Ten cool facts about the ancient Kepler-444 stellar system

A paper I worked on with Tiago Campante from the University of Birmingham and many others has just been published. It’s a truly astounding system. Here are 10 cools facts

  1. The star is 11.2 billion years old. The Universe was just 20% of its current age when this star formed.
  2. The star is just 36 parsec away. It is in our stellar backyard.
  3. The star is a high proper motion star. The star moves at half an arcsecond a year.
  4. The star is a thick disk star. It is part of an older region in our galaxy.
  5. The star is the densest where we have measured seismic oscillations. We used these oscillations to measure the star’s age and density.
  6. Five sub-earth-sized planets orbit the star. This system hosts a planet almost as small as Kepler-37b.
  7. The planets all have orbital periods of less than 10 days. This is the most compact planetary system.
  8. These planets are the oldest know terrestrial planets. Only the giant planets around Kapteyn’s Star are older.
  9. These planets must have been formed from a Type 1bc or II supernovae material, not Type Ia. Type Ia supernovae are caused by white dwarfs and white dwarfs were not abundant in the early galaxy.
  10. The orbital periods of the planets are all very close to mutuals resonances. The orbital period ratios of the five planets are 125:100:75:60:48. i.e. for every 125 orbits of the inner planet, the outer planet orbits 48 times.


The paper is available from http://arxiv.org/abs/1501.06227.

The first K2 multiplanet system

Ian Crossfield and collaborators posted a paper on arXiv earlier today announcing a system of three planets orbiting an M-dwarf star. These planets were found in data from Campaign 1 of the K2 Mission. This is a pretty spectacular effort given the data was only released three weeks ago! This announcement follows the detection of the first planet found by K2 by Andrew Vanderburg and team in December of 2014. Hopefully this is the first of many discoveries from Ian and collaborators.

Light curve of EPIC 201367065 taken from Crossfield et al. 2015. Transits from three planets can be seen.


Exoplanet Travel Series Posters

The NASA Planetquest team have released three cool 50’s sci-fi style posters. One of them is for a planet from a paper Elisa Quintana and I recently put out called Kepler-186f. They also have posters for HD 40307g and Kepler-16b. They are all awesome but Kepler-16b is my favorite. I hear there are another three in the works and the hope is that there will eventually be a total of 20.