Sorting Out the Candidates

July 2, 2014

At this point, I have created rgb images for all the objects I want to check out in the field of view of interest. There were hundreds of objects, but that is why computer programming exists. So that they do all the hard work. Unfortunately, there are some things that machines aren’t that good at. So, as a human, my job is to look at these images and identify candidates. Brown dwarfs are dim in the visible and shiny in the infrared. So, my job is to look for dots that are like that. Take this picture, for example:

J193057.83-230909.0

The bottom left one is from DSS Red, which was taken the earliest, around 1990 or so, the top left one is from 2MASS, which was taken around 2000, and the right ones are from WISE, taken around 2010. The top and bottom left only differ on how the colors are scaled in terms of brightness. The top left one is linear stretch, and the bottom left one is logarithmic stretch. As you can see, logarithmic stretch is very helpful because  with linear, the star on top is so bright that the other dots are comparatively almost nothing. With logarithmic stretch though, a star 10 times as bright can be treated as if it were only twice as bright, and 100 times as bright as if it were only three times as bright. This allows dim objects to pop out.

This one is of interest because you can observe proper motion here. Each one were taken around a decade apart, and as you can see, the dots have moved slightly. It suggests of an object relatively close. As to whether it is a brown dwarf, I am not sure, but I am keeping tabs on it just in case. It is something I am gonna have to discuss with the professor.

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The Point of My Research

June 2, 2014

I talked with my prof and got further information on what the point of the project is. It has to do with the Kepler space telescope. If you haven’t heard, two of its four wheels, which are used to point the telescope to a location, are broken, and so the telescope can’t maintain its sight to a position in the sky. Not only is there the fact that it is rotating around the Earth, the light from the sun has momentum. The light will push the telescope, and the irregularity of the telescope’s shape causes it to torque. The only way for the telescope to not be perturbed is to lie perpendicular to the sun. Unfortunately, that means that it can only observe in the plane of ecliptic, and it can’t maintain the same field of view throughout the year as the telescope has to maintain perpendicularity to the sun as the Earth orbits the sun. Nevertheless, useful science can be done. The telescope will observe certain fields of view, and when time is up, it will rotate again to another field of view that will maintain perpendicularity.

The point where my research comes in has to do with the way the above procedure means that the antenna is not facing the Earth properly. That means in order for them to continually observe an area in space, they will have to keep the information in the hard drive, and then send it back to Earth once the observation period is over. That means they have a limited amount of data they can store, and so the mission will have to be picky in which data they store. Looking for brown dwarfs to observe is supposed to help out Kepler in keeping . There are areas where not much brown dwarfs discovered, so what I am doing is helping that process out.

For now, I am just installing the astropy library for Python language. l will be looking at some picture of brown dwarfs, download them, and hopefully astropy can take those pictures and present them to me.

Source

http://keplerscience.arc.nasa.gov/K2/MissionConcept.shtml