Wolf 359

from Wikipedia, the free encyclopedia
Stern
Wolf 359 (CN Leonis)
Amateur shot of the star field with Wolf 359 (the striking red star slightly above the center of the image)
Amateur shot of the star field with Wolf 359 (the striking red star slightly above the center of the image)
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation lion
Right ascension 10 h 56 m 28.8 s
declination + 07 ° 00 ′ 52 ″
Apparent brightness 13.51 mag
Typing
rel. Brightness
(J-band) 		(7.09 ± 0.02) mag
Known exoplanets 2
B − V color index +2.03 
U − B color index +1.17 
R − I index +2.18 
Spectral class M6.5 Ve
Variable star type UV 
Astrometry
Radial velocity (19.32 ± 0.15) km / s
parallax (415.16 ± 1.62)  mas
distance (7.78 ± 0.04)  ly
(2.39 ± 0.01)  pc
Visual absolute brightness M vis (+16.69) mag
Proper movement 
Rec. Share: (−3808.09 ± 0.30)  mas / a
Dec. portion: (−2692.61 ± 0.42)  mas / a
Physical Properties
Dimensions 0.09  M ☉
radius 0.16  R ☉
Luminosity

(0.001)  L ☉

Effective temperature (2800 ± 100)  K.
Rotation time 24 hours
Age 100 to 400 mill.  A
Other names
and catalog entries
Gliese catalog GJ 406 [1]
2MASS catalog 2MASS J10562886 + 0700527 [2]
Other names Wolf 359 • CN Leonis • LHS 36 • G 45-20

Template: Infobox Star / Maintenance / MagJ

Wolf 359 is a red dwarf in the constellation Leo . At a distance of about 7.8 light years , it is the fifth closest star to the solar system . Nevertheless, Wolf 359 cannot be seen with the naked eye because of its low brightness. The star was only discovered in 1918 by the German astronomer Max Wolf using astrophotography and named in a star catalog he published.

description

Wolf 359 is one of the faintest shining stars known to date. With around 10 percent of the solar mass, it is a borderline case between a brown and a red dwarf . Its core temperature was only just enough to start a nuclear fusion of hydrogen to helium and to generate energy from it.

As an extreme red dwarf of the M6 spectral type , the star glows dark red. Wolf 359 tends to have irregular bursts in which its brightness increases sharply for a short time. This property is typical of many red dwarfs, so this type is also known as a flare star . As a variable star , Wolf 359 is called CN Leonis .

Planetary system

In 2019 the possible discovery of 2 planets around Wolf 359 using the radial velocity method was announced. The study combined the data gathered over the years from several Échelle spectrographs . The inner planet Wolf 359 c is already outside the habitable zone despite a distance of only 0.018 AU . The outer planet Wolf 359 b is much further out with about 1.8 AU and due to the low luminosity of Wolf 359 it hardly receives any more energy from the star.

Because of its low luminosity, the habitable zone around Wolf 359 is very close to the star. A hypothetical planet with liquid water would have to orbit Wolf 359 in only 0.004 AU (628,000 km). That is less than twice the distance from the earth to the moon. The result would be a bound rotation and orbiting the star would only take around eight hours at this distance. Planets at a greater distance would be too cold for liquid water.

Wolf 359 planets
planet
 Discovered Mass
( earth masses ) 		Radius
( earth radii ) 		Major semiaxis of
the railway
( AU ) 		Rotation time
( days ) 		eccentricity
Wolf 359 b 2019 43.5   +29.5−23.9 - 1.845   +0.289−0.258 2938 ± 436 0.04   +0.27−0.04
Wolf 359 c 2019 3.8   +2.0−1.6 - 0.018 ± 0.002 2.69 ± 0.01 0.15   +0.20−0.15

Visual observation

Constellation Leo with the position of Wolf 359

Wolf 359 is quite easy to find just below the Leo constellation. The strikingly red, 5.8 mag bright star 56 Leonis can serve as a guide. Wolf 359 is 50 arc minutes north of it.

Wolf 359 is so faint that it can only be seen in a larger instrument with a diameter of 35 cm or more. Visual observation is hardly possible in smaller instruments.

Mention in science fiction

  • In the Star Trek universe, Wolf 359 is the scene of a crushing defeat of the Federation against the Borg , to which reference is made in later episodes, series, films and games.
  • In the computer game Freespace , a Terran fleet is stationed at Wolf 359. A transfer there is only mentioned in the case of penalties for failed missions.
  • In the novel Chindi by Jack McDevitt Wolf 359 is mentioned as a goal of the second interstellar journey of humanity.
  • In the novel The Collapse (Volume 1 of the series Die Nanokriege ) by John Ringo , a larger terraforming project takes place at Wolf 359 .
  • In the novel The Red Fog (1979) from the science fiction series about the character of Commander Perkins ( Franz Schneider Verlag ), the earth is threatened by a red fog that transports Wolf 359 from the eighth planet of the sun to earth with the help of the dimension breaker becomes.
  • In the radio play Planetaktion Z of the Mark Brandis science fiction series , a rescue maneuver is flown towards Wolf 359.

See also

Web links

Commons : Wolf 359  - Collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d e f g h Wolf 359. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed June 15, 2019 .
  2. ↑ a b c M. Tuomi, HRA Jones, G. Anglada-Escudé, RP Butler, P. Arriagada, SS Vogt, J. Burt, G. Laughlin, B. Holden, JK Teske, SA Shectman, JD Crane, I. Thompson, S. Keizer, JS Jenkins, Z. Berdiñas, M. Diaz, M. Kiraga, JR Barnes: Frequency of planets orbiting M dwarfs in the solar neighborhood . In: arxiv . 2019. arxiv : 1906.04644 .
  3. ↑ a b Wolf 359 b. In: Extrasolar Planets Encyclopaedia . Retrieved June 15, 2019 .
  4. ↑ a b CN Leo. In: VSX. AAVSO , accessed November 10, 2018 .
  5. ^ A b c Cassy L. Davison, RJ White, TJ Henry, AR Riedel, W.-C. Jao, JI Bailey, SN Quinn, JR Cantrell, JP Subasavage, JG Winters: A 3D Search for Companions to 12 Nearby M Dwarfs . In: The Astronomical Journal . 149, No. 3, 2015, p. 106. arxiv : 1501.05012 . bibcode : 2015AJ .... 149..106D . doi : 10.1088 / 0004-6256 / 149/3/106 .
  6. ↑ a b c Ya. V. Pavlenko, HRA Jones, Yu. Lyubchik, J. Tennyson, DJ Pinfield: Spectral energy distribution for GJ406 . In: Astronomy & Astrophysics . 447, No. 2, 2006, pp. 709-717. arxiv : astro-ph / 0510570 . bibcode : 2006A & A ... 447..709P . doi : 10.1051 / 0004-6361: 20052979 .
  7. ↑ M. Wolf: Two stars with great proper motion in Leo. Astronomische Nachrichten, Volume 206 (1918), Issue 24, No. 4944, p. 237 (there star No. 699), bibcode : 1918AN .... 206..237W
  8. ^ M. Wolf: Catalog of 1053 more strongly moved fixed stars. Publications of the Baden Observatory in Heidelberg, Volume 7 (1919), No. 10, 195–219, bibcode : 1919VeHei ... 7..195W