WISE 1541-2250
Encyclopedia
WISE 1541-2250 (full designation is WISEPA J154151.66-225025.2) is a brown dwarf
, located in constellation . It is one of six Y-type brown dwarfs (along with WISE 0410+1502
, WISE 1405+5534
, WISE 1738+2732
, WISE 1828+2650 and WISE 2056+1459
) among 106 brown dwarfs (counting components of two binary systems of brown dwarfs), discovered in 2011 by the Wide-field Infrared Survey Explorer
.
s distance from the Sun, and the seventh-nearest of all star systems, at slightly more than twice the distance of the nearest known star system Alpha Centauri
. Its spectrophotometric distance estimate is 8.2 pc
(26.7 ly
), and its trigonometric parallax
with baseline 1.2 years is 0.351 ± 0.108 arcsec, giving distance 2.8 + 1.3/– 0.6 pc (9.3 + 4.1/– 2.2 ly), which is in agreement with spectrophotometric distance estimate only at the 3
σ
level
. Another (photometric) distance estimate (in better agreement with trigonometric parallax) is 1.8 + 0.2/– 0 pc (5.9 + 0.6/– 0 ly). If this is true, WISE 1541-2250 may be located even closer than Barnard's Star
.
The object is among the first known examples of a Y class brown dwarf, the coldest spectral class of stars, and has temperature about 350 K
.
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...
, located in constellation . It is one of six Y-type brown dwarfs (along with WISE 0410+1502
WISE 0410+1502
WISE 0410+1502 is a brown dwarf of spectral class Y0, located in constellation . It is one of six Y-type brown dwarfs among 106 brown dwarfs , discovered in 2011 by the Wide-field Infrared...
, WISE 1405+5534
WISE 1405+5534
WISE 1405+5534 is a brown dwarf of spectral class Y0 , located in constellation...
, WISE 1738+2732
WISE 1738+2732
WISE 1738+2732 is a brown dwarf of spectral class Y0, located in constellation . It is one of six Y-type brown dwarfs among 106 brown dwarfs , discovered in 2011 by the Wide-field Infrared...
, WISE 1828+2650 and WISE 2056+1459
WISE 2056+1459
WISE 2056+1459 is a brown dwarf of spectral class Y0, located in constellation . It is one of six Y-type brown dwarfs among 106 brown dwarfs , discovered in 2011 by the Wide-field Infrared...
) among 106 brown dwarfs (counting components of two binary systems of brown dwarfs), discovered in 2011 by the Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer is a NASA infrared-wavelength astronomical space telescope launched on December 14, 2009, and decommissioned/hibernated on February 17, 2011 when its transmitter was turned off...
.
Overview
WISE 1541-2250 is probably the nearest known brown dwarf at approximately 9 light-yearLight-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s distance from the Sun, and the seventh-nearest of all star systems, at slightly more than twice the distance of the nearest known star system Alpha Centauri
Alpha Centauri
Alpha Centauri is the brightest star in the southern constellation of Centaurus...
. Its spectrophotometric distance estimate is 8.2 pc
Parsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
(26.7 ly
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
), and its trigonometric 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"...
with baseline 1.2 years is 0.351 ± 0.108 arcsec, giving distance 2.8 + 1.3/– 0.6 pc (9.3 + 4.1/– 2.2 ly), which is in agreement with spectrophotometric distance estimate only at the 3
68-95-99.7 rule
In statistics, the 68-95-99.7 rule, or three-sigma rule, or empirical rule, states that for a normal distribution, nearly all values lie within 3 standard deviations of the mean....
σ
Standard deviation
Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the average...
level
68-95-99.7 rule
In statistics, the 68-95-99.7 rule, or three-sigma rule, or empirical rule, states that for a normal distribution, nearly all values lie within 3 standard deviations of the mean....
. Another (photometric) distance estimate (in better agreement with trigonometric parallax) is 1.8 + 0.2/– 0 pc (5.9 + 0.6/– 0 ly). If this is true, WISE 1541-2250 may be located even closer than Barnard's Star
Barnard's star
Barnard's Star, also known occasionally as Barnard's "Runaway" Star, is a very low-mass red dwarf star approximately six light-years away from Earth in the constellation of Ophiuchus . In 1916, the American astronomer E.E...
.
The object is among the first known examples of a Y class brown dwarf, the coldest spectral class of stars, and has temperature about 350 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...
.