MACS 2129-1

{{Infobox Galaxy

| name = MACS 2129-1

| image =

| caption =

| epoch = J2000

| ra = {{RA|21|29|22.20}}{{cite simbad|title= [GRM2013] MACS2129-1|access-date=2024-10-24}}

| dec = {{DEC|-07|41|31.2}}

| z = 2.15

| h_radial_v = 244,898 km/s

| dist_ly = ~{{nowrap| {{convert|10|e9ly|e9pc|abbr=unit|lk=on}} }}
(light travel distance)
{{nowrap| {{convert|18|e9ly|e9pc|abbr=unit|lk=on}} }}
(present proper distance)

| type = Disc galaxy

| mass =

| appmag_v = 23.8

| size_v =

| constellation name = Aquarius

| size = ~50,000 ly (diameter)

| notes =

| names = [GRM2013] MACS J2129-0741 1

}}

MACS 2129-1 is an early universe so-called 'dead' disk galaxy discovered in 2017 by the Hubble Space Telescope from NASA.{{Cite web|title=Hubble Captures Massive Dead Disk Galaxy that Challenges Theories of Galaxy Evolution {{!}} Astronomy {{!}} hubblesite.org|url=https://hubblesite.org/contents/news-releases/2017/news-2017-26.html|access-date=2023-10-03|website=HubbleSite {{!}} hubblesite.org|date=21 June 2017|language=en-US}} It lies approximately 10 billion light-years away from Earth (current distance 18 billion light years) .{{Cite web|title=Hubble Spots Massive, 'Dead' Disk Galaxy in Early Universe {{!}} Astronomy {{!}} Sci-News.com|url=http://www.sci-news.com/astronomy/hubble-massive-dead-disk-galaxy-early-universe-04980.html|access-date=2021-01-25|website=Breaking Science News {{!}} Sci-News.com|date=23 June 2017 |language=en-US}}{{cite journal |bibcode=2017Natur.546..510T |title=A massive, dead disk galaxy in the early Universe |last1=Toft |first1=Sune |last2=Zabl |first2=Johannes |last3=Richard |first3=Johan |last4=Gallazzi |first4=Anna |last5=Zibetti |first5=Stefano |last6=Prescott |first6=Moire |last7=Grillo |first7=Claudio |last8=Man |first8=Allison W. S. |last9=Lee |first9=Nicholas Y. |last10=Gómez-Guijarro |first10=Carlos |last11=Stockmann |first11=Mikkel |last12=Magdis |first12=Georgios |last13=Steinhardt |first13=Charles L. |journal=Nature |year=2017 |volume=546 |issue=7659 |pages=510–513 |doi=10.1038/nature22388 |pmid=28640271 |pmc=6485677 |arxiv=1706.07030 }} MACS 2129-1 has been described as 'dead' as it has ceased making new stars.