Harvard University

Astronomy Lab and Clay Telescope


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Eclisping Binary

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The goal of this lab is to extract information about the masses, radii and the separation between the members of the double-lined spectroscopic binary NSVS01031772 using both the radial velocity (RV) data provided and the light curve data you will collect using the Clay Telescope atop the Science Center over the next few weeks.

This system is a low-mass binary system. Owing to their low surface brightness, such systems are quite difficult to detect even though they should be numerous. Indeed there is little accurate observational data currently available to constrain the mass-radius relationship for stars less massive that 0.6M, even though these are by far the most numerous stars in the Galaxy! The stellar mass-radius relationship is very important for constraining evolutionary models (e.g. to understand the energy generation rate and therefore the lifetime of the main sequence stars), and is also crucial to infer the masses and radii of planets found to orbit these stars. This means that the data you will collect in this lab are of significant scientific interest!

Here is the original paper which you should read and reference for more information about the system. Your writeup should be 5-8 pages, single spaced, 12pt font, including figures, and should be structured as follows:


State the objective of this lab and its scientific relevance.


Outline the steps you follow to estimate the masses, radii and separation between the stars, explaining:



You can do a quick look light curve as the data is coming in and your TF will guide you through this in lab, but for the real analysis we want to do things properly. We will need to flat field our images and make a lightcurve in Excel or your other favorite plotting tool. Eventually, you will be given an Excel template with all the data to do your final analysis.