Ring Nebula

---

title: "Ring Nebula" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["planetary-nebulae", "lyra", "messier-objects", "ngc-objects", "orion–cygnus-arm", "astronomical-objects-discovered-in-1779", "discoveries-by-charles-messier"] description: "Planetary nebula in Lyra" topic_path: "general/planetary-nebulae" source: "https://en.wikipedia.org/wiki/Ring_Nebula" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Planetary nebula in Lyra ::

::data[format=table title="Infobox Planetary nebula"]

Field	Value
type	Planetary
name	Ring Nebula
image	Webb captures detailed beauty of Ring Nebula (NIRCam image) (weic2320b).jpg
caption	The Ring Nebula as seen in infrared and visible light by a multiple exposure of images from the James Webb Space Telescope's NIRCam, showing an outer layer of hydrogen that is very faint in visible light
credit	NASA/STScI/AURA
epoch	J2000
ra
dec
dist_ly
dist_pc
radius_ly
appmag_v	8.8
last	Murdin
date	2000
chapter	Ring Nebula (M57, NGC 6720)
editor	Paul Murdin
title	Encyclopedia of Astronomy and Astrophysics
id	Article ID #5323
publisher	Institute of Physics Publishing
bibcode	2000eaa..bookE5323.
doi	10.1888/0333750888/5323
isbn	978-0-333-75088-9
size_v
author	O'Dell, C. R.
author2	Balick, B.
author3	Hajian, A. R.
author4	Henney, W. J.
author5	Burkert, A.
title	Knots in Nearby Planetary Nebulae
journal	Astronomical Journal
volume	123
bibcode	2002AJ....123.3329O
doi	10.1086/340726
doi-access	free
constellation	Lyra
<!-- invalid parameter	diameter_ly
absmag_v
names	M 57, NGC 6720,{{cite simbad
title	M 57
access-date	2006-12-19
::

| type = Planetary | name = Ring Nebula | image = Webb captures detailed beauty of Ring Nebula (NIRCam image) (weic2320b).jpg | caption = The Ring Nebula as seen in infrared and visible light by a multiple exposure of images from the James Webb Space Telescope's NIRCam, showing an outer layer of hydrogen that is very faint in visible light | credit = NASA/STScI/AURA | epoch = J2000 | ra = | dec = | dist_ly = | dist_pc = | radius_ly = | appmag_v = 8.8 | last=Murdin | first=P. | date=2000 | chapter=Ring Nebula (M57, NGC 6720) | editor=Paul Murdin | title=Encyclopedia of Astronomy and Astrophysics | id = Article ID #5323 | publisher=Institute of Physics Publishing | bibcode=2000eaa..bookE5323. | doi=10.1888/0333750888/5323 | isbn=978-0-333-75088-9 | size_v = | author=O'Dell, C. R. | author2=Balick, B. | author3=Hajian, A. R. | author4=Henney, W. J. | author5=Burkert, A. | date=2002 | title=Knots in Nearby Planetary Nebulae | journal=Astronomical Journal | volume=123 | issue=6 | pages=3329–3347 | bibcode=2002AJ....123.3329O | doi=10.1086/340726 | doi-access=free | constellation = Lyra | absmag_v = | names = M 57, NGC 6720,{{cite simbad | title=M 57 | access-date=2006-12-19 |df=ymd

The Ring Nebula is a planetary nebula in the northern constellation of Lyra, about mid-way between the prominent stars Beta and Gamma Lyrae.{{cite book | title=The Night Sky Companion: A Yearly Guide to Sky-Watching 2009 | series=The Patrick Moore Practical Astronomy Series | first=Tammy | last=Plotner | year=2009 | publisher=Springer Science & Business Media | isbn=978-0-387-79509-6 | page=98 | url=https://books.google.com/books?id=bTthlUmBQpAC&pg=PA98

::figure[src="https://upload.wikimedia.org/wikipedia/commons/5/5b/The_Ring_Nebula_M57_Goran_Nilsson_&_The_Liverpool_Telescope.jpg" caption="HaRGB image of the Ring Nebula (M57) showing the faint outer shells. The spiral galaxy [[IC 1296]] can also be seen in the top left. Data from the [[Liverpool Telescope]] on [[La Palma]], Islas Canarias ([[Canary Islands]]), [[Spain]]."] ::

A planetary nebula is formed when a star, during the last stages of its evolution before becoming a white dwarf, expels a vast luminous envelope of ionized gas into the surrounding interstellar space. The progenitor star for the ring nebula is now a carbon-oxygen white dwarf with an apparent visual magnitude of +15.75. Based on parallax measurements, this star is located at a distance of approximately 2570 ly from the Sun. After expanding for 1,610 years, the nebula currently has a diameter of .

