This is an artist's concept of a gas giant planet orbiting the cool, red dwarf star Gliese 876, located 15 light-years away in the autumn constellation Aquarius. The planet was discovered in 1998. But new Hubble Space Telescope measurements of the star's wobble, caused by the gravitational tug of the planet, firmly establish the planet's mass as being no more than approximately twice that of Jupiter's. The planet is only one fifth the distance from the star as the Earth is from the Sun. Though it is too far away to be photographed by present day telescopes, the planet is presumably a gas giant world that might be encircled by moons, as imagined in this illustration. Gliese 876 also has an inner planet with a mass only half that of Jupiter's, as estimated by earlier ground-based observations. The inner gas planet in the system appears as a bright star-like object near the red dwarf. Despite its close proximity to Earth, the red dwarf star is one third the mass of our Sun and is too faint to be seen by the naked eye.
Credits
NASA and G. Bacon (STScI)| About The Object | |
|---|---|
| Object Name | Gliese 876b; Gl 876b; GJ 876b; Ross 780b |
| Object Description | Extrasolarplanet; Companion to Star Gliese 876 (Ross 780) |
| R.A. Position | 22h 53m 16.73s |
| Dec. Position | -14° 15' 49.3" |
| Constellation | Aquarius |
| Distance | 15.19 light-years (4.66 parsecs) |
| About The Data | |
| Data Description | Principal Astronomers: T. Forveille (CFHT/Observatoire de Grenoble), G. F. Benedict and B. McArthur (McDonald Observatory), X. Delfosse (Observatoire de Grenoble), E. Nelan (STScI), R. P. Butler (Carnegie Institute), W. Spiesman (McDonald Observatory), G. W. Marcy (UC Berkeley), B. Goldman (NMSU), C. Perrier (Observatorie de Grenoble), W. Jefferys (University of Texas), M. Mayor (Observatorie de Geneve) |
| Instrument | HST>FGS |
| Exposure Dates | June - August, November 1999; May 2000; November 2001, Exposure Time: 4 hours |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
