Friday 31 January 2025
A team of astronomers has created a new set of templates for understanding the light curves of RR Lyrae stars, which are crucial for studying the properties of these ancient stars and the universe as a whole.
RR Lyrae stars are a type of variable star that pulsates in brightness due to changes in their internal structure. By analyzing the patterns of these pulsations, scientists can learn about the mass, size, and composition of these stars, as well as the distances to nearby galaxies and even the expansion rate of the universe.
Previous studies have used templates for RR Lyrae light curves based on data from the Sloan Digital Sky Survey (SDSS), but these templates only covered five specific bands of light: u, g, r, i, and z. However, new telescopes like the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will soon be collecting data in a sixth band, y.
To prepare for this shift, researchers constructed new templates for RR Lyrae light curves in the y-band using data from the SDSS, archival observations from the Pan-STARRS1 survey, and new observations made with the Lulin One-meter Telescope (LOT). They analyzed over 250 RR Lyrae stars to create a set of nine unique template light curves for RRab stars (the most common type of RR Lyrae) and three for RRc stars.
The team used a combination of automated data processing and visual inspections to select the best-fit templates from the collected data. They also developed new software tools to analyze the light curves and identify patterns that could be used to improve the accuracy of their results.
The resulting y-band templates will be useful for scientists studying RR Lyrae stars in the early years of LSST, when the telescope’s data will be less dense than usual. By comparing these new templates to actual observations, researchers can better understand the properties of these ancient stars and refine their estimates of distances to nearby galaxies.
The creation of these y-band templates is an important step towards unlocking the secrets of RR Lyrae stars and the universe they inhabit. With this new tool in hand, scientists will be able to make more accurate measurements of the expansion rate of the universe, better understand the properties of dark matter and dark energy, and gain a deeper understanding of the evolution of galaxies over billions of years.
Cite this article: “New Templates Unveil Insights into Ancient RR Lyrae Stars”, The Science Archive, 2025.
Rr Lyrae Stars, Variable Star, Light Curve, Astronomy, Template, Sloan Digital Sky Survey, Vera C. Rubin Observatory, Legacy Survey Of Space And Time, Lsst, Y-Band, Pan-Starrs1 Survey.
Reference: Chow-Choong Ngeow, Chia-Yu Cheng, “Adding RR Lyrae $y$-Band Template Light Curves to gatspy” (2024).
