Detail ： GJ 504 b is an exoplanet orbiting a sun-like star GJ 504. It is estimated to be three to six times more massive than Jupiter, making it the least massive planet ever directly imaged. This faint and cold planet, often referred to as the "second Jupiter," was discovered as part of the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) Project. The SEEDS project aimed to conduct direct observations of exoplanets to discover and explore their features using the coronagraph imager HiCIAO and the adaptive optics system with 188 elements AO 188.
GJ 504 is a star in the constellation Virgo, about 60 light-years away from Earth. The planet GJ 504 b is captured in the upper right of the star, at the center of the image. The apparent distance between GJ 504 and GJ 504 b is 44 astronomical units (au), which is similar to the distance between the Sun and Pluto.
Exoplanets are incredibly faint, making direct imaging very challenging. However, direct observation enables us not only to discover these planets but also to characterize them. For instance, GJ 504 b was found to have a very low temperature of approximately 500 Kelvin (or 230 degrees Celsius), and its atmosphere is less cloudy compared to those of other exoplanets previously discovered.
Distance from Earth:About 60 light-years
Instrument: HiCIAO (High Contrast Instrument for the Subaru Next Generation Adaptive Optics) + AO188
Relevant Links
- Subaru Telescope's Imaging Discovery of a Second Jupiter Shows the Power and Significance of the SEEDS Project (August 4, 2013 Science Results)
- Direct Imaging Discovery of a "Second Jupiter" (originally August 4, 2013 Subaru Telescope YouTube)
Source: Subaru Telescope
