Bubble Nebula
Emission nebula in the constellation Cassiopeia
title: "Bubble Nebula" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["astronomical-objects-discovered-in-1787", "caldwell-objects", "cassiopeia-(constellation)", "h-ii-regions", "ngc-objects", "sharpless-objects"] description: "Emission nebula in the constellation Cassiopeia" topic_path: "general/astronomical-objects-discovered-in-1787" source: "https://en.wikipedia.org/wiki/Bubble_Nebula" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Emission nebula in the constellation Cassiopeia ::
::data[format=table title="Infobox nebula"]
| Field | Value |
|---|---|
| name | NGC 7635 |
| image | File:The Bubble Nebula - NGC 7635 - Heic1608a.jpg |
| caption | Wide field image of NGC 7635 as captured by the Hubble Space Telescope |
| type | H II REGION |
| epoch | J2000 |
| ra | |
| dec | |
| dist_ly | 7100 to 11000 |
| dist_pc | 3,400 |
| appmag_v | 10 |
| size_v | 15 × 8 |
| radius_ly | 3 to 5 |
| constellation | Cassiopeia |
| notes | Shell around SAO 20575 |
| names | Bubble Nebula |
| Sharpless 162 (Sh2-162) | |
| Caldwell 11 | |
| :: |
| name = NGC 7635 | image = File:The Bubble Nebula - NGC 7635 - Heic1608a.jpg | caption = Wide field image of NGC 7635 as captured by the Hubble Space Telescope | type = H II REGION | epoch = J2000 | ra = | dec = | dist_ly = 7100 to 11000 | dist_pc = 3,400 | appmag_v = 10 | size_v = 15 × 8 | radius_ly = 3 to 5 | absmag_v = | constellation = Cassiopeia | notes = Shell around SAO 20575 | names = Bubble Nebula Sharpless 162 (Sh2-162) Caldwell 11
The Bubble Nebula, also known as NGC 7635, Sharpless 162, or Caldwell 11, is an H II region emission nebula in the constellation Cassiopeia. It lies close to the open cluster Messier 52. The "bubble" is created by the stellar wind from a massive hot, 8.7 magnitude young central star, SAO 20575 (BD+60°2522). The nebula is near a giant molecular cloud which contains the expansion of the bubble nebula while itself being excited by the hot central star, causing it to glow. It was discovered in November 1787 by William Herschel. The star BD+60°2522 is thought to have a mass of about .
Amateur observation
::figure[src="https://upload.wikimedia.org/wikipedia/commons/5/5c/Bubble_Nebula.jpg" caption="NGC 7635 and its environs imaged through an 8-inch amateur telescope"] ::
With an 8 or telescope, the nebula is visible as an extremely faint and large shell around the star. The nearby 7th magnitude star on the west hinders observation, but one can view the nebula using averted vision. Using a 16 to scope, one can see that the faint nebula is irregular, being elongated in the north south direction.
Notes
References
- {{cite web | author = SIMBAD | author-link = SIMBAD | title = Results for NGC 7635 | date = February 23, 2007 | publisher = SIMBAD, Centre de Données Astronomiques de Strasbourg | url = http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=NGC+7635
- {{cite book | last1 = Kepple | first1 = George Robert | last2 = Sanner | first2 = Glen W. | title = The Night Sky Observer's Guide | volume = 1 | date = 1998 | publisher = Willmann-Bell, Inc. | isbn = 978-0-943396-58-3 | pages = 108–109
- {{cite web | author = HubbleSite | author-link = HubbleSite | title = An Expanding Bubble in Space | date = 2000 | url= http://hubblesite.org/newscenter/archive/releases/2000/04/image/a/}}
- {{Cite APOD | title = The Bubble | date = July 16, 2004 | access-date = }}
- {{Cite APOD | title = NGC 7635: The Bubble Nebula | date = November 7, 2005 | access-date = }}
- {{Cite APOD | title = NGC 7635: The Bubble | date = October 18, 2006 | access-date = }}
References
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