On the Incidence Rate of Blazhko Stars

TL;DR

This paper investigates the high incidence rate of Blazhko modulation in RR Lyrae stars using Kepler K2 data, confirming nearly universal occurrence after bias correction and emphasizing the need for comprehensive time series analysis.

Contribution

The study extends previous analysis to additional Kepler campaigns, reaffirming the near 100% incidence rate of Blazhko stars after bias correction.

Findings

Incidence rate of Blazhko stars is approximately 90-100%.

Full time series modeling is crucial for detecting shallow signals.

Results are consistent across multiple Kepler campaigns.

Abstract

In a recent paper (Kovacs 2018) we examined the incidence rate of the modulated RR Lyrae stars by using the data from Campaigns 01 - 04 of the Kepler K2 mission. We found an observed rate of ~90%, implying near 100% underlying rate, after correcting for detection bias due to observational noise. In this work we extend the sample to Campaign 08 and check the reliability of our earlier estimate. We get the same high rate, stressing the importance of full time series modelling (including systematics) in searching for shallow signals in the presence of large amplitude variabilities.