NGC 1806

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NGC 1806
NGC 1806 HST.jpg
NGC 1806 image taken by the Hubble Space Telescope
Observation data (J2000 epoch)
Class VI [1]
Constellation Dorado
Right ascension 05h 02m 11.180s [2]
Declination −67° 59′ 05.89″ [2]
Apparent magnitude (V)11.00 [3]
Physical characteristics
Mass7.6×104 [3]   M☉
Estimated age1.60±0.05 Gyr [3]
Other designationsNGC 1806, KMHK 462, [SL63] 184
See also: Globular cluster, List of globular clusters

NGC 1806 is a globular cluster located within the Large Magellanic Cloud within the constellation of Dorado (the dolphin-fish), an area of the sky best seen from the Earth's southern hemisphere. It was discovered in 1836 by the British astronomer John Herschel. At an aperture of 50 arcseconds, its apparent V-band magnitude is 11.00, but at this wavelength, it has 0.05 magnitudes of interstellar extinction. [3]

NGC 1806 is about 1.6 billion years old. Its estimated mass is 7.6×104  M☉, and its total luminosity is 1.42×105  L☉, leading to a mass-to-luminosity ratio of 0.54 M☉/L☉. [3] All else equal, older star clusters have higher mass-to-luminosity ratios; that is, they have lower luminosities for the same mass. [3]

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<span class="mw-page-title-main">NGC 1846</span> Globular cluster in the constellation Dorado

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

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<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">NGC 419</span> Globular cluster located in the constellation Tucana

NGC 419 is a globular cluster located approximately 57,000 pc (190,000 ly) from Earth in the constellation Tucana. It was discovered on September 2, 1826, by James Dunlop. It was described by Dreyer as "pretty large, pretty bright, round, gradually brighter middle". At a distance of about 186,000 light years, it is located within the Small Magellanic Cloud. At an aperture of 50 arcseconds, its apparent V-band magnitude is 10.30, but at this wavelength, it has 0.15 magnitudes of interstellar extinction.

<span class="mw-page-title-main">NGC 458</span> Open cluster located in the constellation Tucana

NGC 458 is an open cluster located in the constellation Tucana. It was discovered on September 6, 1826, by James Dunlop. It was also observed by John Herschel and DeLisle Stewart. It was described by Dreyer as "pretty faint, large, round, very gradually brighter middle". It was also noted in the second Index Catalogue that it was "probably a cluster, extremely small, close, no nebulosity seen by D.S. ." At an aperture of 31 arcseconds, its apparent V-band magnitude is 11.73, but at this wavelength, it has 0.12 magnitudes of interstellar extinction.

<span class="mw-page-title-main">NGC 1978</span> Globular cluster in the constellation Dorado

NGC 1978 is an elliptical shaped globular cluster or open cluster in the constellation Dorado. It is located within the Large Magellanic Cloud. It was discovered by James Dunlop on November 6, 1826. At an aperture of 50 arcseconds, its apparent V-band magnitude is 10.20, but at this wavelength, it has 0.16 magnitudes of interstellar extinction. It appears 3.9 arcminutes wide. NGC 1978 has a radial velocity of 293.1 ± 0.9 km/s.

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 "NGC 1806". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 8 January 2019.
  3. 1 2 3 4 5 6 Song, Ying-Yi; Mateo, Mario; Bailey, John I.; Walker, Matthew G.; Roederer, Ian U.; Olszewski, Edward W.; Reiter, Megan; Kremin, Anthony (2021). "Dynamical masses and mass-to-light ratios of resolved massive star clusters – II. Results for 26 star clusters in the Magellanic Clouds". Monthly Notices of the Royal Astronomical Society. 504 (3): 4160–4191. arXiv: 2104.06882 . doi: 10.1093/mnras/stab1065 .


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