The Gaia Parallax Discrepancy for the Cluster Pismis 19 and Separating δ Scutis from Cepheids
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Fecha
2025-04
Profesor/a Guía
Facultad/escuela
Idioma
en
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Editor
Institute of Physics
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Licencia CC
CC BY 4.0 Attribution 4.0 International
Licencia CC
https://creativecommons.org/licenses/by/4.0/
Resumen
Pre-Gaia distances for the open cluster Pismis 19 disagree with Gaia parallaxes. A Two Micron All Sky Survey (2MASS) JKs red clump distance was therefore established for Pismis 19 (2.90 ± 0.15 kpc), which reaffirms that zero-point corrections for Gaia are required. OGLE GD-CEP-1864 is confirmed as a member of Pismis 19 on the basis of DR3 proper motions and its 2MASS+Vista Variables in the Vía Láctea color-magnitude position near the tip of the turnoff. That 0.3 day variable star is likely a δ Scuti rather than a classical Cepheid. The case revealed a pertinent criterion to segregate those two populations in tandem with the break in the Wesenheit Leavitt Law (≃0.5 day). Just shortward of that period discontinuity are δ Scutis, whereas beyond the break lie first overtone classical Cepheids mostly observed beyond the first crossing of the instability strip. © 2025. The Author(s). Published by the American Astronomical Society.
Notas
Indexación: Scopus.
Palabras clave
Variable Star, Magellanic Clouds, Photometry
Citación
Astrophysical Journal Open Access Volume 982, Issue 21 April 2025 Article number 165
DOI
10.3847/1538-4357/adb9e4