Editing Small Magellanic Cloud

{{Short description|Dwarf irregular galaxy, satellite galaxy of the Milky Way}}
{{Infobox galaxy
|name = Small Magellanic Cloud
|image = [[File:Small Magellanic Cloud (Digitized Sky Survey 2).jpg|300px]]
|caption = The Small Magellanic Cloud<br/>(Source: [[Digitized Sky Survey]] 2)
|epoch = [[Epoch (astronomy)#Julian years and J2000|J2000]]
|type = SB(s)m pec<ref name="ned">{{cite web
|title=NASA/IPAC Extragalactic Database
|work=Results for Small Magellanic Cloud
|url=http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=Small+Magellanic+Cloud&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
| access-date=2006-12-01 }}</ref>
| ra = {{RA|00|52|44.8}}<ref name="ned" />
| dec = {{DEC|-72|49|43}}<ref name="ned" />
| dist_ly = [[1 E20 m|203.7 ± 1.5]] [[light-year|kly]] (62.44 ± 0.47 [[parsec|kpc]])<ref name=Graczyk2020>{{cite journal | doi=10.3847/1538-4357/abbb2b | title=A Distance Determination to the Small Magellanic Cloud with an Accuracy of Better than Two Percent Based on Late-type Eclipsing Binary Stars | year=2020 | last1=Graczyk | first1=Dariusz | last2=Pietrzyński | first2=Grzegorz | last3=Thompson | first3=Ian B. | last4=Gieren | first4=Wolfgang | last5=Zgirski | first5=Bartłomiej | last6=Villanova | first6=Sandro | last7=Górski | first7=Marek | last8=Wielgórski | first8=Piotr | last9=Karczmarek | first9=Paulina | last10=Narloch | first10=Weronika | last11=Pilecki | first11=Bogumił | last12=Taormina | first12=Monica | last13=Smolec | first13=Radosław | last14=Suchomska | first14=Ksenia | last15=Gallenne | first15=Alexandre | last16=Nardetto | first16=Nicolas | last17=Storm | first17=Jesper | last18=Kudritzki | first18=Rolf-Peter | last19=Kałuszyński | first19=Mikołaj | last20=Pych | first20=Wojciech | journal=The Astrophysical Journal | volume=904 | issue=1 | page=13 | arxiv=2010.08754 | bibcode=2020ApJ...904...13G | s2cid=224706414 | doi-access=free }}</ref>
|z = 0.000527<ref name="ned" />
|appmag_v = 2.7<ref name="ned" />
|size_v = {{DEC|5|20}} × {{DEC|3|5}}<ref name="ned" />
|size = {{convert|5.78|kpc|ly|sigfig=3|abbr=off}}<ref name="ned" /><br />(diameter; 25.0 mag/arcsec<sup>2</sup> B-band isophote)<ref name=RC3>{{cite book | url=https://ui.adsabs.harvard.edu/abs/1991rc3..book.....D | bibcode=1991rc3..book.....D | year=1991 | title=Third Reference Catalogue of Bright Galaxies | last1=De Vaucouleurs | first1=Gerard | last2=De Vaucouleurs | first2=Antoinette | last3=Corwin | first3=Herold G. | last4=Buta | first4=Ronald J. | last5=Paturel | first5=Georges | last6=Fouque | first6=Pascal }}</ref>
|stars=3 billion<ref>{{cite book | author = Jonathan Powell | date = 17 September 2018 | title = Rare Astronomical Sights and Sounds | publisher = Springer | pages = | isbn = 978-3-319-97701-0 | url = https://books.google.com/books?id=Df5uDwAAQBAJ}}</ref>
|constellation name = [[Tucana]] and [[Hydrus]]
|notes = Companion dwarf to the<br/>[[Milky Way]]
|names = SMC,<ref name="ned" /> [[New General Catalogue|NGC]] 292,<ref name="ned" /> [[Principal Galaxies Catalogue|PGC]] 3085,<ref name="ned" /> Nubecula Minor<ref name="ned" />
}}

