NGC 6164 and 6165

NGC 6164/6165
Emission nebula
Bipolar nebula
NGC 6164 and 6165 are the nebula's two lobes to the left and right of the central star respectively.
Observation data: J2000 epoch
Right ascension16h 33m 42s
Declination−48° 04′ 47″
Distance3,870 ly   (1,188 pc)
Apparent magnitude (V)6.71
ConstellationNorma
Physical characteristics
Dimensions3.0' × 3.0'
DesignationsNGC 6164-65, AM 1630-475, ESO 226-EN 012
See also: Lists of nebulae

NGC 6164 and 6165 compose a bipolar emission nebula located 3,870 light years away in the constellation Norma. Known as the Dragon's Egg nebula due to its proximity to the Fighting Dragons of Ara, it was discovered by astronomer John Herschel on 1 July 1834.

Physical characteristics

The nebula has two distinct lobes, with NGC 6164 constituting the one to the north of the central star, and NGC 6165, the one to the south. It is surrounded by a faint halo.

Its shape gives it the appearance of a planetary nebula resulting from the death of an old star similar to the Sun, but it is in reality an emission nebula. The gas from this nebula was ejected by the star located at its center, and this is also the source of its ionisation. In the Henry Draper Catalogue, this star is designated as HD 148937. It is a very young O-type star whose age is between three and four million years. Surrounded by its magnetic field, this star is about 40 times more massive than the Sun, and is expected to go supernova in three to four million years.

See also

References

  1. 1 2 "Ngc 6164 and Ngc 6165". Amateur Astronomy Photo of the Day. 22 July 2025.
  2. 1 2 "NGC 6164 and NGC 6165". ASTRODRUDIS.
  3. ↑ information@eso.org. "The nebula NGC 6164/6165 in the constellation of Norma". www.eso.org. Retrieved 2024-07-25.
  4. ↑ Starr, Michelle (2024-04-11). "Enigmatic 'Dragon's Egg' Star Is a Magnetic Monster And We Finally Know Why". ScienceAlert. Retrieved 2024-07-25.
  5. ↑ Nemiroff, Robert; Bonnell, Jerry (25 December 2022). "NGC 6164: Dragon's Egg Nebula and Halo". Astronomy Picture of the Day. NASA.
  6. ↑ Herschel, John Frederick William (1847). "Results of astronomical observations made during the years 1834, 5, 6, 7, 8, at the Cape of Good Hope; being the completion of a telescopic survey of the whole surface of the visible heavens, commenced in 1825". London.
  7. ↑ Herschel, John F. W. (John Frederick William); United States Military Academy, former owner DSI (1847). Results of astronomical observations made during the years 1834, 5, 6, 7, 8, at the Cape of Good Hope : being the completion of a telescopic survey of the whole surface of the visible heavens, commenced in 1825. Smithsonian Libraries. London : Smith, Elder and Co.
  8. 1 2 "A Halo for NGC 6164". www.as.arizona.edu. Retrieved 2024-07-25.
  9. ↑ info@noirlab.edu. "Nebula NGC 6164-5". www.noirlab.edu. Retrieved 2024-07-25.
  10. ↑ Henize, Karl G. (1959-01-01). "A new planetary nebula NGC 6164-65 (Cederblad 135a, b)". The Astronomical Journal. 64: 51. Bibcode:1959AJ.....64S..51H. doi:10.1086/108043. ISSN 0004-6256.
  11. 1 2 "APOD: 2014 May 22 - A Halo for NGC 6164". apod.nasa.gov. Retrieved 2024-07-25.
  12. ↑ "APOD: 2025 April 24 - NGC 6164: A Dragon's Egg". apod.nasa.gov. Retrieved 2026-08-19.
  13. ↑ Lim, Beomdu; Naze, Yael; Chang, Seok-Jun; Hutsemekers, Damien (2023-12-05). "A Morpho-Kinematic Study of the Enigmatic Emission Nebula NGC 6164/5 Surrounding the Magnetic O-type Star HD 148937". The Astrophysical Journal. 961 (1): 72. arXiv:2312.03211. Bibcode:2024ApJ...961...72L. doi:10.3847/1538-4357/ad12c4.
  14. ↑ Wade, G. A.; Grunhut, J.; Gräfener, G.; Howarth, I. D.; Martins, F.; Petit, V.; Vink, J. S.; Bagnulo, S.; Folsom, C. P.; Nazé, Y.; Walborn, N. R.; Townsend, R. H. D.; Evans, C. J. (2012-01-01). "The spectral variability and magnetic field characteristics of the Of?p star HD 148937". Monthly Notices of the Royal Astronomical Society. 419 (3): 2459–2471. arXiv:1108.4847. Bibcode:2012MNRAS.419.2459W. doi:10.1111/j.1365-2966.2011.19897.x. ISSN 0035-8711.