HD 30177 b is an extrasolar planet

Extrasolar planet

An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...

 located approximately 178 light-year

Light-year

A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...

s away 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....

 of Dorado

Dorado

Dorado is a constellation in the southern sky. It was created in the late 16th century and is now one of the 88 modern constellations. Its name refers to the dolphinfish , which is known as dorado in Spanish, although it has also been depicted as a swordfish...

, orbiting the 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...

 HD 30177

HD 30177

HD 30177 is an 8th magnitude star located approximately 178 light-years away in the constellation Dorado. The star is a yellow dwarf, a type of yellow star that fuses hydrogen in its core. Since if this star is a late G-type, it is cooler and less massive than the Sun, but larger in radius. It is...

. This is one of the most massive planets ever detected by the radial velocity method. In addition, the planet orbits far from the star, about 4 AU

Astronomical unit

An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....

 away, taking 2770 days (7.58 years) to orbit the star. Even though the massive planet is orbiting at 4 AU from the star, the radial velocity semi-amplitude is high, around 146.8±2.8 m/s. Since the inclination

Inclination

Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

 (and thus the true mass) is not known, this planet candidate may in fact 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...

.

This planet was discovered on June 13, 2002 by Tinney

Chris Tinney

Chris Tinney is an astronomer at the University of New South Wales who is focused on extrasolar planet and brown dwarf research. He is a member of the Anglo-Australian Planet Search team which has discovered over twenty planets by doppler spectroscopy. He is also the former head of astronomy at the...

, Butler

R. Paul Butler

R. Paul Butler is an astronomer who searches for extrasolar planets.He received a BA and an MS from San Francisco State University, completing a Master's thesis with Geoffrey Marcy, and then completed his doctoral studies at the University of Maryland, College Park in 1993...

, and Marcy

Geoffrey Marcy

Geoffrey W. Marcy is an American astronomer, who is currently Professor of Astronomy at the University of California, Berkeley, famous for discovering more extrasolar planets than anyone else, 70 out of the first 100 to be discovered, along with R...

 et al. using the Doppler spectroscopy

Doppler spectroscopy

Doppler spectroscopy, also known as radial velocity measurement, is a spectroscopic method for finding extrasolar planets. It involves the observation of Doppler shifts in the spectrum of the star around which the planet orbits....

 from the Anglo-Australian Telescope

Anglo-Australian Telescope

The Anglo-Australian Telescope is a 3.9 m equatorially mounted telescope operated by the Australian Astronomical Observatory and situated at the Siding Spring Observatory, Australia at an altitude of a little over 1100 m...

.