Large Data and the Amateur Astronomer

From Brooklyn Technical High School Physics Major, Nicholas Vasilescu via Tom Evangelist

The stars and the universe have long captured our attention – as amateur astronomy is, and has been, a popular hobby throughout the world. One of the most fun parts of Astronomy class in high school is going out at night with classmates and using telescopes to observe stars in our galaxy and the planets in our solar system. For a few thousand dollars one who is passionate about Astronomy can purchase high end gear, including telescopes, and work on scoping out the stars and planets. In recent decades, amateur astronomers have helped scientists hunt previously unidentified objects in our galaxy and universe as they have access to some of the most powerful telescopes on satellites launched by NASA and the European Space Agency. In addition to hunting in the sky with their own telescope equipment, amateur astronomers can use their computers to access incredibly large data from these massive telescopes that are in space.  

NASA’s TESS – Transiting Exoplanet Survey Satellite The fully integrated Transiting Exoplanet Survey Satellite (TESS), which will find thousands of new planets orbiting other stars.

This can all be accomplished with data from the Transiting Exoplanet Surveying Satellite (TESS), a collaboration between the Massachusetts Institute of Technology (MIT) and the National Aeronautics and Space Administration (NASA). Launched by NASA in April of 2018, TESS was designed to search for exoplanets (planets outside our solar system) by mapping 26 observation sectors of the sky. Specifically, the satellite made two 13.7 day orbits around each sector, during which cameras took images every two seconds. In order to make this process more efficient, TESS first mapped all the sectors in the southern sky, which comprised 13 of the 26 sectors, by July 2019. TESS then spent the next year mapping the northern sky. On July 4, 2020, TESS completed all 26 sectors of the sky. According to NASA’s website, after more than two years of surveying the sky, TESS discovered 66 new exoplanets and approximately 2,100 exoplanet candidates.

NASA made data from all 26 sectors public on the Mikulski Archive for Space Telescopes (MAST), an astronomical data archive funded by NASA that contains data from missions, such as Hubble and Kepler. MAST is easily accessed on the internet here. Besides this, the Quick Look Pipeline (QLP) team has released more than 9 million data files of light curves, many from possible exoplanet candidates. These internet resources, which are available to the public, can be useful to anyone who is passionate about astronomy and wants to learn about the latest discoveries. For example, coders can create programs that go through TESS data to find possible exoplanet candidates via instances where the light curves go down periodically.

Now, TESS is on an extended mission through the fall of 2022 in which a new set of target stars will be selected in order to cover regions closer to the ecliptic. Regardless of what TESS is able to do during this extended mission, TESS is a big improvement from its predecessor, the Kepler Space Telescope, which was launched back in 2009 and was retired shortly after TESS began its mission in 2018. Unlike Kepler, TESS has been able to observe and discover exoplanets in a large portion of the sky. Specifically, Kepler focused on a narrow portion of the sky between the constellations Vega and Cygnus, while TESS focused on the entire sky. Also, TESS has been finding exoplanet candidates at a faster rate than Kepler has ever had. In just over three years TESS has found more than 2,600 candidates and 177 confirmed exoplanets, while Kepler spent about a decade finding just over 5,000 candidates and 2,662 confirmed exoplanets. Even though the actual exoplanet discoveries for TESS might seem low, researchers at MIT and NASA are working around the clock to confirm whether candidates are actually exoplanets or not.

TESS and other astronomical data on the internet has become so hot that there are many open source/free programs that allow researchers and amateurs to research through large data. For example, one of these tools is Astropy, a Python library that was designed specifically for astronomical data. Astropy is built for astrophysics researchers to use computers to create programs to look through large astronomical data. Astroquery is another Python astronomy package that allows anyone to create programs that automatically retrieve information online from MAST and also Set of Identifications, Measurements and Bibliography for Astronomical Data (SIMBAD), which is similar to MAST and is maintained by a European space exploration agency at the Centre de données astronomiques de Strasbourg (CDS), France. With some knowledge of Python and access to tools like Astropy and Astroquery, anyone can search through massive amounts of astronomical data (made available for free) on the MAST and SIMBAD websites.  

So, for today’s amateur astronomers, the toolkit isn’t only $2,000 in telescopes and related equipment. Rather, anyone interested in researching the stars can do it at home with a good computer connected to the internet and a willingness to learn programming languages like Python and use Python libraries like Astropy and Astroquery.