Post on 22-Aug-2020
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Explore the Universe:A Further Look Into Imaging Exoplanet Transits
Elizabeth Duongeduong1@umd.eduBiological Sciences
Introduction
Imaging
ConclusionsObservation Prep
Findings
We would like to acknowledge UMD Observatory Director, Elizabeth Warner, Dr. Alan Peel, and the SDU Scholars Program
The Explore the Universe Capstone features a partnership with the UMD
Observatory to observe exoplanet transits. After imaging the transits, we then process and calibrate the images
to analyze the transit data.Exoplanets are planets outside our solar system. A transit is when an
object within a star’s orbit blocks our view of the star, causing a decrease in detected brightness from the star. This
dip in brightness is useful in understanding information about the
exoplanet itself.
In order to actually find our stars we are suppose to observe, we need to
sync onto nearby stars and use coordinates for the star, but often still need manual adjustments to find our
stars. Once we find the star we are observing, we set up the telescope to track an easily visible star so that the telescope stays with the star as the
Earth rotates. Now that tracking is on, we can have the telescope take
hundreds of images until the transit ends. Before we are done for the
night, we need to take darks, biases, and flats, which are images that help
with calibrating our camera to remove background noise and hot/cold pixels.
Before we can observe we have to check with the Exoplanet Transit
Database (ETD) to know when and where transits are occurring during the night. Transits can be anywhere
from half an hour to 6 or 7 hours long. Along with the times and the location
in the sky of the transit, ETD also gives us an image of the sky chart,
allowing us to find the star by noticing patterns in nearby stars. With all the information form ETD, we can
begin observing.
The goal of this research project wasto be able to display a light curve of an exoplanet transit. However, in the
process, we learned different astronomical tools such as using a telescope, calibrating images, data
processing, and utilizing differential photometry skills through new and
various software. This was meaningful to us because it provided
a hands on experience with work that would never be available
outside of the field of astronomy.
Once we have our images, we employ the software AstroImageJ (AIJ). This processing software allows for us to combine our calibration frames into master images for each, which help
cancel out various noise in the “science” images. By comparing the
brightness of our target to itself and nearby stars as the software cycles
through our transit images, it creates a graph showing the brightness of
our target as time passes, resulting in a light curve highlighting the exoplanet passing by the star.
Ethan Kramerethankrm@gmail.comAerospace Engineering
Science, Discovery, and the Universe
Ethan and Elizabeth at the observatory with the 7” AP Refractor telescope (Dec 4, 2018)
A screenshot of the Exoplanet Transit Database and its related information
The graph of the recorded light curve ofexoplanet XO-2B transit, including reference stars
A screenshot of the software AstroImageJ while processing transit recorded data