WD 0806−661 (L 97-3, GJ 3483) is a DQ

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...

with an extremely cold Y-type

substellar A substellar object, sometimes called a substar, is an astronomical object the mass of which is smaller than the smallest mass at which hydrogen fusion can be sustained (approximately 0.08 solar masses). This definition includes brown dwarfs and fo ...

companion (designated "B"), located in the constellation

Volans Volans is a constellation in the southern sky. It represents a flying fish; its name is a shortened form of its original name, Piscis Volans. Volans was one of twelve constellations created by Petrus Plancius from the observations of Pieter Di ...

at 63

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 101 ...

s from Earth. The companion was discovered in 2011, and is the only known Y-type companion to a star or stellar remnant. At the time of its discovery WD 0806-661 B had the largest actual (2500 AU) and apparent separation (more than 2

arcminute A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...

s) of any known planetary-mass object, as well as being the coldest directly imaged substellar object then known.

WD 0806-661 B

Component WD 0806-661 B was discovered in 2011 with the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...

. Its discovery paper is ''Luhman et al., 2011''. The secondary has a mass between 7 and 9 and a temperature between 325–350 Kelvin (52-77 °C; 125-170 °F). At the time of its discovery, WD 0806−661 B was the coldest "

brown dwarf Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen (hydrogen-1, 1H) into helium in their cores, unlike a main sequence, main-sequence star. Instead, they have ...

" that has ever been found. The object is too faint to acquire a spectrum even with the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most ver ...

, however the spectral type of this object was estimated to be Y1 based on its detection in Hubble images at near-infrared wavelengths. The photometric colors of this object suggest that it is

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 typi ...

-poor. The metal-poor composition of the companion could explain the DQ spectral type of the primary white dwarf. Hydrogen-deficient

AGB stars The asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars. This is a period of stellar evolution undertaken by all low- to intermediate-mass stars (about 0.5 to 8 solar masses) late ...

might evolve into DB white dwarfs and then into DQ white dwarfs as they cool down. In August 2022, WD 0806-661 and its planetary-mass companion were included among 20 systems to be named by the third

NameExoWorlds NameExoWorlds (also known as IAU NameExoWorlds) is the name of various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, which would later be considered for official ad ...

project.

References

External links

Simbad — component b
{{DEFAULTSORT:WD 0806-661 Volans (constellation) Binary stars White dwarfs Y-type stars 3483 J08065373−6618167 Planetary systems with one confirmed planet

WD 0806-661 B

See also

References

External links