NGC 6496

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NGC 6496
NGC 6496.jpg
Processed Hubble image of the globular cluster
Observation data
Class XII [1]
Constellation Scorpius
Right ascension 17h 59m 03.68s [2]
Declination −44° 15 57.4 [2]
Distance 36.9  kly (11.3  kpc) [3]
Apparent dimensions (V)5.6'
Physical characteristics
Mass8.2×104 [4]   M
Metallicity  = –0.70 [5] dex
Estimated age12.42  Gyr [5]
See also: Globular cluster, List of globular clusters

NGC 6496 is a globular cluster which is in the direction of the Milky Way's galactic bulge based on observations collected with the WFPC2 on board the Hubble Space Telescope. NGC 6496 was originally believed[ who? ] to be a member of the disc system of the galactic center, but scientists questioned this classification. It was instead suggested[ who? ] that NGC 6496, together with two other clusters, NGC 6624 and NGC 6637, could be halo clusters with strongly inclined orbits. NGC 6496 lies in the Southern sky at RA=17:59:03.68 and Dec=-44:15:57.4. [6]

Contents

The first CMD presented of NGC 6496 had photometry reaching 2 mag below the horizontal branch, disclosing for the first time the usual red arm of the metal-rich clusters. The extinction towards NGC 6496 is uncertain, with estimates ranging between and . [7]

The cluster has a relatively metal-rich composition of [Fe/H] = –0.46 dex and is of an open, uncrowded nature. Few attempts were made to find variable stars in NGC 6496. In one of the studies, thirteen variable stars were detected by Dr. Moe Abbas and Dr. Andrew Layden from Bowling Green State University. [8]

Related Research Articles

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<span class="mw-page-title-main">Messier 3</span> Globular cluster in the constellation Canes Venatici

Messier 3 is a globular cluster of stars in the northern constellation of Canes Venatici.

<span class="mw-page-title-main">Messier 80</span> Globular cluster in the constellation Scorpius

Messier 80 is a globular cluster in the constellation Scorpius. It was discovered by Charles Messier in 1781, being one of his first discoveries.

<span class="mw-page-title-main">Messier 19</span> Globular cluster in Ophiuchus

Messier 19 or M19 is a globular cluster in the constellation Ophiuchus. It was discovered by Charles Messier on June 5, 1764 and added to his catalogue of comet-like objects that same year. It was resolved into individual stars by William Herschel in 1784. His son, John Herschel, described it as "a superb cluster resolvable into countless stars". The cluster is located 4.5° WSW of Theta Ophiuchi and is just visible as a fuzzy point of light using 50 mm (2.0 in) binoculars. Using a telescope with a 25.4 cm (10.0 in) aperture, the cluster shows an oval appearance with a 3 × 4 core and a 5 × 7 halo.

<span class="mw-page-title-main">Messier 53</span> Globular cluster in the constellation Coma Berenices

Messier 53 is a globular cluster in the Coma Berenices constellation. It was discovered by Johann Elert Bode in 1775. M53 is one of the more outlying globular clusters, being about 60,000 light-years away from the Galactic Center, and almost the same distance (about 58,000 light-years from the Solar System. The cluster has a core radius of 2.18 pc, a half-light radius of 5.84 pc, and a tidal radius of 239.9 pc.

<span class="mw-page-title-main">Messier 56</span> Globular cluster in Lyra

Messier 56 is a globular cluster in the constellation Lyra. It was discovered by Charles Messier in 1779. It is angularly found about midway between Albireo and Sulafat. In a good night sky it is tricky to find with large (50–80 mm) binoculars, appearing as a slightly fuzzy star. The cluster can be resolved using a telescope with an aperture of 8 in (20 cm) or larger.

<span class="mw-page-title-main">Messier 62</span> Globular cluster in the constellation Ophiuchus

Messier 62 or M62, also known as NGC 6266, is a globular cluster of stars in the south of the equatorial constellation of Ophiuchus. It was discovered in 1771 by Charles Messier, then added to his catalogue eight years later.

<span class="mw-page-title-main">Messier 68</span> Globular cluster in the constellation Hydra

Messier 68 is a globular cluster found in the east south-east of Hydra, away from its precisely equatorial part. It was discovered by Charles Messier in 1780. William Herschel described it as "a beautiful cluster of stars, extremely rich, and so compressed that most of the stars are blended together". His son John noted that it was "all clearly resolved into stars of 12th magnitude, very loose and ragged at the borders".

<span class="mw-page-title-main">Messier 69</span> Globular cluster in the constellation Sagittarius

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 Lacaille actually described M69.

