Astronomy & Telescopes

Exoplanet Detection With Microlensing

By Keith Cowing

Status Report

astro-ph.EP

May 20, 2025

Filed under astro-ph.EP, astronomy, exoplanet, microlensing, Nancy Grace Roman Space Telescope, water snowline

Exoplanet Detection With Microlensing — Distribution of known exoplanet masses plotted vs. semi-major axis (left) and semimajor axis normalized to the location of the snow-line (right) at a_snow = 2.7AU M/M_Sun (green dashed line). Planets found by the Doppler/RV method (black lines with upward error bars indicating the sin i uncertainty, where i refers to line-of-sight inclination), transits (blue squares), microlensing (red error bar crosses), direct detection, (magenta triangles) timing (green triangles) and transit timing variations (gold diamonds). Small cyan spots indicate Kepler planets and planet candidates without mass measurements. Black letters show the locations of our Solar System’s planets. Microlensing discoveries. — astro-ph.EP

Microlensing is the method of exoplanet detection that discovers solar system analog exoplanets.

These are planets low in mass located in wide orbits around their host stars. Even though thousands of exoplanets are discovered, they are mostly hot planets close to their hosts. There is a dearth of exoplanets discovered beyond the snowline where exoplanets are thought to be formed.

This was recognized as a very important science issue; 2010 decadal survey declared detecting exoplanets with microlensing and measuring their masses as one of the three main science goals of NASA’s next flagship mission, Nancy Grace Roman Space Telescope.

Nancy Grace Roman Space Telescope is scheduled to launch in late 2026, no later than May 2027. It will observe 6 seasons of galactic bulge to discover and measure masses of 1000+ such wide orbit low mass solar system analog planets.

Aparna Bhattacharya

Comments: Preprint of a chapter for the ‘Encyclopedia of Astrophysics’ (Editor-in-Chief Ilya Mandel, Section Editor Dimitri Veras) to be published by Elsevier as a Reference Module
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2505.10621 [astro-ph.EP] (or arXiv:2505.10621v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2505.10621
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Submission history
From: Aparna Bhattacharya
[v1] Thu, 15 May 2025 18:00:04 UTC (4,827 KB)
https://arxiv.org/abs/2505.10621

Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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