编辑“︁NGC 3621”︁

{{Infobox galaxy
 | name               = NGC 3621
 | image              = NGC 3621.jpg
 | image_size         = 300px
 | caption            = [[歐洲南天天文台]][[拉西亞天文台]]所拍攝的NGC 3621
 | credit             = [[ESO]] and Joe DePasquale
 | epoch              = [[J2000]]
 | pronounce          = 
 | constellation name = [[長蛇座]]
 | ra                 = {{RA|11|18|16.52}}<ref name="AJ750_2_122"/>
 | dec                = {{DEC|–32|48|50.7}}<ref name="AJ750_2_122"/>
 | z                  = {{nowrap|0.002435 ± 0.000007}}<ref name="APJ128_1_16"/>
 | h_radial_v         = +727<ref name="APJSS96_1_123"/>km/s
 | gal_v              = 
 | dist_ly            = {{nowrap|21,700,000 光年 (6.64 Mpc)}}<ref name="APJ676_1_184"/>
 | group_cluster      = 
 | type               = SA(s)d<ref name="AJ750_2_122"/>
 | mass               = 2 × 10<sup>10</sup><ref name="AJ750_2_122"/>
 | stars              = 
 | appmag_v           = 10.0
 | size_v             = 12,3′× 6,8′
 | notes              = 
 | names              = {{odlist|UGCA=232|MCG=-05-27-008|PGC=34554}}<ref>{{cite simbad|title=NGC 3621|accessdate=2021-02-24}}</ref>
 | references         = 
}}

'''NGC 3621'''是一個[[螺旋星系]]，位於[[長蛇座]]，距離[[地球]]約2,200萬[[光年]]（6.7 Mpc）<ref name="APJ676_1_184"/><ref name=1979A&A....74..235M>{{Cite journal |title= The structure of nearby groups of galaxies - Quantitative membership probabilities |author= Materne, J. |date= April 1979 |journal= Astronomy and Astrophysics |volume= 74 |number= 2 |pages= 235–243 |bibcode= 1979A&A....74..235M }}</ref>，也是一個[[場星系]]。

該[[星系]]相對明亮，在中等尺寸的[[望遠鏡]]中可以清楚地看到。該星系的直徑約為93,000光年(29,000 pc)，從邊緣觀察時傾斜角為25°。它的亮度相當於[[太陽]]的130億倍。該[[星系]]形態分類為SA(s)d<ref name="AJ750_2_122"/>，這是一個具有鬆散纏繞臂的普通螺旋星系<ref name="Buta2007"/>。NGC 3621儘管看似孤立<ref name="Buta2007"/>，實際上隸屬於獅子座支線星系群<ref name="OMeara2013"/>。

該星系有一個與[[西佛星系]]光譜相匹配的活躍核，表明其核心存在一個超大質量[[黑洞]]。根據[[恆星]]在[[原子核]]中的運動，該黑洞的質量可能高達太陽質量的三百萬倍<ref name="AJ690_1_1031"/>。


2024年4月，天文學家在NGC 3621中觀測到一顆超新星：SN 2024ggi<ref>[https://www.wis-tns.org/object/2024ggi Transient Name Server entry for SN 2024ggi.] {{Wayback|url=https://www.wis-tns.org/object/2024ggi |date=20240507180743 }} Retrieved 12 April 2024.</ref>。

== 圖集 ==
<gallery>
File:NGC 3621 HST.jpg|[[哈伯太空望遠鏡]]拍攝的NGC 3621照片<ref name="HST-potw1341a" /> 
File:NGC 3621 ESO VLT.jpg|[[甚大望遠鏡]]拍攝的NGC 3621照片<ref name="EOS-potw1148a" />
File:NGC 3621 Hubble WikiSky.jpg|[[哈伯太空望遠鏡]]拍攝的NGC 3621照片
File:NGC 3621 GALEX WikiSky.jpg|[[星系演化探測器]]拍攝的NGC 3621照片
File:NGC 3621SST.jpg|[[史匹哲太空望遠鏡]]拍攝的NGC 3621照片
File:Ngc3621-hst-606R814G555B435.jpg|[[哈伯太空望遠鏡]]拍攝的NGC 3621照片
</gallery>

