THE LUMINOUS SEYFERT-1 TYPE-II SUPERNOVA 1997AB

We report the discovery of SN 1997ab, a supernova with a Seyfert 1 typ e spectrum similar to SN 1987E SN 1997ab was first seen at B=14.7+/-0. 5 on a digitized objective prism spectrum taken on April 11, 1996 for the Hamburg Quasar Survey with the Calar Alto 80cm Schmidt telescope a nd was automatically selected as a low redshift QSO candidate. Spectra and images taken with CAFOS at the 2.2m telescope on Calar Alto on Fe b. 28 and March 2, 1997 show the SN at B=16.2 with strong Balmer lines , broad Fe II emission bumps at lambda(rest)=5250 Angstrom and 4580 An gstrom, a strong IR Ca II tripler and the HeI 7065 Angstrom and 5876 A ngstrom lines. The SN is located 3.7 '' southwest off the center of th e faint (B approximate to 17.7) dwarf irregular HS 0948+2018. Accordin g to sharp HII region type [O III], [N II], [S II] lines and sharp B a imer line components, the radial velocity of the parent galaxy is 3750 km s(-1). This yields a brightness on April 11, 1996 of M-B = -19.1 ( for H-0 = 65 km s(-1) Mpc(-1)) and of M-B = -17.6 on March 2, 1997. Wi th its high luminosity and slow fading SN 1997ab is similar to SN 1988 Z and SN 1987F. SN 1997ab can be expected to be observable for several years.