From that cacophony, we try to extract tiny, characteristic brightenings caused by planets, and we only have one chance to see a signal before it’s gone. Our observations pointed an elderly, ailing telescope with blurred vision at one the most densely crowded parts of the sky, where there are already thousands of bright stars that vary in brightness, and thousands of asteroids that skim across our field. Iain notes: “These signals are extremely difficult to find. This meant that new data reduction techniques had to be developed to look for signals within the Kepler dataset. Kepler was not designed to find planets using microlensing, nor to study the extremely dense star fields of the inner Galaxy. Roughly one out of every million stars in our Galaxy is visibly affected by microlensing at any given time, but only a few percent of these are expected to be caused by planets. This produces a short burst in brightness that can last from hours to a few days. Predicted by Albert Einstein 85 years ago as a consequence of his General Theory of Relativity, microlensing describes how the light from a background star can be temporarily magnified by the presence of other stars in the foreground. Such planets may perhaps have originally formed around a host star before being ejected by the gravitational tug of other, heavier planets in the system. These new events do not show an accompanying longer signal that might be expected from a host star, suggesting that these new events may be free-floating planets.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |