Investigating exoplanet databases

Let's look at several of the big databases you can find on-line.

• NASA Exoplanet archive
• Extrasolar planets encyclopedia
• Exoplanets.org site

Each site has a big database of information, plus tools which can allow you to make lists and tables, or graphs and pictures.

Can you do the following? Which site(s) are best for answering each question?

1. Make a graph showing the locations of exoplanets in the sky,
   1. using RA/Dec coordinates; see
   2. using galactic coordinates see
   3. using ecliptic coordinates; see

   Can you draw any conclusions from the locations? Perhaps the graph of discoveries in ecliptic coordinates should give you a clue about the new mode of operation for Kepler K2.

   Bonus! Can you make a graph using the Hammer-Aitoff projection, like this one?

2. What type of stars do these exoplanets orbit? Does the method of discovery favor some types over others?
   1. Choose only stars which were discovered by the transit technique. Make a histogram of the stellar spectral type for these stars.
   2. Choose only stars which were discovered by the radial velocity technique. Make a histogram of the stellar spectral type for these stars.
   3. Is there a difference between these two sets of host stars?
   4. Just what does the "spectral type" in these tables mean?
3. Consider the parallax measurements for each exoplanet's host star.
   1. What fraction of host stars do NOT have a good measurement of parallax?
   2. Split up the exoplanets into those discovered before 2009 and after 2009. Is the fraction with parallax measurements the same? Explain.
4. Has anyone written a Master's or Ph.D. thesis on the topic of moons around exoplanets?
5. When and where should you go to find meetings about exoplanet atmospheres?
6. You really want to visit Iceland. Can you find a good excuse to spend your advisor's grant money?
7. Believe it or not, it's going to be clear tonight! You decide to observe an exoplanet transit.
   1. Will any transits by known exoplanets take place tonight, as seen from Tokyo?
   2. How many (if any) will provide a full transit, from start to finish, at airmass less than 2.0 and visible while the Sun is below the horizon?

   Bonus! Your friend at NAOJ helps you to use the small telescope at the Mitaka campus. How big is this telescope? Which transit(s) could it detect?

8. You receive an E-mail from your eccentric uncle. "Hey," it reads, "I've been looking at this star, and I think it may have a planet passing in front of it. Could you check it, please? The first column is time in days, and the second column is counts."

   Attached to the E-mail is an ASCII text file with numbers.

   1. Make a plot showing flux as a function of time.
   2. Does this star show transits? If so, what is the period?

   Bonus! Make a phased light curve.

For more information

• Looking for a paper in the technical literature?
  • The Astrophysics Data Service can help you to search.
  • The advanced search form in arXiv is another good place to look.

Copyright © Michael Richmond. This work is licensed under a Creative Commons License.