NGC 4151

{{Short description|Galaxy in the constellation Canes Venatici}}

{{Infobox Galaxy

| name = NGC 4151

| image = NGC4151 Galaxy from the Mount Lemmon SkyCenter Schulman Telescope courtesy Adam Block.jpg

|caption = Image of NGC 4151 from the 0.8m Schulman Telescope at the Mount Lemmon SkyCenter

| epoch = J2000

| type = (R')SAB(rs)ab,{{cite web

| publisher= NASA/IPAC Extragalactic Database

| title= Results for NGC 4151

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

| access-date= 2007-03-27

}} Sy1{{cite simbad

| title= NGC 4151

| access-date= 2014-06-06

}}

| ra = {{RA|12|10|32.6}}

| dec = {{DEC|+39|24|21}}

| dist_ly = {{convert|15.8|±|0.4|Mpc|e6ly|abbr=on|lk=off}}{{cite journal|doi=10.3847/1538-4357/abb377|title=The Cepheid Distance to the Seyfert 1 Galaxy NGC 4151|year=2020|last1=Yuan|first1=W.|last2=Fausnaugh|first2=M. M.|last3=Hoffmann|first3=S. L.|last4=Macri|first4=L. M.|last5=Peterson|first5=B. M.|last6=Riess|first6=A. G.|last7=Bentz|first7=M. C.|last8=Brown|first8=J. S.|last9=Bontà|first9=E. Dalla|last10=Davies|first10=R. I.|last11=Rosa|first11=G. De|last12=Ferrarese|first12=L.|last13=Grier|first13=C. J.|last14=Hicks|first14=E. K. S.|last15=Onken|first15=C. A.|last16=Pogge|first16=R. W.|last17=Storchi-Bergmann|first17=T.|last18=Vestergaard|first18=M.|journal=The Astrophysical Journal|volume=902|issue=1|page=26|arxiv=2007.07888|bibcode=2020ApJ...902...26Y|s2cid=220546047 |doi-access=free }}

| z = 0.003262
995 ± 3 km/s

| appmag_v = 11.5

| size_v = 6.4{{prime}} × 5.5{{prime}}

| constellation name = Canes Venatici

| notes =

| names = UGC 7166, PGC 38739

}}

NGC 4151 is an intermediate spiral Seyfert galaxy with weak inner ring structure located {{convert|15.8|Mpc|e6ly|abbr=off|lk=on}} from Earth{{cite web |title= 'Eye of Sauron' Provides New Way of Measuring Distances to Galaxies |url= http://www.keckobservatory.org/recent/entry/eye_of_sauron_provides_new_way_of_measuring_distances_to_galaxies |access-date= 2014-11-27 |date= 2014-11-26 |publisher= W. M. Keck Observatory |author= W. M. Keck Observatory |archive-url= https://web.archive.org/web/20141205035754/http://www.keckobservatory.org/recent/entry/eye_of_sauron_provides_new_way_of_measuring_distances_to_galaxies |archive-date= 2014-12-05 |url-status= dead }} in the constellation Canes Venatici. The galaxy was first mentioned by William Herschel on March 17, 1787; it was one of the six Seyfert galaxies described in the paper {{cite journal

| author=C. K. Seyfert

| title=Nuclear Emission in Spiral Nebulae

| journal=Astrophysical Journal

| date=1943

| volume=97

| pages=28–40

| bibcode=1943ApJ....97...28S

| doi=10.1086/144488

}} which defined the term. It is one of the nearest galaxies to Earth to contain an actively growing supermassive black hole.{{cite web|title=NGC 4151: An active black hole in the "Eye of Sauron"|url=http://www.astronomy.com/News-Observing/News/2011/03/NGC%204151%20active%20black%20hole%20in%20the%20Eye%20of%20Sauron.aspx|publisher=Astronomy magazine|access-date=2011-03-14|date=2011-03-11|archive-date=2019-03-29|archive-url=https://web.archive.org/web/20190329112815/http://www.astronomy.com/News-Observing/News/2011/03/NGC|url-status=dead}} The black hole would have a mass on the order of 2.5 million to 30 million solar masses.{{cite journal|doi=10.3847/1538-4357/ac05b6|arxiv=2106.02758 |title=The Black Hole Mass of NGC 4151 from Stellar Dynamical Modeling |year=2021 |last1=Roberts |first1=Caroline A. |last2=Bentz |first2=Misty C. |last3=Vasiliev |first3=Eugene |last4=Valluri |first4=Monica |last5=Onken |first5=Christopher A. |journal=The Astrophysical Journal |volume=916 |issue=1 |page=25 |bibcode=2021ApJ...916...25R |s2cid=235358825 |doi-access=free }} It was speculated that the nucleus may host a binary black hole, with about 40 million and about 10 million solar masses respectively, orbiting with a 15.8-year period.{{Cite journal| arxiv=1209.4524 | display-authors=4 | author1=Bon | author2=Jovanović | author3=Marziani | author4=Shapovalova | author5=Bon | author6=Borka Jovanović | author7=Borka | author8=Sulentic | author9=Popović | title=The First Spectroscopically Resolved Sub-parsec Orbit of a Supermassive Binary Black Hole | journal=The Astrophysical Journal | volume=759 | issue=2 | pages=118–125 | date=2012| doi=10.1088/0004-637X/759/2/118 |bibcode = 2012ApJ...759..118B | s2cid=119257514 }} This is, however, still a matter of active debate.

Some astronomers nickname it the "Eye of Sauron" from its appearance.{{cite web |url= http://chandra.harvard.edu/photo/2011/n4151/ |title= NGC 4151: An Active Black Hole in the "Eye of Sauron" |publisher= Chandra X-ray Center |author= Chandra X-ray Observatory |date= 10 March 2011 }}

One supernova has been observed in NGC 4151: SN 2018aoq (Type II-P, mag 15.3).[https://www.wis-tns.org/object/2018aoq Transient Name Server entry for SN 2018aoq.] Retrieved 5 January 2023.{{Cite journal |last1=Tsvetkov |first1=D. Yu. |last2=Pavlyuk |first2=N. N. |last3=Vozyakova |first3=O. V. |last4=Shatsky |first4=N. I. |last5=Tatarnikov |first5=A. M. |last6=Nikiforova |first6=A. A. |last7=Baklanov |first7=P. V. |last8=Blinnikov |first8=S. I. |last9=Ushakova |first9=M. G. |last10=Larionova |first10=E. G. |last11=Borman |first11=G. A. |date=2021 |title=Type II-P Supernova SN 2018aoq in NGC 4151: Light Curves, Models, and Distance |url=https://doi.org/10.1134/S1063773721050078 |journal=Astronomy Letters |language=en |volume=47 |issue=5 |pages=291–306 |doi=10.1134/S1063773721050078|bibcode=2021AstL...47..291T }}