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{{short description|Constellation in the southern celestial hemisphere}} | |||
{{about|a constellation of stars|the Roman goddess|Fornax (mythology)}} | |||
{{about|the constellation |the Roman goddess|Fornax (mythology)}} | |||
{{Infobox Constellation | |||
{{Infobox constellation | |||
| name = Fornax | | name = Fornax | ||
| abbreviation = For | | abbreviation = For | ||
| genitive = Fornacis | | genitive = Fornacis | ||
| pronounce = {{IPAc-en|ˈ|f| |
| pronounce = {{IPAc-en|ˈ|f|ɔːr|n|æ|k|s}}, genitive {{IPAc-en|f|ɔːr|ˈ|n|eɪ|s|ᵻ|s}} | ||
| symbolism = the ] | | symbolism = the ] | ||
| RA = 3 | | RA = {{RA|3}} | ||
| dec= −30 | | dec= {{DEC|−30}} | ||
| family = ] | | family = ] | ||
| quadrant = SQ1 | | quadrant = SQ1 | ||
Line 22: | Line 24: | ||
| stardistancely = 16.20 | | stardistancely = 16.20 | ||
| stardistancepc = 4.97 | | stardistancepc = 4.97 | ||
| numbermessierobjects = |
| numbermessierobjects = 0 | ||
| meteorshowers = |
| meteorshowers = 0 | ||
| bordering = ]<br />]<br />]<br />] | | bordering = ]<br />]<br />]<br />] | ||
| latmax = ] | | latmax = ] | ||
| latmin = ] | | latmin = ] | ||
| month = December | | month = December | ||
| notes=}} | | notes= | ||
}} | |||
'''Fornax''' ({{IPAc-en|ˈ|f|ɔr|n|æ|k|s}}) is a ] in the ], partly ringed by the celestial river ]. Its name is ] for furnace. It was named by French astronomer ] in 1756. Fornax is one of the 88 modern constellations. | |||
The three brightest stars—], ] and ]—form a flattened triangle facing south. With an apparent magnitude of 3.91, Alpha Fornacis is the brightest star in Fornax. Six star systems have been found to have exoplanets. The ] galaxy is a small faint satellite galaxy of the ]. ] is a relatively close ]. | |||
'''Fornax''' ({{IPAc-en|icon|ˈ|f|ɔr|n|æ|k|s}}) is a ] in the southern sky. Its name is ] for ]. It was named by French astronomer ] in 1756. Fornax is one of the 88 modern constellations. | |||
The ]'s ] is located within the Fornax constellation.<ref>{{Cite web |title=Hubble Ultra Deep Field |url=https://hubblesite.org/contents/media/images/3886-Image |access-date=February 2, 2024 |website=hubblesite.org}}</ref> | |||
It is the 41st largest ] in the ], occupying an area of 398 ] It is located in the first quadrant of the ] (SQ1) and can be seen at ] between +50° and -90° during the month of December. | |||
==History== | ==History== | ||
] in this card from '']'' (1825).]] | |||
de Lacaille originally called the constellation "Fornax Chemica" (the ] furnace){{sfn|Ridpath|Tirion|2001|pp=148-149}}, representing a small ] vessel used for heating ] ]s. | |||
The French astronomer ] first described the ] in French as ''le Fourneau Chymique'' (the Chemical Furnace) with an ] and receiver in his early catalogue,<ref name=wagman/> before abbreviating it to ''le Fourneau'' on his planisphere in 1752,<ref name=ridpathlac>{{cite web |url=http://www.ianridpath.com/startales/lacaille.html |title=Lacaille's Southern Planisphere of 1756 |work=Star Tales |author=Ridpath, Ian |publisher=Self-published |access-date=7 November 2016|author-link=Ian Ridpath }}</ref><ref>{{cite journal |author=Lacaille, Nicolas Louis |year=1756 |title=Relation abrégée du Voyage fait par ordre du Roi au cap de Bonne-espérance |journal=Mémoires de l'Académie Royale des Sciences |pages=519–592 |url=http://gallica.bnf.fr/ark:/12148/bpt6k35505/f786 |language=fr}}</ref> after he had observed and catalogued almost 10,000 southern stars during a two-year stay at the ]. He devised fourteen new constellations in uncharted regions of the ] not visible from Europe. All but one honoured instruments that symbolised the ].{{efn|1=The exception is ], named for the ]. The other thirteen (alongside Fornax) are ], ], ], ], ], ], ], ], ], ], ] and ].<ref name=wagman/>}} Lacaille Latinised the name to ''Fornax Chimiae'' on his 1763 chart.<ref name=wagman>{{cite book |last=Wagman |first=Morton |date=2003 |title=Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others |publisher=The McDonald & Woodward Publishing Company |location=Blacksburg, Virginia |isbn=978-0-939923-78-6 |pages=6–7, 152}}</ref><!-- Cites previous three sentences --> | |||
{{clear|left}} | |||
==Characteristics== | |||
The constellation Eridanus borders Fornax to the east, north and south, while Cetus, Sculptor and Phoenix gird it to the north, west and south respectively. Covering 397.5 square degrees and 0.964% of the night sky, it ranks 41st of the 88 constellations in size,<ref name=tirionconst>{{cite web| url=http://www.ianridpath.com/constellations1.html | title=Constellations: Andromeda–Indus | work= Star Tales |author= Ridpath, Ian |author-link = Ian Ridpath |publisher=Self-published | access-date= 7 November 2016}}</ref> The three-letter abbreviation for the constellation, as adopted by the ] in 1922, is "For".<ref name="pa30_469">{{cite journal | last=Russell | first=Henry Norris |author-link=Henry Norris Russell | title=The New International Symbols for the Constellations | journal=] | volume=30 | page=469 | bibcode=1922PA.....30..469R | date=1922}}</ref> The official constellation boundaries, as set by Belgian astronomer ] in 1930, are defined by a polygon of 8 segments (''illustrated in infobox''). In the ], the ] coordinates of these borders lie between {{RA|01|45|24.18}} and {{RA|03|50|21.34}}, while the ] coordinates are between −23.76° and −39.58°.<ref name="boundary">{{Cite journal | title=Fornax, Constellation Boundary | journal=The Constellations | publisher=International Astronomical Union | url=https://www.iau.org/public/themes/constellations/#for| access-date=7 November 2016}}</ref> The whole constellation is visible to observers south of latitude ].{{efn|1=While parts of the constellation technically rise above the horizon to observers between 50°N and ], stars within a few degrees of the horizon for to all intents and purposes unobservable.<ref name=tirionconst/>}} | |||
==Features== | |||
==Notable features== | |||
] | ] | ||
===Stars=== | ===Stars=== | ||
{{see also|List of stars in Fornax}} | {{see also|List of stars in Fornax}} | ||
