4.14 UGC 7323 This SAB(s)dm galaxy shows on optical images a luminous
amorphous central concentration and a diffuse spiral structure. H II
regions are seen throughout the disc although the spiral structure is
not clear. The nucleus is unresolved on the continuum map and the centre
of rotation was determined using the rotation curve. The rotation curve
is fairly symmetric; it reaches a maximum of 100 km s^-1^ at 135
arcsec. The curve has a solid-body shape up to 60 arcsec then the slope
is decreasing, suggesting that it is about to reach a plateau. This
behaviour is confirmed by the position-velocity plot of WHISP, showing
that the maximum is reached within the optical limit (the size of the H
i disc is 150 arcsec and the optical one is 130 arcsec).
NGC 4242.---SBm: Faint nuclear point source embedded in a very low
surface brightness disk. The central disk is elongated and at
considerably higher surface brightness than the outer disk. The outer
disk is very LSB. It has a few patches and knots, but no sign of
UGC 7323: As for UGC 5414 and 7232, no meaningful fit can be obtained for
Canes Venatici II Cloud
April 29/30, 1979
NGC 4242 is probably a member of the
intermediate redshift group with
in the Ursa Major complex region, discussed
in the description of NGC 4144 (Scd; panel
319). The group is called the CVn II Cloud by
de Vaucouleurs (1975). Other members of the
group include NGC 3675 (panels 139, S4, S13,
S14), NGC 3769 (panel 311), NGC 3782 (panel
328), NGC 3949 (panel 265), IC 749/750
(panels 195, 306).
NGC 4242 is covered with HII regions
starting at about B = 19. Individual stars are
clearly present at B = 21 and perhaps brighter.
There is an unresolved (pointlike at 0.8"
resolution) nucleus. The redshift of NGC 4242 is
v_o = 564 km/s.
"Atlas and Catalogue", Univ. Washington, Seattle, 1966.
Ap. J., 156, 847, 1969.
SAB(s)dm (de Vaucouleurs), Sc+ (Holmberg)
Low surface brightness. Weak, diffuse bar. Several filamentary, very faint
arms. Partially resolved
See HA, 105, 231, 1937.