A Cepheid-Based Distance to the Seyfert Galaxy NGC 6814

We present a Cepheid-based distance to the nearby Seyfert galaxy NGC\,6814 from {\it Hubble Space Telescope} observations. We obtained F555W and F814W imaging over the course of 12 visits with logarithmic time spacing in 2013 August$-$October. We detected and made photometric measurements for 16,469 unique sources across all images in both filters, from which we identify 90 excellent Cepheid candidates spanning a range of periods of $13-84$ days. We find evidence for incompleteness in the detection of candidates at periods <21 days. Based on the analysis of Cepheid candidates above the incompleteness limit, we determine a distance modulus for NGC\,6814 relative to the LMC of $\mu_{\rm rel\,LMC}=13.200^{+0.031}_{-0.031}$ mag. Adopting the recent constraint of the distance modulus to the LMC determined by Pietrzynski et al., we find $m-M=31.677^{+0.041}_{-0.041}$ which gives a distance of $21.65 \pm 0.41$ Mpc to NGC 6814.
Comment: 10 pages, 3 tables and 7 figures, accepted for publication in ApJ