Lacaille gave ]s to 27 stars now named Alpha to Omega Fornacis, labelling two stars 3.5 degrees apart as Gamma, three stars Eta, two stars Iota, two Lambda and three Chi. Phi Fornacis was added by Gould, and Theta and Omicron were dropped by Gould and Baily respectively. Upsilon, too, was later found to be two stars and designated as such.<ref name=wagman/> Overall, there are 59 stars within the constellation's borders brighter than or equal to ] 6.5.{{efn|1=Objects of magnitude 6.5 are among the faintest visible to the unaided eye in suburban-rural transition night skies.<ref>{{cite web|url=http://www.skyandtelescope.com/resources/darksky/3304011.html?page=1&c=y|title=The Bortle Dark-Sky Scale|last=Bortle|first=John E.|date=February 2001|work=]|publisher=Sky Publishing Corporation|access-date=7 November 2016|archive-date=31 March 2014|archive-url=https://web.archive.org/web/20140331202746/http://www.skyandtelescope.com/resources/darksky/3304011.html?page=1&c=y|url-status=dead}}</ref>}}<ref name=tirionconst/> However, there are no stars brighter than the fourth magnitude.<ref name=tirionfor>{{cite web| url=http://www.ianridpath.com/startales/fornax.html | title=Fornax | work= Star Tales |author= Ridpath, Ian |author-link = Ian Ridpath |publisher=Self-published | access-date= 7 November 2016}}</ref> | |||
] is a binary star that can be resolved by small amateur telescopes. The primary is a yellow-tinged ] star of magnitude 3.9 and the secondary is a yellow star of magnitude 6.5; the secondary may actually be a ]. It has a period of 300 years and is 46 light-years from Earth. ] is a yellow-hued ] of magnitude 4.5, 169 light-years from Earth.{{sfn|Ridpath|Tirion|2001|pp=148-149}} | |||
The three brightest stars form a flattish triangle, with ] (also called Dalim<ref name="IAU-LSN">{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |access-date=30 July 2018}}</ref>) and ] marking its eastern and western points and ] marking the shallow southern apex.<ref>{{cite book |last=Thompson |first=Mark |title=A Down to Earth Guide to the Cosmos |publisher=Random House |date=2013 |isbn=978-1-4481-2691-0 |url=https://books.google.com/books?id=SOfRFJBy-igC&pg=PT132|page=132}}</ref> Originally designated 12 Eridani by John Flamsteed, Alpha Fornacis was named by Lacaille as the brightest star in the new constellation.<ref name=wagman/> It is a binary star that can be resolved by small amateur telescopes. With an apparent magnitude of 3.91, the primary is a yellow-white subgiant 1.21 times as massive as the Sun that has begun to cool and expand after exhausting its core hydrogen, having swollen to 1.9 times the Sun's radius. Of magnitude 6.5, the secondary star is 0.78 times as massive as the Sun. It has been identified as a ], and has either accumulated material from, or merged with, a third star in the past. It is a strong source of X-rays.<ref name=Fuhrmann2015>{{cite journal | last1=Fuhrmann | first1=K. | last2=Chini | first2=R. | title=Multiplicity among F-type Stars. II | journal=The Astrophysical Journal | volume=809 | issue=1 | id=107 | pages=19 | date=2015 | doi=10.1088/0004-637X/809/1/107 | bibcode=2015ApJ...809..107F | doi-access=free }}</ref> The pair is 46.4 ± 0.3 light-years distant from Earth.<ref name="vanLeeuwen2007">{{cite journal | first=F. | last=van Leeuwen | title=Validation of the New Hipparcos Reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–64 | date=2007 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | arxiv=0708.1752| s2cid=18759600 }}</ref> | |||
] is a yellow-hued ] of spectral type G8IIIb of magnitude 4.5 that has cooled and swelled to 11 times the Sun's diameter,<ref name=cadars>{{cite journal|author=Pasinetti Fracassini, L. E.|author2=Pastori, L.|author3=Covino, S.|author4=Pozzi, A.|date=2001|title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) – Third edition – Comments and statistics|journal=Astronomy & Astrophysics|volume=367|issue=2|pages=521–24|bibcode=2001A&A...367..521P|doi=10.1051/0004-6361:20000451|arxiv = astro-ph/0012289 |s2cid=425754}}</ref> 178 ± 2 light-years from Earth.<ref name=GaiaDR2beta>{{cite DR2|5064312731759992960}}</ref> It is a ] giant, which means it has undergone ] and is currently generating energy through the fusion of helium at its core.<ref name=Kubiak2002>{{cite journal | title=Metal Abundance of Red Clump Stars in Baade's Window | last1=Kubiak | first1=M. | last2=McWilliam | first2=A. | last3=Udalski | first3=A. | last4=Gorski | first4=K. | journal=Acta Astronomica | volume=52 | pages=159–75 | date=2002 | bibcode=2002AcA....52..159K}}</ref> | |||
] is 370 ± 10 light-years distant from Earth.<ref name="vanLeeuwen2007"/> It is a blue giant star of spectral type B9.5IIIspSi that is 3.65 ± 0.18 times as massive and around 245 times as luminous as the Sun, with 3.2 ± 0.4 times its diameter.<ref name=aaa334_181>{{cite journal | last1=North | first1=P. | title=Do SI stars undergo any rotational braking? | journal=Astronomy and Astrophysics | volume=334 | pages=181–87 |date=1998 | bibcode=1998A&A...334..181N |arxiv = astro-ph/9802286 }}</ref> It varies in luminosity over a period of 1.89 days—the same as its rotational period. This is because of differences in abundances of metals in its atmosphere; it belongs to a class of star known as an ].<ref name="Leone 2000">{{cite journal | last1=Leone | first1=F. | last2=Catanzaro | first2=G. | last3=Malaroda | first3=S. | title=A spectroscopic study of the magnetic chemically peculiar star nu Fornacis | journal=Astronomy and Astrophysics | volume=359 | pages=635–638 | date=2000 | bibcode=2000A&A...359..635L }}</ref><ref name=gcvs>{{cite journal | last1=Samus | first1=N. N. | last2=Durlevich | first2=O. V. | |||
| title=General Catalogue of Variable Stars | journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S | volume=1 | year=2009 | bibcode=2009yCat....102025S }}</ref> | |||
Shining with an apparent magnitude of 5.89, ] is a binary star system located 104.4 ± 0.3 light-years distant from Earth.<ref name=GaiaDR2eps>{{cite DR2|5071514326764428544}}</ref> Its component stars orbit each other every 37 years. The primary star is around 12 billion years old and has cooled and expanded to 2.53 times the diameter of the Sun, while having only 91% of its mass. | |||
