LSR J1835+3259 explained

LSR J1835+3259 is a nearby ultracool dwarf^[1] of spectral class M8.5, located in constellation Lyra, the discovery of which was published in 2003. Previously it was concluded that this star is a young brown dwarf,^[2] but no lithium 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 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 by analyzing the emitted radio waves. The potential auroras were probably 1 million times brighter than those ever observed on Earth.^[3] 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 and its moon Io.^[4]

References

• Dittmann . Jason A. . Trigonometric Parallaxes for 1507 Nearby Mid-to-late M Dwarfs . 2014 . . 784 . 2 . 156 . 1312.3241 . 10.1088/0004-637X/784/2/156 . 2014ApJ...784..156D. Irwin . Jonathan M. . Charbonneau . David . Berta-Thompson . Zachory K. . 18789867 . Table with parallaxes.

External links

• The 100 Nearest Star Systems (RECONS)

Notes and References

1. Saur. Joachim. Fischer. Christian. Wennmacher. Alexandre. Feldman. Paul D.. Roth. Lorenz. Strobel. Darrell F.. Reiners. Ansgar. May 2018. The UV Spectrum of the Ultracool Dwarf LSR J1835+3259 Observed with the Hubble Space Telescope. Astrophysical Journal. en. 859. 1. 74. 10.3847/1538-4357/aabb55. 0004-637X. 1804.01165. 2018ApJ...859...74S. 56408309 . free .
2. Berdyugina. S. V.. Harrington. D. M.. Kuzmychov. O.. Kuhn. J. R.. Hallinan. G.. Kowalski. A. F.. Hawley. S. L.. September 2017. First Detection of a Strong Magnetic Field on a Bursty Brown Dwarf: Puzzle Solved. Astrophysical Journal. en. 847. 1. 61. 10.3847/1538-4357/aa866b. 1709.02861. 2017ApJ...847...61B. 118904301. 0004-637X . free .
3. Web site: Monstrous Aurora Detected Beyond our Solar System. O'Neill. Ian. July 29, 2015. news.discovery.com. Discovery. July 29, 2015. July 31, 2015. https://web.archive.org/web/20150731022645/http://news.discovery.com/space/alien-life-exoplanets/monstrous-aurora-detected-beyond-our-solar-system-150729.htm. dead.
4. Web site: First Alien Auroras Found, Are 1 Million Times Brighter Than Any On Earth. Q. Choi. Charles. July 29, 2015. space.com. July 29, 2015.