Observation
When a planetary-sized object passes in front of a background star, its gravitational field causes a momentary increase in the visible brightness of the background star. This is known as microlensing. Astrophysicist Takahiro Sumi of Osaka University in Japan and colleagues, who form the Microlensing Observations in Astrophysics (MOA) and the Optical Gravitational Lensing Experiment (OGLE) collaborations, carried out a study of microlensing which they published in 2011. They observed 50 million stars in our galaxy using the 1.8 meter MOA-II telescope at New Zealand's Mount John Observatory and the 1.3 meter Warsaw University Telescope at Chile's Las Campanas Observatory. They found 474 incidents of microlensing, just 10 of which were brief enough to be planets of around Jupiter's size with no associated star in the immediate vicinity. The researchers estimated from their observations that there are nearly two free-floaters for every star in our galaxy. Other estimations suggest a much larger number, up to 100,000 times more free-floating planets than stars in our Milky Way.
Read more about this topic: Rogue Planet
Famous quotes containing the word observation:
“Morality without religion is only a kind of dead reckoning—an endeavor to find our place on a cloudy sea by measuring the distance we have run, but without any observation of the heavenly bodies.”
—Henry Wadsworth Longfellow (1807–1882)
“Men look on knowledge which they learn—or might learn—from others as they do on the most beautiful structures which are not their own: in outward objects, they would rather behold their own hogsty than their neighbor’s palace; and in mental ones, would prefer one grain of knowledge gained by their own observation to all the wisdom of a thousand Solomons.”
—Sarah Fielding (1710–1768)
“The Artist is he who detects and applies the law from observation of the works of Genius, whether of man or Nature. The Artisan is he who merely applies the rules which others have detected.”
—Henry David Thoreau (1817–1862)