Gravity? We’ve heard a lot about exoplanets lately. To me, one of the more fascinating classes is the “Hot Jupiter” class (of which the first exoplanet to be discovered orbiting a main sequence star- 51 Pegasi b- is considered to belong). So what makes an exoplanet a Hot Jupiter and why are they interesting?
Hot Jupiters generally:
- Have a mass that is greater than or equal to that of Jupiter
- Have high surface temperatures
- Caused by their close orbits to their stars (they average a distances in the range of 0.015-0.5 AUs from their parent stars)
- Interesting to note, there are generally low differences between the day sides and the night sides because high speed winds distribute the heat across the surface.
- Have highly circular orbits (because of tides)
- Migrated to their current position because there would not have been enough material to form in their current locations
It is this last characteristic that makes Hot Jupiters so interesting. Not only are we not entirely sure how they get their current locations, but also why aren’t they eaten by their parent star? One theory is that the planet star’s gravitational forces stabilize the orbit before this can happen.
Exoplanets are an exciting field leading us to confirm or question what we think we know about space!
Further Reading:
- Wikipedia- Hot Juptier
- Wikipedia- Planet Migration
- Space.com- Why isn’t Hot Jupiter Eaten
- Space.com- Hot Jupiter Defies Planetary Formation
- Physics.org- Astronomers Determine Atmospheric Composition of a Hot Jupiter