<ref name=Jofre2015>{{cite journal | last1=Jofré | first1=E. | last2=Petrucci | first2=R. | last3=Saffe | first3=C. | last4=Saker | first4=L. | last5=Artur de la Villarmois | first5=E. | last6=Chavero | first6=C. | last7=Gómez | first7=M. | last8=Mauas | first8=P. J. D. | title=Stellar parameters and chemical abundances of 223 evolved stars with and without planets | journal=Astronomy & Astrophysics | display-authors=1 | volume=574 | pages=A50 | year=2015 | arxiv=1410.6422 | bibcode=2015A&A...574A..50J | doi=10.1051/0004-6361/201424474 | s2cid=53666931 }}</ref> ] is a binary star system composed of a blue main-sequence star of spectral type B9.5V and magnitude 4.96, and a white main sequence star of spectral type A7V and magnitude 7.88. The system is 470 ± 10 light-years distant from Earth.<ref name=GaiaDR2omega>{{cite DR2|5069213731825915648}}</ref> | |||
] is a triple star system composed of a yellow giant and a pair of red dwarfs. | |||
] is a long-period variable and carbon star. | |||
] is a ] of spectral type M9 that has around 7% the mass of the Sun. Approximately 21 light-years distant from Earth, it is a faint object with an apparent magnitude of 18.69.<ref name="RECONS TOP100">{{cite journal |author=Research Consortium on Nearby Stars |publisher=] |date = 1 January 2012 |title=The 100 nearest star systems |journal=RECONS |url=http://www.astro.gsu.edu/RECONS/TOP100.posted.htm |access-date = 12 February 2017|author-link=Research Consortium on Nearby Stars }}</ref> Observations published in 2007 showed that the atmosphere of LP 944-20 contains much ] and that it has dusty ]s.<ref>{{ cite journal | title=Lithium in LP944-20 |author1=Pavlenko, Ya. V. |author2=Jones, H. R. A. |author3=Martín, Eduardo L. |author4=Guenther, E. |author5=Kenworthy, M. A. |author6=Zapatero-Osorio, María Rosa | journal=] | volume=380 | issue=3 | pages=1285–96 | date=September 2007 | doi=10.1111/j.1365-2966.2007.12182.x |doi-access=free | bibcode=2007MNRAS.380.1285P | arxiv = 0707.0694 |s2cid=11186385 }}</ref> Smaller and less luminous still is ], a T-type brown dwarf of spectral type T6. With a surface temperature of 1040–1100 ], it has 2.4–4.1% the mass of the Sun, a diameter 9.2 to 10.6% of that of the Sun, and an age of 0.4–1.7 billion years.<ref>{{cite journal | title= Method for Determining the Physical Properties of the Coldest Known Brown Dwarfs |author1=Burgasser, Adam J. |author2=Burrows, Adam |author3=Kirkpatrick, J. Davy |journal=The Astrophysical Journal | volume =639| issue= 2| pages=1095–1113| year=2006 | doi=10.1086/499344 | bibcode=2006ApJ...639.1095B|arxiv = astro-ph/0510707 | s2cid=9291848 }}</ref> | |||
Six star systems in Fornax have been found to have planets: | |||
* ] is a star about 1.2 times as massive as the Sun with a planet about as massive as ], discovered by doppler spectroscopy in 2009. The planet has an orbit of around 17.24 days.<ref name="O’Toole2009">{{cite journal | title=A Neptune-mass Planet Orbiting the Nearby G Dwarf HD16417 | last1=O’Toole | first1=Simon | last2=Tinney | first2=C. G. | last3=Butler | first3=R. Paul | last4=Jones | first4=Hugh R. A. | last5=Bailey | first5=Jeremy | last6=Carter | first6=Brad D. | last7=Vogt | first7=Steven S. | last8=Laughlin | first8=Gregory | last9=Rivera | first9=Eugenio J. | journal=The Astrophysical Journal | volume=697 | issue=2 | pages=1263–1268 | date=2009 | arxiv=0902.4024 | bibcode=2009ApJ...697.1263O | doi=10.1088/0004-637X/697/2/1263 | s2cid=16341718 }}</ref> | |||
* ] is an orange dwarf with a mass around 78% that of the Sun, 151 ± 10 light-years away from Earth. It was found to have an orbiting planet approximately double the mass of Jupiter with a period of 380 days.<ref name="Moutou2009">{{cite journal | title=The HARPS search for southern extra-solar planets XVII. Six long-period giant planets around BD -17 0063, HD 20868, HD 73267, HD 131664, HD 145377, HD 153950 | url=http://www.aanda.org/articles/aa/full_html/2009/11/aa10941-08/aa10941-08.html | last1=Moutou | first1=C. | last2=Mayor | first2=M. | last3=Lo Curto | first3=G. | last4=Udry | first4=S. | last5=Bouchy | first5=F. | last6=Benz | first6=W. | last7=Lovis | first7=C. | last8=Naef | first8=D. | last9=Pepe | first9=F. | last10=Queloz | first10=D. | last11=Santos | first11=N. C. | journal=Astronomy and Astrophysics | volume=496 | issue=2 | pages=513–19 | date=2009 | arxiv=0810.4662 | bibcode=2009A&A...496..513M | doi=10.1051/0004-6361:200810941 | s2cid=116707055 }}</ref> | |||
* ] is a star around 1.4 times as massive that has begun to cool and expand off the main sequence, reaching double the Sun's diameter. It has a planet around as massive as Jupiter orbiting it every 2.2 days.<ref>{{cite journal | title=WASP-64 b and WASP-72 b: two new transiting highly irradiated giant planets | vauthors=Gillon M, Anderson DR, Collier-Cameron A, Doyle AP, Fumel A, Hellier C, Jehin E, Lendl M, Maxted PF, Montalbán J, Pepe F, Pollacco D, Queloz D, Ségransan D, Smith AM, Smalley B, Southworth J, Triaud AH, Udry S, West RG | journal=Astronomy & Astrophysics |volume= 552| id=A82|pages= 13 |year=2013 | doi= 10.1051/0004-6361/201220561 |bibcode=2013A&A...552A..82G|arxiv = 1210.4257 | s2cid=53687206 }}</ref> | |||
* ] and ] are a pair of sunlike yellow main sequence stars that orbit each other. Each has been found to have planets. | |||
* ] is a near naked eye visible star in Fornax, 31.3 parsecs away. In May 2019, it was announced to have at least 3 exoplanets as observed by transit method of the Transiting Exoplanet Survey Satellite. | |||
===Deep-sky objects=== | ===Deep-sky objects=== | ||
] | |||
Fornax has been the target of investigations into the furthest reaches of the ]. The ] is located within Fornax, and the ], a small ], lies primarily within Fornax. At a meeting of the ] in ], a team from ] described 40 unknown "dwarf" galaxies in this constellation; follow-up observations with the ] and the ]'s ] revealed that ] are much smaller than previously known dwarf galaxies, about {{convert|120|ly|pc}} across.<ref>, 2007''</ref> | |||
