Poster Presentation

Preliminary Multi-bands Light Curves of Classical Cepheids from Pan-STARRS1 3π data using PSPS

I-Ling, Lin, Chow-Choong, Ngeow, Ying-Tung Chen, Jhen-Kuei, Guo, Chien-Cheng Lin (IANCU)

Cepheids are useful standard candles that can be used to determine the distances to nearby galaxies. Properties of Cepheids are well investigated in BVI filters; however they are not well studied in grizy filters. Therefore, the main goal of our project is to characterize the known Galactic Cepheids and to derive their mean magnitudes in Pan-STARRS1 (PS1, the Panoramic Survey Telescope and Rapid Response System) grizy photometry system. This will allow us to calibrate the Cepheids’ period-luminosity relations in PS1 system. PS1 is a multi-bands and multi-epoch survey project by using a dedicated 1.8 meter wide field telescope (located at Mount Haleakela, Mauna Kea, Hawaii). Observed data are reduced and analysed by IPP (Image Processing Pipeline) team located in University of Hawaii. There are multiple ways to retrieve the PS1 data, one of them being the Published Science Products Subsystem (PSPS) via Pan-STARRS Science Interface (PSI) – a web interface to allow user to access PS1 data. In this work, we downloaded PS1 3π data through PSI. We adapted a differential photometry method in our analysis to deal with possible calibration issue in PS1 3π data. Using this method, we can obtain relative light curves of Cepheids by removing systematic effects. Preliminary light curves for several Cepheids based on the differential photometry method are presented here.