RR Lyrae in NGC 6101

We identify one new variable, which is either a potential long-period red giant variable or eclipsing binary, and recover all previously identified RR Lyraes. One previously studied RR Lyrae is reclassified as an RRc type, while two period estimations have been significantly refined.

We confirm that NGC 6101 is Oosterhoff type II with a high ratio of n(c)/n(ab+c)=0.833 with a very long mean RRab period of 0.86d. By using theoretical RR Lyrae period-luminosity-metallicity relations, we use our V- and I-band RR Lyrae data to gain an independent estimate of the reddening towards this cluster of E(B-V)=0.15+/-.04 and derive a distance of 12.8+/-0.8kpc. The majority of the work in this study was undertaken by upper secondary school students involved in the Space to Grow astronomy education project in Australia.