IC 1101是位于距離地球大(da)約10.45億(yi)光(guang)(guang)年的(de)阿(a)貝(bei)爾2029星系(xi)群(qun)的(de)中心星系(xi),其(qi)半徑(jing)約為200萬光(guang)(guang)年(包含星系(xi)暈),相當(dang)于銀河系(xi)直徑(jing)的(de)20多倍,是已知最大(da)的(de)星系(xi)。
這個星(xing)系是在(zai)1790年(nian)6月(yue)19日由英國天文學家(jia)威廉(lian)·赫歇爾發(fa)(fa)(fa)現(xian)(xian)的(de)(de)。它(ta)于1895年(nian)被約翰·路(lu)易·埃米爾·德(de)雷耳(er)收錄在(zai)星(xing)云和星(xing)團索引目錄(IC)中的(de)(de)第1101個天體(ti)。當它(ta)被發(fa)(fa)(fa)現(xian)(xian)時,以它(ta)的(de)(de)外(wai)觀被認為是一個星(xing)云。后(hou)來(lai)愛德(de)溫·哈(ha)伯在(zai)1932年(nian)發(fa)(fa)(fa)現(xian)(xian)一些具(ju)有星(xing)云外(wai)觀的(de)(de)天體(ti)實際上(shang)就是獨立的(de)(de)星(xing)系,對這些天空中物體(ti)進行的(de)(de)后(hou)續分析,發(fa)(fa)(fa)現(xian)(xian)IC 1101是一個獨立的(de)(de)星(xing)系。
IC 1101是(shi)位(wei)于阿貝爾2029星(xing)(xing)系(xi)(xi)(xi)團中(zhong)心最亮的星(xing)(xing)系(xi)(xi)(xi),被分類(lei)為超巨(ju)大橢圓星(xing)(xing)系(xi)(xi)(xi)(E)到透(tou)鏡狀星(xing)(xing)系(xi)(xi)(xi)(S0),位(wei)于室女座,距(ju)離地球(qiu)10.45億光年(nian)(±0.73億光年(nian))。這個星(xing)(xing)系(xi)(xi)(xi)的形態類(lei)型是(shi)有爭(zheng)議的,因(yin)為它可能形狀像(xiang)一(yi)個平坦的圓盤,但從地球(qiu)上(shang)觀測只能看到其最寬處(chu)。然而,大多數(shu)雙凸(tu)透(tou)鏡星(xing)(xing)系(xi)(xi)(xi)的尺寸范圍從15到37千秒差(cha)距(ju)(5萬到12萬光年(nian))。
IC 1101是(shi)已知最大的(de)(de)星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)之一,它的(de)(de)體(ti)積非(fei)常巨大,足以容納數千(qian)(qian)個銀(yin)河(he)系(xi)(xi)(xi)(xi)(xi)。以前的(de)(de)資料顯(xian)示(shi)該星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)半(ban)徑(jing)(jing)為210±10萬(wan)光(guang)(guang)年(nian),但(dan)是(shi)如何定義(yi)這種星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)的(de)(de)大小,在(zai)天文(wen)學的(de)(de)文(wen)獻(xian)中(zhong)(zhong)仍有爭議。來自星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)的(de)(de)藍(lan)光(guang)(guang)攝影干版(對恒(heng)星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)的(de)(de)取樣不包(bao)(bao)括擴散的(de)(de)暈)給(gei)予的(de)(de)有效半(ban)徑(jing)(jing)(輻射出一半(ban)光(guang)(guang)量(liang)的(de)(de)半(ban)徑(jing)(jing))是(shi)65±12千(qian)(qian)秒(miao)差(cha)距(21.2±3.9萬(wan)光(guang)(guang)年(nian))。這個星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)有非(fei)常大的(de)(de)低(di)強度漫射光(guang)(guang),半(ban)徑(jing)(jing)延伸至600千(qian)(qian)秒(miao)差(cha)距(200萬(wan)光(guang)(guang)年(nian))。IC 1101的(de)(de)研(yan)究(jiu)人員確認(ren)若包(bao)(bao)含(han)暈可(ke)能是(shi)宇(yu)宙中(zhong)(zhong)最大和最亮(liang)的(de)(de)星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)。估計IC 1101內有100萬(wan)億(yi)顆恒(heng)星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing),遠多于(yu)(yu)銀(yin)河(he)系(xi)(xi)(xi)(xi)(xi)4000億(yi)顆或仙女座(zuo)星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)的(de)(de)1萬(wan)億(yi)顆。充滿熾熱氣(qi)體(ti)的(de)(de)阿貝爾(er)2029星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)團釋(shi)放發光(guang)(guang)X射線,它包(bao)(bao)含(han)著質(zhi)量(liang)相當于(yu)(yu)100萬(wan)億(yi)顆太陽的(de)(de)暗物質(zhi),這個星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)團可(ke)容納上千(qian)(qian)個星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)。如果IC 1101位(wei)于(yu)(yu)我(wo)們(men)銀(yin)河(he)系(xi)(xi)(xi)(xi)(xi)的(de)(de)位(wei)置,大麥(mai)哲倫星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)、小麥(mai)哲倫星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)、仙女座(zuo)星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)、三角座(zuo)星(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)(xing)系(xi)(xi)(xi)(xi)(xi)將(jiang)被包(bao)(bao)含(han)在(zai)內。
像多數巨(ju)大星(xing)系(xi),IC1101擁有大量(liang)的(de)富金(jin)屬(shu)恒星(xing),其(qi)中(zhong)有些比(bi)太陽還古老70億年,因(yin)此(ci)呈現金(jin)黃色(se)的(de)色(se)澤。其(qi)中(zhong)心有非(fei)常明亮的(de)射電源,可能與一(yi)個400~1000億倍(bei)太陽質量(liang)的(de)超大質量(liang)黑洞相關聯。