The '''Small Magellanic Cloud''' ('''SMC''') is a [[dwarf galaxy]] near the [[Milky Way]].<ref name="apod">{{cite APOD |date=2006-06-17 |title=The Small Cloud of Magellan |access-date=2008-07-07}}</ref> Classified as a dwarf [[irregular galaxy]], the SMC has a D<sub>25</sub> isophotal diameter of about {{convert|5.78|kpc|ly|sigfig=3|abbr=off}},<ref name="ned" /><ref name=RC3 /> and contains several hundred million stars.<ref name="apod"/> It has a total mass of approximately 7 billion [[solar mass]]es.<ref name="Bekki Stanimirović pp. 342–350">{{cite journal | last1=Bekki | first1=Kenji | last2=Stanimirović | first2=Snežana |author2-link=Snežana Stanimirović| title=The total mass and dark halo properties of the Small Magellanic Cloud | journal=Monthly Notices of the Royal Astronomical Society | publisher=Oxford University Press (OUP) | volume=395 | issue=1 | date=2009-05-01 | issn=0035-8711 | doi=10.1111/j.1365-2966.2009.14514.x | pages=342–350| doi-access=free | arxiv=0807.2102 | bibcode=2009MNRAS.395..342B | s2cid=18268139 }}</ref> At a distance of about 200,000 [[light-year]]s, the SMC is among the nearest intergalactic neighbors of the Milky Way and is one of the most distant objects visible to the [[naked eye]].

The SMC is visible from the entire [[Southern Hemisphere]] and can be fully glimpsed low above the southern horizon from [[tropics|latitudes]] south of about [[15th parallel north|15° north]]. The galaxy is located across the [[constellation]] of [[Tucana]] and part of [[Hydrus]], appearing as a faint, hazy patch resembling a detached piece of the [[Milky Way]]. The SMC has an average apparent diameter of about 4.2° (8 times the Moon's) and thus covers an area of about 14 square degrees (70 times the Moon's). Since its [[surface brightness]] is very low, this [[deep-sky object]] is best seen on clear [[new moon|moonless]] nights and away from [[light pollution|city lights]]. The SMC forms a pair with the [[Large Magellanic Cloud]] (LMC), which lies 20° to the east, and, like the LMC, is a member of the [[Local Group]]. It is currently a satellite of the Milky Way but is likely a former satellite of the LMC.

==Observation history==
[[File:Panoramic Large and Small Magellanic Clouds.jpg|thumb|left|Panoramic Large and Small Magellanic Clouds as seen from [[ESO]]'s [[Very Large Telescope|VLT]] observation site. The galaxies are on the left side of the image.]]
[[File:Tucana IAU.svg|thumb|left|Constellation of [[Tucana]]: the SMC is the green shape at the south (bottom) of the picture]]
In the southern hemisphere, the Magellanic clouds have long been included in the lore of native inhabitants, including [[Pacific Ocean|south sea]] islanders and [[indigenous Australians]]. [[Persia]]n astronomer [[Abd Al-Rahman Al Sufi|Al Sufi]] mentions them in his ''[[Book of Fixed Stars]]'', repeating a quote by the [[polymath]] [[Ibn Qutaybah]], but had not observed them himself. [[Europe]]an sailors may have first noticed the clouds during the [[Middle Ages]] when they were used for navigation. [[Kingdom of Portugal|Portuguese]] and [[Dutch Republic|Dutch]] sailors called them the Cape Clouds, a name that was retained for several centuries. During the circumnavigation of the Earth by [[Ferdinand Magellan]] in 1519&ndash;1522, they were described by [[Antonio Pigafetta]] as dim clusters of stars.<ref>{{cite book
 | first=Bengt E. | last=Westerlund | date=1997
 | title=The Magellanic Clouds
 | publisher=Cambridge University Press
 | isbn=978-0-521-48070-3 }}</ref> In [[Johann Bayer]]'s celestial atlas ''[[Uranometria]]'', published in 1603, he named the smaller cloud, Nubecula Minor.<ref>{{cite book
 | first=Stephen James | last=O'Meara | date=2002
 | title=The Caldwell Objects
 | publisher=Cambridge University Press
 | isbn=978-0-521-82796-6 }}</ref> In [[Latin]], Nubecula means a little cloud.<ref>{{cite book
 | first=Charlton Thomas | last=Lewis | date=1918
 |author2=Kingery, Hugh Macmaster
  | title=An elementary Latin dictionary
 | url=https://archive.org/details/bub_gb_2ncKAAAAIAAJ | publisher=American Book Company
 | isbn=978-0-19-910205-1 }}</ref>
[[File:Small_Magellanic_Cloud.png|thumb|left|Small Magellanic Cloud as photographed by an [[amateur astronomy|amateur astronomer]]. Unrelated stars have been edited out.]]

