View source for NGC 7793

{{Short description|Galaxy in the constellation Sculptor}}
{{Infobox galaxy
 | name             = {{PAGENAME}}
 | image            = File:Jets and explosions in NGC 7793 (15301077796).jpg
 | caption          = [[Hubble Space Telescope]] image of the small bulge and spiral arms of NGC 7793
 | alt              = 
 | epoch            = [[J2000]]
 | pronounce        = 
 | constellation name = [[Sculptor (constellation)|Sculptor]]
 | ra               = {{RA|23|57|49.753}}<ref name="GaiaDR2"/>
 | dec              = {{DEC|−32|35|27.71}}<ref name="GaiaDR2"/>
 | z                = 0.000749{{r|ned}}
 | h_radial_v       = {{val|227|fmt=commas|u=km/s}}<ref name="Tully_et_al_2016"/>
 | gal_v            = 
 | dist_pc          = 
 | dist_ly          = {{cvt|3.7325|Mpc|Mly|1|adj=ri1|order=flip|lk=on}}<ref name="Lianou_et_al_2019"/>
 | group_cluster    = Sculptor Group<ref name="karachentsevetal2003"/>
 | type             = SA(s)d<ref name="ned" />
 | mass             = Stellar:&nbsp;{{Val|3.2|e=9}}
 | mass_light_ratio = <!-- In solar units  -->
 | size             = ~{{convert|15.61|kpc|ly|abbr=on|lk=on|order=flip}} (estimated){{r|ned}}
 | stars            = 
 | appmag_v         = 10.0<ref name="König_Binnewies_2017"/>
 | appmag_b         = 
 | absmag_v         = 
 | size_v           =  {{Val|9.3|×|6.3|u=arcminute}}<ref name="König_Binnewies_2017"/>
 | half_light_radius_pc        = <!-- physical dimension, pc preferred -->
 | half_light_radius_arcminsec = <!-- apparent dimension -->
 | h1_scale_length_pc          = <!-- physical dimension, pc preferred -->
 | h1_scale_length_arcminsec   = <!-- apparent dimension -->
 | xray_radius_pc              = <!-- physical dimension, pc preferred -->
 | xray_radius_arcminsec       = <!-- apparent dimension -->
 | notes            = 
 | names            = {{odlist | IRAS= 23552-3252 | PGC=73049 | name= ESO 349- G 012 | MCG= -06-01-009}}<ref name="ned"/>
 | references       = 
}}

'''NGC 7793''' is a [[flocculent spiral galaxy]] in the southern [[constellation]] of [[Sculptor (constellation)|Sculptor]]. It was discovered on July 14, 1826, by Scottish astronomer [[James Dunlop]].<ref name="selig">{{cite web | url = https://cseligman.com/text/atlas/ngc77a.htm#7793 | title = New General Catalogue Objects: NGC{{nbsp}}7793 | last = Seligman | first = Courtney | website = Celestial Atlas | access-date = 25 April 2025 }}</ref><ref name="Dunlop1828"/> The galaxy is located at a distance of {{cvt|3.7325|Mpc|Mly|1|disp=output number only}}<ref name="Lianou_et_al_2019"/>&nbsp;million [[light year]]s and is receding with a heliocentric [[radial velocity]] of {{val|227|fmt=commas|u=km/s}}.<ref name="Tully_et_al_2016"/> NGC 7793 is one of the five brightest galaxies within the [[Sculptor Group]].<ref name="König_Binnewies_2017"/><ref name="karachentsevetal2003"/>

The [[Galaxy morphological classification|morphological class]] of NGC 7793 is SA(s)d,<ref name="ned"/> indicating it is [[unbarred spiral galaxy]] (SA) with no inner ring structure (s) and the [[spiral arm|arms]] are loosely wound and disorganized (d). It is flocculent in appearance with a very small bulge and a star cluster at the nucleus.<ref name="König_Binnewies_2017"/> The [[galactic disk]] is inclined at an angle of 53.7° to the line of sight from the Earth. The visible profile is elliptical in form with an [[angular size]] of {{Val|9.3|×|6.3|u=arcminute}}<ref name="König_Binnewies_2017"/> and a major axis aligned along a [[position angle]] of 99.3°.<ref name="ned"/> There are two nearby [[dwarf galaxy]] companions.<ref name="Mondal_et_al_2021"/>