History

This nebula was discovered by the French astronomer Charles Messier while searching for comets in late January 1779. Messier's report of his independent discovery of Comet Bode reached fellow French astronomer Antoine Darquier de Pellepoix two weeks later, who then independently rediscovered the nebula while following the comet. Darquier later reported that it was "...as large as Jupiter and resembles a planet which is fading" (which may have contributed to the use of the persistent "planetary nebula" terminology). | last1 = Olson | first1 = Don | last2 = Caglieris | first2 = Giovanni Maria | date = June 2017 | title = Who Discovered the Ring Nebula? | magazine = Sky & Telescope | pages = 32–7 | first=Robert A. | last=Garfinkle | date=1997 | title=Star-hopping: Your Visa to Viewing the Universe | publisher=Cambridge University Press | isbn=978-0-521-59889-7 | oclc=37355269 | first=Charles | last=Messier | date=1780 | chapter=Catalogue des Nébuleuses & des amas d'Étoiles | title=Connoissance des Temps for 1783 | pages=225–249

In 1800, German Count Friedrich von Hahn announced that he had discovered the faint central star at the heart of the nebula a few years earlier. He also noted that the interior of the ring had undergone changes, and said he could no longer find the central star. In 1864, English amateur astronomer William Huggins examined the spectra of multiple nebulae, discovering that some of these objects, including M57, displayed the spectra of bright emission lines characteristic of fluorescing glowing gases. Huggins concluded that most planetary nebulae were not composed of unresolved stars, as had been previously suspected, but were nebulosities. | last=Frommert | first=Hartmut |author2=Kronberg, Christine | url=http://messier.seds.org/xtra/Bios/huggins.html | title=William Huggins (February 7, 1824 – May 12, 1910) | publisher=SEDS | access-date=2008-04-11 |df=ymd | last=Huggins | first=W. |author2=Miller, W. A. | title=On the Spectra of Some of the Nebulae. And On the Spectra of Some of the Fixed Stars | journal=Proceedings of the Royal Society of London | date=1863–1864 | volume=13 | pages=491–493 | jstor=112077 | doi=10.1098/rspl.1863.0094 | doi-access=free

Observation

::figure[src="https://upload.wikimedia.org/wikipedia/commons/8/81/M57-v2.png" caption="Location of the Ring Nebula in the constellation Lyra"] ::

M57 is found south of the bright star Vega, which forms the northwestern vertex of the Summer Triangle asterism. The nebula lies about 40% of the distance from Beta (β) to Gamma (γ) Lyrae, making it an easy target for amateur astronomers to find.

The nebula disk has an angular size of 1.5 × 1 arcminutes, making it too small to be resolved with 10×50 binoculars. It is best observed using a telescope with an aperture of at least 20 cm, but even a 7.5 cm telescope will reveal its elliptical ring shape. | last = Dunlop | first = Storm | author-link = Storm Dunlop | title = Atlas of the Night Sky | url = https://archive.org/details/collinsatlasofni0000dunl | url-access = registration | publisher = Collins | date = 2005 | isbn = 978-0-00-717223-8 Using a UHC or OIII filter greatly enhances visual observation, particularly in light polluted areas. The interior hole can be resolved by a 10 cm instrument at a magnification of 100×. The central star, at magnitude 14.8, is difficult to spot.

Properties

M57 is 0.787 kpc from Earth. It has a visual magnitude of 8.8. Photographs taken over a period of 50 years show the rate of nebula expansion is roughly 1 arcsecond per century. Spectroscopic observations show that the expansion velocity along the line of sight is 20–. M57 is illuminated by a central white dwarf with an apparent magnitude of 15.75.

The interior parts of this nebula have a blue-green tinge that is caused by the doubly ionized oxygen emission lines at 495.7 and 500.7 nm. These emission lines are so-called "forbidden lines" which occur only in regions of very low density containing no more than a few thousand atoms per cubic centimeter. In the outer region of the ring, part of the reddish hue is caused by hydrogen emission at 656.3 nm, forming part of the Balmer series of lines. Forbidden lines of ionized nitrogen or N II contribute to the reddishness at 654.8 and 658.3 nm. | first=Hannu | last=Karttunen | date=2003 | title=Fundamental Astronomy | url=https://archive.org/details/fundamentalastro00kart_973 | url-access=limited | pages=314 | publisher=Springer | isbn=978-3-540-00179-9

Nebula structure

M57 is thought to be a prolate spheroid with strong concentrations of material along its equator. From Earth, the symmetrical axis is viewed at about 30°. Overall, the observed nebulosity has been estimated to be expanding for approximately 1,610 ± 240 years.

Central star

The central star was discovered by Hungarian astronomer Jenő Gothard on September 1, 1886, from images taken at his observatory in Herény, near Szombathely. Within the last two thousand years, the central star of the Ring Nebula has left the asymptotic giant branch. It no longer produces its energy through nuclear fusion and, in evolutionary terms, it is now becoming a compact white dwarf star.

The central star now consists primarily of carbon and oxygen with a thin outer envelope composed of lighter elements. Its mass is about , with a surface temperature of . Currently it is about 300 times more luminous than the Sun, but its apparent magnitude is only +15.75. | last=O'Dell | first=C. R. |author2=Sabbadin, F. |author3=Henney, W. J. | date=2007 | title=The Three-Dimensional Ionization Structure and Evolution of NGC 6720, The Ring Nebula | journal=Astronomical Journal | volume=134 | issue=4 | pages=1679–1692 | bibcode=2007AJ....134.1679O | doi=10.1086/521823 | doi-access=free}}

In 2025 JWST observed a dust disk around the central star.

Notes

Radius = distance × sin(angular size / 2) = * sin(230″ / 2) = 8.8 apparent magnitude − 5 × (log10( distance / 10 pc)) = absolute magnitude

References

References

1. (2016-10-16). "M 57".
2. (2025). "JWST observations of the Ring Nebula (NGC 6720): III. A dusty disk around its Central Star". The Astrophysical Journal.
3. {{cite Gaia DR3. 2090486618786534784
4. (2007). "Nebulae and how to observe them". Springer.
5. (2004). "Sky Vistas: Astronomy for Binoculars and Richest-field Telescopes". Springer.
6. (2010). "Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer's New General Catalogue". Cambridge University Press.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::