Between 1834 and 1838, [[John Frederick William Herschel]] made observations of the southern skies with his {{convert|14|in|cm|adj=on}} reflector from the [[Royal Observatory, Cape of Good Hope|Royal Observatory]]. While observing the Nubecula Minor, he described it as a cloudy mass of light with an oval shape and a bright center. Within the area of this cloud, he catalogued a concentration of 37 nebulae and clusters.<ref>{{cite book
 | first=John Frederick William | last=Herschel
 | date=1849 | title=Outlines of Astronomy
 | publisher=Lea & Blanchard
 | location=Philadelphia
 | isbn=978-0-665-18744-5 }}</ref>

In 1891, [[Harvard College Observatory]] opened an observing station at [[Arequipa Region|Arequipa]] in [[Peru]]. Between 1893 and 1906, under the direction of [[Solon Irving Bailey|Solon Bailey]], the {{convert|24|in|mm|adj=on}} telescope at this site was used to survey photographically both the Large and Small Magellanic Clouds.<ref>{{cite book
 | first=Malcolm S. | last=Longair | date=2006
 | title=The Cosmic Century: A History of Astrophysics and Cosmology
 | url=https://archive.org/details/cosmiccenturyhis0000long | url-access=registration | publisher=Cambridge University Press
 | isbn=978-0-521-47436-8 }}</ref> [[Henrietta Swan Leavitt]], an astronomer at the [[Harvard College Observatory]], used the plates from Arequipa to study the variations in relative luminosity of stars in the SMC. In 1908, the results of her study were published, which showed that a type of [[variable star]] called a "cluster variable", later called a [[Cepheid variable]] after the prototype star [[Delta Cephei]], showed a definite relationship between the variability period and the star's apparent brightness. Leavitt realized that since all the stars in the SMC are roughly the same distance from Earth, this result implied a similar relationship between period and absolute brightness.<ref>{{cite journal
 | last=Leavitt | first=Henrietta S.
 | title=1777 variables in the Magellanic Clouds
 | journal=Annals of Harvard College Observatory
 | date=1908 | volume=60 | pages=87&ndash;108
 | bibcode=1907AnHar..60...87L }}</ref> This important [[period-luminosity relation]] allowed the distance to any other Cepheid variable to be estimated in terms of the distance to the SMC.<ref>{{cite book
 | first=Antonio | last=Aparicio
 |author2=Herrero, Artemio |author3=Sánchez, Francisco
  | date=1998 | title=Stellar Astrophysics for the Local Group
 | publisher=Cambridge University Press | isbn=978-0-521-56327-7 }}</ref> She hoped a few Cepheid variables could be found close enough to Earth so that their [[parallax]], and hence distance from Earth, could be measured. This soon happened, allowing Cepheid variables to be used as [[standard candle]]s, facilitating many astronomical discoveries.<ref name=PLhistory>{{cite journal |last=Fernie |first=J.D. |title=The Period–Luminosity Relation: A Historical Review |journal=Publications of the Astronomical Society of the Pacific |date=December 1969 |volume=81 |issue=483 |page=707 |bibcode=1969PASP...81..707F |doi=10.1086/128847|doi-access=free }}</ref>

