Determine the membership of four SX Phoenicis candidates

Determine whether KT-29, V104, V111, and V112 are members of the globular cluster M22, despite their classification as non-members by R17, by obtaining evidence beyond their consistency with the SX Phoenicis period-luminosity relation.

Background

KT-29, V104, V111, and V112 are classified as non-members in the R17 catalogue, but their positions relative to the SX Phoenicis period-luminosity relation are compatible with cluster membership. The paper consequently leaves their membership unresolved; the period-luminosity relation alone does not establish membership, so additional observational or astrometric evidence is required.

References

Although classified as non-members by R17, they could be members according to the period-luminosity relation of SX Phe stars.

— A Homogenized Catalogue of Variable Stars in the Globular Cluster M22: Membership, Physical Parameters, and Distance  (2609.11850 - Yepez et al., 10 Sep 2026) in Appendix, Section “Comments about individual stars,” subsection “SX Phe stars”