NGC 4151

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title: "NGC 4151" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["galaxies-discovered-in-1787", "intermediate-spiral-galaxies", "seyfert-galaxies", "canes-venatici", "ngc-objects", "ugc-objects", "principal-galaxies-catalogue-objects", "x-ray-astronomy", "astronomical-x-ray-sources", "articles-containing-video-clips", "astronomical-objects-discovered-in-1787", "ngc-4151-group"] description: "Galaxy in the constellation Canes Venatici" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/NGC_4151" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Galaxy in the constellation Canes Venatici ::

::data[format=table title="Infobox Galaxy"]

Field	Value
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<ref name	"simbad"{{cite simbad
title	NGC 4151
access-date	2014-06-06
ra
dec
dist_ly	15.8 ±
z	0.003262
995 ± 3 km/s
appmag_v	11.5
size_v	6.4 × 5.5
constellation name	Canes Venatici
size	~16.66 kpc (estimated)
names	UGC 7166, PGC 38739
::

| 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 | title= NGC 4151 | access-date= 2014-06-06 | ra = | dec = | dist_ly = 15.8 ± | z = 0.003262 995 ± 3 km/s | appmag_v = 11.5 | size_v = 6.4 × 5.5 | constellation name = Canes Venatici | size = ~16.66 kpc (estimated) | notes = | names = UGC 7166, PGC 38739

NGC 4151 is an intermediate spiral Seyfert galaxy with weak inner ring structure located 15.8 Mpc from Earth 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

Some astronomers nickname it the "Eye of Sauron" from its appearance.

NGC 4151 is a member of a group of 9 galaxies known as the NGC 4151 Group. The NGC 4151 Group is part of the Ursa Major Cloud, which is part of the Virgo Supercluster.

Supernova

One supernova has been observed in NGC 4151: SN 2018aoq (TypeII-P, mag 15.3) was discovered by the Lick Observatory Supernova Search (LOSS) on 1 April 2018.

X-ray source

::figure[src="https://upload.wikimedia.org/wikipedia/commons/0/09/NGC_4151.jpg" caption="NGC 4151. X-rays (blue), optical data (yellow), radio observation (red)"] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/0/07/NGC_4151_-_HST.png" caption="HST]] (WFC3)."] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/f4/Seyfert_galaxy_NGC4151_(GL-2002-001035).jpg" caption="Optical and ultraviolet images of the black hole in the center of NGC 4151"] ::

::figure[src="https://upload.wikimedia.org/wikipedia/commons/b/b4/X-ray_'Echoes'_Probe_Habitat_of_Monster_Black_Hole.ogv" caption="Astronomers using data from the European Space Agency's [[XMM-Newton]] satellite have found a long-sought X-ray signal from NGC 4151. When the black hole's X-ray source flares, its accretion disk reflects the emission about half an hour later."] ::

X-ray emission from NGC 4151 was apparently first detected on December 24, 1970, with the X-ray observatory satellite Uhuru, although the observation spanned an error-box of 0.56 square degrees and there is some controversy as to whether UHURU might not have detected the BL Lac object 1E 1207.9 +3945, which is inside their error box – the later HEAO 1 detected an X-ray source of NGC 4151 at 1H 1210+393, coincident with the optical position of the nucleus and outside the error box of Uhuru.

To explain the X-ray emission two different possibilities have been proposed:

• radiation of material falling onto the central black hole (which was growing much more quickly about 25,000 years ago) was so bright that it stripped electrons away from the atoms in the gas in its path, and then electrons recombined with these ionized atoms
• the energy released by material flowing into the black hole in an accretion disk created a vigorous outflow of gas from the surface of the disk, which directly heated gas in its path to X-ray emitting temperatures

References

References

1. (2020). "The Cepheid Distance to the Seyfert 1 Galaxy NGC 4151". The Astrophysical Journal.
2. W. M. Keck Observatory. (2014-11-26). "'Eye of Sauron' Provides New Way of Measuring Distances to Galaxies". W. M. Keck Observatory.
3. (2011-03-11). "NGC 4151: An active black hole in the "Eye of Sauron"". Astronomy magazine.
4. (2021). "The Black Hole Mass of NGC 4151 from Stellar Dynamical Modeling". The Astrophysical Journal.
5. (2012). "The First Spectroscopically Resolved Sub-parsec Orbit of a Supermassive Binary Black Hole". The Astrophysical Journal.
6. Chandra X-ray Observatory. (10 March 2011). "NGC 4151: An Active Black Hole in the "Eye of Sauron"". Chandra X-ray Center.
7. Tully, R. Brent. (1988). "Nearby galaxies catalog". Cambridge University Press.
8. (July 2017). "Galaxy Groups Within 3500 km s-1". The Astrophysical Journal.
9. (May 1992). "Groups of galaxies within 80 Mpc. II. The catalogue of groups and group members.". Astronomy and Astrophysics Supplement Series.
10. (November 2000). "Nearby Optical Galaxies: Selection of the Sample and Identification of Groups". The Astrophysical Journal.
11. (March 2013). "Anatomy of Ursa Majoris". Monthly Notices of the Royal Astronomical Society.
12. "SN 2018aoq". [[International Astronomical Union.
13. (2021). "Type II-P Supernova SN 2018aoq in NGC 4151: Light Curves, Models, and Distance". Astronomy Letters.
14. Gursky H. (Apr 1971). "Detection of X-Rays from the Seyfert Galaxies NGC 1275 and NGC 4151 by the UHURU Satellite". Astrophys J.
15. Wood KS. (December 1984). "The HEAO A-1 X-ray source catalog". Astrophys. J. Suppl. Ser..
16. Chandra X-Ray Observatory. (2011-03-10). "The 'Eye of Sauron'". NASA.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::