Using this period-luminosity relation, in 1913, the distance to the SMC was first estimated by [[Ejnar Hertzsprung]]. First, he measured thirteen nearby cepheid variables to find the [[absolute magnitude]] of a variable with a period of one day. By comparing this to the periodicity of the variables as measured by Leavitt, he was able to estimate a distance of 10,000 parsecs (30,000 light years) between the Sun and the SMC.<ref>{{cite book | first=John R. | last=Gribbin | date=1999 | title=The Birth of Time: How Astronomers Measured the Age of the Universe | publisher=Yale University Press | isbn=978-0-300-08346-0 | url-access=registration | url=https://archive.org/details/birthoftimehowas00grib }}</ref> This later proved to be a gross underestimate of the true distance, but it did demonstrate the potential usefulness of this technique.<ref>{{cite journal
 | last=Hoffleit | first=Dorrit
 | title=The Selector of Highlights: A Brief Biographical Sketch of Harlow Shapley
 | journal=The Journal of the American Association of Variable Star Observers
 | date=1992 | volume=21 | issue=2 | pages=151–156
 | bibcode=1992JAVSO..21..151H }}</ref>

Announced in 2006, measurements with the [[Hubble Space Telescope]] suggest that either the Large and Small Magellanic Clouds may be moving too fast to be orbiting the [[Milky Way]], or that the Milky Way Galaxy is more massive than was thought.<ref>{{cite web|title=Press release: Magellanic Clouds May Be Just Passing Through|url=https://www.cfa.harvard.edu/news/just-passing-through|publisher=Harvard University|date=January 9, 2007}}</ref>

== Features ==
[[File:VISTA’s view of the Small Magellanic Cloud.jpg|thumb|[[VISTA (telescope)|VISTA]]'s view of the Small Magellanic Cloud. [[47 Tucanae]] (NGC 104) is visible to the right of the Small Magellanic Cloud.|alt=]]

The SMC contains a central bar structure, and astronomers speculate that it was once a [[barred spiral galaxy]] that was disrupted by the Milky Way to become [[Barred irregular galaxy|somewhat irregular]].<ref>{{cite web |url=http://coolcosmos.ipac.caltech.edu//cosmic_classroom/multiwavelength_astronomy/multiwavelength_museum/smc.html |title=Small Magellanic Cloud |publisher=NASA/[[Infrared Processing and Analysis Center|IPAC]] |access-date=2008-07-07 |archive-date=2015-11-07 |archive-url=https://web.archive.org/web/20151107043237/http://coolcosmos.ipac.caltech.edu/cosmic_classroom/multiwavelength_astronomy/multiwavelength_museum/smc.html |url-status=dead }}</ref>

There is a [[Magellanic Bridge|bridge of gas]] connecting the Small Magellanic Cloud with the Large Magellanic Cloud (LMC), which is evidence of tidal interaction between the galaxies.<ref name=Mathewson>{{cite journal |title=Structure and Evolution of the Magellanic Clouds |author=Mathewson DS |author2= Ford VL |journal=IAU Symposium |date=1984 |volume=108 |pages=125 }}</ref> This bridge of gas is a star-forming site.<ref name=Heydari>{{cite journal |doi=10.1051/0004-6361:20031360 |author=Heydari-Malayeri M |display-authors=4 |author2=Meynadier F |author3=Charmandaris V |author4=Deharveng L |author5=Le Bertre T |author6= Rosa MR |author7=Schaerer D |title=The stellar environment of SMC N81|date=2003 |journal=Astron. Astrophys. |volume=411 |issue=3 |pages=427–436 |bibcode=2003A&A...411..427H|arxiv = astro-ph/0309126 |s2cid=8240730 }}</ref>
The Magellanic Clouds have a common envelope of neutral hydrogen, indicating they have been gravitationally bound for a long time. 

