The Distance Measurement of NGC 1313 With Cepheids

TL;DR

This paper measures the distance to galaxy NGC 1313 using Cepheid variable stars observed with Hubble, providing a precise distance estimate consistent with previous studies and indicating low reddening.

Contribution

First detection and analysis of Cepheids in NGC 1313 using Hubble data, deriving a new accurate distance measurement with detailed photometry and period-luminosity relations.

Findings

Distance to NGC 1313 is 4.61 Mpc with small uncertainties.

Identified 26 Cepheids with periods between 3 and 14 days.

Reddening to NGC 1313 is minimal.

Abstract

We present the detection of Cepheids in the barred spiral galaxy NGC 1313, using the Wide Field and Planetary Camera 2 on the Hubble Space Telescpoe. Twenty B (F450W) and V (F555W) epochs of observations spanning over three weeks were obtained, on which the profile-fitting photometry of all stars in the monitored field was performed using the package HSTphot. A sample of 26 variable stars have been identified to be Cepheids, with periods between 3 and 14 days. Based on the derived period-luminosity relations in B and V bands, we obtain an extinction-corrected distance modulus of mu = 28.32 +- 0.08 (random) +- 0.06 (systematic), employing the Large Magellanic Cloud as the distance zero point calibrator. The above moduli correspond to a distance of 4.61 +- 0.17 (random) +- 0.13 (systematic) Mpc, consistent with previous measurements reported in the literature with uncertainties. In addition, the reddening to NGC 1313 is found to be small.