De Vaucouleurs Atlas Type: (R)SA0/a or (R)E1
Telescope: LCO 2.4-m
North up , East left
Field Dimensions: 8.0 x 7.4 arcminutes
RC3 Type: (R)SA0-
RSA Type: E1
Surface Brightness Range Displayed: 16.5-27.0 mag per square arcsec
Absolute Blue Magnitude: -18.8
De Vaucouleurs Atlas Description:
On images lacking sufficient depth, this galaxy looks like an ordinary elliptical. In both RC2 and RSA, the galaxy is classified as type E1 or E2. Deeper exposures, such as the SRC-J southern sky survey , reveal a faint disk or ring around the apparent elliptical, causing Corwin et al. (1985) to revise the classification to (R)SA0-. Schweizer, van Gorkom, and Seitzer (1989) showed that the apparent optical ring is also a ring of HI gas counter-rotating with respect to the stars in the elliptical. This suggested to them that the ring in IC 2006 is made of material from a small companion accreted by the elliptical or part of the process of forming the elliptical. In view of these findings, Buta and Combes (1996) audaciously classified the galaxy as type ``(R)E", which is clearly unusual.
The image we show is a deep I-band image from the SBF database (Tonry et al. 2001). In this image, faint spiral structure is visible in the ring, which is our basis for the classification S0/a.