Large Magellanic Cloud Cepheids in the ASAS data

TL;DR

This paper presents a catalog of 65 LMC Cepheids from the ASAS data, analyzing their period-luminosity relation, period variations, and comparing observations with stellar evolution models.

Contribution

It provides the first extensive catalog of LMC Cepheids from ASAS, extending the period-luminosity relation analysis to longer periods and comparing period variations with models.

Findings

PL relation in V-band agrees with OGLE for periods <40 days

Evidence for a shallower PL relation for periods >40 days

Limited number of Cepheids show significant long-term period variations

Abstract

A catalog of Cepheids in the Large Magellanic Cloud (LMC) from the ASAS project is presented. It contains data on 65 fundamental mode pulsators with periods longer than about 8 days. The period-luminosity (PL) relation in the V-band does not significantly differ from the relation determined by Soszynski et al. (2008) from the OGLE data extended toward longer periods but with much larger spread. For objects with periods longer than 40 days there is an evidence for a shallower PL relation. The rates of long-term period variations significant at 3 sigma level are found only for 7 objects. The rates for 25 objects determined with the 1 sigma significance are confronted with the values derived from stellar evolution models. The models from various sources yield discrepant predictions. Over the whole data range, a good agreement with measurements is found for certain models but not from the same source.