A Terrestrial Planet in a ~1 AU Orbit Around One Member of a ~15 AU Binary
A. Gould, A. Udalski, I.-G. Shin, I. Porritt, J. Skowron, C. Han, J., C. Yee, S. Koz{\l}owski, J.-Y. Choi, R. Poleski, {\L}. Wyrzykowski, K., Ulaczyk, P. Pietrukowicz, P. Mr\'oz, M.K. Szyma\'nski, M. Kubiak, I., Soszy\'nski, G. Pietrzy\'nski, B.S. Gaudi, G.W. Christie

TL;DR
This paper reports the detection of a low-mass terrestrial planet around a star in a binary system using gravitational microlensing, highlighting the potential for discovering similar planets and informing models of planet formation.
Contribution
First detection of a terrestrial planet in a binary system via microlensing, demonstrating the method's effectiveness and suggesting increased sensitivity with current strategies.
Findings
Planet has 2 Earth masses and is located at ~0.8 AU from its host.
Host star is very low mass, less luminous than the Sun.
System's configuration suggests such planets are common.
Abstract
We detect a cold, terrestrial planet in a binary-star system using gravitational microlensing. The planet has low mass (2 Earth masses) and lies projected at ~ 0.8 astronomical units (AU) from its host star, similar to the Earth-Sun distance. However, the planet temperature is much lower, T<60 Kelvin, because the host star is only 0.10--0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host is itself orbiting a slightly more massive companion with projected separation 10--15 AU. Straightforward modification of current microlensing search strategies could increase their sensitivity to planets in binary systems. With more detections, such binary-star/planetary systems could place constraints on models of planet formation and evolution. This detection is consistent with such systems being very common.
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
