier 12 location. Image: IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg)

Posted in: Globular Cluster Tagged: Allan Sandage, Delta Ophiuchi, Gumball Globular, Johann Elert Bode, Lambda Ophiuchi, M12, Messier 10, Messier 12, NGC 6218, Ophiuchus Constellation, William Henry Smyth, William Herschel

Astronomy

  • Astronomy News
  • Astronomy Picture of the Day
  • Constellation Guide
  • NASA
  • SEDS Messier Database
  • Wikisky

Messier Objects

Messier 1: Crab Nebula
Messier 2
Messier 3
Messier 4
Messier 5
Messier 6: Butterfly Cluster
Messier 7: Ptolemy Cluster
Messier 8: Lagoon Nebula
Messier 9
Messier 10
Messier 11: Wild Duck Cluster
Messier 12: Gumball Globular
Messier 13: Hercules Globular Cluster
Messier 14
Messier 15: Great Pegasus Cluster
Messier 16: Eagle Nebula
* Pillars of Creation
Messier 17: Omega Nebula
Messier 18
Messier 19
Messier 20: Trifid Nebula
Messier 21
Messier 22: Sagittarius Cluster
Messier 23
Messier 24: Sagittarius Star Cloud
Messier 25
Messier 26
Messier 27: Dumbbell Nebula

Messier 28
Messier 29
Messier 30
Messier 31: Andromeda Galaxy
Messier 32: Le Gentil
Messier 33: Triangulum Galaxy
Messier 34
Messier 35
Messier 36: Pinwheel Cluster
Messier 37
Messier 38: Starfish Cluster
Messier 39
Messier 40: Winnecke 4
Messier 41
Messier 42: Orion Nebula
* Trapezium Cluster
Messier 43: De Mairan's Nebula
Messier 44: Beehive Cluster
Messier 45: Pleiades
* Maia Nebula
* Merope Nebula
Messier 46
Messier 47
Messier 48
Messier 49
Messier 50: Heart-Shaped Cluster
Messier 51: Whirlpool Galaxy
Messier 52
Messier 53
Messier 54
Messier 55: Summer Rose Star
Messier 56
Messier 57: Ring Nebula
Messier 58
Messier 59
Messier 60
Messier 61
Messier 62
Messier 63: Sunflower Galaxy
Messier 64: Black Eye Galaxy
* Leo Triplet
Messier 65
Messier 66
* NGC 3628: Hamburger Galaxy
Messier 67: King Cobra Cluster
Messier 68
Messier 69
Messier 70
Messier 71
Messier 72
Messier 73
Messier 74: Phantom Galaxy
Messier 75
Messier 76: Little Dumbbell Nebula
Messier 77: Cetus A
Messier 78
Messier 79
Messier 80
Messier 81: Bode's Galaxy
Messier 82: Cigar Galaxy
Messier 83: Southern Pinwheel Galaxy
Messier 84
Messier 85
Messier 86
Messier 87: Virgo A
Messier 88
Messier 89
Messier 90
Messier 91
Messier 92
Messier 93
Messier 94: Cat's Eye Galaxy
Messier 95
Messier 96
Messier 97: Owl Nebula
Messier 98
Messier 99: Coma Pinwheel
Messier 100
Messier 101: Pinwheel Galaxy
Messier 102: Spindle Galaxy
Messier 103
Messier 104: Sombrero Galaxy
Messier 105
Messier 106
Messier 107
Messier 108: Surfboard Galaxy
Messier 109
Messier 110: Edward Young Star

Categories

  • Asterism
  • Dark Nebula
  • Double Star
  • Elliptical Galaxy
  • Emission Nebula
  • Galaxy Cluster
  • Galaxy Group
  • Globular Cluster
  • Irregular Galaxy
  • Lenticular Galaxy
  • Milky Way Star Cloud
  • Open Cluster
  • Planetary Nebula
  • Reflection Nebula
  • Spiral Galaxy
  • Star-Forming Region
  • Supernova Remnant
  • Uncategorized

Messier-Objects.com

Privacy Policy
Terms and Conditions

Copyright © 2019 Messier Objects.

Omega WordPress Theme by ThemeHall

This website uses cookies to personalise content and ads, and to analyse user traffic. By continuing to use the site, you agree to the use of cookies. Accept Reject Read More
Privacy & Cookies Policy