FUNA Lunch Talk:

Timothy J. Rodigas

Carnegie Department of Terrestrial Magnetism

Imaging Planets and Disks with an Eye on the Future

May 30

12:10PM, Room 230, NRAO, Edgemont Road


We are probably still decades away from being able to directly image an Earth-like planet around another star. However, with each passing year, we make significant advances towards achieving this goal. Young gas giant planets can now be directly imaged, giving us clues to their atmospheric compositions--the kind of information we will one day seek for Earth 2.0. In the meantime, several other questions need to be answered: What do other planetary systems look like? What is the connection between planets and debris disks? Do the ingredients necessary for life exist around other stars?

In this talk, I will present research results on four different topics related to answering these questions. First, I will discuss my work on radial velocity (RV) eccentricity bias. For years astronomers have been puzzled about the large number of RV-detected planets that have eccentric orbits (e > 0.1). I will show that this problem can be partially explained when two circular-orbit planets masquerade as a single planet on an eccentric orbit. I use this finding to predict that planets with mildly eccentric orbits are the most likely to have massive companions on wide orbits, potentially detectable by future direct imaging observations. Second, I will present direct imaging results on an old RV planetary system--an attempt at combining two powerful planet detection techniques that will one day be crucial for determining the true mass distribution of extrasolar planets. I will also discuss a new program I am leading to image long-period companions with MagAO. Third, I will present direct imaging results on several bright debris disks (including a brand new one) in the visible and near-infrared using the LBT and MagAO. Imaging at these wavelengths is a window into the composition of the dust grains scattering the star light, allowing us to determine how much (if any) water ice and/or organic materials are present. Finally, I will present my bold foray into theory to understand and characterize the observational signatures planets dynamically leave on debris disks. I will show how bigger planets create broader disks, meaning we can use debris disk widths to estimate an interior shepherding planet's mass. This will prove especially useful to planet imagers in the coming years for both searching for and characterizing new disk-shepherding planets.