NGC 7702 - (R)SAB(r)0+

NGC 7702

De Vaucouleurs Atlas Type: (R)SAB(r)0+

Filter: B

Telescope: CTIO 1.5-m
North up , East left
Field Dimensions: 3.0 x 2.3 arcminutes

RC3 Type: (R)SA(r)0+
RSA Type: RSa(r)
Surface Brightness Range Displayed: 18.5-26.0 mag per square arcsec
Absolute Blue Magnitude: -19.9

De Vaucouleurs Atlas Description:

In this inclined system, the inner ring is a very bright feature, one of the brightest for this type of galaxy. The ring is enhanced near its major axis but there is no trace of a primary bar crossing the ring. Instead, there is a small nuclear bar. The presence of this feature suggests that NGC 7702 once had a primary bar that has mostly dissolved, with the bright ring arcs possibly being the traces of ansae . In contrast to the extreme brightness of the inner ring , the outer ring is exceptionally faint. The outer ring is elliptical in projected shape, but in a different position angle from the inner ring (insert). Thus, the two features have different intrinsic shapes. In many respects, NGC 7702 looks like a double-ringed, early-type barred galaxy (like NGC 7633 , for example), but it lacks a clear primary bar .

An interesting feature of the galaxy, noted by Buta (1991), is that the inner ring is a zone of slightly enhanced blue colors. Spectra of the ring revealed no H-alpha emission, and the feature could now be a ``dying" ring in the sense that no new star formation has occurred in the feature for some time.