Holmberg II

{{Short description|Dwarf Galaxy in the constellation Ursa Major}}

{{Infobox galaxy

| name = Holmberg II

| image = Irregular_galaxy_Holmberg_II_(captured_by_the_Hubble_Space_Telescope).tif

| image_size = 250px

| caption = An image of Holmberg II, NASA/JPL-Caltech/K. Gordon (STScI), SINGS

| epoch = J2000

| constellation name = Ursa Major

| ra = {{RA|08|19|04.98}} {{cite web

| title=NASA/IPAC EXTRAGALACTIC DATABASE

| work=Data for Holmberg II

| url=https://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=ugc+4305&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

| accessdate=2008-09-19

}}

| dec = {{DEC|+70|43|12.1}}

| h_radial_v = {{val|142|1}}

| z = 0.000474 ± 0.000003

| dist_ly = 11.06 Mly

| type = Im

| appmag_v = 11.10

| size_v = 7′.9 × 6′.3

| notes =

| names = UGC 4305, PGC 23324, MCG +12-8-33, IRAS 08140+7052, Arp 268, DDO 50, Holmberg II, KUG 0814+708

}}

Holmberg II is an irregular dwarf galaxy in the constellation Ursa Major. Its apparent magnitude is 11,1^m and it is 11 million light years away from Earth. The galaxy is dominated by huge glowing gas bubbles, which are regions of star formation.{{cite web

|title=Galaxy caught blowing bubbles

|url=http://www.spacetelescope.org/news/heic1114/

|accessdate=29 September 2011

}}{{Cite news|url=https://esahubble.org/images/heic1114a/|title=Holmberg II has star many formation sites |date= 29 September 2011|website=ESA}}

Holmberg II also hosts an ultraluminous X-ray source. One hypothesis suggests that is caused by an intermediate mass black hole that is pulling surrounding material. Holmberg II was discovered by Erik Bertil Holmberg.