TINJAUAN METODE PELENSAAN MIKRO GRAVITASI UNTUK DETEKSI EKSOPLANET

• Main Author: Luckyta Fasyni, Achmad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42861
• Institution: Institut Teknologi Bandung

Gravitational microlensing event occurs when a foreground star passes in front of a background star. It brightens the light of the background star. The gravitational eld of the foreground star warps space to create a gravitational lens that magnies light. Due to the relative motion between lens and source, the magnication varies with time, manifested in the light curve obtained by observation. If a planet is orbiting the foreground star. It, too, will gravitationally lens the background star for a shorter duration. This feature is the main clue to the detection of exoplanets through gravitational microlensing method. The shape of the magnication light curve for a binary lens is determined by the source trajectory through the caustics. The caustic structure is depended by two main parameters: mass ratio of lens q and orbital separation of lens d. based on the modeling with MEPL code, a greater mass ratio will reveal a greater magnication factor and more prominent perturbation feature when the source crosses planetary caustics. While a smaller mass ratio will reveal a greater magnication factor when the source crosses the central caustic, or high magnication event. A greater mass ratio will result in a greater caustic, so the probability of detection increases. The closer the planet to the Einstein radius, the perturbation feature on the light curve will increasingly stand out so that the probability of detection increases. The greater magnication value and the more prominent perturbation feature on the light curve will increase the probability of exoplanet detection. To conduct a survey-follow up observation on exoplanetary microlensing, the instrument ability to monitor large areas of the sky in a high cadence is important to obtain dense and continuous magnication data sampling of the observed light curve. Based on the established observation of microlensing, at least the National Obseravatory requires a 1.4 square degree eld of view CCD camera and a 1.3 meter diameter telescope to conduct both wide-eld survey and high cadence follow up observation on exoplanetary microlensing.