M59-UCD3

{{Short description|Ultra-compact dwarf galaxy in the constellation of Virgo}}

{{Infobox galaxy

| name = M59-UCD3

| epoch = J2000

| constellation name = Virgo

| image = M59-UCD3 M85-HCCI.png

| image_size = 250px

| caption = Images of two ultracompact dwarf galaxies. M59-UCD3 is in the inset to the left, while M85-HCC1 is in the inset to the right.

| ra = {{RA|12|42|11.041}}

| dec = {{DEC|+11|38|41.21}}

| half_light_radius_pc = 20 ± 4 pc

| appmag_v = 16.34 ± 0.05

| absmag_v = −14.60 ± 0.09

| h_radial_v = 373 ± 18

| mass = ({{val|1.8|0.3}}){{e|8}}

| names = SDSS J124211.04+113841.2{{cite simbad|title= SDSS J124211.04+113841.2|access-date=2024-10-31}}

}}

M59-UCD3 is an ultra-compact dwarf galaxy located near the Messier 59 galaxy. {{as of|2015}}, it is the second-densest galaxy currently observed, second to M85-HCC1.{{cite journal|last1=Sandoval|first1=Michael A.|last2=Vo|first2=Richard P.|last3=Romanowsky|first3=Aaron J.|last4=Strader|first4=Jay|last5=Choi|first5=Jieun|last6=Jennings|first6=Zachary G.|last7=Conroy|first7=Charlie|last8=Brodie|first8=Jean P.|last9=Foster|first9=Caroline|last10=Villaume|first10=Alexa|last11=Norris|first11=Mark A.|last12=Janz|first12=Joachim|last13=Forbes|first13=Duncan A.|title=Hiding in Plain Sight: Record-breaking Compact Stellar Systems in the Sloan Digital Sky Survey|journal=The Astrophysical Journal|date=23 July 2015|volume=808|issue=1|pages=L32|doi=10.1088/2041-8205/808/1/L32|arxiv=1506.08828|bibcode = 2015ApJ...808L..32S |s2cid=55254708 }}{{cite news |url= http://www.spacedaily.com/reports/Undergraduates_discover_the_densest_galaxies_known_999.html |title= Undergraduates discover the densest galaxies known |date= 29 July 2015 |publisher= Space Daily }}