HST Cycle 19 Exposure Time Calculators

The Exposure Time Calculator (ETC) is a web-based application that assists users in calculating the exposure time needed for their HST observations, or the Signal-to-Noice Ratio (SNR) they can attain with a given HST observing time. These quantities are key for the preparation of proposals and observations during Phase I and Phase II of the proposing cycle and therefore have to be sufficiently accurate for each of the supported observing modes of all the HST instruments. Developing a general tool that shares communality among the different instruments is complicated, not only form the point of view of attaining accuracy of the calculations but also regarding reliability, portability, and maintainability. We are currently developing a new version of the ETC for Cycle 19 in Python to improve these qualities and to provide a basis for JWST Exposure Time Calculators. This poster describes the improvements over the previous ETC and the current status of the new version.