Hubble spies NGC 4394

Discovered in 1784 by the German–British astronomer William Herschel, NGC 4394 is a barred spiral galaxy situated about 55 million light-years from Earth. The galaxy lies in the constellation of Coma Berenices (Berenice's Hair), and is considered to be a member of the Virgo Cluster.

NGC 4394 is the archetypal barred spiral galaxy, with bright spiral arms emerging from the ends of a bar that cuts through the galaxy’s central bulge. These arms are peppered with young blue stars, dark filaments of cosmic dust, and bright, fuzzy regions of active star formation. At the centre of NGC 4394 lies a region of ionised gas known as a LINER. LINERs are active regions that display a characteristic set of emission lines in their spectra— mostly weakly ionised atoms of oxygen, nitrogen and sulphur.

Although LINER galaxies are relatively common, it’s still unclear where the energy comes from to ionise the gas. In most cases it is thought to be the influence of a black hole at the centre of the galaxy, but it could also be the result of a high level of star formation. In the case of NGC 4394, it is likely that gravitational interaction with a nearby neighbour has caused gas to flow into the galaxy’s central region, providing a new reservoir of material to fuel the black hole or to make new stars.

Credit:

ESA/Hubble & NASA
Acknowledgement: Judy Schmidt (Geckzilla)

About the Image

Id:potw1618a
Type:Observation
Release date:2 May 2016, 06:00
Size:3662 x 3950 px

About the Object

Name:NGC 4394
Type:Local Universe : Galaxy : Type : Barred
Distance:55 million light years
Constellation:Coma Berenices
Category:Galaxies

Image Formats

Large JPEG
8.4 MB
Screensize JPEG
461.0 KB

Zoomable


Wallpapers

1024x768
422.0 KB
1280x1024
733.1 KB
1600x1200
1.1 MB
1920x1200
1.4 MB
2048x1536
1.9 MB

Coordinates

Position (RA):12 25 55.75
Position (Dec):18° 12' 48.96"
Field of view:3.05 x 3.29 arcminutes
Orientation:North is 0.2° left of vertical

Colours & filters

BandWavelengthTelescope
Optical
g
475 nm Hubble Space Telescope
ACS
Optical
b
450 nm Hubble Space Telescope
WFC2
Optical
b
450 nm Hubble Space Telescope
WFC2
Infrared
I
814 nm Hubble Space Telescope
ACS
Optical
g
475 nm Hubble Space Telescope
ACS
Infrared
I
814 nm Hubble Space Telescope
ACS
Infrared
I
814 nm Hubble Space Telescope
WFPC2

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