== 參考資料 ==
{{reflist|refs=

<ref name="Buta2007">{{Citation
 | first1    = Ronald J.
 | last1     = Buta
 | first2    = Harold G.
 | last2     = Corwin
 | first3    = Stephen C.
 | last3     = Odewahn
 | title     = Atlas of Galaxies
 | publisher = [[Cambridge University Press]]
 | pages     = 13–17
 | date      = 2007
 | isbn      = 978-0521820486
 | url       = https://books.google.com/books?id=g-P7dCbB5MEC&pg=PA16
 | postscript= .}}</ref>

<ref name="OMeara2013">{{Citation
 | first1    = Stephen James
 | last1     = O'Meara
 | title     = Deep-Sky Companions: Southern Gems
 | publisher = Cambridge University Press
 | page      = 203
 | date      = 2013
 | isbn      = 978-1107015012
 | url       = https://books.google.com/books?id=S5QIEKns33sC&pg=PA203
 | postscript= .
 | bibcode   = 2013dcsg.book.....O}}</ref>

<ref name="APJ676_1_184">{{Citation
 | last1     = Tully        | first1 = R. Brent
 | last2     = Shaya        | first2 = Edward J.
 | last3     = Karachentsev | first3 = Igor D.
 | last4     = Courtois     | first4 = Hélène M.
 | last5     = Kocevski     | first5 = Dale D.
 | last6     = Rizzi        | first6 = Luca
 | last7     = Peel         | first7 = Alan
 | display-authors = 1
 | title     = Our Peculiar Motion Away from the Local Void
 | journal   = The Astrophysical Journal
 | volume    = 676
 | issue     = 1
 | pages     = 184–205
 |date=March 2008
 | doi       = 10.1086/527428
 | bibcode   = 2008ApJ...676..184T
 | arxiv     = 0705.4139
 | s2cid = 14738309
 | postscript= .}}</ref>

<ref name="APJSS96_1_123">{{Citation
 | last1     = Tully        | first1 = R. Brent
 | last2     = Shaya        | first2 = Edward J.
 | last3     = Karachentsev | first3 = Igor D.
 | last4     = Courtois     | first4 = Hélène M.
 | last5     = Kocevski     | first5 = Dale D.
 | last6     = Rizzi        | first6 = Luca
 | last7     = Peel         | first7 = Alan
 | title     = Recalibration of the H<sub>–0.5</sub> magnitudes of spiral galaxies
 | journal   = Astrophysical Journal Supplement Series
 | volume    = 96
 | issue     = 1
 | pages     = 123–157
 | date      = January 1995
 | doi       = 10.1086/192115
 | bibcode   = 1995ApJS...96..123T
 | arxiv     = astro-ph/9405047
 | s2cid = 15737426
 | postscript= .}}</ref>

<ref name=APJ128_1_16>{{citation
 | last1=Koribalski | first1=B. S. | last2=Staveley-Smith | first2=L.
 | last3=Kilborn | first3=V. A. | last4=Ryder | first4=S. D.
 | last5=Kraan-Korteweg | first5=R. C. | last6=Ryan-Weber | first6=E. V.
 | last7=Ekers | first7=R. D. | last8=Jerjen | first8=H.
 | last9=Henning | first9=P. A. | last10=Putman | first10=M. E.
 | last11=Zwaan | first11=M. A. | last12=de Blok | first12=W. J. G.
 | last13=Calabretta | first13=M. R. | last14=Disney | first14=M. J.
 | last15=Minchin | first15=R. F. | last16=Bhathal | first16=R.
 | last17=Boyce | first17=P. J. | last18=Drinkwater | first18=M. J.
 | last19=Freeman | first19=K. C. | last20=Gibson | first20=B. K.
 | last21=Green | first21=A. J. | last22=Haynes | first22=R. F.
 | last23=Juraszek | first23=S. | last24=Kesteven | first24=M. J.
 | last25=Knezek | first25=P. M. | last26=Mader | first26=S.
 | last27=Marquarding | first27=M. | last28=Meyer | first28=M.
 | last29=Mould | first29=J. R. | last30=Oosterloo | first30=T.
 | last31=O'Brien | first31=J. | last32=Price | first32=R. M.
 | last33=Sadler | first33=E. M. | last34=Schröder | first34=A.
 | last35=Stewart | first35=I. M. | last36=Stootman | first36=F.
 | last37=Waugh | first37=M. | last38=Warren | first38=B. E.
 | last39=Webster | first39=R. L. | last40=Wright | first40=A. E.
 | title=The 1000 Brightest HIPASS Galaxies: H I Properties
 | journal=The Astronomical Journal | postscript=.
 | volume=128 | issue=1 | pages=16–46 | date=July 2004
 | doi=10.1086/421744 | bibcode=2004AJ....128...16K
 | arxiv=astro-ph/0404436 | s2cid=16229767 | display-authors=1 }}</ref>

