Monday, July 6, 2015

High Precision Photometry of Transiting Exoplanets as I currently know it : Part V

Methodology

 

As stated in Part I, the primary goal of my research is to obtain high precision photometry using MINERVA and the defocusing technique.  Before elucidating on those essential concepts of my research, I will discuss a few fundamentals about what photometry is in the first place.

Differential Photometry 

A professor at Rochester Institute of Technology did a great job of explaining what Differential Photometry is and why it is such a great strategy for astronomers to use.  I will summarize significant concepts elaborated on this long web page and subsequently put it in context of my project specifically.

In my own words, Differential Photometry is the study of how one object's varying brightness (flux) compares to other objects and what physical mechanisms are the cause for such variability.  Although an astronomer may only want to observe and analyze one variable star in particular, it can be extremely helpful to account for how another star, which has a flux that stays constant over time, is behaving.  This other star that is not of interest is called a comparison star.  A proper comparison star is a star that will not vary in brightness throughout the duration of the observation.  The primary benefit for utilizing comparison stars even when one star is of interest is to see how the Earth's atmosphere is affecting the telescopes measurements.  If the comparison star is not variable, then any variability measured by the telescope's camera is most likely due to nuisances such as a atmospheric "seeing", changing air mass, a thin, small cloud, etc.  This does not apply to space-based telescopes.

I will show the RIT professor's example at a later time.

No comments:

Post a Comment