In 2017, using the [[Dark Energy Survey]] plus MagLiteS data, a stellar over-density associated with the Small Magellanic Cloud was discovered, which is probably the result of interactions between the SMC and LMC.<ref name=Pieres>{{cite journal |author=Adriano Pieres |display-authors=etal |date=2017 |title=A stellar over-density associated with the Small Magellanic Cloud|journal=Monthly Notices of the Royal Astronomical Society |volume=468 |issue=2 |pages=1349–1360 |arxiv=1612.03938|doi=10.1093/mnras/stx507 |doi-access=free |bibcode=2017MNRAS.468.1349P }}</ref>

[[File:Head in the Clouds (potw2249a).tiff|thumb|right|Open cluster [[NGC 376]] in the Small Magellanic Cloud, imaged by the [[Hubble Space Telescope]]<ref>{{cite web|url=https://esahubble.org/images/potw2249a/|title=Head in the Clouds |access-date=2023-08-24}}</ref>]]

==X-ray sources==
The Small Magellanic Cloud contains a large and active population of [[X-ray binary|X-ray binaries]]. Recent star formation has led to a large population of massive stars and high-mass X-ray binaries (HMXBs), which are the relics of the short-lived upper end of the [[initial mass function]]. The young stellar population and most known X-ray binaries are concentrated in the SMC's Bar.
HMXB pulsars are rotating neutron stars in binary systems with Be-type ([[spectral type]] 09-B2, [[luminosity class]]es V–III) or [[supergiant]] stellar companions. Most HMXBs are of the Be type which account for 70% in the Milky Way and 98% in the SMC.<ref>Coe et al. 2005</ref> The Be-star equatorial disk provides a reservoir of matter that can be accreted onto the neutron star during [[periastron]] passage (most known systems have large orbital eccentricity) or during large-scale disk ejection episodes. This scenario leads to strings of X-ray outbursts with typical X-ray luminosities L<sub>x</sub>&nbsp;=&nbsp;10<sup>36</sup>–10<sup>37</sup>&nbsp;[[erg]]/s, spaced at the orbital period, plus infrequent giant outbursts of greater duration and luminosity.<ref>Negueruela 1998 for a review</ref>

Monitoring surveys of the SMC performed with NASA's [[Rossi X-ray Timing Explorer]] (RXTE)<ref>Laycock et al. 2005; Galache et al. 2008</ref> see X-ray pulsars in outburst at more than 10<sup>36</sup>&nbsp;erg/s and have counted 50 by the end of 2008. The ROSAT and ASCA missions detected many faint X-ray point sources,<ref>Haberl & Sasaki 2000</ref> but the typical positional uncertainties frequently made identification difficult. Recent studies using XMM-Newton<ref>Haberl et al. 2008; Haberl & Pietsch 2004</ref> and Chandra<ref>Antoniou et al. 2009; Edge et al. 2004, and Laycock et al. 2010</ref> have now cataloged several hundred X-ray sources in the direction of the SMC, of which perhaps half are considered likely HMXBs, and the remainder a mix of foreground stars, and background AGN.

No X-rays above background were observed from the Magellanic Clouds during the September 20, 1966, [[Nike-Tomahawk]] flight.<ref name=Chodil>{{cite journal |display-authors=4|author=Chodil G|author2=Mark H |author3=Rodrigues R |author4=Seward FD |author5=Swift CD |title=X-Ray Intensities and Spectra from Several Cosmic Sources |journal=Astrophys. J. |date=Oct 1967 |volume=150 |issue=10 |pages=57–65 |bibcode=1967ApJ...150...57C |doi=10.1086/149312|doi-access=free }}</ref> Balloon observation from Mildura, Australia, on October 24, 1967, of the SMC set an upper limit of X-ray detection.<ref name=Lewin>{{cite journal |author=Lewin WHG |author2=Clark GW |author3= Smith WB |title=Search for X-rays from the Large and Small Magellanic Clouds |date=1968 |journal=Nature |volume=220 |issue=5164 |pages=249–250 |bibcode=1968Natur.220..249L |doi=10.1038/220249b0 |s2cid=4187949 }}</ref> An X-ray astronomy instrument was carried aboard a [[PGM-17 Thor|Thor]] missile launched from [[Johnston Atoll]] on September 24, 1970, at 12:54 UTC for altitudes above 300&nbsp;km, to search for the Small Magellanic Cloud.<ref name=Price>{{cite journal |author=Price RE |display-authors=4 |author2=Groves DJ |author3=Rodrigues RM |author4=Seward FD |author5=Swift CD |author6=Toor A |title=X-Rays from the Magellanic Clouds |journal=Astrophys. J. |date=Aug 1971 |volume=168 |issue=8 |pages=L7–9 |bibcode=1971ApJ...168L...7P |doi=10.1086/180773 |doi-access=free }}</ref> The SMC was detected with an X-ray luminosity of 5{{e|38}}&nbsp;erg/s in the range 1.5–12&nbsp;keV, and 2.5{{e|39}}&nbsp;erg/s in the range 5–50&nbsp;keV for an apparently extended source.<ref name=Price/>

