View source for NGC 1672

{{short description|Galaxy in the constellation Dorado}}
{{Infobox Galaxy
| name = [[New General Catalogue|NGC]] 1672
| image = NGC1672 - Iotw2205a.jpg
| caption = NGC 1672 imaged by the [[Víctor M. Blanco Telescope]]
| epoch = [[J2000]]
| type = (R')SB(r)bc<ref name="ned" />
| ra = {{RA|04|45|42.5022}}<ref name=ned>{{cite web
 | url = https://ned.ipac.caltech.edu/byname?objname=NGC+1672
 | title = Results for object NGC 1672
 | website = NASA/IPAC Extragalactic Database
 | publisher = California Institute of Technology
 | access-date = 2021-04-29}}</ref>
| dec = {{DEC|-59|14|50.162}}<ref name="ned" />
| dist_ly = {{cvt|15.86|±|0.92|Mpc|Mly|lk=on|order=flip}}<ref name=Tikhonov>{{cite journal|doi=10.1134/S199034132004015X|title=Distance to the Dorado Group|year=2020|last1=Tikhonov|first1=N. A.|last2=Galazutdinova|first2=O. A.|journal=Astrophysical Bulletin|volume=75|issue=4|pages=384–393|arxiv=2009.04090|bibcode=2020AstBu..75..384T|s2cid=221556782}}</ref>
| z = 0.004440<ref name="ned" />
| h_radial_v = {{val|1331|3|u=km/s|fmt=commas}}{{r|ned}} 
| appmag_v = 10.3<ref name="ned" />
| size_v = {{Val|6.6|×|5.5|u=arcminute}}{{r|ned}}
| size = ~{{convert|30.91|kpc|ly|abbr=on|lk=on|order=flip}} (estimated){{r|ned}}
| constellation name = [[Dorado]]
| notes = 
| names = {{odlist | PGC= 15941 | name= ESO 118- G 043 | VV= 826 | IRAS= 04449-5920}}<ref name="ned" />
}}
'''NGC 1672''' is a [[barred spiral galaxy]] located in the [[constellation]] [[Dorado]]. It was discovered by Scottish astronomer [[James Dunlop]] on 5 November 1826.<ref name=cseligman>{{cite web|url=http://cseligman.com/text/atlas/ngc16a.htm#1672|title=New General Catalogue objects: NGC 1650 - 1699|author=Seligman, Courtney|website=cseligman.com|accessdate=2021-04-29}}</ref> It was originally unclear whether it was a member of the [[Dorado Group]], with some sources<ref name="Huchraetal1982">{{Cite journal
 | bibcode = 1982ApJ...257..423H
 | title = Groups of galaxies. I - Nearby groups
 | doi = 10.1086/160000
 | date = June 15, 1982
 | journal = Astrophysical Journal
 | issue = Part 1
 | volume = 257
 | pages = 423&ndash;437
 | author = Huchra, J. P. | author2 = Geller, M. J.
}}</ref> finding it to be a member and other sources<ref name="Maiaetal1989">{{Cite journal
 | bibcode = 1989ApJS...69..809M
 | date = April 1989
 | journal = Astrophysical Journal Supplement Series
 | issn = 0067-0049
 | volume = 69
 | pages = 809&ndash;829
 | doi = 10.1086/191328
 | title = A catalog of southern groups of galaxies
 | author = Maia, M. A. G. | author2 = da Costa, L. N. | author3 = Latham, David W.
| doi-access = free
 }}</ref> rejecting its membership. However, recent [[tip of the red-giant branch]] (TRGB) measurements indicate that NGC 1672 is located at the same distance as other members, suggesting it is indeed a member of the Dorado Group.<ref name=Tikhonov/>

NGC 1672 has a large bar which is estimated to measure around 20 kpc.<ref name="Becketal2002">{{Cite journal
 | bibcode = 2002A&A...391...83B
 | title = Magnetic fields in barred galaxies. I. The atlas
 | date = August 2002
 | doi = 10.1051/0004-6361:20020642
 | journal = Astronomy and Astrophysics
 | volume = 391
 | issue = 1
 | pages = 83&ndash;102
 | author = Beck, R. |display-authors=4  | author2 = Shoutenkov, V. | author3 = Ehle, M. | author4 = Harnett, J. I. | author5 = Haynes, R. F. | author6 = Shukurov, A. | author7 = Sokoloff, D. D. | author8 = Thierbach, M.
|arxiv = astro-ph/0207201 | s2cid = 14749261
 }}</ref>  It has very strong radio emissions emanating from its nucleus, bar, and the inner portion of the spiral arm region.<ref name="Becketal2002" /> The nucleus is [[Seyfert type II]] and is engulfed by a [[starburst region]].<ref name="Becketal2002" /> The strongest polarized emissions come from the northeastern region which is upstream from its dust lanes.<ref name="Becketal2002" />  Magnetic field lines are at large angles with respect to the bar and turn smoothly to the center.<ref name="Becketal2002" />

