NGC 643

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NGC 643
NGC 643 DECam.jpg
NGC 643 with DECam
Observation data (J2000 epoch)
Right ascension 01h 35m 01.43s [1]
Declination −75° 33 24.7 [1]
Distance ~200,000 ly
Apparent magnitude (V)13 [2]
Apparent dimensions (V)1.50 arcmin [3]
Physical characteristics
Other designationsESO 29-SC50
Associations
Constellation Hydrus
See also: Open cluster, List of open clusters

NGC 643 is an open cluster located on the far outskirts of the Small Magellanic Cloud in the southern constellation of Hydrus, approximately 200,000 light-years from Earth. [1] [3] [4] Due to their close proximity to NGC 643, the open cluster ESO 29-SC44 and the galaxies PGC 6117 and PGC 6256 are also designated NGC 643A, NGC 643B and NGC 643C, respectively. [4] NGC 643 is relatively old. Its brightest stars have an apparent magnitude of 19. [2]

Contents

Observation history

NGC 643 was discovered by the British astronomer John Herschel on 18 September, 1835. John Louis Emil Dreyer, compiler of the first New General Catalogue of Nebulae and Clusters of Stars, described NGC 643 as being "very faint, pretty small, round" and as becoming "very gradually a little brighter [in the] middle". [4]

See also

Related Research Articles

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<span class="mw-page-title-main">NGC 346</span> Open cluster in the constellation Tucana

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<span class="mw-page-title-main">NGC 265</span> Open star cluster in the constellation Tucana

NGC 265 is an open cluster of stars in the southern constellation of Tucana. It is located in the Small Magellanic Cloud, a nearby dwarf galaxy. The cluster was discovered by English astronomer John Herschel on April 11, 1834. J. L. E. Dreyer described it as, "faint, pretty small, round", and added it as the 265th entry in his New General Catalogue.

<span class="mw-page-title-main">NGC 1313</span> Galaxy in the constellation Reticulum

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<span class="mw-page-title-main">NGC 1868</span> Globular cluster in the constellation Dorado

NGC 1868 is a globular cluster in the Large Magellanic Cloud in the constellation Dorado. It was discovered by John Herschel in 1834. The cluster is relatively metal-poor and as a result appears relatively blue. It maintains an abundant population of mature giant branch stars which have been used to fit its age to roughly 700 million years old. The cluster is located in a relatively sparse region of the Large Magellanic Cloud which has allowed it to be studied relatively free of crowding from background stars.

<span class="mw-page-title-main">NGC 1783</span> Globular cluster in the constellation Dorado

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<span class="mw-page-title-main">NGC 121</span> Globular cluster in the constellation Tucana

NGC 121 is a globular cluster in the Small Magellanic Cloud, in the constellation of Tucana. It was first discovered by John Herschel on September 20, 1835. The compiler of the New General Catalogue, John Louis Emil Dreyer, described this object as "pretty bright, pretty small, little extended, very gradually brighter middle".

<span class="mw-page-title-main">NGC 152</span> Open cluster in the constellation Tucana

NGC 152 is an open cluster in the constellation Tucana. It was discovered by John Herschel on September 20, 1835. It is located within the Small Magellanic Cloud.

<span class="mw-page-title-main">NGC 220</span> Open cluster in the constellation Tucana

NGC 220 is an open cluster located approximately 210,000 light-years from the Sun in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on August 12, 1834 by John Herschel.

<span class="mw-page-title-main">NGC 267</span> Open cluster in the constellation Tucana

NGC 267 is an open cluster in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on October 4, 1836 by John Herschel.

<span class="mw-page-title-main">NGC 269</span> Open star cluster in the constellation Tucana

NGC 269 is an open cluster in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on November 5, 1836 by John Herschel.

<span class="mw-page-title-main">NGC 299</span> Open star cluster in the constellation Tucana

NGC 299 is an open cluster of stars in the main body of the Small Magellanic Cloud – a nearby dwarf galaxy. It is located in the southern constellation of Tucana, just under 200,000 light years distant from the Sun. The cluster was discovered on August 12, 1834 by English astronomer John Herschel.

<span class="mw-page-title-main">NGC 306</span> Open star cluster in the constellation Tucana

NGC 306 is an open cluster in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on October 4, 1836 by John Herschel.