NGC 7793 hosts the ultra-luminous X-ray pulsar (ULXP) referred to as NGC 7793 P13 (previously believed to harbor a black hole), which consists of a 0.42-second pulsar in a 64-day orbit with a 18–23 solar mass B9Ia companion star.<ref name="Israel_et_al2016"/>

==Supernova==
One [[supernova]] has been observed in NGC 7793. '''SN 2008bk''' ([[Type II supernova#Light_curves_for_Type_II-L_and_Type_II-P_supernovae|type II-P]], mag. 12.6) was discovered by Berto Monard [[:it:Berto_Monard|(bio-it)]] on March 25, 2008.<ref>{{cite journal|bibcode=2008CBET.1315....1M |title=Supernova 2008bk in NGC 7793 |last1=Monard |first1=L. A. G. |journal=Central Bureau Electronic Telegrams |date=2008 |issue=1315 |page=1 | url=http://www.cbat.eps.harvard.edu/cbet/001300/CBET001315.txt}}</ref><ref name="SN2008bk"/><ref>{{cite web | website=Transient Name Server | title=SN{{nbsp}}2008bk | url=https://www.wis-tns.org/object/2008bk | publisher = [[International Astronomical Union|IAU]] | access-date=25 April 2025}}</ref> It reached [[apparent magnitude]] 12.5, making it the second-brightest supernova of 2008.<ref name="supernovae2008"/> The progenitor of this supernova was a [[Red supergiant star|red supergiant]], observed only 547 days prior to the explosion.<ref>{{cite journal | bibcode=2008ApJ...688L..91M |title=VLT Detection of a Red Supergiant Progenitor of the Type II-P Supernova 2008bk | last1=Mattila | first1=S. | last2=Smartt | first2=S. J. | last3=Eldridge | first3=J. J. | last4=Maund | first4=J. R. | last5=Crockett | first5=R. M. | last6=Danziger | first6=I. J. | journal=The Astrophysical Journal | date=2008 | volume=688 | issue=2 | pages=L91–L94 | doi=10.1086/595587 | arxiv=0809.0206 | doi-access=free}}</ref>

==Gallery==
<gallery>
Phot-14b-09-fullres 2.JPG|Visual and infrared image of NGC 7793
SN2008bk.jpg|SN 2008bk before it exploded (left) and after the explosion (right)
</gallery>

==See also==
* [[List of NGC objects (7001–7840)]]
* [[NGC 300]] – ''a similar spiral galaxy that is near NGC 7793''
* [[NGC 2403]] – ''a similar spiral galaxy''

==References==
{{reflist|refs=
<ref name="GaiaDR2">{{Cite Gaia DR2|2313979670138324864}}</ref>

<ref name="Mondal_et_al_2021">{{cite journal | title=Tracing Young Star-forming Clumps in the Nearby Flocculent Spiral Galaxy NGC 7793 with UVIT Imaging | last1=Mondal | first1=Chayan | last2=Subramaniam | first2=Annapurni | last3=George | first3=Koshy | last4=Postma | first4=Joseph E. | last5=Subramanian | first5=Smitha | last6=Barway | first6=Sudhanshu | display-authors=1 | journal=The Astrophysical Journal | volume=909 | issue=2 | id=203 | pages=13 | date=March 2021 | doi=10.3847/1538-4357/abe0b4 | arxiv=2101.11314 | bibcode=2021ApJ...909..203M | s2cid=231718940 | doi-access=free}}</ref>

<ref name="König_Binnewies_2017">{{cite book | title=The Cambridge Photographic Atlas of Galaxies | first1=Michael | last1=König | first2=Stefan | last2=Binnewies | isbn=9781108103091 | date=2017 | page=68 | publisher=Cambridge University Press | url=https://books.google.com/books?id=OEszDwAAQBAJ&pg=PA68}}</ref>

