2MASS J0523−1403 is a very-low-mass

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...

or high-mass brown dwarf about 40 light-years from Earth in the southern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

of Lepus, with a very faint visual magnitude of 21.05 and a low effective temperature of 2074 K. It is visible primarily in large telescopes sensitive to infrared light. 2MASS J0523−1403 was first observed as part of the Two Micron All-Sky Survey (

2MASS The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and ...

Characteristics

2MASS J0523−1403 has a

luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...

of , a radius of , and an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of 2074 K. These values are currently the lowest known for a main-sequence star. It has a

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

of L2.5 and a V−K color index of 9.42. The mass is calculated to be (). Observation with the Hubble Space Telescope has detected no companion beyond 0.15

arcsecond 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 ...

. Sporadic radio emissions were detected by the

VLA VLA or vla may refer to: Organizations * Vermont Library Association, professional organization for librarians from Vermont * Veterinary Laboratories Agency, a UK government agency for researching animal and public health * Victoria Legal Aid, an ...

in 2004. H-alpha (Hα) emissions have also been detected, a sign of

chromospheric activity A chromosphere ("sphere of color") is the second layer of a star's atmosphere, located above the photosphere and below the solar transition region and corona. The term usually refers to the Sun's chromosphere, but not exclusively. In the S ...

Hydrogen burning limit

Members of the RECONS group have recently identified 2MASS J0523−1403 as representative of the smallest possible stars. Its small radius is at the local minimums of the radius–luminosity and radius–temperature trends. This local minimum is predicted to occur at the

hydrogen burning limit This glossary of astronomy is a list of definitions of terms and concepts relevant to astronomy and cosmology, their sub-disciplines, and related fields. Astronomy is concerned with the study of celestial objects and phenomena that originate outsid ...

due to differences in the radius-mass relationships of stars and brown dwarfs. Unlike hydrogen-burning stars, brown dwarfs decrease in radius as mass increases due to their cores being supported by degeneracy pressure. As the mass increases an increasing fraction of the brown dwarf is degenerate causing the radius to shrink as mass increases. The minimum stellar mass is estimated to be between 0.07 and 0.077 , comparable to the mass of 2MASS J0523−1403.

References

{{DEFAULTSORT:2MASS J0523-1403 Lepus (constellation) L-type stars J05233822-1403022 TIC objects

Characteristics

Hydrogen burning limit

See also

References