LSR J1835+3259 is a nearby
ultracool dwarf of
spectral class
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 ...
M8.5,
located in constellation
Lyra
, from ; pronounced: ) is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star ...
, the discovery of which was published in 2003.
Previously it was concluded that this star is a young
brown dwarf
Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main sequence, main-sequence stars. Their mass is approximately 13 to 80 Jupiter mass, times that of Jupiter ()not big en ...
,
but no
lithium
Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...
absorption lines are detected for this object, which is a strong indicator for young brown dwarfs that need 10–100 million years to deplete lithium.
Distance
Trigonometric
parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphica ...
of this object, measured in 2001–2002 with the USNO 61 inch (1.5 m) reflector under
US Naval Observatory (USNO) parallax program, is 0.1765 ± 0.0005
arcsec, corresponding to a distance of 5.67 ± 0.02
pc, or 18.48 ± 0.05
ly.
Characteristics
The first potential extrasolar
auroras detected occurred in the atmosphere of LSR J1835+3259. They were found in July 2015 by the
Karl G. Jansky Very Large Array in
New Mexico
New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...
by analyzing the emitted radio waves. The potential auroras were probably 1 million times brighter than those ever observed on Earth. The optical emission is mainly red in colour, because the charged particles are interacting with hydrogen in its atmosphere. It is not known what the cause is. Some have speculated that material may be being stripped off the surface of the brown dwarf via stellar winds to produce its own electrons. Another possible explanation is an as-yet-undetected planet or moon around the dwarf, which is throwing off material to light it up, as is the case with
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...
and its moon
Io. High resolution imaging using the
High Sensitivity Array
The Very Long Baseline Array (VLBA) is a system of ten radio telescopes which are operated remotely from their Array Operations Center located in Socorro, New Mexico, as a part of the National Radio Astronomy Observatory (NRAO). These ten radio ...
resolved the quiescent radio emission into two radio lobes, showing that it has a similar structure as
Jupiter radiation belts. The radiation belt is seen in three epochs, spanning more than one year. The two lobes are separated by up to 18 ultracool dwarf radii and the right-circularly polarized aurora appears right in the middle of the two lobes.
References
Table with parallaxes
External links
{{Stars of Lyra
M-type main-sequence stars
Lyra
J18353790+3259545