Date and Time of the Query: 2019-05-20 T16:18:00 PDT
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Notes for object NGC 4304

3 note(s) found in NED.

1. 1994CAG1..B...0000S
Re:NGC 4304
Feb 12/13, 1978
103aO + GG385
45 min
The two principal arms in NGC 4304 spring
from the ends of the bar, which is relatively
smooth but is less well defined than in NGC 1300.
Dust exists in the bar, but the lanes are
less regular than the two straight lanes that are
characteristic of the strong shock lanes in SBb
and SBbc galaxies of luminosity class I. Nevertheless,
the dust-lane pattern is believed to trace
the velocity field (the streamlines) near the bar
(e.g., Huntley 1978, 1980). Note that the dust
lanes are nearly perpendicular to the bar on one
side and are along the bar on the other.
Copious star formation occurs in both of the
main arms. The HII regions have high surface
brightness. They are individually unresolved at
the 1" level, but a complex of them in one of the
arms has a halo diameter of about 5". The redshift
of NGC 4304 is v_o = 2327 km/s.
Low-surface-brightness spiral fragments of
arms branching from the two main arms exist on
the outside of the main pattern. Such sets of
outer low-surface-brightness, often called fossil,
arms, are common features of spirals of all types.

2. 1985SGC...C...0000C
Re:NGC 4304
Plate 562
Bright nucleus, dust lane on bar, similar to NGC 1300 but more open.
Edge of plate.
Plate 1468
Bright nucleus, short bar, radial streamers.
Plate 1540
Overexposed center, bright patchy arms.

3. 1979AJ.....84..472S
Re:NGC 4304
Excellent type example.
The two characteristic thin dust lanes out of the nucleus
and along opposite sides of the bar are broken, but present;
hence the "bc" nature of the bar.
Arms are very lumpy, and resolution into HII regions may be
productive at the 1.5 arcsec level, but need H{alpha} plates
to increase the contrast with the high surface brightness arms.

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