Related topics: orbit · stars · planets · solar system

Scientist develops novel algorithm to aid search for exoplanets

Inspired by movie streaming services such as Netflix or Hulu, a Southwest Research Institute scientist developed a technique to look for stars likely to host giant, Jupiter-sized planets outside of our solar system. She developed ...

The low density of some exoplanets is confirmed

The Kepler mission and its extension, called K2, discovered thousands of exoplanets. It detected them using the transit technique, measuring the dip in light intensity whenever an orbiting planet moved across the face of ...

Name an exoplanet

In recent years, astronomers have discovered thousands of planets and planetary systems orbiting around nearby stars. Some are small and rocky like the Earth, whilst others are gas giants like Jupiter. It is now believed ...

A new view of exoplanets with NASA's upcoming Webb Telescope

While we now know of thousands of exoplanets—planets around other stars—the vast majority of our knowledge is indirect. That is, scientists have not actually taken many pictures of exoplanets, and because of the limits ...

Eighteen Earth-sized exoplanets discovered

Scientists at the Max Planck Institute for Solar System Research (MPS), the Georg August University of Göttingen, and the Sonneberg Observatory have discovered 18 Earth-sized planets beyond the solar system. The worlds are ...

Planet-hunter CubeSat images Los Angeles

A small satellite designed to hunt for new planets beyond the solar system recently looked down at Earth to capture an image of California's "City of Stars."

Rare-Earth metals in the atmosphere of a glowing-hot exoplanet

KELT-9 b is the hottest exoplanet known to date. In the summer of 2018, a joint team of astronomers from the universities of Bern and Geneva found signatures of gaseous iron and titanium in its atmosphere. Now these researchers ...

Two studies cast doubt on existence of exomoon

Two teams working independently have looked at the possibility of an exomoon circling the exoplanet Kepler-1625b, which orbits the star Kepler-1625. They report little to no evidence supporting its existence. One team, led ...

Five planets revealed after 20 years of observation

Over 4000 exoplanets have been discovered since the first one in 1995, but the vast majority of them orbit their stars with relatively short periods of revolution. Indeed, to confirm the presence of a planet, it is necessary ...

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Extrasolar planet

An extrasolar planet, or exoplanet, is a planet beyond our Solar System, orbiting a star other than our Sun. As of June 2009[update], 353 exoplanets are listed in the Extrasolar Planets Encyclopaedia. The vast majority have been detected through radial velocity observations and other indirect methods rather than actual imaging. Most announced exoplanets are massive gas giant planets thought to resemble Jupiter, but this is a selection effect (bias) due to limitations in detection technology. Projections based on recent detections of much smaller worlds suggest that lightweight, rocky planets will eventually be found to outnumber extrasolar gas giants.

Extrasolar planets became a subject of scientific investigation in the mid-19th century. Many astronomers supposed that such planets existed, but they had no way of knowing how common they were or how similar they might be to the planets of our Solar System. The first confirmed radial velocity detection was made in 1995, revealing a gas giant planet in a four-day orbit around the nearby G-type star 51 Pegasi. The frequency of detections has tended to increase on an annual basis since then. It is estimated that at least 10% of sun-like stars have planets, and the true proportion may be much higher. The discovery of extrasolar planets sharpens the question of whether some might support extraterrestrial life.

Currently Gliese 581 d, the fourth planet of the red dwarf star Gliese 581 (approximately 20 light years from Earth), appears to be the best example yet discovered of a possible terrestrial exoplanet that orbits within the habitable zone surrounding its star. Although initial measurements suggested that Gliese 581 d resided outside the so-called "Goldilocks Zone", additional measurements place it firmly within.

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