HR 8799 e
Encyclopedia
HR 8799 e is a large exoplanet, orbiting the star HR 8799
, which lies 128 lightyears from Earth. This gas giant
is between 5 and 10 times the mass of Jupiter
, the largest planet in our solar system. All four planets in the HR 8799 system are large, compared to all gas giants in the Solar System
.
, and is fairly close to its star, lying just between the orbits of Saturn
and Uranus
in our solar system.
HR 8799 e is the innermost known planet as it orbits closer to its star than the other three known planets in this planetary system
. This planet orbits at an estimated distance of 14.5 AU based on the relationship between angular separation measured by direct imaging observations and the star's distance from Earth. The estimated period of this planet if the orbit is face-on is about 50 years.
HR 8799
HR 8799 is a young main sequence star located 129 light years away from Earth in the constellation of Pegasus, with roughly 1.5 times the Sun's mass and 4.9 times its luminosity. It is part of a system that also contains a debris disk and at least four massive planets...
, which lies 128 lightyears from Earth. This gas giant
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
is between 5 and 10 times the mass of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
, the largest planet in our solar system. All four planets in the HR 8799 system are large, compared to all gas giants in the Solar System
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
.
Description
HR 8799 e is the fourth planet orbiting HR 8799 in order of discovery. It is a massive gas giantGas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
, and is fairly close to its star, lying just between the orbits of Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
and Uranus
Uranus
Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...
in our solar system.
HR 8799 e is the innermost known planet as it orbits closer to its star than the other three known planets in this planetary system
Planetary system
A planetary system consists of the various non-stellar objects orbiting a star such as planets, dwarf planets , asteroids, meteoroids, comets, and cosmic dust...
. This planet orbits at an estimated distance of 14.5 AU based on the relationship between angular separation measured by direct imaging observations and the star's distance from Earth. The estimated period of this planet if the orbit is face-on is about 50 years.