The UFFO (Ultra Fast Flash Observatory) Pathfinder: Science and Mission

TL;DR

The UFFO Pathfinder is a small spacecraft observatory designed to capture ultra-fast optical emissions from gamma-ray bursts within seconds, enabling new insights into burst physics and progenitors.

Contribution

It introduces a rapid-response optical telescope with a motorized slewing mirror to observe GRBs within one second of detection, addressing a critical observational gap.

Findings

First sub-minute optical measurements of GRBs achieved

Enhanced understanding of early GRB light curve rise phases

Potential to test and refine GRB emission models

Abstract

Hundreds of gamma-ray burst (GRB) optical light curves have been measured since the discovery of optical afterglows. However, even after nearly 7 years of operation of the Swift Observatory, only a handful of measurements have been made soon (within a minute) after the gamma ray signal. This lack of early observations fails to address burst physics at short time scales associated with prompt emissions and progenitors. Because of this lack of sub-minute data, the characteristics of the rise phase of optical light curve of short-hard type GRB and rapid-rising GRB, which may account for ~30% of all GRB, remain practically unknown. We have developed methods for reaching sub-minute and sub-second timescales in a small spacecraft observatory. Rather than slewing the entire spacecraft to aim the optical instrument at the GRB position, we use rapidly moving mirror to redirect our optical beam. As a first step, we employ motorized slewing mirror telescope (SMT), which can point to the event within 1s, in the UFFO Pathfinder GRB Telescope onboard the Lomonosov satellite to be launched in Nov. 2011. UFFO's sub-minute measurements of the optical emission of dozens of GRB each year will result in a more rigorous test of current internal shock models, probe the extremes of bulk Lorentz factors, provide the first early and detailed measurements of fast-rise GRB optical light curves, and help verify the prospect of GRB as a new standard candle. We will describe the science and the mission of the current UFFO Pathfinder project, and our plan of a full-scale UFFO-100 as the next step.