SIMBAD references

It has been argued in the recent literature that the horizontal-branch (HB) evolutionary tracks of Castellani, Chieffi, & Pulone (1991, ApJS 76, 911) are superior to those of Lee & Demarque (1990, ApJS 73, 709) in accounting for the properties of RR Lyrae variables in Galactic globular clusters (GGCs). In the present study, we show that the conclusions reached by Catelan & de Freitas Pacheco (1993, AJ 106, 1858) on the role played by age as a second parameter affecting the HB morphologies of the GGCs NGC 288 and NGC 362, originally based upon the analysis of the latter tracks, are confirmed when the Castellani et al. set is employed instead. More specifically, we confirm that an age difference between these clusters as small as ≃2-3Gyr can only be consistent with HB models if additional parameters are varying between them, and/or both clusters are younger than ≃10Gyr, and/or stellar evolution at the core He-burning phase is not properly understood.