Distance to the Active Galaxy NGC 6951 via the type Ia Supernova 2000E^*

¹ Department of Optics & Quantum Electronics, University of Szeged, POB 406, Szeged 6701, Hungary
² Visiting Astronomer, German-Spanish Astronomical Centre, Calar Alto, Spain
³ Konkoly Observatory of the Hungarian Academy of Sciences, POB 67, Budapest 1525, Hungary
⁴ Department of Experimental Physics, University of Szeged, Dóm tér 9, Szeged 6720, Hungary
⁵ Guest Observer, Piszkéstető Station, Konkoly Observatory, Hungary
⁶ Department of Physical Geography, ELTE University, Ludovika tér 2, Budapest 1088, Hungary
⁷ Baja Observatory, POB 766, Baja 6500, Hungary

Corresponding author: J. Vinkó, vinko@physx.u-szeged.hu

Received: 11 October 2000
Accepted: 9 April 2001

Abstract

CCD-photometry and low-resolution spectroscopy of the bright supernova SN 2000E in NGC 6951 are presented. Both the light curve extending up to 150 days past maximum and the spectra obtained at 1 month past maximum confirm that SN 2000E is of type Ia. The reddening of SN 2000E is determined as , its error is mainly due to uncertainties in the predicted SN colour at late epochs. The light curves are analyzed with the Multi-Colour Light Curve Shape (MLCS) method. The shape of the late light curve suggests that SN 2000E was overluminous by about 0.5 mag at maximum comparing with a fiducial SN Ia. This results in an updated distance of Mpc of NGC 6951 (corrected for interstellar absorption). The SN-based distance modulus is larger by about +0.7 mag than the previous Tully-Fisher estimates. However, possible systematic errors due to ambiguities in the reddening determination and estimates of the maximum luminosity of SN 2000E may plague the present distance measurement.