What is UMBRAS' goal? Why UMBRAS? How does UMBRAS Work? What does it look like? Where will UMBRAS go? When can it be done? Who is UMBRAS? 04-03-11 Who else works on occulters? Publications 04-03-11 Other Technical Information Newsletters 02-01-07

What is UMBRAS? UMBRAS (Umbral Missions Blocking Radiating Astronomical Sources) is a technique and a class of space science missions. The UMBRAS goal is direct observation of planets around other stars. 'Direct observation' means images, photometry, and spectroscopy, as contrasted to the measurement of stellar reflex motion and variations in starlight flux used to demonstrate the discovery of extrasolar planets found so far. UMBRAS uses a companion spacecraft with a space telescope placed far from Earth. The companion spacecraft carries an occulting screen designed to reduce the glare from a star so that a search for planets may be conducted around them. The object is to get pictures which show planets next to stars and moving around or with them through space, which has never been done before. The diagram at right is a conceptual simplification of the arrangement of the essential elements in the UMBRAS mission: Space Telescope Occulter Sun Star The plan view is from above the sun-occulter-telescope plane looking back at the occulting vehicle and telescope (not drawn to scale). The occulter is placed between target star and telescope blocking the starlight and allowing fainter objects to be viewed near the star around the edge of the occulter.