NGC 6891

Last updated
NGC 6891
Nebula
Planetary nebula
Ngc6891-hst-R658GB502.jpg
Hubble Space Telescope image of NGC 6891
Observation data: J2000.0 epoch
Right ascension 20h 15m 08.84s [1]
Declination +12° 42′ 15.6″ [1]
Distance12,400 [2]   ly
Apparent magnitude (V)12.51±0.23 [3]
Constellation Delphinus
DesignationsPN G054.1-12.1, PK 54-12.1, IRAS 20127+1233 [1]
See also: Lists of nebulae

NGC 6891 is a bright, asymmetrical planetary nebula located in the northern constellation of Delphinus. [4] [5] [6] It was discovered on 22 September 1884, by Scottish astronomer Ralph Copeland, who observed it using visual spectroscopy with a 6.1-inch refractor at the Dun Echt Observatory in Aberdeen, Scotland. [7] [1]

Contents

Characteristics

NGC 6891 displays a triple-shell structure, consisting of a bright inner nebula, an attached intermediate shell, and a detached outer halo. [8] High-resolution imaging reveals filaments, knots, and intricate details in the interior surrounding the central white dwarf star named HD 192563, along with at least two ellipsoidal shells oriented differently and a spherical outer halo expanding faster than the inner regions. [9] The bright optical regions have an apparent diameter of approximately 15 arcseconds. [7] The nebula shows evidence of multiple mass ejection episodes from its progenitor star. [8] [4]

Observation

NGC 6891 has an apparent visual magnitude of around 10.5 to 12 and appears as a small, bluish disc in amateur telescopes of 6 inches (150 mm) aperture or larger, with the central star faintly visible under good conditions. [3] It lies near the celestial equator in Delphinus and is observable from both hemispheres. [6] The nebula has been imaged in detail by the Hubble Space Telescope, contributing to studies of planetary nebula structure, formation, evolution, and distance determination. [4]

Reference

  1. 1 2 3 4 "Simbad - Object view". simbad.cds.unistra.fr. Retrieved 2026-03-06.
  2. ↑ Stanghellini, Letizia; Shaw, Richard A.; Villaver, Eva (2008). "The Magellanic Cloud Calibration of the Galactic Planetary Nebula Distance Scale". The Astrophysical Journal. 689 (1): 194–202. arXiv: 0807.1129 . doi:10.1086/592395. ISSN   0004-637X.
  3. 1 2 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. ISSN   0004-6361.
  4. 1 2 3 "Hubble's View of Planetary Nebula Reveals Complex Structure - NASA Science". 2021-11-29. Retrieved 2026-03-06.
  5. ↑ Lazaro, Enrico de (2021-11-30). "Hubble Spots Beautiful Planetary Nebula: NGC 6891 | Sci.News". Sci.News: Breaking Science News. Retrieved 2026-03-06.
  6. 1 2 "NGC 6891 - Planetary Nebula in Delphinus | TheSkyLive". theskylive.com. Retrieved 2026-03-06.
  7. 1 2 "Planetary Nebula NGC 6891 | Deep⋆Sky Corner". www.deepskycorner.ch. Retrieved 2026-03-06.
  8. 1 2 Guerrero, Martín A.; Miranda, Luis F.; Manchado, Arturo; Vázquez, Roberto (2000). "The triple-shell structure and collimated outflows of the planetary nebula NGC 6891". Monthly Notices of the Royal Astronomical Society. 313 (1): 1–7. doi: 10.1046/j.1365-8711.2000.03159.x . ISSN   0035-8711.
  9. ↑ Palen, Stacy; Balick, Bruce; Hajian, Arsen R.; Terzian, Yervant; Bond, Howard E.; Panagia, Nino (2002). "Hubble Space Telescope Expansion Parallaxes of the Planetary Nebulae NGC 6578, NGC 6884, NGC 6891, and IC 2448". The Astronomical Journal. 123 (5): 2666–2675. doi:10.1086/339838. ISSN   0004-6256.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.