NGC 3842

{{short description|Galaxy in the constellation Leo}}

{{Infobox Galaxy

| name = NGC 3842

| image = File:NGC 3837-3851 legacy dr10.jpg

|caption= legacy surveys image of NGC 3842 (center). The image also shows NGC 3837, NGC 3841, NGC 3844, NGC 3845, NGC 3851 and UGC 6697

| constellation name = Leo

| epoch = J2000

| type = E

| ra = {{RA|11|44|02.2}}{{cite web

| title=NASA/IPAC Extragalactic Database

| work=Results for NGC 3842

| url=http://nedwww.ipac.caltech.edu/

| access-date=2011-12-05}}

| dec = {{DEC|19|56|59.3}}

| dist_ly = {{convert|99.6|Mpc|Mly|abbr=on|lk=on|order=flip}}

| z = 0.021068 ± 0.000031

|h_radial_v = {{nowrap|6316 ± 9 km/s}}

| group_cluster = Leo Cluster

| appmag_v = 12.78

| size_v = 1.4 x 1.0

| notes = brightest member of the Leo Cluster, has a 9.7 billion solar mass black hole

| names = UGC 6704, PGC 36487, MCG 3-30-72, ZWG 97.95,

|image_size=250}}

NGC 3842 is an elliptical galaxy in the constellation of Leo. It was discovered by William Herschel. It is notable for containing one of the largest black holes ever detected, reported to have a mass of 9.7 billion solar masses.{{cite web|last=Rincon |first=Paul |url=https://www.bbc.co.uk/news/science-environment-16034045 |title=Team sees biggest black holes yet |publisher=bbc.co.uk |date=2011-12-05 |access-date=2011-12-05}} It is around 330 million light-years distant from Earth.

NGC 3842 is the brightest member{{Cite news|url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC%203842|title=NGC 3842|access-date=2018-04-19}} of the Leo Cluster.{{Cite news|url=http://www.skyandtelescope.com/observing/are-you-ready-willing-and-abell/|title=Are You Ready, Willing, and Abell? - Sky & Telescope|date=2017-04-26|work=Sky & Telescope|access-date=2018-04-19|language=en-US}}{{Cite news|url=http://news.berkeley.edu/2011/12/05/record-black-holes-bigger-than-our-solar-system/|title=Record massive black holes discovered lurking in monster galaxies|date=2011-12-05|work=Berkeley News|access-date=2018-04-19|language=en-US}}