<span class="mw-page-title-main">NGC 330</span> Open star cluster in the constellation Tucana

NGC 330 is an open cluster in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on 1 August, 1826 by James Dunlop. It was described by Dreyer as "a globular cluster, very bright, small, a little extended, stars from 13th to 15th magnitude." At an aperture of 31.0 arcseconds, the apparent V-band magnitude is 9.60, but at this wavelength, it also has 0.36 magnitudes of interstellar extinction.

<span class="mw-page-title-main">NGC 361</span> Open star cluster in the Small Magellanic Cloud

NGC 361 is an open cluster in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on September 6, 1826 by James Dunlop. It was described by Dreyer as "very very faint, pretty large, very little extended, very gradually brighter middle." At an aperture of 31.0 arcseconds, its apparent V-band magnitude is 12.24, but at this wavelength, it has 0.40 magnitudes of interstellar extinction.

<span class="mw-page-title-main">NGC 376</span> Globular cluster located in the constellation Tucana

NGC 376 is a young open cluster of stars in the southern constellation of Tucana. It was discovered on September 2, 1826, by Scottish astronomer James Dunlop. Dreyer, a Danish/British astronomer, described it as a "globular cluster, bright, small, round." It is irregular in form, with a central spike.

<span class="mw-page-title-main">NGC 411</span> Globular cluster located in the constellation Tucana

NGC 411 is a globular cluster located approximately 55,000 pc (180,000 ly) from Earth in the constellation Tucana. It was discovered in 1826 by James Dunlop. It was described by Dreyer as "extremely faint, pretty large, round, gradually very little brighter middle." At a distance of about 180,000 light years (55,000 parsecs), it is located within the Small Magellanic Cloud. It has a mass of about 3.0×104 M, and a luminosity of about 8.0×104 L.

<span class="mw-page-title-main">NGC 416</span> Globular cluster located in the constellation Tucana

NGC 416 is a globular cluster located in the constellation Tucana. It was discovered on September 5, 1826, by James Dunlop. It was described by Dreyer as "faint, pretty small, round, gradually brighter middle." At a distance of about 199,000 ± 9,800 ly (61,000 ± 3,000 pc), it is located within the Small Magellanic Cloud. At an aperture of 31 arcseconds, its apparent V-band magnitude is 11.42, but at this wavelength, it has 0.25 magnitudes of interstellar extinction.

<span class="mw-page-title-main">N11 (emission nebula)</span> Emission nebula in the constellation Dorado

N11 is the brightest emission nebula in the north-west part of the Large Magellanic Cloud in the Dorado constellation. The N11 complex is the second largest H II region of that galaxy, the largest being the Tarantula Nebula. It covers an area approximately 6 arc minutes across. It has an elliptical shape and consists of a large bubble, generally clear interstellar area, surrounded by nine large nebulae. It was named by Karl Henize in 1956.

<span class="mw-page-title-main">NGC 3664</span> Galaxy in the constellation Leo

NGC 3664 is a magellanic barred spiral galaxy in the constellation of Leo. It is located about 80 million light years away from Earth, which means, given its apparent dimensions, that NGC 3664 is approximately 50,000 light years across. It was discovered by Wilhelm Tempel on March 14, 1879. It is a member of the NGC 3640 Group of galaxies, which is a member of the Leo II Groups, a series of galaxies and galaxy clusters strung out from the right edge of the Virgo Supercluster.

References

  1. 1 2 3 "NGC 643 NASA/IPAC Extragalactic Database Results". ned.ipac.caltech.edu. Retrieved November 1, 2018.
  2. 1 2 de Vaucouleurs, G. (1957). "NGC 643: A New Outlying Cluster of the Small Magellanic Cloud". Publications of the Astronomical Society of the Pacific. 69 (408): 252–255. Bibcode:1957PASP...69..252D. doi: 10.1086/127060 . JSTOR   40676443.
  3. 1 2 "Revised NGC Data for NGC 643". spider.seds.org. Retrieved November 1, 2018.
  4. 1 2 3 "New General Catalog Objects: NGC 600 - 649". cseligman.com. Retrieved November 1, 2018.