HD 75289
Encyclopedia
HD 75289 is a 6th magnitude
star
in the constellation
of Vela
. Like our Sun
, it is a yellow dwarf
but slightly more massive, hotter and luminous. The spectral type of the star is G0 V. Under exceptionally good circumstances it might be visible to the unaided eye; however, usually binoculars
are needed.
In 2004, a possible red dwarf
companion was detected.
with half the mass of Jupiter
was detected by radial velocity method. This planet is a typical hot Jupiter
that takes only about 3.51 days to revolve at an orbital distance of 0.0482 AU
.
star orbiting HD 75289. The stars share the same proper motion
so they are probably related. Apparent distance between the two stars is about 21.5 arcseconds, at a distance of 94 light years that would be 621 astronomical unit
s. However, the radial distance between the stars is unknown, so they are probably further apart. In any case, one revolution around the primary would take thousands of years to complete.
The study that found the red dwarf also rules out any further stellar companions beyond 140 AUs and massive brown dwarf
companions from 400 AU up to 2000 AU.
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...
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....
of Vela
Vela (constellation)
Vela is a constellation in the southern sky. Its name is Latin for the sails of a ship, and it was originally part of a larger constellation, the ship Argo Navis, which was later divided into three parts, the others being Carina and Puppis.-Stars:...
. Like our 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...
, it is a yellow dwarf
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
but slightly more massive, hotter and luminous. The spectral type of the star is G0 V. Under exceptionally good circumstances it might be visible to the unaided eye; however, usually binoculars
Binoculars
Binoculars, field glasses or binocular telescopes are a pair of identical or mirror-symmetrical telescopes mounted side-by-side and aligned to point accurately in the same direction, allowing the viewer to use both eyes when viewing distant objects...
are needed.
In 2004, a possible red dwarf
Red 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....
companion was detected.
Planetary system
In 1999 a planet HD 75289 bHD 75289 b
HD 75289 b is an extrasolar planet orbiting the star HD 75289 in Vela constellation. It has a minimum mass half that of Jupiter, and it orbits in a very short orbit completing one circular revolution around the star in three and a half days. By studying the starlight scientists have concluded that...
with half the mass of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
was detected by radial velocity method. This planet is a typical hot Jupiter
Hot Jupiter
Hot Jupiters are a class of extrasolar planet whose mass is close to or exceeds that of Jupiter...
that takes only about 3.51 days to revolve at an orbital distance of 0.0482 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
.
HD 75289 B
HD 75289 B is a possible 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 orbiting HD 75289. The stars share the same proper motion
Proper motion
The proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...
so they are probably related. Apparent distance between the two stars is about 21.5 arcseconds, at a distance of 94 light years that would be 621 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s. However, the radial distance between the stars is unknown, so they are probably further apart. In any case, one revolution around the primary would take thousands of years to complete.
The study that found the red dwarf also rules out any further stellar companions beyond 140 AUs and massive 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...
companions from 400 AU up to 2000 AU.