| 词条 | NGC 1140 |
| 释义 |
| name = NGC 1140 | image = A galactic nursery.jpg | image_size = 260px | caption = NGC 1140, imaged by Hubble | epoch = J2000 | constellation name = Eridanus | ra = {{RA|02|54|33.542}}[1] | dec = {{DEC|-10|01|42.60}}[1] | z = 0.005007[2] | h_radial_v = 1150 km/s[2] | dist_ly = {{convert|18.233|+/-|1.283|Mpc|Mly|abbr=on|lk=on|order=flip}}[2] | group_cluster = | type = IBm pec[2] | size = | appmag_v = 12.25[2] | appmag_b = 12.84[3] | absmag_v = −19.05[2] | size_v = 1.7′ × 0.9′[2] | notes = Wolf–Rayet galaxy | names = Markarian 1063, VV 482, MCG-02-08-019, PGC 10966[3] }}NGC 1140 is an irregular galaxy in the southern constellation of Eridanus. Estimates made using the Tully–Fisher method put the galaxy at about 59 million light years (18 megaparsecs).[2] It was discovered on 22 November 1786 by William Herschel, and was described as "pretty bright, small, round, stellar" by John Louis Emil Dreyer, the compiler of the New General Catalogue.[4] NGC 1140 is a starburst galaxy, meaning it is forming stars at a very fast rate. In fact, while it is only a tenth as wide as the Milky Way, it is producing stars at a rate of {{solar mass|0.65|link=y}}/yr,[14] about the same as the Milky Way. The image taken by the Hubble Space Telescope shows bright blue and red regions of star formation, similar to NGC 1569.[15] The starburst is estimated to have began about 5 million years ago.[14] Its low metallicity (the ratio of hydrogen and helium to other elements) makes NGC 1140 similar to primordial galaxies.[5] Wolf–Rayet stars, a class of blue, massive, and luminous stars, are present in this galaxy; in fact, NGC 1140 has so many of them that their spectra also appear in the galaxy's spectrum.[6] These types of galaxies are known Wolf–Rayet galaxies, and are fairly rare because Wolf–Rayet stars have short lives.[7]References1. ^1 {{cite journal|title=2MASS All-Sky Catalog of Point Sources|date=2003|journal=VizieR On-line Data Catalog|author1=Cutri, R. M.|bibcode=2003yCat.2246....0C}} {{Ngc15}}2. ^1 2 3 4 5 6 7 {{cite web|url=http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC+1140&extend=no&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=NED results for object NGC 1140|publisher=National Aeronautics and Space Administration / Infrared Processing and Analysis Center|accessdate=4 March 2017}} 3. ^1 {{cite simbad|title=NGC 1140|access-date=4 March 2017}} 4. ^{{cite web|url=http://cseligman.com/text/atlas/ngc11.htm#1140|title=New General Catalogue objects: NGC 1100 - 1149|author=Seligman, Courtney|website=cseligman.com|accessdate=4 March 2017}} 5. ^1 {{cite web|url=https://www.spacetelescope.org/images/potw1529a/|title=A galactic nursery | ESA/Hubble|website=www.spacetelescope.org|date=2015|accessdate=4 March 2017}} 6. ^1 2 {{cite journal|title=Photometric and spectroscopic studies of star-forming regions within Wolf-Rayet galaxies|author1=Karthick, M. Chrisphin|author2=López-Sánchez, Ángel R.|author3=Sahu, D. K.|author4=Sanwal, B. B.|author5=Bisht, Shuchi|journal=Monthly Notices of the Royal Astronomical Society|volume=439|issue=1|pages=157–178|date=2014|bibcode=2014MNRAS.439..157K|doi=10.1093/mnras/stt2301|arxiv=1311.7504}} 7. ^{{cite web|url=https://www.spacetelescope.org/images/potw1526a/|title=Intense and short-lived | ESA/Hubble|website=www.spacetelescope.org|date=2015|accessdate=4 March 2017}} 5 : NGC objects|Principal Galaxies Catalogue objects|Starburst galaxies|Irregular galaxies|Eridanus (constellation) |
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