Research Highlights
Nature Astronomy: Free-floating Binary Planets from Ejections During Close Stellar
Encounters
Exoplanets -- planets beyond our solar system -- have been found in increasing amounts
over the years as our telescope techonology continues to improve. However, a number
of exoplanets about the same size of Jupiter have been found in pairs, floating together
through space with no host star to orbit around. These types of systems have been
dubbed JuMBOs, or Jupiter-Mass Binary Objects. Recently, Dr. Rosalba Perna and collaborators
have developed a theory to help explain the mysterious prevalence of the JuMBOs scattered
throughout the galaxy!
The key of this new theory lies in close fly-bys between two stars. One star is host
to the two Jupiter-size exoplanets, and when the second star gets close enough, the
two planets can be ejected out of their original host star's influence.
A sketch method through which JuMBOs are produced. On the left, we see the schematic
of the mechanism developed. Host star M1 has the two Jupiter-size exoplanets, marked by the blue dots. A fly-by of star M2 then causes these planets to be ejected out of the system together. The diagram on
the right shows the various variables needed to work out the theory's mathematical
details, such as the various orbit angles and the interloping star's velocity.
Nature Physics: Ultracold Chemistry as a Testbed for Few-body Physics
Dr. Jesus Pérez-Ríos and collaborators have recently published a new review article
in Nature Physics! With it, they seek to give insight into how cold systems with only a few particles
can serve as a unique tool to explore chemistry in these environments!
The potential of these systems span a broad range of interesting applications, from quantum computing to highly detailed study of chemical reactions. For example, ultracold studies provide access to behaviors at a quantum mechanical level, allowing researchers the ability to carefully prepare the molecules to control their chemical behaviors and reactivities! With temperatures as low as a few microkelvin (less than -400 °F), these molecules are incredibly cold. However, the interactions that they participate in can have energies thousands of times larger than that!
A diagram depicting the relevant energy scales and distances for these ultracold interactions.
a) A zoomed in view of the peak, showing how close the various rotational and vibrational
energy states are separated. b) Energy interactions on a longer distance scale, showing
that the overall large-scale interactions have behaviors more aligned with the small
scale energy differences, as opposed to the short-scale strong interactions.
Cover Article: Instrumental uncertainties in radiative corrections for the MUSE experiment
Dr. Bernauer, an assistant professor in our department, along with collaborators,
have published a paper in the EPJA that has been selected as the cover article, increasing the visibility of this important
work!
A sketch of the MUSE experimental set-up at the Paul Scherrer Institute in Switzerland.
The MUon proton Scattering Experiment (MUSE) based in Switzerland has made significant headway in accurately measuring the size of protons -- positively charged particles at the heart of any atom. The MUSE experiment measures the proton radius through scattering muons -- particles that behave almost like electrons, except that they are almost 200 times heavier!
Research Groups and Connected Research Centers