1995/04/11 by Shashi M. Kanbur, S. M. Kanbur, Kanbur, Shashi M. +2
Chemistry · Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Molecular spectroscopy and chirality #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9504033
Plain Latex version 3.141, 25 pages including figures and tables. (Requires style file laa.sty) Astronomy and Astrophysics in press
arxiv created 1995/04/11 · openalex publication_date 1995/04/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper, we derive a physical argument for the existence of Period-luminosity and period-luminosity-colour relations at maximum light. We examine in detail a sample of Cepheids in the Large Magellanic Cloud, and compare the variance of some PL and PLC type distance indicators based on mean and maximum light. We show that a PLC relation based on maximum light leads to a distance estimator with a dispersion about 10 % smaller than its counterpart using mean light. We also show that a PLC type relation constructed using observations at both maximum and mean light has a significantly ( > 50 %) smaller dispersion than a PLC relation using either maximum or mean light alone. A comparable ( > 30 %) reduction in the dispersion of the corresponding distance estimator, however, in this case requires the relation be applied to a large ( n > 30) group of equidistant Cepheids in, e.g., a distant galaxy. Recent HST observations of IC4182, M81 and M100 already provide suitable candidate data sets for this relation.