A study of RW Ursae Minoris shell

Abstract

We find an expansion parallax for the slow nova RW UMi (Nova Ursae Minoris 1956). A narrow-band H-alpha image shows that the diameter of the nova shell in 1995 was 2.94(+0.37)(-0.49) arcsec. We derive a distance of 5250(+590)(-1050) pc, and an absolute magnitude at maximum of M-v = -7.7(+0.3)(-0.4) which are consistent with previous estimates for the nova. We also revised known relations between various parameters of nova systems.