Using graphical and pictorial representations to teach introductory astronomy students about the detection of extrasolar planets via gravitational microlensing

TL;DR

This paper introduces a new educational tool using graphical and pictorial representations to help introductory astronomy students understand how gravitational microlensing detects extrasolar planets, enhancing their reasoning skills.

Contribution

The paper presents a novel Lecture-Tutorial with carefully designed visual representations to improve teaching of gravitational microlensing in introductory astronomy courses.

Findings

Students develop more expert-like reasoning abilities.

The visual representations facilitate understanding of complex astrophysical phenomena.

The tutorial is effective in teaching gravitational microlensing concepts.

Abstract

The detection and study of extrasolar planets is an exciting and thriving field in modern astrophysics, and an increasingly popular topic in introductory astronomy courses. One detection method relies on searching for stars whose light has been gravitationally microlensed by an extrasolar planet. In order to facilitate instructors' abilities to bring this interesting mix of general relativity and extrasolar planet detection into the introductory astronomy classroom, we have developed a new Lecture-Tutorial, "Detecting Exoplanets with Gravitational Microlensing." In this paper, we describe how this new Lecture-Tutorial's representations of astrophysical phenomena, which we selected and created based on theoretically motivated considerations of their pedagogical affordances, are used to help introductory astronomy students develop more expert-like reasoning abilities.