HD 107146
Encyclopedia
HD 107146 is a G2V
(yellow dwarf
) star
, located 88 light years from Earth
. In 2003, astronomers recognized the excess infrared and submillimeter emission indicative of circumstellar dust
, the first time such a debris disk
phenomenon was noted around a star of similar spectral types as the Sun
, though having a much younger age. In 2004 the Hubble Space Telescope
detected the presence of a spatially resolved disc surrounding the star Observations have given the age of the star at between 80 and 200 Myr
.
. The dusty ring is cool, with a temperature of 51 K
, and has a mass of 0.10 M⊕. Analysis of the debris disk in the far-infrared and submillimeter wavelengths, carried out using the Hubble Space Telescope, suggests the presence of small grains in the disk. The disk appears to be slightly elongated to form an ellipse
with its minor axis at a position angle of 58° ± 5°; working under the assumption that the disk is in fact circular gives it an inclination
of 25° ± 5° from the plane of the sky. Recent analysis suggests the possible presence of a planet at 45-75 AU.
Stellar 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...
(yellow dwarf
Yellow dwarf
A G-type main-sequence star , often called a yellow dwarf, is a main-sequence star of spectral type G and luminosity class V. Such a star has about 0.8 to 1.2 solar masses and surface temperature of between 5,300 and 6,000 K., Tables VII, VIII...
) 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 88 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 2003, astronomers recognized the excess infrared and submillimeter emission indicative of circumstellar dust
Circumstellar dust
Circumstellar Dust is astronomical dust around a star. It can be in the form of a spherical shell or a disk, e.g. an accretion disk. Circumstellar dust can be responsible for significant extinction and is usually the source of an infrared excess for stars that have it.The motion of circumstellar...
, the first time such a debris disk
Debris disk
A debris disk is a circumstellar disk of dust and debris in orbit around a star. Sometimes these disks contain prominent rings, as seen in the image of Fomalhaut on the right. Debris disks have been found around both evolved and young stars, as well as at least one debris disk in orbit around a...
phenomenon was noted around a star of similar spectral types as the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, though having a much younger age. In 2004 the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
detected the presence of a spatially resolved disc surrounding the star Observations have given the age of the star at between 80 and 200 Myr
Myr
The symbol myr was formerly used in English-language geology, and remains as the standard usage in astronomy, as a unit of one million years.It is an abbreviation for 'million years' and lower case is used in geology, while upper case is used in astronomy....
.
Circumstellar disc
The star's circumstellar disc has dimensions of approximately 210 x 300 AUAstronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
. The dusty ring is cool, with a temperature of 51 K
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
, and has a mass of 0.10 M⊕. Analysis of the debris disk in the far-infrared and submillimeter wavelengths, carried out using the Hubble Space Telescope, suggests the presence of small grains in the disk. The disk appears to be slightly elongated to form an ellipse
Ellipse
In geometry, an ellipse is a plane curve that results from the intersection of a cone by a plane in a way that produces a closed curve. Circles are special cases of ellipses, obtained when the cutting plane is orthogonal to the cone's axis...
with its minor axis at a position angle of 58° ± 5°; working under the assumption that the disk is in fact circular gives it an 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...
of 25° ± 5° from the plane of the sky. Recent analysis suggests the possible presence of a planet at 45-75 AU.