Object name: NGC3945
Designation(s): NGC3945, NGC3975, NGC3978,
NGC 3945 is a double ring galaxy in Ursa Major just above the bowl of the big dipper. It is about 65 million light-years distant (64 by redshift). It is classed by NED as SB(rs)0+ with a LINER core. The NGC project says more simply SB0. It reminds me of NGC 2859 I posted February 2012. It too has a double ring structure but is seen a bit more face on. I see a small fuzzy blob on the east-northeast outer edge of the outer ring. NED shows nothing at its position. It is seen on the POSS plates so is real. Is it the remains of something NGC 3945 is digesting? I have no idea. A Hubble image of the galaxy's core shows several dust clouds I wasn't able to resolve. An amateur's processing of the HST data can be found at: http://www.flickr.com/photos/77452188@N05/7281940538/lightbox/ . The galaxy lacks a central bulge. At one time it was thought such galaxies didn't have a central supermassive black hole at their core but the HST data says it likely has one, about twice the size of the one in our core though the data is fuzzy enough it could also indicate no black hole but that is of a low probability from how I read the papers. At 65 million light-years the galaxy is about 120 thousand light-years across, about the size of our galaxy if some current papers resizing the Milky Way are correct.
Related Designation(s):2MASS J11531361+6040325, 2MASS J11555370+6031460, 2MASS J11561030+6031209, 2MASX J11531372+6040320, 2MASX J11555367+6031461, 2MASX J11561045+6031300, 2MASXi J1153143+604034, 2MASXi J1155536+603146, 6C B115332.3+604801, AKARI J1156107+603123, ASK 213392.0, ASK 213393.0, CGCG 1150.5+6056, CGCG 1153.5+6047, CGCG 292-042, CGCG 292-047, CXO J115313.60+604032.2, GALEXASC J115313.66+604033.8 , GALEXASC J115553.91+603146.7 , GALEXASC J115610.30+603121.2 , HOLM 306A, HOLM 306B, IRAS 11506+6056, IRAS 11535+6047, IRAS F11535+6048, LDCE 0867 NED046, MCG +10-17-096, MCG +10-17-103, MCG +10-17-105, Mr18:[BFW2006] 04350 NED01, Mr18:[BFW2006] 04350 NED03, Mr19:[BFW2006] 08707 NED01, Mr19:[BFW2006] 08707 NED03, Mr20:[BFW2006] 14810 NED02, NFGS 100, NGC 3945, NGC 3945:[L2011a] X0001, NGC 3975, NGC 3978, NGC3945, NGC3975, NGC3978, NSA 037448, NSA 140394, NSA 160772, NVSS J115610+603121, PGC 037258, PGC 037480, PGC 037502, SDSS J115553.68+603146.2, SDSS J115553.69+603145.8, SDSS J115553.69+603145.9, SDSS J115553.69+603146.2, SDSS J115610.31+603121.0, SDSS J115610.31+603121.1, SDSS J115610.32+603121.1, SDSS J115610.32+603121.4, SDSS J115610.33+603121.1, SDSS-g-fon-0563, SDSS-i-fon-0529, SDSS-r-fon-0559, SSTSL2 J115313.67+604032.5, UGC 06860, UGC 06910, UZC J115313.6+604032, UZC J115610.3+603121, [BEC2010] HRS 071, [BFW2006] J178.97370+60.52950 , [BFW2006] J179.04299+60.52262 , [GMM2009b] 31, [M98j] 157 NED02, [PVK2003] J178.97374+60.52942 , [PVK2003] J179.04303+60.52254 , [TTL2012] 088320, [TTL2012] 088321,