NGC 4569 - SAB(rs:)ab pec

NGC 4569

De Vaucouleurs Atlas Type: SAB(rs:)ab pec

Filter: B

Telescope: OHP 1.2-m
North left , East down
Field Dimensions: 8.1 x 6.1 arcminutes

RC3 Type: SAB(rs)ab
RSA Type: Sab(s)I-II
Surface Brightness Range Displayed: 17.0-26.0 mag per square arcsec
Absolute Blue Magnitude: -21.3

De Vaucouleurs Atlas Description:

There is no doubt that NGC 4569 is barred. However, the morphology of the galaxy is unusual and the bar is difficult to recognize. In the inner regions, an elongated region riddled with dust lanes appears misaligned with the galaxy major axis. This is the bar region, which includes some star formation in addition to considerable dust. From the bar-like zone, two very smooth arms emerge and form a weak but large pseudoring. This feature could be spurious as the apparent ring may be made largely of a single arm. One of the arms continues further out into the generally smooth background disk.

The strange appearance of NGC 4569 may be due to its location near the core of the Virgo Cluster . Van den Bergh (1998) has argued that NGC 4569 is the Virgo Cluster 's best example of an ``anemic spiral", one where the HI gas has been largely removed from the outer regions by ram-pressure stripping. NGC 4569 may also be interacting with the small Im galaxy IC 3583 to its north. The inner dust and patchiness, combined with the general smooth disk and arm structure, are the basis for the Sab classification.

Koopmann and Kenney (2004) classify NGC 4569 as T/N [s], meaning it has a severely truncated star-forming disk.