ESO 306-17

{{Short description|Galaxy in the constellation Columba}}

{{Infobox galaxy

| name = ESO 306-17

| image = ESO 306-17.jpg

| image_size =

| caption = Image of ESO 306-17 by the Hubble Space Telescope
Release date: 4 March 2010

| alt =

| epoch = J2000.0

| constellation name = Columba

| ra = {{RA|05|40|06.73}}

| dec = {{DEC|-40|50|10.6}}

| z = {{Val|0.035805|0.000083}}

| h_radial_v = {{val|10734|25|fmt=commas|ul=km/s}}

| gal_v = {{val|10544|26|fmt=commas|ul=km/s}}

| dist_ly = {{cvt|158.6|+/-|11.1|Mpc|Mly|sigfig=4|abbr=on|lk=on|order=flip}}{{hub|0.6774}}
{{small|(Comoving)}}{{cite web|url=https://ned.ipac.caltech.edu/byname?objname=ESO%20306-17&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1|title=Results for object NGC ESO 306-17 (ESO 306-17)|work=NASA/IPAC Extragalactic Database|publisher=California Institute of Technology|accessdate=2021-02-13}}

{{cvt|506|Mly|Mpc|sigfig=4|abbr=on|lk=on}}{{hub|0.6774}}
{{small|(Light-travel)}}

| group_cluster =

| type = E+3

| mass =

| mass_light_ratio =

| size = {{cvt|328.04|x|216.50|kpc|ly|sigfig=4|abbr=on|lk=on|disp=x|
(|)|order=flip}}
{{small|(diameter; 90% total B-band light)}}{{efn|name=Size correction|The quoted diameter in this infobox was based on NED's provided scale "Virgo + GA + Shapley" of 769 pc/arcsec multiplied with given angular diameters.}}
{{cvt|122.42|x|88.15|kpc|ly|sigfig=4|abbr=on|lk=on|disp=x|
(|)|order=flip}}
{{small|(diameter; "total" magnitude)}}{{efn|name=Size correction}}

| stars =

| appmag_v =

| appmag_b = 13.36{{cite web|url=http://leda.univ-lyon1.fr/ledacat.cgi?o=ESO%20306-17|title=Search specification: ESO 306-17|work=HyperLeda|publisher=Université Claude Bernard Lyon 1|accessdate=2021-02-13}}

| absmag_v =

| size_v = {{val|2.5|x|1.5|ul=arcminute}} {{small|(V-band)}}

| half_light_radius_pc =

| half_light_radius_arcminsec =

| h1_scale_length_pc =

| h1_scale_length_arcminsec =

| xray_radius_pc =

| xray_radius_arcminsec =

| notes =

| names = {{odlist|UGC=|MCG=-07-12-009|PGC=17570}}{{cite simbad|title=ESO 306-17|accessdate=2021-02-13}}

| references =

}}

ESO 306-17 is a fossil group giant elliptical galaxy in the Columba constellation, about 1.07 million light-years in diameter,{{Cite web |last=Boyle |first=Alan |date=2010-03-04 |title=A giant among galaxies? |url=https://www.nbcnews.com/science/cosmic-log/giant-among-galaxies-flna6c10404059 |access-date=2024-09-08 |website=NBC News |language=en}} and roughly 517 million light-years away.

The galaxy is situated alone in a volume of space about it. It is theorized that the galaxy cannibalized its nearest companions, hence, being a fossil group.{{Cite web |last=Baldwin |first=Emily |date=4 March 2010 |title=Bully galaxy rules the neighbourhood |url=https://www.astronomynow.com/news/n1003/04fossil/ |url-status=dead |archive-url=https://web.archive.org/web/20100307025601/http://www.astronomynow.com/news/n1003/04fossil/ |archive-date=2010-03-07 |website=Astronomy Now}} The galaxy is a giant elliptical of type cD3 (E+3), one of the largest types of galaxies.