HOME

TheInfoList



OR:

, - style="background-color: #A0B0FF;" colspan="3" , Planet , - bgcolor="#FFFAFA" , Gliese 849b ,
data
Gliese 849, or GJ 849, is a small, solitary star in the
equatorial Equatorial may refer to something related to: *Earth's equator **the tropics, the Earth's equatorial region **tropical climate *the Celestial equator ** equatorial orbit **equatorial coordinate system ** equatorial mount, of telescopes * equatorial ...
constellation of
Aquarius Aquarius may refer to: Astrology * Aquarius (astrology), an astrological sign * Age of Aquarius, a time period in the cycle of astrological ages Astronomy * Aquarius (constellation) * Aquarius in Chinese astronomy Arts and entertainme ...
. It has a reddish hue and is invisible to the naked eye with an
apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...
of 10.41. The distance to this star is based on parallax, but it is drifting closer to the
Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
with a radial velocity of −15.3 km/s. It has a pair of confirmed
gas giant A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are also called failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" ...
companions. The stellar classification of GJ 849 is M3.5V, which means this is a small red dwarf star generating energy through
hydrogen fusion Stellar nucleosynthesis is the creation (nucleosynthesis) of chemical elements by nuclear fusion reactions within stars. Stellar nucleosynthesis has occurred since the original creation of hydrogen, helium and lithium during the Big Bang. As a ...
at its
core Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the centra ...
region. Various studies have found super-solar abundances in the spectra, indicating that the elemental abundances of higher mass elements is significantly higher than in the Sun. The star has about half the mass and size of the Sun, and is spinning slowly with a rotation period of approximately 39 days. The estimated age of the star is more than three billion years. It is radiating a mere 2.9% of the
luminosity of the Sun The solar luminosity (), is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal ...
from its photosphere at an effective temperature of 3,490 K.


Planetary system

In late 2006, a long-period Jupiter-like exoplanet was reported to be orbiting the red dwarf in a period just over 5 years in length. There was also a linear trend in the
radial velocities The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the rate of change of the distance or range between the two points. It is equivalent to the vector projection o ...
which suggested another longer period companion. The trend in the radial velocities was confirmed in 2013. An orbit for the second exoplanet was finally determined in 2015. The first planet discovered, Gliese 849 b, was the first planet discovered orbiting a red dwarf with a semi-major axis greater than 0.21 AU.


See also

* List of star systems within 25–30 light-years *
Gliese 317 Gliese 317 is a small red dwarf star with two exoplanetary companions in the southern constellation of Pyxis. It is located at a distance of 49.6 light-years from the Sun based on stellar parallax, parallax measurements, and is drift ...
* Gliese 649 *
Gliese 581 Gliese 581 () is a red dwarf star of spectral type M3V at the center of the Gliese 581 planetary system, about 20 light years away from Earth in the Libra constellation. Its estimated mass is about a third of that of the Sun, and it i ...
*
List of extrasolar planets These are lists of exoplanets. Most of these were discovered by the Kepler space telescope. There are an additional 2,054 potential exoplanets from Kepler's first mission yet to be confirmed, as well as 978 from its " Second Light" mission and ...


References


External links

* * * __NOTOC__ {{DEFAULTSORT:Gliese 849 M-type main-sequence stars Planetary systems with two confirmed planets Aquarius (constellation) BD-05 5715 0849 109388 J22094029-0438267