<ref name="AJ750_2_122">{{Citation
 | last1     = Bresolin
 | first1    = Fabio
 | last2     = Kennicutt
 | first2    = Robert C.
 | last3     = Ryan-Weber
 | first3    = Emma
 | title     = Gas Metallicities in the Extended Disks of NGC 1512 and NGC 3621. Chemical Signatures of Metal Mixing or Enriched Gas Accretion?
 | journal   = The Astronomical Journal
 | volume    = 750
 | issue     = 2
 | page      = 122
 | date      = May 2012
 | doi       = 10.1088/0004-637X/750/2/122
 | bibcode   = 2012ApJ...750..122B
 | arxiv     = 1203.0956
 | s2cid = 118616035
 | postscript= .}}</ref>

<ref name="AJ690_1_1031">{{Citation
 | last1     = Barth
 | first1    = Aaron J.
 | last2     = Strigari
 | first2    = Louis E.
 | last3     = Bentz
 | first3    = Misty C.
 | last4     = Greene
 | first4    = Jenny E.
 | last5     = Ho
 | first5    = Luis C.
 | title     = Dynamical Constraints on the Masses of the Nuclear Star Cluster and Black Hole in the Late-Type Spiral Galaxy NGC 3621
 | journal   = The Astronomical Journal
 | volume    = 690
 | issue     = 1
 | pages     = 1031–1044
 | date      = January 2009
 | doi       = 10.1088/0004-637X/690/1/1031
 | bibcode   = 2009ApJ...690.1031B
 | arxiv     = 0809.1066
 | s2cid = 12574940
 | postscript= .}}</ref>

<ref name="HST-potw1341a">{{cite news
 | title     = A special spiral galaxy for over 200 000 Facebook fans
 | url     = https://www.spacetelescope.org/images/potw1341a/
 | newspaper     = Hubble Space Telescope – Picture of the Week
 | access-date     = 23 January 2020
 | archive-date     = 2020-10-26
 | archive-url     = https://web.archive.org/web/20201026225007/https://www.spacetelescope.org/images/potw1341a/
 | dead-url     = no
 }}</ref>

<ref name="EOS-potw1148a">{{cite news
 | title     = A galaxy full of surprises — NGC 3621 is bulgeless but has three central black holes
 | url     = https://www.eso.org/public/images/potw1148a/
 | newspaper     = European Southern Observatory – Picture of the Week
 | access-date     = 23 January 2020
 | archive-date     = 2023-11-28
 | archive-url     = https://web.archive.org/web/20231128162750/https://www.eso.org/public/images/potw1148a/
 | dead-url     = no
 }}</ref>

}} <!-- end of reflist -->



== 外部連結 ==
{{Commons category}}
* [http://www.eso.org/public/news/eso1104/ A Picture-perfect Pure-disc Galaxy] {{Wayback|url=http://www.eso.org/public/news/eso1104/ |date=20230808103514 }} — [[ESO]] Photo release.

{{Catalogs|NGC=3621}}
{{Ngc40}}

[[Category:長蛇座]]
[[Category:NGC天体|3621]]
[[Category:螺旋星系]]