Anomalies in the Kepler Asteroseismic Legacy Project Data A re-analysis of 16 Cyg A & B, KIC 8379927 and 6 solar-like stars

Astronomy Unit, Queen Mary University of London, Mile End Road, London E1 4NS, UK
e-mail: i.w.roxburgh@qmul.ac.uk

Received: 27 April 2017
Accepted: 4 July 2017

Abstract

I compare values of the frequencies, separation ratios, errors and covariance matrices from a new analysis of 9 solar-like stars with the Legacy project values reported by Lund et al and, for 16Cyg A&B and KIC 8379927, with values derived by Davies et al. There is good agreement between my results and Davies’s for these 3 stars, but no such agreement with the Legacy project results. My frequencies differ from the Legacy values, there are inconsistencies in the Legacy frequency covariance matrices which are not positive definite, and the Legacy errors on separation ratios are up to 40 times larger than mine and the values and upper limits derived from the Legacy frequency covariances. There are similar anomalies for 6 other solar-like stars: frequencies and separation ratio errors disagree and 2 have non positive definite covariance matrices. There are inconsistencies in the covariance matrices of 27 the 66 stars in the full Legacy set and problems with the ratio errors for the vast majority of these stars.