Probing the effect of gravitational microlensing on the measurements of the Rossiter-McLaughlin effect

TL;DR

This paper investigates how gravitational microlensing by planets can influence the measurement of the Rossiter-McLaughlin effect, especially for massive, long-period planets, revealing potential biases in radial velocity data.

Contribution

It provides a quantitative analysis of microlensing effects on the Rossiter-McLaughlin effect, highlighting cases where the impact is significant and often neglected in previous studies.

Findings

Microlensing can significantly affect RV measurements for massive, long-period planets.

The effect may cause the transit depth to vanish in extreme cases.

Microlensing contributions should be considered in precise RV analyses.

Abstract

In general, in the studies of transit light-curves and the Rossiter-McLaughlin (RM), the contribution of the planet's gravitational microlensing is neglected. Theoretical studies, have, however shown that the planet's microlensing can affect the transit light-curve and in some extreme cases cause the transit depth to vanish. In this letter, we present the results of our quantitative analysis of microlening on the RM effect. Results indicate that for massive planets in on long period orbits, the planet's microlensing will have considerable contribution to the star's RV measurements. We present the details of our study, and discuss our analysis and results.