Table of Contents
This is not necessarily a reproducible experiment, as the data collected and operation were done using the Trottier Observatory at Simon Fraser University which is available only by special permission. The original data has since been lost to time. The data input takes the form of Flexible Image Transport System (FITS) files specific to the hardware and collection method at the Trottier Observatory.
This project uses sky calibration and aperture photometry methods to measure the periodic magnitude fluctuation (known as a light curve) of a cepheid variable star, RR Leo, in the class of RR Lyrae stars. With the star's light curve measured out, one can then calculate for parameters of interest, such as brightness fluctuation period, peak brightness, and distance to name a few. An RR Lyrae star was chosen due to its relatively rapid periodicity, allowing an overnight observation to wholly describe the fluctuations.
The Charge-Coupled Device (CCD) image sensor is used by most modern telescopes, especially for optical and ultraviolet observations. CCDs use the photoelectric effect to convert incoming photons into electronic information in the metric of Analog-To-Digital units (ADU).
The CCD however has systematic reading biases that must be accounted for. These sources are dark currents, offset bias, sky brightness, pixel-to-pixel variations in sensitivity (Flat Field corrections), quantum efficiency, atmospheric absorption and dust. The purpose of the code in Observation.py is to correct these.
The "calibrated science frame"
where
These "Master" data sets are obtained by Sigma-Clipping multiple exposures onto each other to account for randome noise fluctuations.
Behzad Safarian Kashani - LinkedIn - bsafariak@gmail.com
Project Link: https://github.com/bsafaria/Photometry-RR-Lyrae
I would like to thank Dr. Joanna Woo from Simon Fraser University, the Director of the Trottier Observatory in April 2021, for approving the overnight observation and operation.