So yesterday I talked a lot about #JWST, but that's not actually what I work on the most right now! Until we get JWST data I'm over in #Spitzer land, a previous #NASA space telescope that is unfortunately no longer operational.
Even though it's not actively collecting data, there is still so much #science we can do with what exists! ðŸ”
I have a grant from NASA to uniformly reanalyze ALL of the Spitzer #exoplanet phase curve data:
So what's a phase curve and why do we care?
Well first we need to talk a little bit about this really weird type of exoplanet called a Hot Jupiter.
In our Solar System we have a relatively well ordered set of planets. There are 4 rocky planets closer to the Sun and 4 gaseous planets further from the Sun. For a long time we expected all planetary systems to look like this too!
But as it typically goes with science, once we started finding planets around other stars it turned out that many of them are nothing like we expected
The very first exoplanets we found were about the size of Jupiter and REALLY REALLY REALLY close to their stars!
Mercury is the closest planet to the Sun and it orbits in about 88 days. But some of these new exoplanets we were finding orbit their stars in *only a few days* 🔥
The temperature of a planet generally scales with the distance it is from the star (with a few exceptions I won't get into here).
Think about it like standing next to a bonfire, the closer you are the more heat you'll feel.
So these Jupiter sized planets weren't only really close to their star, they were REALLY REALLY hot!
I'm talking more than 1000 degrees Celsius! Meanwhile the dayside temperature of Mercury is *only* about 450 degrees Celsius
This completely changed our view of how and where planets of that size can form and exist!
One particularly interesting result of being this close to the star is that the planet is "locked" to the star due to tides. This is the same reason why we always see the same side of the moon!
So not only is the planet getting absolutely *blasted* with heat, it's only getting blasted on one side of it.
This led to lots of new questions about how atmospheres in these extreme conditions move heat around
Conveniently, the fact that these planets are so close to their star and so hot makes them easier for us to study to answer our questions!
First of all, it doesn't take so long for the planet to orbit the star, so it's reasonable to point a telescope at it for the entire length of the orbit.
Second of all, it's really hot, which means it's brighter! A brighter planet means it's easier to detect.
Enter the now inoperable #Spitzer space telescope!
Erin M. May, PhD
Seth Is Podcasting 🌻