Monthly Exoplanet Paper Roundup: K2-146, System Architectures, a Mass-Period Gap, and Tidally Locked Habitability

Okay, so maybe I haven’t been the most on top of this, but in my defense it’s been a very crazy few months for me. Hopefully will be able to get to this more regularly!

Note that all links are to arXiv papers, which are free and available to the public. You can also follow links from arXiv to the peer-reviewed, published versions when available.

Quick Bites

K2-146 planets b and c, characterized by Lam et al. 2019 and Hamann et al. 2019.

K2-146: Discovery of Planet c, Precise Masses from Transit Timing, and Observed Precession (Hamann et al.) and It takes two planets in resonance to tango around K2-146 (Lam et al.): Dropping onto the arXiv within one day of each other, both these papers detect a new planet, K2-146 c. I read a draft of Aaron’s paper (a fellow UChicago dynamicist) back in the fall, so it just goes to show how much work and time goes into something like this! As you can see from this little plot I made, both teams found similar results, a testament to the accuracy of their methods.

Architectures of Exoplanetary Systems. I: A Clustered Forward Model for Exoplanetary Systems around Kepler’s FGK Stars (Ye et al.): This is a very cool paper that uses clusters to reproduce the observed distribution of Kepler systems, implying that there is some level of intra-system correlation, particularly for periods and multiplicity. They also find that the Kepler dichotomy might be explained by higher mutual inclinations rather than a separate population of single planet systems.

A Gap in the Mass Distribution for Warm Neptune and Terrestrial Planets (Armstrong et al.): One thing that is really exciting to me as the number of detected exoplanets continues to climb is that we can really start to tease out real patterns in the population of planets. Things like the Fulton gap, which was identified in Kepler data. A similar gap is presented in this paper, but it’s defined in the mass-period plane (and doesn’t seem to coincide with the Fulton radius-period gap). Explanation still TBD!

The Bio-habitable Zone and atmospheric properties for Planets of Red Dwarfs (Wandel & Gale): Small, cool stars are the most common type of star, and some of the most promising targets for finding terrestrial planets in the habitable zone. Because the HZ is so close to the star, however, these potentially habitable planets might be tidally locked. This paper dives into whether tidally locked planets can be habitable—spoiler, the answer is YES!