Monday, June 27, 2011

Research (What I'm doing)

My research consists of looking at M dwarf stars (M being a type of star called a spectral type and dwarf is just the classification of a star that is still fusing hydrogen in its core. These are generally stars in the middle of their life cycle.  Here's a good picture of the main sequence:
At the bottom there are different letters representing different spectral types of stars. The bottom axes has units of temperature running from cold on the right to hot on the left and the left hand axes has units of luminosity running from least luminous on bottom to most luminous on top. So these stars are very cool dim stars and thus hard to detect. They're also very low mass stars.
I'm looking at the spectra (which is a graph of wavelength vs. flux). Spectra are good for classifying stars because spectral features show up nicely; spectral features are essentially just things that show up in your graphs because of elements absorbing or emitting light at different wavelengths.
The first part of this process is finding the stars in the Sloan Data Release 7 Catalog (courtesy of West et al 2011) that lie within the coordinates of the Palomar Transient Factory Field (PTF Field). This is important because with both Sloan and the PTF we have double the data about each of these stars (which should reduce uncertainties and make our data more significant, etc). Stars within an RA of 10.2396 and 13.7604 in decimal degrees and a Dec of 1.15 and -1.15 decimal degrees. Anyway, I'm looking at these stars and measuring certain properties of them like radial velocities (velocity away from the sun) and hydrogen alpha emission which tells us whether the m-dwarf is active or not.

I'll put some pictures in my next post.

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