==General structure==
The center of the galaxy contains a high surface brightness bar, and four filament-like [[spiral arm]]s extend outward from the ends of this bar. The spiral arms are asymmetric; one of the arms in the northeast part of the disk is significantly brighter than its counterpart on the other side.  The spiral arms also contain numerous [[star formation]] regions, some of which may be as large as {{pprime|4}}.<ref name="carnegieatlas">{{cite book 
  | author=A. Sandage | author2= J. Bedke
  | date=1994
  | title=Carnegie Atlas of Galaxies
  | publisher=[[Carnegie Institution of Washington]]
  | location=Washington, D.C.
  | isbn=978-0-87279-667-6 }}</ref>

==Nucleus==

The classification of the nucleus of NGC 1672 is uncertain.  Most galaxies may be classified by their [[Electromagnetic spectrum|spectra]] as having one of three different types of nuclei:<ref name="veron1997">{{cite journal
  | author=P. Veron | author2=A. C. Goncalves | author3=M. P. Veron-Cetty
  | title=AGNs with composite spectra
  | journal=Astronomy and Astrophysics
  | date=1997
  | volume=319
  | pages=52–66
  | bibcode=1997A&A...319...52V
  }}</ref>
*A nuclear H II region, a region which has a spectrum similar to that of [[star formation]] regions in the [[Milky Way]] and which therefore is associated with nuclear star formation activity.
*A [[Seyfert galaxy|Seyfert nucleus]], a type of [[active galactic nucleus]] (AGN) that may contain a [[supermassive black hole]].
*A [[low-ionization nuclear emission-line region]], a type of nuclear region with [[spectral line]] emission from weakly [[ion]]ized gas that could contain either a star formation region or a supermassive black hole.

NGC 1672, however, is one of several nearby galaxies that does not fit into this classification scheme, as its spectrum appears intermediary between these three classes of objects.<ref name="veron1997"/>  It may in fact contain both nuclear star formation regions and an AGN.  In some wave bands (such as in [[ultraviolet light]]), the star formation regions are the primary source of emission.<ref name="kinneyetal1993">{{cite journal
  | author=A. L. Kinney |display-authors=4  | author2=R. C. Bohlin | author3=D. Calzetti|author3-link= Daniela Calzetti | author4=N. Panagia | author5=R. F. G. Wyse
  | title=An atlas of ultraviolet spectra of star-forming galaxies
  | journal=Astrophysical Journal Supplement Series
  | date=1993
  | volume=86
  | pages=5–93
  | bibcode=1993ApJS...86....5K
  | doi=10.1086/191771| doi-access=free}}</ref>

==Supernovae==
Two [[supernova]]e have been observed in NGC 1672:
* SN 2017gax ([[Type Ib and Ic supernovae|type&nbsp;Ib/c]], mag. 14.1) was discovered by the ''Distance Less Than 40 Mpc Survey'' (DLT40) on 14 August 2017.<ref>{{cite web | website=Transient Name Server | title=SN{{nbsp}}2017gax | url=https://www.wis-tns.org/object/2017gax | publisher = [[International Astronomical Union|IAU]] | access-date=11 March 2025}}</ref>
* SN 2022aau ([[Type II supernova|type&nbsp;II]], mag. 16.3) was discovered by DLT40 on 20 January 2022.<ref>{{cite web | website=Transient Name Server | title=SN{{nbsp}}2022aau  | url=https://www.wis-tns.org/object/2022aau | publisher = [[International Astronomical Union|IAU]] | access-date=11 March 2025}}</ref>

==Gallery==
<gallery>
NGC 1672 HST.jpg | A [[Hubble Space Telescope]] image of the center region of NGC 1672
NGC 1672 GALEX WikiSky.jpg | A [[GALEX]] [[ultraviolet]] image of NGC 1672
NGC 1672 (weic2403k).jpg | A [[James Webb Space Telescope]] image of NGC 1672
</gallery>

==See also==
* [[NGC 1300]] - A barred spiral galaxy.
* [[NGC 7552]] - A very similar-looking barred spiral galaxy.
* [[List of NGC objects (1001–2000)]]

==References==
{{reflist}}

==External links==
{{commons category|NGC 1672}}
* [https://hubblesite.org/contents/media/images/2007/15/2092-Image.html Hubblesite Newscenter: Pictures and description]

{{Sky|04|45|42.5022|-|59|14|50.162}}
{{Catalogs|NGC=1672}}
{{NGC20}}
{{Dorado}}

{{DEFAULTSORT:NGC 1672}}
[[Category:Barred spiral galaxies]]
[[Category:Seyfert galaxies]]
[[Category:LINER galaxies]]
[[Category:Dorado]]
[[Category:NGC objects|1672]]
[[Category:IRAS catalogue objects|04449-5920]]
[[Category:Principal Galaxies Catalogue objects|015941]]
[[Category:Dorado Group]]
[[Category:Discoveries by James Dunlop]]
[[Category:Astronomical objects discovered in 1826|18261105]]