NSF-BSF: The Frequency and Mass-Ratio Distribution of Super-Earths in KMTNet

A team led by the Smithsonian Institution Astrophysical Observatory will measure the frequency and masses of planets around distant stars in wide orbits down to the mass of several times the Earths. The survey will use ground-based data and the findings will help us understand the context in which the Solar System and humanity exist in the Universe.

In addition, the investigating team will search for black holes within the dataset. This project will advance the workforce by training a postdoc and providing undergraduate students with the opportunity to participate in cutting edge research. It will also strengthen ties between scientists in the United States, Israel, and the Republic of Korea.

This project is supported by both the National Science Foundation and the US-Israel Binational Science Foundation to further collaborations between the astrophysical communities in the two countries.

The core of the project is to develop an algorithm to objectively search for, and detect, planets in over 10,000 events from the Korea Microlensing Telescope Network (KMTNet) survey. This sample of events is a factor of several larger than previous work. A search algorithm will result in a statistically robust sample of planets.

Injection and recovery methods will be used to evaluate the efficacy of the detection algorithm and to calculate limits on planets for the individual light curves. Combining these limits with the detected planets will yield the mass-ratio distribution and frequency of planets. Of particular importance are super-Earth planets, which cannot be detected by other techniques at the orbital separations probed by this study.

This project will also develop a new technique for measuring astrometry on the KMTNet images in order to search for microlensing by black holes. If there are microlensing events in the KMTNet dataset due to stellar-mass black holes 5 to 30 times the mass of the Sun, their masses should be measurable with this work.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.