'''Local Group''' | |||
] is a ] 500,000 light-years from Earth. It is in the ] Galaxy.{{sfn|Levy|2005|p=176}} | |||
] is a ] 500,000 light-years from Earth. It is in the ] Galaxy.{{sfn|Levy|2005|p=176}} ] is a ] in Fornax with a magnitude of approximately 9.0, 1,280 light-years from Earth. Its central star is of magnitude 11.4, an unusually bright specimen. It is five times the size of the famed ] in ] at 6.5 arcminutes. Unlike the Ring Nebula, NGC 1360 is clearly elliptical.{{sfn|Levy|2005|pp=134–135}} | |||
], a galaxy which was identified as the most distant object in the universe from Earth as of January 2011, is located in Fornax. It was detected using the Hubble UDF image. | |||
The ] galaxy is a ] that is part of the ] of galaxies. It is not visible in amateur telescopes, despite its relatively small distance of 500,000 light-years.{{sfn|Ridpath|Tirion|2001|pp=148–149}} | |||
] is an ] in the constellation, reported in November 2010, that was discovered to have originated outside of the galaxy.<ref>{{Cite web|url=http://www.bbc.co.uk/news/science-environment-11775803|title='Alien' planet detected circling dying star|publisher=]|date={{date|2010-11-18}}|accessdate={{date|2010-11-20}}}}</ref> | |||
] is a small galactic stream in Fornax. This small galaxy was destroyed by Milky Way 6 billion years ago. There was candidate for extragalactic planet, HIP 13044 b. | |||
] is a ] in Fornax, about 60 million light-years from Earth. At magnitude 9, it is visible in medium amateur telescopes.{{sfn|Ridpath|Tirion|pp=148-149}} It is notable as a ] with strong spectral emissions indicating ionized gases and a central ]. | |||
'''Outside''' | |||
] is another ] located at a distance of 60 million light-years from Earth. Like NGC 1097, it is also a ]. Its bar is a center of ] and shows extensions of the spiral arms' ]s. The bright nucleus indicates the presence of an ] - a galaxy with a ] at the center, accreting matter from the bar.<ref name="objects"/> It is a 10th magnitude galaxy associated with the ].{{sfn|Ridpath|Tirion|pp=148-149}} | |||
] is a ] in Fornax |
] is a ] in Fornax, about 45 million light-years from Earth. At magnitude 9, it is visible in medium amateur telescopes.{{sfn|Ridpath|Tirion|2001|pp=148–149}} It is notable as a ] with strong spectral emissions indicating ionized gases and a central ]. | ||
'''Fornax Cluster''' | |||
] is a ] with extensive radio lobes that corresponds to the optical galaxy NGC 1316, a 9th-magnitude galaxy.{{sfn|Ridpath|Tirion|2001|pp=148-149}} One of the closer ] to Earth at a distance of 80 million light-years, Fornax A appears in the ] as a large ] with ]s near its core. These dust lanes have caused astronomers to discern that it recently ] with a small ]. Because it has a high rate of ]e, NGC 1316 has been used to determine the size of the universe. Its radio lobes are unique in that the ]s producing them are not particularly powerful, giving the lobes a more diffuse, knotted structure due to interactions with the ].<ref name="objects">{{cite book |title = 300 Astronomical Objects: A Visual Reference to the Universe |last1 = Wilkins |first1 = Jamie |last2 = Dunn |first2 = Robert |publisher = Firefly Books |location = Buffalo, New York |date = 2006 |isbn = 978-1-55407-175-3}}</ref> Associated with this ] is an entire cluster of galaxies.{{sfn|Ridpath|Tirion|2001|pp=148-149}} | |||
] | |||
The ''']''' is a ] lying at a distance of 19 mega]s (62 million ]s).<ref name="Georgievetal2006">{{Cite journal | last1 = Jordán | first1 = A. | last2 = Blakeslee | first2 = J. P. | last3 = Côté | first3 = P. | last4 = Ferrarese | first4 = L. | last5 = Infante | first5 = L. | last6 = Mei | first6 = S. | last7 = Merritt | first7 = D. | author7-link = David Merritt | |||
The ] galaxy is a ] that is part of the ] of galaxies. It is not visible in amateur telescopes, despite its relatively small distance of 500,000 light-years.{{sfn|Ridpath|Tirion|2001|pp=148-149}} | |||
| last8 = Peng | first8 = E. W. | last9 = Tonry | first9 = J. | last10 = West | first10 = Michael J. | date = June 2006 | journal =The Astrophysical Journal Supplement Series | volume = 452 | issue = 1 | pages = 141–153 | title = The ACS Fornax Cluster Survey. I. Introduction to the Survey and Data Reduction Procedures | bibcode = 2007ApJS..169..213J | doi = 10.1086/512778 |arxiv = astro-ph/0702320 | s2cid = 17845709 | display-authors = 8 }}</ref> It is the second richest galaxy cluster within 100 million light-years, after the considerably larger ], and may be associated with the nearby ]. It lies primarily in the constellation Fornax, with its southern boundaries partially crossing into the constellation of Eridanus, and covers an area of sky about 6° across or about 28 sq degrees.<ref>{{cite journal |last1= Drinkwater |first1= Michael J. |last2= Gregg |first2= Michael J. |last3= Colless |first3= Matthew |date= 19 Feb 2011 |title= Substructure and Dynamics of the Fornax Cluster |journal= The Astrophysical Journal |volume= 548 |issue= 2 |pages= L139–L142 |url= https://iopscience.iop.org/article/10.1086/319113 |doi= 10.1086/319113|arxiv=astro-ph/0012415 |access-date= 11 Mar 2021|hdl= 1885/40020 |s2cid= 13456590 |hdl-access= free }}</ref> The Fornax cluster is a part of larger ].<ref>{{cite book |last1=O'Meara |first1=Stephen James |title=Deep-Sky Companions: Southern Gems |date=2013 |publisher=] |isbn=978-1-107-01501-2|page=107 |url=https://books.google.com/books?id=S5QIEKns33sC&pg=PA107}}</ref> Down are some famous objects in this cluster: | |||
] is another ] located at a distance of 56 million light-years from Earth. Like NGC 1097, it is also a ]. Its bar is a center of ] and shows extensions of the spiral arms' ]s. The bright nucleus indicates the presence of an ] – a galaxy with a ] at the center, accreting matter from the bar.<ref name="objects"/> It is a 10th magnitude galaxy associated with the ].{{sfn|Ridpath|Tirion|2001|pp=148–149}} | |||
