Messier 69

Messier 69 or M69, also known NGC 6637, is a globular cluster in the southern constellation of Sagittarius. It can be found 2.5° to the northeast of the star Epsilon Sagittarii and is dimly visible in 50 mm aperture binoculars. The cluster was discovered by Charles Messier on August 31, 1780, the same night he discovered M70. At the time, he was searching for an object described by Nicolas-Louis de Lacaille in 1751–2 and thought he had rediscovered it, but it is unclear if Nicolas-Louis de Lacaille actually described M69.[8]

This cluster is at a distance of about 28,700[3] light-years away from Earth and 5,200 ly from the Galactic Center,[9] with a spatial radius of 45 light-years.[6] It is a relatively metal-rich globular cluster that is a likely member of the Galactic bulge population.[10] M69 has a mass of 2.0×105 M with a half-mass radius of 11.6 ly,[5] a core radius of 29.2 ly, and a tidal radius of 91.9 ly.[3] The center of the cluster has a luminosity density of 6,460 L·pc−3.[9] It is a close neighbor of globular cluster M70, with perhaps only 1,800 light-years separating the two objects.[11]

Messier 69
Messier 69 Hubble WikiSky
M69 by Hubble Space Telescope; 3.5′ view
Credit: NASA/STScI/WikiSky
Observation data (J2000 epoch)
ClassV[1]
ConstellationSagittarius
Right ascension 18h 31m 23.10s[2]
Declination−32° 20′ 53.1″[2]
Distance29 kly (8.8 kpc)[3]
Apparent magnitude (V)+8.31[4]
Apparent dimensions (V)10′.8[3]
Physical characteristics
Mass2.0×105 M[5] M
Radius45 ly[6]
Tidal radius91.9 ly.[3]
Metallicity = –0.78[7] dex
Estimated age13.06 Gyr[7]
Other designationsGCl 96, M69, NGC 6637[4]

Gallery

Cosmic riches

As globular clusters go, M69 is one of the most metal-rich on record.[12]

M69map

Map showing location of M69 (Roberto Mura)

References

  1. ^ Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
  2. ^ a b Goldsbury, Ryan; et al. (December 2010), "The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters", The Astronomical Journal, 140 (6): 1830–1837, arXiv:1008.2755, Bibcode:2010AJ....140.1830G, doi:10.1088/0004-6256/140/6/1830.
  3. ^ a b c d e Kharchenko, N. V.; et al. (2013), "Global survey of star clusters in the Milky Way. II. The catalogue of basic parameters", Astronomy and Astrophysics, 558: 8, arXiv:1308.5822, Bibcode:2013A&A...558A..53K, doi:10.1051/0004-6361/201322302, A53.
  4. ^ a b "NGC 6637". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 17, 2006.
  5. ^ a b Mandushev, G.; et al. (December 1991), "Dynamical masses for galactic globular clusters", Astronomy and Astrophysics, 252: 94, Bibcode:1991A&A...252...94M.
  6. ^ a b From trigonometry: distance × sin( diameter_angle / 2 ) = 28,700 × 0.00157 = 45 ly. radius
  7. ^ a b Forbes, Duncan A.; Bridges, Terry (May 2010), "Accreted versus in situ Milky Way globular clusters", Monthly Notices of the Royal Astronomical Society, 404 (3): 1203–1214, arXiv:1001.4289, Bibcode:2010MNRAS.404.1203F, doi:10.1111/j.1365-2966.2010.16373.x.
  8. ^ Thompson, Robert Bruce; Thompson, Barbara Fritchman (2007), Illustrated Guide to Astronomical Wonders: From Novice to Master Observer, Maker Media, Inc., ISBN 978-1680451917
  9. ^ a b Piotto, G.; et al. (September 2002), "HST color-magnitude diagrams of 74 galactic globular clusters in the HST F439W and F555W bands", Astronomy and Astrophysics, 391 (3): 945–965, arXiv:astro-ph/0207124, Bibcode:2002A&A...391..945P, doi:10.1051/0004-6361:20020820.
  10. ^ Heasley, J. N.; et al. (August 2000), "Hubble Space Telescope Photometry of the Metal-rich Globular Clusters NGC 6624 and NGC 6637", The Astronomical Journal, 120 (2): 879–893, Bibcode:2000AJ....120..879H, doi:10.1086/301461.
  11. ^ Frommert, Hartmut; Kronberg, Christine (July 20, 2011), "Globular Cluster M69", SEDS Messier pages, Students for the Exploration and Development of Space (SEDS), retrieved December 3, 2018.
  12. ^ "Cosmic riches". ESA/Hubble Picture of the Week. Retrieved October 3, 2012.

