Galaxy scrapbook
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by Budgieye moderator
Anyone can add images of galaxies, with some educational content.
Barnard's Galaxy Dwarf galaxy in local group, with supernova remnant
NGC 6822 NGC6822 IC 4895, IC4895 Caldwell 57 Caldwell57 and a nebula, a supernova remnant (the green object)
http://iopscience.iop.org/article/10.1086/300580/fulltext/
no SDSS ObjId for dwarf or supernova, it is too bright so is masked
http://skyserver.sdss.org/dr8/en/tools/explore/obj.asp?id=1237678596486987958
http://talk.galaxyzoo.org/#/subjects/AGZ0004iyv
http://apod.nasa.gov/apod/ap020123.html
Explanation: Nearby galaxy NGC 6822 is irregular in several ways.
First, the galaxy's star distribution merits a formal classification
of dwarf irregular, and from our vantage-point the small galaxy
appears nearly rectangular. What strikes astronomers as more peculiar,
however, is NGC 6822's unusually high abundance of HII regions,
locales of ionized hydrogen that surround young stars. Large HII
regions, also known as emission nebulas, are visible surrounding the
small galaxy, particularly toward the upper right. Toward the lower
left are bright stars that are loosely grouped into an arm. Pictured
above, NGC 6822, also known as Barnard's Galaxy, is located only about
1.5 million light years away and so is a member of our Local Group of Galaxies. The galaxy, home to famous nebulas including Hubble V, is
visible with a small telescope toward the constellation of
Sagittarius.http://www.britannica.com/topic/NGC-6822
This topic is discussed in the following articles: extragalactic
distance determination Galaxy: Hubble’s discovery of extragalactic
objects During the early 1920s Hubble detected 15 stars in the small,
irregular cloudlike object NGC 6822 that varied in luminosity, and he
suspected that they might include Cepheids. After considerable effort,
he determined that 11 of them were in fact Cepheid variables, with
properties indistinguishable from those of normal Cepheids in the
Milky Way Galaxy and in the Magellanic Clouds. Their periods...Posted
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by c_cld
Sorry Budgieye, the DR8 image ra=16.25874965&dec=2.02971249 is IC 1613 / UGC 668/ PGC 3844.
NGC6822 is further south outside the SDSS footprint. (RA = 296.24059 Dec = -14.80343 [19:44:57.742 -14:48:12.35] )
IC 1613 was also shot by Hubble, but not so spectacular as NGC6822:
Posted
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by Budgieye moderator
Oooops
Posted