<span class="mw-page-title-main">Messier 70</span> Globular cluster in the constellation Sagittarius

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<span class="mw-page-title-main">NGC 4833</span> Globular cluster in the constellation Musca

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<span class="mw-page-title-main">NGC 5466</span> Class XII globular cluster in the constellation Boötes

NGC 5466 is a class XII globular cluster in the constellation Boötes. Located 51,800 light years from Earth and 52,800 light years from the Galactic Center, it was discovered by William Herschel on May 17, 1784, as H VI.9. This globular cluster is unusual insofar as it contains a certain blue horizontal branch of stars, as well as being unusually metal poor like ordinary globular clusters. It is thought to be the source of a stellar stream discovered in 2006, called the 45 Degree Tidal Stream. This star stream is an approximately 1.4° wide star lane extending from Boötes to Ursa Major.

<span class="mw-page-title-main">NGC 5986</span> Globular cluster in the constellation Lupus

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.

<span class="mw-page-title-main">NGC 6723</span> Globular cluster in the constellation Sagittarius

NGC 6723 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.

<span class="mw-page-title-main">NGC 6934</span> Globular cluster in the constellation Delphinus

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.

<span class="mw-page-title-main">NGC 2808</span> Globular cluster in the constellation Carina

NGC 2808 is a globular cluster in the constellation Carina. The cluster belongs to the Milky Way, and is one of our home galaxy's most massive clusters, containing more than a million stars. It is estimated to be 12.5-billion years old.

<span class="mw-page-title-main">NGC 1851</span> Globular cluster in the constellation Columba

NGC 1851 is a relatively massive globular cluster located in the southern constellation of Columba. Astronomer John Dreyer described it as not very bright but very large, round, well resolved, and clearly consisting of stars. It is located 39.5 kilolight-years from the Sun, and 54.1 kilolight-years from the Galactic Center. The cluster is following a highly eccentric orbit through the galaxy, with an eccentricity of about 0.7.

<span class="mw-page-title-main">NGC 1261</span> Globular cluster in the constellation Horologium

NGC 1261 is a globular cluster of stars in the southern constellation of Horologium, first discovered by Scottish astronomer James Dunlop in 1826. The cluster is located at a distance of 53 kilolight-years from the Sun, and 59 kilolight-years from the Galactic Center. It is about 10.24 billion years old with 341,000 times the mass of the Sun. The cluster does not display the normal indications of core collapse, but evidence suggests it may have instead passed through a post core-collapse bounce state within the past two billion years. The central luminosity density is 2.22 L·pc−3, which is low for a globular cluster. Despite this, it has a Shapley–Sawyer Concentration Class of II, indicating a dense central concentration.

<span class="mw-page-title-main">NGC 6541</span> Globular cluster in the constellation Corona Australis

NGC 6541 is a globular cluster in the southern constellation of Corona Australis. It is estimated to be around 14 billion years old.

<span class="mw-page-title-main">NGC 5286</span> Globular cluster in the constellation Centaurus

NGC 5286 is a globular cluster of stars located some 35,900 light years away in the constellation Centaurus. At this distance, the light from the cluster has undergone reddening from interstellar gas and dust equal to E(B – V) = 0.24 magnitude in the UBV photometric system. The cluster lies 4 arc-minutes north of the naked-eye star M Centauri. It was discovered by Scottish astronomer James Dunlop, active in Australia, and listed in his 1827 catalog.

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. 1 2 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, S2CID   119183070.
  3. Boyles, J.; et al. (November 2011), "Young Radio Pulsars in Galactic Globular Clusters", The Astrophysical Journal, 742 (1): 51, arXiv: 1108.4402 , Bibcode:2011ApJ...742...51B, doi:10.1088/0004-637X/742/1/51, S2CID   118649860.
  4. Marks, Michael; Kroupa, Pavel (August 2010), "Initial conditions for globular clusters and assembly of the old globular cluster population of the Milky Way", Monthly Notices of the Royal Astronomical Society, 406 (3): 2000–2012, arXiv: 1004.2255 , Bibcode:2010MNRAS.406.2000M, doi:10.1111/j.1365-2966.2010.16813.x, S2CID   118652005. Mass is from MPD on Table 1.
  5. 1 2 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, S2CID   51825384.
  6. Richtler, T; Grebel, E (1994). "The cases of the "disk" globular clusters NGC 6496, NGC 6624, and NGC 6637". Astronomy and Astrophysics. 290: 412–420. Bibcode:1994A&A...290..412R.
  7. Armandroff, Taft E. (1988). "Color-magnitude diagrams for six metal-rich, low-latitude globular clusters". The Astronomical Journal. 96: 588. Bibcode:1988AJ.....96..588A. doi:10.1086/114833.
  8. Abbas, Moe; et al. (February 2015), "Variable Stars in Metal-Rich Globular Clusters. IV. Long-Period Variables in NGC 6496", The Astronomical Journal, 149 (2): 40, arXiv: 1410.3305 , Bibcode:2015AJ....149...40A, doi:10.1088/0004-6256/149/2/40, S2CID   118503316.
  9. "A heavy-metal home" . Retrieved 30 May 2016.