| 词条 | NGC 4440 |
| 释义 |
| name = NGC 4440 | image = SDSS NGC 4440.jpg | image_size = 250px | caption = SDSS image of NGC 4440 | epoch = J2000 | type = SB(rs)a[1] | ra = {{RA|12|27|53.6}}[1] | dec = {{DEC|12|17|36}}[1] | dist_ly = 56,400,000 ly[2] | group_cluster = Virgo Cluster | z = 0.002415/724 km/s[1] | appmag_v = 12.70[1] | size_v = 1.9 x 1.5[1] | constellation name = Virgo | names = PGC 40927, UGC 7581, VCC 1047 [1] |size=~30,550 ly (estimated)[1] }}NGC 4440 is a barred spiral galaxy located about 55 million light-years away[3] in the constellation of Virgo.[4] NGC 4440 was discovered by astronomer William Herschel on April 17, 1784.[5] It is a member of the Virgo Cluster.[6] Physical characteristicsNGC 4440 has a strong bar in its structure. Surrounding the bar, there are two very open spiral arms.[7] See also
External links{{WikiSky}}References1. ^1 2 3 4 5 6 7 {{cite web | title=NASA/IPAC Extragalactic Database | work=Results for NGC 4440 | url=http://nedwww.ipac.caltech.edu/ | accessdate=2017-09-30}} {{Ngc45}}2. ^{{cite web| title = parsecs to lightyears conversion| url = http://www.unitconversion.org/length/parsecs-to-light-years-conversion.html| accessdate = 2017-09-30}} 3. ^{{Cite web|url=https://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=NGC+4440&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES|title=Your NED Search Results|website=ned.ipac.caltech.edu|access-date=2017-09-30}} 4. ^{{Cite web|url=https://dso-browser.com/deep-sky/5486/ngc-4440/galaxy|title=Galaxy NGC 4440 - Barred Spiral Galaxy in Virgo Constellation · Deep Sky Objects Browser|last=Rojas|first=Sebastián García|website=DSO Browser|language=en|access-date=2017-09-30}} 5. ^{{Cite web|url=http://cseligman.com/text/atlas/ngc44.htm#4440|title=New General Catalog Objects: NGC 4400 - 4449|website=cseligman.com|language=en-US|access-date=2017-09-30}} 6. ^{{Cite web|url=https://ned.ipac.caltech.edu/cgi-bin/NEDatt?objname=NGC+4440|title=Detailed Object Classifications|website=ned.ipac.caltech.edu|access-date=2017-09-30}} 7. ^{{Cite web|url=http://kudzu.astr.ua.edu/devatlas/NGC_4440______g___________.html|title=NGC 4440 - SB(rs)a|last=|first=|date=|website=The De Vaucouleurs Atlas of Galaxies|archive-url=|archive-date=|dead-url=|access-date=2017-09-30}} 7 : Barred spiral galaxies|Virgo (constellation)|NGC objects|Principal Galaxies Catalogue objects|UGC objects|Astronomical objects discovered in 1784|Virgo Cluster |
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