External links

Coordinates: Sky map 18h 31m 23.23s, −32° 20′ 52.7″

Canada at the 2018 Commonwealth Games

Canada competed at the 2018 Commonwealth Games in Gold Coast, Australia from April 4 to April 15, 2018. It was Canada's 21st appearance at the Commonwealth Games, having competed at every Games since their inception in 1930.

On October 6, 2016, two time Commonwealth Games gold medalist Claire Carver-Dias was named as the chef de mission of the team.For the first time ever, there has been entry quotas set for all sports and therefore each country is restricted in the number of athletes it could enter.Canada's team consisted of 282 athletes competing in 17 sports. The team consisted of 137 male athletes and 146 female athletes. This included a record 21 para-sport athletes. Canada competed in all sports on the program except netball, which it failed to qualify in. Also, Canada did not qualify an athlete in the discipline of powerlifting.

On February 28, 2018, diver Meaghan Benfeito was named as the country's flag bearer at the opening ceremony.The goal of the Canadian team was at least 100 medals to be won across all sports.

List of NGC objects (6001–7000)

This is a list of NGC objects 6001–7000 from the New General Catalogue (NGC). The astronomical catalogue is composed mainly of star clusters, nebulae, and galaxies. Other objects in the catalogue can be found in the other subpages of the list of NGC objects.

The constellation information in these tables is taken from The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer, which was accessed using the "VizieR Service". Galaxy types are identified using the NASA/IPAC Extragalactic Database. The other data of these tables are from the SIMBAD Astronomical Database unless otherwise stated.

M69

M69 or M-69 may refer to:

M-69 (Michigan highway), a state highway in Michigan

M69 motorway, a motorway in England

Marine Highway 69, a designation of the Gulf Intracoastal Waterway which runs along the Texas coastline

Miles M.69 Marathon, an aircraft

Messier 69, a globular cluster in the constellation Sagittarius

M69 Grenade A training grenade

M-69 Incendiary cluster bomb

Messier object

The Messier objects are a set of 110 astronomical objects cataloged by the French astronomer Charles Messier in his Catalogue des Nébuleuses et des Amas d'Étoiles ("Catalogue of Nebulae and Star Clusters").

Because Messier was interested in finding only comets, he created a list of non-comet objects that frustrated his hunt for them. The compilation of this list, in collaboration with his assistant Pierre Méchain, is known as the Messier catalogue. This catalogue of objects is one of the most famous lists of astronomical objects, and many Messier objects are still referenced by their Messier number.

The catalogue includes some astronomical objects that can be observed from Earth's Northern Hemisphere such as deep-sky objects, a characteristic which makes the Messier objects extremely popular targets for amateur astronomers.A preliminary version first appeared in the Memoirs of the French Academy of Sciences in 1771,

and the last item was added in 1966 by Kenneth Glyn Jones, based on Messier's observations.

The first version of Messier's catalogue contained 45 objects and was published in 1774 in the journal of the French Academy of Sciences in Paris. In addition to his own discoveries, this version included objects previously observed by other astronomers, with only 17 of the 45 objects being Messier's.

By 1780 the catalogue had increased to 80 objects. The final version of the catalogue containing 103 objects was published in 1781 in the Connaissance des Temps for the year 1784.

However, due to what was thought for a long time to be the incorrect addition of Messier 102, the total number remained 102. Other astronomers, using side notes in Messier's texts, eventually filled out the list up to 110 objects.The catalogue consists of a diverse range of astronomical objects, ranging from star clusters and nebulae to galaxies. For example, Messier 1 is a supernova remnant, known as the Crab Nebula, and the great spiral Andromeda Galaxy is M31. Many further inclusions followed in the next century when the first addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding Messier's side note in his 1781 edition exemplar of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones in 1967.

List
See also

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