NGC 6316 | |
---|---|
Observation data (J2000 epoch) | |
Class | III [1] |
Constellation | Ophiuchus |
Right ascension | 17h 16m 37.42s [2] |
Declination | −28° 08′ 24.0″ [2] |
Distance | 36.86 ± 0.98 kly (11.3 ± 0.3 kpc) [3] |
Apparent magnitude (V) | 9.03 [2] |
Apparent dimensions (V) | 4.9′ × 4.9′ [1] |
Physical characteristics | |
Metallicity | = -0.45 [4] -0.87 [5] -0.90 [3] dex |
Estimated age | 13.1 ± 0.5 Gyr [3] |
Notable features | Relatively metal-rich globular cluster |
Other designations | GCl 57, VDBH 219 [2] |
NGC 6316 is a globular cluster located in the constellation Ophiuchus. Its Shapley-Sawyer Concentration Class is III, meaning that it has a "strong inner core of stars" and was discovered by the German-born British astronomer William Herschel on 24 May 1784. [6] It is at a distance of about 37,000 light years away from the Earth. [3] NGC 6316 has a metallicity of -0.45 [4] , although new studies suggest this cluster to be more metal Poor, with a metallicity of -0.87 [5] and -0.9 [3] ; this means that its ratio of hydrogen/helium to other elements is only 35% that of the Sun, but still enough to be considered a "metal-rich" globular cluster. [7]
The Local Group is the galaxy group that includes the Milky Way, where Earth is located. It has a total diameter of roughly 3 megaparsecs (10 million light-years; 9×1019 kilometres), and a total mass of the order of 2×1012 solar masses (4×1042 kg). It consists of two collections of galaxies in a "dumbbell" shape; the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about 800 kiloparsecs (3×10 6 ly; 2×1019 km) and are moving toward one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies.
Messier 107 or M107, also known as NGC 6171 or the Crucifix Cluster, is a very loose globular cluster in a very mildly southern part of the sky close to the equator in Ophiuchus, and is the last such object in the Messier Catalogue.
Messier 2 or M2 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 15 or M15 is a globular cluster in the constellation Pegasus. It was discovered by Jean-Dominique Maraldi in 1746 and included in Charles Messier's catalogue of comet-like objects in 1764. At an estimated 12.5±1.3 billion years old, it is one of the oldest known globular clusters.
Messier 70 or M70, also known as NGC 6681, is a globular cluster of stars to be found in the south of Sagittarius. It was discovered by Charles Messier in 1780. The famous comet Hale–Bopp was discovered near this cluster in 1995.
Messier 75 or M75, also known as NGC 6864, is a giant globular cluster of stars in the southern constellation Sagittarius. It was discovered by Pierre Méchain in 1780 and included in Charles Messier's catalog of comet-like objects that same year.
NGC 2204 is an open cluster of stars in the Canis Major constellation. It was discovered by the German-English astronomer William Herschel on 6 February 1785. The cluster has an integrated visual magnitude of 8.6 and spans a diameter of 10.0′. Resolving the individual member stars is a challenge with a 10 to 12-inch amateur telescope. It is located at a distance of approximately 13,400 light years from the Sun. The cluster shows a mean radial velocity of +91.38±0.30 km/s relative to the Sun, and is orbiting the inner galactic disk region about 1 kpc below the galactic plane.
NGC 1427 is a low-luminosity elliptical galaxy located approximately 71 million light-years away from Earth. It was discovered by John Frederick William Herschel on November 28, 1837. It is a member of the Fornax Cluster. The galaxy has a stellar mass of 7.9 × 1010M☉, and a total mass of 9.4 × 1010M☉. However, the mass of the dark matter halo surrounding the galaxy is around 4.3 × 1012M☉.
