Lecture 11 - Retrograde Planets Chris Suberlak and Phoebe...

Info icon This preview shows pages 1–17. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Retrograde Planets Chris Suberlak and Phoebe Upton Sanderbeck February 11, 2014
Image of page 2
“Simple models of close-in exoplanet formation involving assembly near the ice line and quiescent migration through a gaseous protoplanetary disk predict that orbits should have only negligible misalignments with the spin of the host star” (Schlaufman 2010)
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Before the first detection of an exoplanet... - 7 degree tilt of the normal of the ecliptic to solar spin axis suggested planet formation and dynamics that resulted in low obliquity. The probability that two random vectors are aligned within 7 degrees is near 0.0037! (Woolfson 2013) This did not seem like a coincidence.
Image of page 4
Why were retrograde planets an unexpected/interesting discovery? - Challenged the paradigm of planet formation - Suggested a dynamically complex system - Raised the question: is this phenomenon a consequence of formation or later dynamical interactions?
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Detection
Image of page 6
Methods of determining obliquity 1. Rossiter-McLaughlin effect - Most widely-used, easiest method 2. Starspots 3. Asteroseismology 4.Estimation of rotational velocity
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Rossiter-McLaughlin Effect In prograde system, we see a net redshift to blueshift. In retrograde, blue to red.
Image of page 8
Rossiter-McLaughlin Effect
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Starspots - Transit will have a perturbation - Must observe multiple transits - Look at evolution of “blip” in transit (Sanchis-Ojeda et al. 2011; Nutzman et al. 2011; D ́esert et al. 2011)
Image of page 10
Asteroseismology - Measures star pulsations - Most effective for low density stars - Preferentially finds retrograde planets around red giants (right now we know of very few) (Chaplain et al. 2013) http://www.youtube.com/watch? v=46bF5tnqye8
Image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Asteroseismology Huber et al. 2013 found the first non-HJ retrograde system using asteroseismology… and it was a multi-planet system (Kepler 56)
Image of page 12
Using estimates of rotational velocity - Works well for small-planet systems (indepedent of transit size) - Estimate rotational velocity V as a function of mass and age (Schlaufman 2010) - Spectroscopically determine projected rotational velocity Vsin(i) to get sin(i) - Selection bias: star temp
Image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Using estimates of rotational velocity
Image of page 14
Observations
Image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
First misaligned exoplanet: XO-3, Observational evidence Hebrard et al 2008
Image of page 16
Image of page 17
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern