Gravitational microlensing tagged posts

Although thousands of planets have been discovered in the Milky Way, most reside less than a few thousand light years from Earth. Yet our galaxy is more than 100,000 light years across, making it difficult to investigate the galactic distribution of planets. But now, a research team has 5nd a way to overcome this hurdle.

In a study published in the Astrophysical Journal Letters, researchers led by Osaka University and NASA have used a combination of observations and modeling to determine how the planet-hosting probability varies with the distance from the ga...

Light curve of the microlensing event OGLE-2016-BLG-1469. The upper panel shows the enlarged view of the anomaly around the peak. The two lower panels show the residual from the binary-lens models with (orbit+parallax) and without (standard) considering higher-order effects. Credit: Han et al., 2017.

Using gravitational microlensing, astronomers have recently found a binary star composed of two brown dwarfs. The newly discovered system is the third brown-dwarf binary detected with this technique. Gravitational microlensing is an invaluable method of detecting new extrasolar planets and brown dwarfs, regardless of the light they emit...

Neptune-mass exoplanets like the one shown in this artist’s rendering may be the most common in the icy regions of planetary systems. Beyond a certain distance from a young star, water and other substances remain frozen, leading to an abundant population of icy objects that can collide and form the cores of new planets. In the foreground, an icy body left over from this period drifts past the planet. Credit: NASA/Goddard/Francis Reddy

A new statistical study of planets found by gravitational microlensing suggests that Neptune-mass worlds are likely the most common type of planet to form in the icy outer realms of planetary systems...

This artist’s illustration shows a gas giant planet circling a pair of red dwarf stars. The Saturn-mass planet orbits roughly 300 million miles from the stellar duo. The two red dwarf stars are a mere 7 million miles apart. Credit: NASA, ESA, and G. Bacon (STScI)

Astronomers using NASA’s Hubble Space Telescope, and a trick of nature, have confirmed the existence of a planet orbiting two stars in the system OGLE-2007-BLG-349, 8,000 light-years away towards the center of our galaxy. The planet orbits ~300 million miles from the stellar duo, about the distance from the asteroid belt to our sun. It completes an orbit around both stars roughly every 7 years. The 2 red dwarf stars are a mere 7 million miles apart, or 14 times the diameter of the moon’s orbit around Earth.

The Hubble observations...