] is a ] with extensive radio lobes that corresponds to the optical galaxy ], a 9th-magnitude galaxy.{{sfn|Ridpath|Tirion|2001|pp=148–149}} One of the closer ] to Earth at a distance of 62 million light-years, Fornax A appears in the ] as a large ] with ]s near its core. These dust lanes have caused astronomers to discern that it recently ] with a small ]. Because it has a high rate of ]e, NGC 1316 has been used to determine the size of the universe. The ]s producing the radio lobes are not particularly powerful, giving the lobes a more diffuse, knotted structure due to interactions with the ].<ref name="objects">{{cite book |title = 300 Astronomical Objects: A Visual Reference to the Universe |last1 = Wilkins |first1 = Jamie |last2 = Dunn |first2 = Robert |publisher = Firefly Books |location = Buffalo, New York |date = 2006 |isbn = 978-1-55407-175-3}}</ref> Associated with this ] is an entire cluster of galaxies.{{sfn|Ridpath|Tirion|2001|pp=148-149}} | |||
] is a large ] in the Southern ] ], the central galaxy in the ]. | |||
<ref name="forn1">{{cite web |title=Multiwavelength Atlas of Galaxies - NGC 1399 |url=http://astronomy.swin.edu.au/~gmackie/atlas/index/n1399/n1399.html| access-date=2011-06-18}}</ref> | |||
The galaxy is 66 million light-years away from Earth. With a diameter of 130 000 light-years, it is one of the largest galaxies in the Fornax cluster and slightly larger than ]. ] discovered this galaxy on October 22, 1835. | |||
] is a ] located in the constellation ]. It is located at a distance of circa 53 million ]s from Earth and has apparent dimensions of 3.89' x 1.349'.<ref>{{cite web |title=NGC 1386 - Galaxy - WIKISKY |url=http://server7.wikisky.org/starview?object=NGC+1386 |website=WIKISKY |access-date=17 June 2021}}</ref> It is a ], the only one in ]. | |||
] is an ] in the ] ]. Its ] has been estimated using the ] to be 31.01 ± 0.21 which is about 52 Mly.<ref name="Georgievetal2006"/> It is the brightest dwarf irregular member of the ] and is in the foreground of the cluster's central galaxy ].<ref name="Georgievetal2006" /> | |||
] is a ] in the constellation ]. It was discovered by ] on November 28, 1837.<ref>{{Cite book|url=https://books.google.com/books?id=wyWjVWYWoO8C&pg=PA636|title=Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer's New General Catalogue|last=Steinicke|first=Wolfgang|date=August 19, 2010|publisher=Cambridge University Press|isbn=9781139490108|pages=636|language=en}}</ref> It is moving away from the ] 1341 km/s. NGC 1460 has a ] of SB0, which indicates it is a barred lenticular galaxy. But, this one contains a huge bar at its core. The bar is spreading from center to the edge of the galaxy, as seen on Hubble image in the box. This bar is one of the largest seen in barred lenticular galaxies. | |||
There are also first ultracompact dwarf galaxies discovered. | |||
'''Distant universe''' | |||
] seen with ].<ref>{{cite web|title=MUSE Probes Uncharted Depths of Hubble Ultra Deep Field – Deepest ever spectroscopic survey completed|url=https://www.eso.org/public/news/eso1738/|website=www.eso.org|access-date=30 November 2017}}</ref>]] | |||
] and its location near Fornax]] | |||
Fornax has been the target of investigations into the furthest reaches of the ]. The ] is located within Fornax, and the ], a small ], lies primarily within Fornax. At a meeting of the ] in ], a team from ] described 40 unknown "dwarf" galaxies in this constellation; follow-up observations with the ] and the ]'s ] revealed that ] are much smaller than previously known dwarf galaxies, about {{convert|120|ly|pc}} across.<ref>{{cite journal | title=Weighing Ultracompact Dwarf Galaxies in the Fornax Cluster |author1=Hilker, Michael |author2=Baumgardt, Holger |author3=Infante, Leopoldo |author4=Drinkwater, Michael |author5=Evstigneeva, Ekaterina |author6=Gregg, Michael | url=http://www.eso.org/sci/publications/messenger/archive/no.129-sep07/messenger-no129-49-52.pdf |archive-url=https://web.archive.org/web/20110604174928/http://www.eso.org/sci/publications/messenger/archive/no.129-sep07/messenger-no129-49-52.pdf |archive-date=2011-06-04 |url-status=live | journal= The Messenger | issue=129 |date= September 2007|volume=129 |page=49 |bibcode=2007Msngr.129...49H }}</ref> | |||
` | |||
] is a candidate protogalaxy located in Fornax,<ref name="Space-20121212">{{cite web |last=Wall |first=Mike |title=Ancient Galaxy May Be Most Distant Ever Seen |url=http://www.space.com/18879-hubble-most-distant-galaxy.html |date=December 12, 2012 |publisher=] |access-date=December 12, 2012 |quote=13.75 ] – 0.38 = 13.37 }}</ref><ref name="NASA-2011-01-26">NASA, , 26 January 2011</ref><ref name="heic1103">{{cite web |date=26 January 2011 |title=Hubble finds a new contender for galaxy distance record |publisher=Space Telescope (heic1103 – Science Release) |url=http://www.spacetelescope.org/news/heic1103/ |access-date=2011-01-27}}</ref><ref name="STScI-2011-05">{{Cite web| publisher=HubbleSite| title=NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe| url=http://hubblesite.org/newscenter/archive/releases/2011/05/text/| accessdate=26 January 2011| language=| archiveurl=https://archive.today/20130415015002/http://hubblesite.org/newscenter/archive/releases/2011/05/text/| archivedate=15 April 2013}}</ref> although recent analyses have suggested it is likely to be a lower redshift source.<ref name="Brammer2013">{{cite journal | bibcode = 2013ApJ...765L...2B | title=A Tentative Detection of an Emission Line at 1.6 mum for the z ~ 12 Candidate UDFj-39546284 | journal=The Astrophysical Journal | volume=765 | issue=1 | page=L2 | year=2013 | doi=10.1088/2041-8205/765/1/l2|arxiv = 1301.0317 | last1 = Brammer | first1 = Gabriel B.| s2cid=119226564 }}</ref><ref name="Bouwens2013">{{cite journal | bibcode = 2013ApJ...765L..16B | title=Photometric Constraints on the Redshift of z ~ 10 Candidate UDFj-39546284 from Deeper WFC3/IR+ACS+IRAC Observations over the HUDF | journal=The Astrophysical Journal | volume=765 | issue=1 | page=L16 | year=2013 | doi=10.1088/2041-8205/765/1/l16|arxiv = 1211.3105 | last1 = Bouwens | first1 = R. J. | last2 = Oesch | first2 = P. A. | last3 = Illingworth | first3 = G. D. | last4 = Labbé | first4 = I. | last5 = van Dokkum | first5 = P. G. | last6 = Brammer | first6 = G. | last7 = Magee | first7 = D. | last8 = Spitler | first8 = L. R. | last9 = Franx | first9 = M. | last10 = Smit | first10 = R. | last11 = Trenti | first11 = M. | last12 = Gonzalez | first12 = V. | last13 = Carollo | first13 = C. M.| s2cid=118570916 }}</ref> | |||