The fourth [[Uhuru (satellite)|Uhuru]] catalog lists an early X-ray source within the [[constellation]] [[Tucana]]: 4U 0115-73 (3U 0115-73, 2A 0116-737, SMC X-1).<ref name=Forman>{{cite journal |author=Forman W |display-authors= 4 |author2= Jones C |author3=Cominsky L |author4=Julien P |author5=Murray S |author6=Peters G |title=The fourth Uhuru catalog of X-ray sources |journal= Astrophys. J. Suppl. Ser. |date=1978 |volume=38 |page=357 |doi=10.1086/190561 |bibcode=1978ApJS...38..357F|doi-access=free }}</ref> Uhuru observed the SMC on January 1, 12, 13, 16, and 17, 1971, and detected one source located at 01149-7342, which was then designated SMC X-1.<ref name=Leong>{{cite journal |author=Leong C |display-authors=4 |author2=Kellogg E |author3=Gursky H |author4=Tananbaum H |author5= Giacconi R |title=X-Ray Emission from the Magellanic Clouds Observed by UHURU |journal=Astrophys. J. |date=Dec 1971 |volume=170 |issue=12 |pages=L67–71 |bibcode=1971ApJ...170L..67L |doi=10.1086/180842 }}</ref> Some X-ray counts were also received on January 14, 15, 18, and 19, 1971.<ref name=Tananbaum73>{{cite book |author=Tananbaum HD |title=X- and Gamma-Ray Astronomy |chapter=UHURU Results on Galactic X-ray Sources |volume=55 |editor=Bradt H |editor2= Giacconi R |publisher=International Astronomical Union |pages=9–28 |bibcode=1973IAUS...55....9T |location=Dordrecht, Holland |year=1973 |doi=10.1007/978-94-010-2585-0_2 |isbn=978-90-277-0337-8 }}</ref> The third [[Ariel 5]] catalog (3A) also contains this early X-ray source within Tucana: 3A 0116-736 (2A 0116-737, SMC X-1).<ref name=McHardy81>{{cite journal |author=McHardy IM |author2= Lawrence A |author3= Pye JP |author4=Pounds KA |title=The Ariel V /3 A/ catalogue of X-ray sources. II - Sources at high galactic latitude /absolute value of B greater than 10 deg/ |journal=Monthly Notices of the Royal Astronomical Society |date=Dec 1981 |volume=197 |issue= 4 |pages=893–919 |bibcode=1981MNRAS.197..893M |doi=10.1093/mnras/197.4.893|doi-access=free }}</ref> The SMC X-1, a HMXRB, is at J2000 [[right ascension]] (RA) {{RA|01|15|14}} [[declination]] (Dec) {{Dec|73|42|22}}.

Two additional sources detected and listed in 3A include SMC X-2 at 3A 0042-738 and SMC X-3 at 3A 0049-726.<ref name=McHardy81/>

==Mini Magellanic Cloud (MMC)==
It has been proposed by astrophysicists D. S. Mathewson, V. L. Ford, and N. Visvanathan that the SMC may, in fact, be split in two, with a smaller section of this galaxy behind the main part of the SMC (as seen from Earth's perspective), and separated by about 30,000 ly. They suggest the reason for this is due to a past interaction with the LMC that split the SMC, and that the two sections are still moving apart. They dubbed this smaller remnant the Mini Magellanic Cloud.<ref name="MathewsonFord1986">{{cite journal|last1=Mathewson|first1=D. S.|last2=Ford|first2=V. L.|last3=Visvanathan|first3=N.|title=The structure of the Small Magellanic Cloud|journal=The Astrophysical Journal|volume=301|date=1986|pages=664|issn=0004-637X|doi=10.1086/163932|bibcode = 1986ApJ...301..664M }}</ref><ref name="CrowlSarajedini2001">{{cite journal|last1=Crowl|first1=Hugh H.|display-authors=etal|title=The Line-of-Sight Depth of Populous Clusters in the Small Magellanic Cloud|journal=The Astronomical Journal|volume=122|issue=1|date=2001|pages=220–231|issn=0004-6256|doi=10.1086/321128|arxiv=astro-ph/0104227v1|bibcode = 2001AJ....122..220C |s2cid=45263795}}</ref>

