Object name: NGC4643
NGC 4643, located in central Virgo about 77 million light-years distant, is, at first glance in most images, a rather normal but featureless barred spiral as seen in the Sloan Survey image attached. Looks can be deceiving, however. When the image is really stretched beyond normal, even in my very short 40 minutes of exposure time it turns into a polar ring galaxy. Also, the disk has a nice ring with a diameter exactly that of the central bar. This ring gives it the "r" in its classification of SB(rs)0/a Linear. It is also responsible for it being classed both as S0 and Sa. Outside this ring is a nonconcentric arc. It is concentric for much of a bit over 180 degrees it covers but note it is much closer to the inner ring at the northwest end of the bar compared to the southeast end of the bar. But it is its polar ring that nearly all imagers of this one miss. It is at nearly right angles to the bar extending far to the Northeast and southwest of the faint outer envelope.
Related Designation(s):1AXG J124320+0157, 2dFGRS N390Z102, 2MASS J12432012+0158419, 2MASX J12432013+0158422, CGCG 015-008, CGCG 1240.8+0216, EVCC 2212, HDCE 0729 NED010, IRAS 12407+0215, IRAS F12407+0215, LDCE 0904 NED235, LGG 315:[G93] 002, MCG +00-33-005, NGC 4643, NGC4643, NSA 172734, PGC 042797, PRC D-22, SDSS J124319.16+015838.2, SDSS J124320.13+015841.7, UGC 07895, USGC U490 NED41, UZC J124320.1+015842, [BEC2010] HRS 243, [M98j] 174 NED200,