] was a notable ] explosion from a galaxy 4.5 billion light years away near the ],<ref name="EA-20191120">{{cite news |author=ESA/Hubble Information Centre |title=Hubble studies gamma-ray burst with the highest energy ever seen |url=https://www.eurekalert.org/pub_releases/2019-11/eic-hsg112019.php |date=20 November 2019 |work=] |access-date=20 November 2019 }}</ref><ref name="ES-20191124">{{cite news |last=Byrd |first=Deborah |title=Epic cosmic explosion detected via faster-than-light particles - Space-based observatories detected a violent explosion in a galaxy billions of light-years away. It became the brightest source of high-energy cosmic gamma rays seen so far. Specialized Earth-based telescopes detected it via faster-than-light particles cascading through Earth's atmosphere. |url=https://earthsky.org/space/jan-14-2019-gamma-ray-burst-brightest-so-far |date=24 November 2019 |work=] |access-date=24 November 2019 }}</ref><ref name="NAT-20191120a">{{cite journal |last=Zhang |first=Ben |title=Extreme emission seen from γ-ray bursts - Cosmic explosions called γ-ray bursts are the most energetic bursting events in the Universe. Observations of extremely high-energy emission from two γ-ray bursts provide a new way to study these gigantic explosions. |date=20 November 2019 |journal=] |volume=575 |issue=7783 |pages=448–449 |doi=10.1038/d41586-019-03503-6 |arxiv=1911.09862 |pmid=31748718 |doi-access=free }}</ref> that was initially detected in January 2019.<ref name="GSFC-20190114">{{cite news |last=Palmer |first=David |title=GRB 190114C: Swift detection of a very bright burst with a bright optical counterpart |url=https://gcn.gsfc.nasa.gov/gcn/gcn3/23688.gcn3 |date=14 January 2019 |work=] |access-date=20 November 2019 }}</ref><ref name="AT-20190115">{{cite news |last=Mirzoyan |first=Razmik |title=First time detection of a GRB at sub-TeV energies; MAGIC detects the GRB 190114C |url=http://www.astronomerstelegram.org/?read=12390 |date=15 January 2019 |work=] |access-date=20 November 2019 }}</ref> According to astronomers, "the brightest light ever seen from Earth ... biggest explosion in the Universe since the ]".<ref name="LAD-2091122">{{cite news |last=Wood |first=Tom |title=Scientists Detect Biggest Explosion In The Universe Since The Big Bang |url=https://www.ladbible.com/news/technology-scientists-detect-biggest-explosion-in-the-universe-since-the-big-bang-20191122 |date=22 November 2019 |work=] |access-date=23 November 2019 }}</ref> | |||
==Equivalents== | ==Equivalents== | ||
In ], the stars that correspond to Fornax are |
In ], the stars that correspond to Fornax are within the ] (西方白虎, ''Xī Fāng Bái Hǔ'').<ref>{{in lang|zh}} {{Webarchive|url=https://web.archive.org/web/20110716123113/http://aeea.nmns.edu.tw/2006/0607/ap060710.html |date=2011-07-16 }}</ref> | ||
==See also== | ==See also== | ||
*] | * ] | ||
== |
==Notes== | ||
{{notelist}} | |||
* {{cite book |first = David H. |last = Levy |title = Deep Sky Objects |publisher = Prometheus Books |year = 2005 |isbn = 1-59102-361-0 |ref = harv}} | |||
* {{citation |title = Stars and Planets Guide |last1 = Ridpath |first1 = Ian |last2 = Tirion |first2 = Wil |year = 2001 |publisher = Princeton University Press |isbn = 0-691-08913-2}} | |||
* ] and ] (2007). ''Stars and Planets Guide'', Collins, London. ISBN 978-0-00-725120-9. Princeton University Press, Princeton. ISBN 978-0-691-13556-4. | |||
* Hilker M. ''et al.'', Astronomical Science, The Messenger 129 – September 2007. is a quarterly journal presenting ESO's activities to the public. | |||
==References== | |||
{{reflist}} | {{reflist}} | ||
===Cited texts=== | |||
* {{cite book |first = David H. |last = Levy |title = Deep Sky Objects |publisher = Prometheus Books |date = 2005 |isbn = 978-1-59102-361-6 |url-access = registration |url = https://archive.org/details/deepskyobjects00davi }} | |||
* {{citation |title = Stars and Planets Guide |last1 = Ridpath |first1 = Ian |last2 = Tirion |first2 = Wil |date = 2001 |publisher = Princeton University Press |isbn = 978-0-691-08913-3}} | |||
* ] and ] (2007). ''Stars and Planets Guide'', Collins, London. {{ISBN|978-0-00-725120-9}}. Princeton University Press, Princeton. {{ISBN|978-0-691-13556-4}}. | |||
== External links == | == External links == | ||
{{Commons |
{{Commons}} | ||
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{{Stars of Fornax}} | {{Stars of Fornax}} | ||
{{navconstel}} | {{navconstel}} | ||
{{ConstellationsByLacaille}} | |||
{{Portal bar|Astronomy|Stars|Spaceflight|Outer space|Solar System}} | |||
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Latest revision as of 20:07, 24 August 2024
Constellation in the southern celestial hemisphere This article is about the constellation. For the Roman goddess, see Fornax (mythology).Constellation | |
List of stars in Fornax | |
Abbreviation | For |
---|---|
Genitive | Fornacis |
Pronunciation | /ˈfɔːrnæks/, genitive /fɔːrˈneɪsɪs/ |
Symbolism | the brazier |
Right ascension | 3 |
Declination | −30° |
Quadrant | SQ1 |
Area | 398 sq. deg. (41st) |
Main stars | 2 |
Bayer/Flamsteed stars | 27 |
Stars with planets | 6 |
Stars brighter than 3.00 | 0 |
Stars within 10.00 pc (32.62 ly) | 2 |
Brightest star | α For (3.80) |
Messier objects | 0 |
Meteor showers | 0 |
Bordering constellations | Cetus Sculptor Phoenix Eridanus |
Visible at latitudes between +50° and −90°. Best visible at 21:00 (9 p.m.) during the month of December. |
Fornax (/ˈfɔːrnæks/) is a constellation in the southern celestial hemisphere, partly ringed by the celestial river Eridanus. Its name is Latin for furnace. It was named by French astronomer Nicolas Louis de Lacaille in 1756. Fornax is one of the 88 modern constellations.
