Nu Phoenicis is a

F-type main-sequence star An F-type main-sequence star (F V) is a main-sequence, hydrogen-fusing star of spectral type F and luminosity class V. These stars have from 1.0 to 1.4 times the mass of the Sun and surface temperatures between 6,000 and 7,600 K.Tables VII ...

in the southern constellation of

Phoenix Phoenix most often refers to: * Phoenix (mythology), a legendary bird from ancient Greek folklore * Phoenix, Arizona, a city in the United States Phoenix may also refer to: Mythology Greek mythological figures * Phoenix (son of Amyntor), a ...

. It is visible to the naked eye with an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of 4.95. This is a solar analogue, meaning its observed properties appear similar to the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

, although it is somewhat more massive. At an estimated distance of around 49.5 light years, this star is located relatively near the

. Based on observations of excess infrared radiation from this star, it may possess a dust ring that extends outward several AU from an inner edge starting at 10 AU.

Properties

This is an

with a

spectral type In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

of F9V Fe+0.4, indicating it is similar to the Sun but somewhat hotter and more luminous. The notation 'Fe+0.4' indicates strong iron absorption lines; the star is indeed

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

-rich, with an iron abundance 45% greater than the Sun's. Nu Phoenicis has an estimated mass of 1.17 times the solar mass and a radius of 1.26 times the

solar radius Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: :1\,R_ = 6.957\ ...

. It is shining with about double the

solar luminosity The solar luminosity (), is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal ...

at an effective temperature of 6,070 K. Nu Phoenicis has a

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulg ...

of 3.7 km/s, and a low chromospheric activity index ( = −4.95). These values indicate that the star is not particularly young and has an age of a few billion years; empirical calibrations estimate from the rotational velocity an age of 2.4 billion years, and from the activity index an age of 5.67 billion years. Similarly, stellar evolution models estimate an age between 1 and 6 billion years, with a more probable value of 4.2 billion years. Nu Phoenicis has no known companions, and is considered to be a single star. As a bright star similar to the Sun, it has been targeted in a number of studies searching for planets with the radial velocity method, but no detection has been made. High-precision observations with the

HARPS The High Accuracy Radial Velocity Planet Searcher (HARPS) is a high-precision echelle planet-finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. ...

spectrograph show that the radial velocity of the star has no significant variability, and is constant to 2.67 m/s, a value similar to the estimated jitter level of 2.48 m/s. The star has also been included in the observations of the

Anglo-Australian Planet Search The Anglo Australian Planet Search or (AAPS) is a long-term astronomical survey started in 1998 and continuing to the present. It is being carried out on the 3.9-metre Anglo-Australian Telescope (AAT) of the Anglo-Australian Observatory in Austral ...

, which did not find Jupiter-analogs with periods up to 6,000 days. Nu Phoenicis emits a significant amount of

infrared excess An infrared excess is a measurement of an astronomical source, typically a star, that in their spectral energy distribution has a greater measured infrared flux than expected by assuming the star is a blackbody radiator. Infrared excesses are oft ...

, in comparison to the expected emission from the star's photosphere, indicating it has a circumstellar

debris disk A debris disk (American English), or debris disc (Commonwealth English), 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 di ...

that is warmed by the star and emits

thermal radiation Thermal radiation is electromagnetic radiation generated by the thermal motion of particles in matter. Thermal radiation is generated when heat from the movement of charges in the material (electrons and protons in common forms of matter) i ...

. The excess has been detected in long

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, t ...

s, between 30 and 100 μm, indicating relatively cold dust many astronomical units away from the star. Modeling the emission as a

black body A black body or blackbody is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. The name "black body" is given because it absorbs all colors of light. A black body ...

, the disk has an estimated temperature of 96 K and a radius of 12 AU, contributing to 0.00024% of the system's luminosity.

References

External links

* * {{Stars of Phoenix Phoenicis, Nu 007570 F-type main-sequence stars Phoenicis, Nu Phoenix (constellation) 005862 0370 Durchmusterung objects 0055

Properties

See also

References

External links