GJ 758
Encyclopedia
GJ 758 is a G-type main sequence
star
located approximately 50 light years away from the Earth
, in the constellation
Lyra. At about magnitude
6 it is a little too faint to be seen with the naked eye
but can be easily seen through a small telescope
or binoculars
.
imaged a substellar companion orbiting the star. This object, designated GJ 758 B, was initially estimated to be of approximately 10-40 Jupiter masses. A second candidate object was also detected, which was given the designation GJ 758 C. Followup studies of the system have further constrained the mass range of GJ 758 B, indicating it to be a brown dwarf
with approximately 30 to 40 Jupiter masses and revealed that GJ 758 C is a background star which is not physically associated with the GJ 758 system.
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
located approximately 50 light years away from the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Lyra. At about magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
6 it is a little too faint to be seen with the naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
but can be easily seen through a small telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
or binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
.
System
In November 2009, a team using the HiCIAO instrument of the Subaru TelescopeSubaru (telescope)
Subaru Telescope is the 8.2 metre flagship telescope of the National Astronomical Observatory of Japan, located at the Mauna Kea Observatory on Hawaii. It is named after the open star cluster known in English as the Pleiades...
imaged a substellar companion orbiting the star. This object, designated GJ 758 B, was initially estimated to be of approximately 10-40 Jupiter masses. A second candidate object was also detected, which was given the designation GJ 758 C. Followup studies of the system have further constrained the mass range of GJ 758 B, indicating it to be a brown dwarf
Brown dwarf
Brown dwarfs are sub-stellar objects which are too low in mass to sustain hydrogen-1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no chemical differentiation by depth...
with approximately 30 to 40 Jupiter masses and revealed that GJ 758 C is a background star which is not physically associated with the GJ 758 system.
See also
- Direct imaging of extrasolar planets
- List of extrasolar planets