The three brightest stars—Alpha, Beta and Nu Fornacis—form a flattened triangle facing south. With an apparent magnitude of 3.91, Alpha Fornacis is the brightest star in Fornax. Six star systems have been found to have exoplanets. The Fornax Dwarf galaxy is a small faint satellite galaxy of the Milky Way. NGC 1316 is a relatively close radio galaxy.
The Hubble's Ultra-Deep Field is located within the Fornax constellation.
It is the 41st largest constellation in the night-sky, occupying an area of 398 square degrees. It is located in the first quadrant of the southern hemisphere (SQ1) and can be seen at latitudes between +50° and -90° during the month of December.
History
The French astronomer Nicolas Louis de Lacaille first described the constellation in French as le Fourneau Chymique (the Chemical Furnace) with an alembic and receiver in his early catalogue, before abbreviating it to le Fourneau on his planisphere in 1752, after he had observed and catalogued almost 10,000 southern stars during a two-year stay at the Cape of Good Hope. He devised fourteen new constellations in uncharted regions of the Southern Celestial Hemisphere not visible from Europe. All but one honoured instruments that symbolised the Age of Enlightenment. Lacaille Latinised the name to Fornax Chimiae on his 1763 chart.
Characteristics
The constellation Eridanus borders Fornax to the east, north and south, while Cetus, Sculptor and Phoenix gird it to the north, west and south respectively. Covering 397.5 square degrees and 0.964% of the night sky, it ranks 41st of the 88 constellations in size, The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "For". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 8 segments (illustrated in infobox). In the equatorial coordinate system, the right ascension coordinates of these borders lie between 01 45 24.18 and 03 50 21.34, while the declination coordinates are between −23.76° and −39.58°. The whole constellation is visible to observers south of latitude 50°N.
Features
Stars
See also: List of stars in FornaxLacaille gave Bayer designations to 27 stars now named Alpha to Omega Fornacis, labelling two stars 3.5 degrees apart as Gamma, three stars Eta, two stars Iota, two Lambda and three Chi. Phi Fornacis was added by Gould, and Theta and Omicron were dropped by Gould and Baily respectively. Upsilon, too, was later found to be two stars and designated as such. Overall, there are 59 stars within the constellation's borders brighter than or equal to apparent magnitude 6.5. However, there are no stars brighter than the fourth magnitude.
The three brightest stars form a flattish triangle, with Alpha (also called Dalim) and Nu Fornacis marking its eastern and western points and Beta Fornacis marking the shallow southern apex. Originally designated 12 Eridani by John Flamsteed, Alpha Fornacis was named by Lacaille as the brightest star in the new constellation. It is a binary star that can be resolved by small amateur telescopes. With an apparent magnitude of 3.91, the primary is a yellow-white subgiant 1.21 times as massive as the Sun that has begun to cool and expand after exhausting its core hydrogen, having swollen to 1.9 times the Sun's radius. Of magnitude 6.5, the secondary star is 0.78 times as massive as the Sun. It has been identified as a blue straggler, and has either accumulated material from, or merged with, a third star in the past. It is a strong source of X-rays. The pair is 46.4 ± 0.3 light-years distant from Earth.
Beta Fornacis is a yellow-hued giant star of spectral type G8IIIb of magnitude 4.5 that has cooled and swelled to 11 times the Sun's diameter, 178 ± 2 light-years from Earth. It is a red clump giant, which means it has undergone helium flash and is currently generating energy through the fusion of helium at its core.
Nu Fornacis is 370 ± 10 light-years distant from Earth. It is a blue giant star of spectral type B9.5IIIspSi that is 3.65 ± 0.18 times as massive and around 245 times as luminous as the Sun, with 3.2 ± 0.4 times its diameter. It varies in luminosity over a period of 1.89 days—the same as its rotational period. This is because of differences in abundances of metals in its atmosphere; it belongs to a class of star known as an Alpha Canum Venaticorum variable.
Shining with an apparent magnitude of 5.89, Epsilon Fornacis is a binary star system located 104.4 ± 0.3 light-years distant from Earth. Its component stars orbit each other every 37 years. The primary star is around 12 billion years old and has cooled and expanded to 2.53 times the diameter of the Sun, while having only 91% of its mass. Omega Fornacis is a binary star system composed of a blue main-sequence star of spectral type B9.5V and magnitude 4.96, and a white main sequence star of spectral type A7V and magnitude 7.88. The system is 470 ± 10 light-years distant from Earth.
Kappa Fornacis is a triple star system composed of a yellow giant and a pair of red dwarfs.
R Fornacis is a long-period variable and carbon star.
LP 944-20 is a brown dwarf of spectral type M9 that has around 7% the mass of the Sun. Approximately 21 light-years distant from Earth, it is a faint object with an apparent magnitude of 18.69. Observations published in 2007 showed that the atmosphere of LP 944-20 contains much lithium and that it has dusty clouds. Smaller and less luminous still is 2MASS 0243-2453, a T-type brown dwarf of spectral type T6. With a surface temperature of 1040–1100 K, it has 2.4–4.1% the mass of the Sun, a diameter 9.2 to 10.6% of that of the Sun, and an age of 0.4–1.7 billion years.
Six star systems in Fornax have been found to have planets:
- Lambda Fornacis is a star about 1.2 times as massive as the Sun with a planet about as massive as Neptune, discovered by doppler spectroscopy in 2009. The planet has an orbit of around 17.24 days.
- HD 20868 is an orange dwarf with a mass around 78% that of the Sun, 151 ± 10 light-years away from Earth. It was found to have an orbiting planet approximately double the mass of Jupiter with a period of 380 days.
- WASP-72 is a star around 1.4 times as massive that has begun to cool and expand off the main sequence, reaching double the Sun's diameter. It has a planet around as massive as Jupiter orbiting it every 2.2 days.
