Messier 23, also known as NGC 6494, is an open cluster of stars in the southern constellation of Sagittarius. It was discovered by Charles Messier on June 20, 1764. M23 can be found with binoculars or a modestly sized telescope. The cluster is positioned in front of "an extensive gas and dust network", although it is unclear if there is an association between the two. It is located near the ecliptic and thus is subject to lunar occultations.
The cluster is located 2,050 light years away. Estimates for the number of cluster members range from 169 up to 414, with a directly-counted mass of 1,206 M☉; 1,332 M☉ by application of the virial theorem. The cluster is around 330 million years old with a near-solar metallicity of [Fe/H] = −0.04. The brightest component (lucida) is of magnitude 9.3. Five of the cluster members are candidate red giants, while the variable VV Sgr is a candidate asymptotic giant branch star.
2MASS Atlas image
|Observation data (J2000 epoch)|
|Right ascension||17h 57m 04s|
|Declination||−18° 59′ 06″|
|Distance||2,050 ly (628 pc)|
|Apparent magnitude (V)||5.5|
|Apparent dimensions (V)||35′|
|Estimated age||330±100 myr|
|Other designations||C 1753-190, Messier 23, NGC 6494|
1993–94 New York Rangers season
The 1993–94 New York Rangers season was the 68th season for the franchise. The highlight of the season was winning the Stanley Cup and hosting the NHL All-Star Game at Madison Square Garden. The Rangers clinched their second Presidents' Trophy and sixth division title by finishing with the best record in the NHL at 52–24–8, setting a then-franchise record with 112 points.
This marked the last season in which the Rangers were under the control of Paramount Communications. Toward the end of the season, Paramount was taken over by Viacom. Shortly thereafter, Viacom divested itself of all of Paramount's interests in Madison Square Garden, including the Rangers, and sold them to ITT Corporation and Cablevision. A couple of years later, ITT would sell their share to Cablevision, who owned the Rangers until 2010, when the MSG properties became their own company.Jean-Marie Messier
Jean-Marie Messier (born 13 December 1956) is a French businessman who was chairman and chief executive of the multinational media conglomerate Vivendi (formerly Vivendi Universal) until 2002. He is also frequently referred to by the nickname "J2M" and "J6M", based on his initials.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.List of open clusters
This is a list of open clusters located in the Milky Way. An open cluster is a gravitationally bound association of up to a few thousand stars that all formed from the same giant molecular cloud. There are over 1,000 known open clusters in the Milky Way galaxy, but the actual total may be up to ten times higher. The estimated half lives of clusters, after which half the original cluster members will have been lost, range from 150 million to 800 million years, depending on the original density.Messier 25
Messier 25, also known as IC 4725, is an open cluster of stars in the southern constellation of Sagittarius. The first recorded observation of this cluster was made by Philippe Loys de Chéseaux in 1745 and it was included in Charles Messier's list of nebulous objects in 1764. The cluster is located near some obscuring features, with a dark lane passing near the center.M25 is at a distance of about 2,000 light-years light-years away from Earth and is 67.6 million years old. The spatial dimension of this cluster is about 13 light-years across. It has an estimated mass of 1,937 M☉, of which about 24% is interstellar matter. A Delta Cephei type variable star designated U Sagittarii is a member of this cluster, as are two red giants, one of which is a binary system.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.NGC 6445
NGC 6445, also known as the Little Gem Nebula or Box Nebula, is a planetary nebula in the constellation Sagittarius. It was discovered by William Herschel on May 28, 1786. The distance of NGC 6445 is estimated to be slightly more than 1,000 parsecs based on the parallax measured by Gaia, which was measured at 0.9740±0.3151 mas.
New General Catalogue 6000 to 6499