HD 196885
Encyclopedia
HD 196885 is a 6th magnitude
binary
star
in the constellation
Delphinus. According to its parallax
of 29.15 milliarcsecond
s, it is located at a distance of 112 light years from Earth
. In 2004, a planet
was announced to be orbiting the star in a 386-day orbit. Follow-up work published in 2008 did not confirm the original candidate but instead found evidence of a planet in a 1349-day orbit.
The star BD+10 4351B, located 192 arcseconds away from HD 196885 is located at the same distance and may be a physically bound companion star, in which case HD 196885 is a triple system. If it is bound, then the separation is at least 6600 AU
(the separation along the line-of-sight
is unknown, so this value represents a lower limit on the true separation).
star
. It has a mass
of 1.33 solar mass
es and a radius
of 1.79 times that of our Sun.
star separated by 0.7 arcseconds from the primary star. At a distance of 112 light years, this corresponds to a separation of 24 AU between the stars. Since the separation along the line-of-sight is unknown, this represents a lower limit on the true separation.
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...
binary
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
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...
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....
Delphinus. According to its parallax
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
of 29.15 milliarcsecond
Minute of arc
A minute of arc, arcminute, or minute of angle , is a unit of angular measurement equal to one sixtieth of one degree. In turn, a second of arc or arcsecond is one sixtieth of one minute of arc....
s, it is located at a distance of 112 light years from 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 2004, a planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
was announced to be orbiting the star in a 386-day orbit. Follow-up work published in 2008 did not confirm the original candidate but instead found evidence of a planet in a 1349-day orbit.
The star BD+10 4351B, located 192 arcseconds away from HD 196885 is located at the same distance and may be a physically bound companion star, in which case HD 196885 is a triple system. If it is bound, then the separation is at least 6600 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
(the separation along the line-of-sight
Line-of-sight propagation
Line-of-sight propagation refers to electro-magnetic radiation or acoustic wave propagation. Electromagnetic transmission includes light emissions traveling in a straight line...
is unknown, so this value represents a lower limit on the true separation).
HD 196885 A
HD 196885 A is an F6IVStellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
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...
. It has a mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of 1.33 solar mass
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
es and a radius
Radius
In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its...
of 1.79 times that of our Sun.
Planetary system
HD 196885 B
HD 196885 B is a red dwarfRed dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....
star separated by 0.7 arcseconds from the primary star. At a distance of 112 light years, this corresponds to a separation of 24 AU between the stars. Since the separation along the line-of-sight is unknown, this represents a lower limit on the true separation.