WISE J072003.20−084651.2

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Double star
WISE J072003.20−084651.2
Observation
dates equinox :  J2000.0 , epoch : J2000.0
AladinLite
Constellation unicorn
Right ascension 07 h 20 m 03.254 s
declination −08 ° 46 ′ 49.90 ″
Apparent brightness  18.3 mag
Astrometry
parallax 166 ± 28 marcsec mas
distance  approx. 20 ly
(approx. 6 pc )
Absolute visual brightness M vis 19.4 mag
Individual data
Names A; B.
Typing:
Spectral class A. M9 ± 1
B. T5
Physical Properties:
Dimensions A. approx. 0.08 M ☉
B. approx. 0.06 M ☉
Age approx. 3–10 billion years
Other names
and catalog entries
Further designations: WISE 0720-0846
  Scholz's star

WISE J072003.20-084651.2 (short WISE 0720-0846 , also Scholz 'star ) is a double system about 20 light years (6 parsecs ) away from the sun in the southern constellation Unicorn .

The star is a red dwarf with the spectral class M9 ± 1 and 86 ± 2 Jupiter masses . The companion is probably a brown dwarf with the spectral class T5 with 65 ± 12 Jupiter masses. The system has 0.15 solar masses . The pair orbit each other at a distance of 0.8 astronomical units (AU). The system has an apparent magnitude of 18.3 mag and is estimated to be between 3 and 10 billion years old. With a parallax of 166 milli arcseconds , more than 60 known star systems are closer to the sun. It is a late discovery compared to neighboring stars because previous research has focused on objects with higher proper motion.

It is estimated that 70,000 years ago the WISE-0720-0846 system passed the sun at a distance of 52,000 AU. It is believed that comets from the Oort cloud that are disturbed in their orbit need around 2 million years to reach the inner solar system. At this approximation, the star is said to have an apparent magnitude of 11.4 mag. It is estimated that about once every 100,000 years a strange star crosses the Oort cloud. Approaching 52,000 AU or closer thereafter occurs approximately every 9 million years.

The proximity of the star to the solar system was first in 2013 by the German astronomer Ralf-Dieter Scholz of the Leibniz Institute for Astrophysics Potsdam reported and the system the informal name Scholz 'Star (English: Scholz's star ) received.

Individual evidence

  1. ↑ a b c d e f g h i j Eric E. Mamajek, Scott A. Barenfeld, Valentin D. Ivanov, Alexei Y. Kniazev, Petri Vaisanen, Yuri Beletsky, Henri MJ Boffin: The Closest Known Flyby of a Star to the Solar system. In: The Astrophysical Journal Letters, 800 (2015), L17. doi: 10.1088 / 2041-8205 / 800/1 / L17 arxiv : 1502.04655
  2. ^ Research Consortium On Nearby Stars: THE ONE HUNDRED NEAREST STAR SYSTEMS. Retrieved March 22, 2015 .
  3. ↑ Science Daily: Featured Research: Closest known flyby of star to our solar system: Dim star passed through Oort Cloud 70,000 years ago. Retrieved March 22, 2015 .
  4. ↑ Eric Mamajek: FAQ about Scholz's star (WISE J072003.20-084651.2), which had the closest known flyby of a star system to the solar system. Accessed March 22, 2015 .
  5. ↑ R.-D. Scholz: Neighbors hiding in the Galactic plane, a new M / L dwarf candidate for the 8 pc sample. In: Astronomy & Astrophysics, 561 (2014), A113 doi: 10.1051 / 0004-6361 / 201323015

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