January 28, 1999
Low Res. (69 KB)
High Res. (399 KB)
Object Name: NGC4051
Telescope: Subaru Telescope / Cassegrain Focus
Instrument: Suprime-Cam (Wide field camera for visible light)
Date: UT 1999 Jan 13
Exposure: 2 min
Field of View: 3 arcmin by 4 arcmin
Orientation: North is right, east is up
Position: RA(J2000.0)=12h3m9.6s, DEC(J2000.0)=+44d31m53s
NGC4051 is a spiral galaxy in the constellation Ursa Major at the distance of 35 million light years. This galaxy belongs to a class called Seyfert 1 galaxies, because of its bright non-stellar nucleus. NGC4051 is among the six classical Seyfert galaxies studied by the astronomer Carl Seyfert in 1943, though its nuclear activity is the lowest among Seyfert 1 galaxies. NGC4051 is morphologically classified as intermediate between barred and un-barred. Its galactic plane is seen inclined to us at about 40 degrees. Three grand-design spiral arms are seen emanating from the ends of a weak bar. This picture taken with the Subaru Telescope reveals numerous HII regions along the sprial arms. These are hot ionized clouds of hydrogen gas formed around newly born stars, and demonstrate the superb resolution of the Subaru Telescope.
Narrow stripes seen in the picture are due to the gaps between the CCD chips in Suptime-Cam. At the center of the galaxy there is a bright non-stellar nucleus, which cannot be seen in this long-exposure picture as it is buried in the light of surrounding stars.