Reeling in the Whirlpool: the distance to M 51 clarified by Cepheids and the Type IIP SN 2005cs

Understand

Despite being one of the best-known galaxies, the distance to the Whirlpool Galaxy, M 51, is still debated.

• Current estimates range from 6.02 to 9.09 Mpc, and different methods yield discrepant results.
• No Cepheid distance has been published for M 51 to date.
• We aim to estimate a more reliable distance to M 51 through two independent methods: Cepheid variables and their period-luminosity relation, and an augmented version of the expanding photosphere method (EPM) on the Type IIP SN 2005cs.