This January, I am researching a binary star system. A binary star is two stars orbiting each other. To the right is an artists rendition of what they look like. Often, a more massive star, in this case the blue star, will draw matter from the other star. My professor and I are currently studying a binary star system that goes by the name Algol, or Beta-Perseus. It is called Beta-Perseus because it is the second brightest star in the Perseus constellation. It has been observed for a long time that Algol varies in brightness. The ancient Persians named it Algol, which means 'The Demon Star', because of that fact. I plan to gather data about Algol's magnitude (brightness) at different points in its approximately three day period, the mass of the binary system, the chemical composition of the stars, their temperatures, and more. Once that is determined, time permitting, I will compare this to other data on binary stars.
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| Image of Algol taken by my professor and I in September. |
There are two types of images that my professor and I took over the fall semester: photometry and spectroscopy. These photos had to be taken over three months to provide a conclusive light curve, more on that later. I been spending the past few days calibrating the images and extracting magnitude data. Images are calibrated with flat images and dark frames. Flat images are taken once a season usually and are done by taking pictures of a white surface and averaging several of these and subtracting the dark images. Dark images are pictures taken with the camera's shutter closed. These are taken every night for every group of pictures you take. These images are averaged to create a master dark. You subtract this from each image and divide the flat frames. This removes the "noise" in the image, providing a cleaner image that gives more accurate data.
After a couple of days of calibrating images, I moved on to extracting magnitude data from images. This is even more tedious than calibrating the over 150 images I have. Once I get all the magnitude data, I will determine what point in the period each picture is and create a light curve. This will show us the difference in magnitude when the stars eclipse each other. That is going to be my main focus for tomorrow. There's a long road ahead of me, here's to hoping for results.
Jake,
ReplyDeleteI am excited to see a Physicist in the group of Biologists. I am just going to ask you how difficult is it to perform this experiment because unlike ours experiment which depends on lab chemicals, your experiment also depend on the environment, the clouds and other weather factors. Are these factors causing problems in your experiment and if yes how do you deal with them?
There are always factors that cause problems in astronomy. If it is something to do with weather, such as extreme cold or cloudiness, we don't take images that night. Every night, we take dark frames, which are pictures which the shutter closed, and subtract those from the image to remove any extra "noise" the atmosphere might be giving us. We also divide the flat frames created earlier in the season to further reduce the "noise".
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