The Exoplanet App. Also... the floodgates lift

Thus begins my backlog of posts, all of which have been in the “almost done” stage of being for varying amounts of time (2 weeks-today).

First, I wanted to draw everyone’s attention to this cool Iphone app that Professor Johnson showed me! It’s called “Exoplanet,” Hanno Rein, and it is basically a visual catalog of exoplanets! You can zoom in on systems, see the orbit, see light curves and other cool stuff! There were a few systems that I have found that are particularly cool:

HD 98649 – Gas giant, 7 Jupiter masses, orbital period of 10400 days (which is around 30 years!)

This planet is so big it makes the sun move! It is worth looking at on the Exoplanet app because not only are its light curves interestingly-shaped, but the animation shows the sun moving! Both planet and sun are orbiting around their mutual center of mass. The eccentricity of this sun’s sole planet is 0.860 (a highly elliptical orbit). It is surprising that not all parameters for this system are posted - maybe the system is so new that no papers have been published on it yet? I want to study this system, but its HUGE period probably makes it impractical to study.

HD 20794 system: b, c and d – each around 2-4 Earth masses, orbital periods of 18, 40, and 90 days, respectively.

This system exists unfortunately right inside the habitable zone of their star. The star is 0.7 times the mass of our sun, and the orbits are nearly circular. I love systems with many planets – three may not be “many,” but it’s more than usual for sure!

PSR 1257 12 b – 0.02 Earth masses, orbital period of 25 days.

How is this possible? How can a planet be so tiny? This seems more like an asteroid than a planet… it is roughly ten times smaller than Mercury. Other planets in this system are 3 and 4 times earth mass, but all the planets orbit too close to be in the habitable zone.

Honestly, there is no limit to cool systems. Each one has something new and interesting – “how is a planet that big orbiting so fast?” – “how did such a skewed system form?” – “why hasn’t that planet collapsed into the sun?”. This app is a good diving board for new research projects!