<ref name="Lianou_et_al_2019">{{cite journal | title=Dust properties and star formation of approximately a thousand local galaxies | display-authors=1 | last1=Lianou | first1=S. | last2=Barmby | first2=P. | last3=Mosenkov | first3=A. A. | last4=Lehnert | first4=M. | last5=Karczewski | first5=O. | journal=Astronomy & Astrophysics | volume=631 | id=A38 | pages=19 | date=November 2019 | doi=10.1051/0004-6361/201834553 | arxiv=1906.02712 | bibcode=2019A&A...631A..38L | s2cid=174801441}}</ref>

<ref name="Tully_et_al_2016">{{cite journal | title=Cosmicflows-3 | display-authors=1 | last1=Tully | first1=R. Brent | last2=Courtois | first2=Hélène M. | last3=Sorce | first3=Jenny G. | journal=The Astronomical Journal | date=August 3, 2016 |volume=152 | issue=2 | pages=50 | doi=10.3847/0004-6256/152/2/50 | arxiv=1605.01765 | bibcode=2016AJ....152...50T | s2cid=250737862 | doi-access=free}}</ref>

<ref name="ned">{{cite web
 | website = NASA/IPAC Extragalactic Database
 | title = Results for object NGC 7793
 | url = https://ned.ipac.caltech.edu/byname?objname=NGC+7793
 | access-date = 2006-11-21}}
</ref>

<ref name="Dunlop1828">{{cite journal | title=A Catalogue of Nebulae and Clusters of Stars in the Southern Hemisphere observed in New South Wales | first=Dunlop | last=James | journal=Philosophical Transactions of the Royal Society | volume=118 | pages = 113–151 | date = 1828 | bibcode=1828RSPT..118..113D | jstor=107841 | doi = 10.1098/rstl.1828.0010 | url=https://zenodo.org/record/1432362 | doi-access = free}}</ref>

<ref name="karachentsevetal2003">{{cite journal | author=I. D. Karachentsev | display-authors=4 | author2=E. K. Grebel | author3=M. E. Sharina | author4=A. E. Dolphin | author5=D. Geisler | author6=P. Guhathakrta | author7=P. W. Hodge | author8=V. E. Karachentseva | author9=A. Sarajedini | author10=P. Seitzer | title=Distances to nearby galaxies in Sculptor | journal=Astronomy and Astrophysics | date=2003 | volume=404 | issue=1 | pages=93–111 | bibcode=2003A&A...404...93K | doi=10.1051/0004-6361:20030170|arxiv = astro-ph/0302045 | s2cid=54977869}}</ref>

<ref name="SN2008bk">{{cite web |title = Supernova 2008bk in NGC 7793 | website = Rochester Astronomy |author = David Bishop |url = https://www.rochesterastronomy.org/sn2008/sn2008bk.html |access-date = 2025-04-25 }}</ref>

<ref name="supernovae2008">{{cite web |title = Bright Supernovae – 2008 | website = Rochester Astronomy |author = David Bishop |url = https://www.rochesterastronomy.org/sn2008/index.html |access-date = 2025-04-25}}</ref>

<ref name="Israel_et_al2016">{{cite journal | title=Discovery of a 0.42-s pulsar in the ultraluminous X-ray source NGC 7793 P13 | last=Israel | first=G.L. | journal=Monthly Notices of the Royal Astronomical Society: Letters | date=September 2016 | volume=466 | pages=L48–L52 | doi=10.1093/mnrasl/slw218 | doi-access=free | arxiv=1609.06538}}</ref>
}}

==External links==
{{commons category}}
* [https://web.archive.org/web/20060220061436/http://www.spitzer.caltech.edu/Media/mediaimages/sig/sig05-017.shtml '''SST''': NGC 7793]
__NOTOC__
{{Catalogs|NGC=7793|PGC=73049}}
{{Ngc80}}
{{Sculptor (constellation)}}

{{DEFAULTSORT:NGC 7793}}
[[Category:Unbarred spiral galaxies]]
[[Category:Sculptor Group]]
[[Category:Sculptor (constellation)]]
[[Category:NGC objects|7793]]
[[Category:Principal Galaxies Catalogue objects|073049]]
[[Category:Astronomical objects discovered in 1826]]
[[Category:MCG objects|-06-01-009]]
[[Category:IRAS catalogue objects|23552-3252]]