- HD 20781 and HD 20782 are a pair of sunlike yellow main sequence stars that orbit each other. Each has been found to have planets.
- HR 858 is a near naked eye visible star in Fornax, 31.3 parsecs away. In May 2019, it was announced to have at least 3 exoplanets as observed by transit method of the Transiting Exoplanet Survey Satellite.
Deep-sky objects
Local Group
NGC 1049 is a globular cluster 500,000 light-years from Earth. It is in the Fornax Dwarf Galaxy. NGC 1360 is a planetary nebula in Fornax with a magnitude of approximately 9.0, 1,280 light-years from Earth. Its central star is of magnitude 11.4, an unusually bright specimen. It is five times the size of the famed Ring Nebula in Lyra at 6.5 arcminutes. Unlike the Ring Nebula, NGC 1360 is clearly elliptical.
The Fornax Dwarf galaxy is a dwarf galaxy that is part of the Local Group of galaxies. It is not visible in amateur telescopes, despite its relatively small distance of 500,000 light-years.
Helmi stream is a small galactic stream in Fornax. This small galaxy was destroyed by Milky Way 6 billion years ago. There was candidate for extragalactic planet, HIP 13044 b.
Outside
NGC 1097 is a barred spiral galaxy in Fornax, about 45 million light-years from Earth. At magnitude 9, it is visible in medium amateur telescopes. It is notable as a Seyfert galaxy with strong spectral emissions indicating ionized gases and a central supermassive black hole.
Fornax Cluster
The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It is the second richest galaxy cluster within 100 million light-years, after the considerably larger Virgo Cluster, and may be associated with the nearby Eridanus Group. It lies primarily in the constellation Fornax, with its southern boundaries partially crossing into the constellation of Eridanus, and covers an area of sky about 6° across or about 28 sq degrees. The Fornax cluster is a part of larger Fornax Wall. Down are some famous objects in this cluster:
NGC 1365 is another barred spiral galaxy located at a distance of 56 million light-years from Earth. Like NGC 1097, it is also a Seyfert galaxy. Its bar is a center of star formation and shows extensions of the spiral arms' dust lanes. The bright nucleus indicates the presence of an active galactic nucleus – a galaxy with a supermassive black hole at the center, accreting matter from the bar. It is a 10th magnitude galaxy associated with the Fornax Cluster.
Fornax A is a radio galaxy with extensive radio lobes that corresponds to the optical galaxy NGC 1316, a 9th-magnitude galaxy. One of the closer active galaxies to Earth at a distance of 62 million light-years, Fornax A appears in the optical spectrum as a large elliptical galaxy with dust lanes near its core. These dust lanes have caused astronomers to discern that it recently merged with a small spiral galaxy. Because it has a high rate of type Ia supernovae, NGC 1316 has been used to determine the size of the universe. The jets producing the radio lobes are not particularly powerful, giving the lobes a more diffuse, knotted structure due to interactions with the intergalactic medium. Associated with this peculiar galaxy is an entire cluster of galaxies.
NGC 1399 is a large elliptical galaxy in the Southern constellation Fornax, the central galaxy in the Fornax cluster. The galaxy is 66 million light-years away from Earth. With a diameter of 130 000 light-years, it is one of the largest galaxies in the Fornax cluster and slightly larger than Milky Way. William Herschel discovered this galaxy on October 22, 1835.
NGC 1386 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 53 million light years from Earth and has apparent dimensions of 3.89' x 1.349'. It is a Seyfert galaxy, the only one in Fornax Cluster.
NGC 1427A is an irregular galaxy in the constellation Eridanus. Its distance modulus has been estimated using the globular cluster luminosity function to be 31.01 ± 0.21 which is about 52 Mly. It is the brightest dwarf irregular member of the Fornax cluster and is in the foreground of the cluster's central galaxy NGC 1399.
NGC 1460 is a barred lenticular galaxy in the constellation Eridanus. It was discovered by John Herschel on November 28, 1837. It is moving away from the Milky Way 1341 km/s. NGC 1460 has a Hubble classification of SB0, which indicates it is a barred lenticular galaxy. But, this one contains a huge bar at its core. The bar is spreading from center to the edge of the galaxy, as seen on Hubble image in the box. This bar is one of the largest seen in barred lenticular galaxies.
There are also first ultracompact dwarf galaxies discovered.
Distant universe
Fornax has been the target of investigations into the furthest reaches of the universe. The Hubble Ultra Deep Field is located within Fornax, and the Fornax Cluster, a small cluster of galaxies, lies primarily within Fornax. At a meeting of the Royal Astronomical Society in Britain, a team from University of Queensland described 40 unknown "dwarf" galaxies in this constellation; follow-up observations with the Hubble Space Telescope and the European Southern Observatory's Very Large Telescope revealed that ultra compact dwarfs are much smaller than previously known dwarf galaxies, about 120 light-years (37 pc) across. ` UDFj-39546284 is a candidate protogalaxy located in Fornax, although recent analyses have suggested it is likely to be a lower redshift source.
GRB 190114C was a notable gamma ray burst explosion from a galaxy 4.5 billion light years away near the Fornax constellation, that was initially detected in January 2019. According to astronomers, "the brightest light ever seen from Earth ... biggest explosion in the Universe since the Big Bang".
Equivalents
In Chinese astronomy, the stars that correspond to Fornax are within the White Tiger of the West (西方白虎, Xī Fāng Bái Hǔ).
See also
Notes
- The exception is Mensa, named for the Table Mountain. The other thirteen (alongside Fornax) are Antlia, Caelum, Circinus, Horologium, Microscopium, Norma, Octans, Pictor, Pyxis, Reticulum, Sculptor and Telescopium.
- While parts of the constellation technically rise above the horizon to observers between 50°N and 66°N, stars within a few degrees of the horizon for to all intents and purposes unobservable.
- Objects of magnitude 6.5 are among the faintest visible to the unaided eye in suburban-rural transition night skies.
References
- "Hubble Ultra Deep Field". hubblesite.org. Retrieved February 2, 2024.
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13.75 Big Bang – 0.38 = 13.37
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Cited texts
- Levy, David H. (2005). Deep Sky Objects. Prometheus Books. ISBN 978-1-59102-361-6.
- Ridpath, Ian; Tirion, Wil (2001), Stars and Planets Guide, Princeton University Press, ISBN 978-0-691-08913-3
- Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0-00-725120-9. Princeton University Press, Princeton. ISBN 978-0-691-13556-4.
External links
- The Deep Photographic Guide to the Constellations: Fornax
- Starry Night Photography – Fornax Constellation
- The clickable Fornax
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