In 2023, it was reported that the SMC is indeed two separate structures with distinct stellar and gaseous chemical compositions, separated by around 5 kiloparsecs.<ref>{{cite journal|arxiv=2312.07750 |last1=Murray |first1=Claire E. |last2=Hasselquist |first2=Sten |last3=Peek |first3=Joshua E. G. |author4=Christina Willecke Lindberg |last5=Almeida |first5=Andres |last6=Choi |first6=Yumi |last7=Craig |first7=Jessica E. M. |last8=Denes |first8=Helga |last9=Dickey |first9=John M. |last10=Di Teodoro |first10=Enrico M. |last11=Federrath |first11=Christoph |last12=Gerrard |first12=Isabella A. |last13=Gibson |first13=Steven J. |last14=Leahy |first14=Denis |last15=Lee |first15=Min-Young |last16=Lynn |first16=Callum |author17=Yik Ki Ma |last18=Marchal |first18=Antoine |last19=McClure-Griffiths |first19=N. M. |last20=Nidever |first20=David |last21=Nguyen |first21=Hiep |last22=Pingel |first22=Nickolas M. |last23=Tarantino |first23=Elizabeth |last24=Uscanga |first24=Lucero |last25=van Loon |first25=Jacco Th. |title=A Galactic Eclipse: The Small Magellanic Cloud is Forming Stars in Two, Superimposed Systems |journal=The Astrophysical Journal |date=2023 |volume=962 |issue=2 |page=120 |doi=10.3847/1538-4357/ad1591 |doi-access=free |bibcode=2024ApJ...962..120M }}</ref>

==See also==
{{Portal|Stars}}
*[[Large Magellanic Cloud]]
*[[Magellanic Clouds]]
* Objects within the Small Magellanic Cloud:
** [[NGC 121]]
** [[NGC 265]]
** [[NGC 290]]
** [[NGC 346]]
** [[NGC 602]]

==References==
{{Reflist|30em}}

==External links==
{{Commons category}}
*[http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=SMC&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 NASA Extragalactic Database entry on the SMC]
*[http://messier.seds.org/xtra/ngc/smc.html SEDS entry on the SMC]
*[http://www.spacetelescope.org/bin/images.pl?embargo=0&viewtype=standard&searchtype=freesearch&lang=en&string=smc SMC at ESA/Hubble] {{Webarchive|url=https://web.archive.org/web/20070927184702/http://www.spacetelescope.org/bin/images.pl?embargo=0&viewtype=standard&searchtype=freesearch&lang=en&string=smc |date=2007-09-27 }}
*[[Astronomy Picture of the Day]] 2010 January 7 [http://apod.nasa.gov/apod/ap100107.html The Tail of the Small Magellanic Cloud] - Likely stripped from the galaxy by gravitational tides, the tail contains mostly gas, dust, and newly formed stars.

{{Sky|00|52|44.8|-|72|49|43|197000}}
{{Milky Way|state=expanded}}
{{Ngc5}}
{{Authority control}}

[[Category:Small Magellanic Cloud| ]]
[[Category:Dwarf barred irregular galaxies]]
[[Category:Peculiar galaxies]]
[[Category:Low surface brightness galaxies]]
[[Category:Milky Way Subgroup]]
[[Category:Tucana]]
[[Category:NGC objects]]
[[Category:Principal Galaxies Catalogue objects|03085]]
[[Category:Astronomical objects known since antiquity]]
[[Category:Magellanic Clouds]]
[[Category:Local Group]]
[[Category:Hydrus]]
[[Category:Magellanic spiral galaxies]]