NGC 5986 is a globular cluster of stars in the southern constellation of Lupus, located at a distance of approximately 34 kilolight-years from the Sun. It was discovered by Scottish astronomer James Dunlop on May 10, 1826. John L. E. Dreyer described it as, "a remarkable object, a globular cluster, very bright, large, round, very gradually brighter middle, stars of 13th to 15th magnitude". Its prograde–retrograde orbit through the Milky Way galaxy is considered irregular and highly eccentric. It has a mean heliocentric radial velocity of +100 km/s. The galacto-centric distance is 17 kly (5.2 kpc), which puts it in the galaxy's inner halo.
NGC 6723, also known as the Chandelier Cluster, is a globular cluster in the constellation Sagittarius. Its magnitude is given as between 6 and 6.8, and its diameter is between 7 and 11 arcminutes. It is a class VII cluster with stars of magnitude 14 and dimmer. It is near the border of Sagittarius and Corona Australis.
NGC 6934 is a globular cluster of stars in the northern constellation of Delphinus, about 52 kilolight-years distant from the Sun. It was discovered by the German-born astronomer William Herschel on 24 September 1785. The cluster is following a highly eccentric orbit through the Milky Way along an orbital plane that is inclined by 73° to the galactic plane. It may share a common dynamic origin with NGC 5466. As of 2018, it has been poorly studied.
NGC 6352 is a globular cluster of stars in the southern constellation of Ara, located approximately 18.3 kly from the Sun. It was discovered by Scottish astronomer James Dunlop on May 14, 1826. The cluster has a Shapley–Sawyer Concentration Class of XI:. A telescope with a 15 cm (5.9 in) aperture is required to resolve the stars within this loose cluster.
SN 1917A is a supernova event in the Fireworks Galaxy, positioned 37″ west and 105″ south of the galactic core. Discovered by American optician George Willis Ritchey on 19 July 1917, it reached a peak visual magnitude of 13.6. Based on a poor quality photographic spectrum taken at least a month after peak light by F. G. Pease and Ritchey, it was identified as a type II core-collapse supernova.
NGC 6541 is a globular cluster in the southern constellation of Corona Australis. It is estimated to be around 14 billion years old.
NGC 2298 is a globular cluster in the southern constellation of Puppis. Discovered by James Dunlop on May 30, 1826, it is probably a former member of the disputed Canis Major Dwarf galaxy.
Liller 1 is a globular cluster in the constellation Scorpius, discovered by the American astronomer William Liller in 1977. It is close to the centre of the Milky Way in its galactic bulge, only 2,600 light-years from the centre. Liller 1 is just under 30,000 light years from Earth.
NGC 6256 is a globular cluster of stars in the southern constellation of Scorpius. It was discovered by the Scottish astronomer James Dunlop on Aug 2, 1826. In J. L. E. Dreyer's New General Catalogue annotation it is described as, "very faint, very large, very gradually bright in the middle, well resolved clearly consisting of stars." The cluster is located at a distance of 22 thousand light-years (6.8 kpc) from the Sun.
NGC 6284 is a globular cluster located in the constellation Ophiuchus. It is designated as IX in the galaxy morphological classification scheme and was discovered by the German-born British astronomer William Herschel on 22 May 1784. Its distance had previously been estimated at 49,900 light years from Earth, but this was revised in 2023 to around 43,000 light years. This same study, based on high-resolution Hubble Space Telescope optical observations, produced the first high-quality colour-magnitude diagram (CMD) of NGC 6284, extending down to about six magnitudes below its main sequence turn-off. The new observations moved its centre of gravity by 1.5–3 arcseconds from previous values, and its density profile showed a steep central cusp, suggesting that NGC 6284 is a post-core collapse (PCC) cluster.
NGC 4561 is a barred spiral galaxy in the constellation Coma Berenices. It was discovered by German-British astronomer William Herschel on April 13, 1784. This galaxy is located at a distance of 82 ± 14 million light-years (25.2 ± 4.3 Mpc) from the Milky Way, and is a member of the Virgo Cluster of galaxies. It is 13th magnitude with an angular size of 1.5′.