Groombridge 34

from Wikipedia, the free encyclopedia
Double star
Groombridge 34
Observation
dates equinox :  J2000.0 , epoch : J2000.0
AladinLite
Constellation Andromeda
Right ascension 00 h 18 m 22.89 s
declination + 44 ° 01 ′ 22.6 ″
Known exoplanets

1

Astrometry
Radial velocity +12.0 km / s
parallax (280.69 ± 0.04)
(280.78 ± 0.05) mas
distance  11.61 ± 0.01 ly
(3.56 ± 0.01 pc )
Proper movement :
Rec. Share: (2891.53 ± 0.06)
(2863.28 ± 0.07) mas / a
Dec. portion: (411.90 ± 0.03)
(336.53 ± 0.04) mas / a
orbit 
period 2600 a
Major semi-axis 41.15 AU
eccentricity 0.00
Orbit inclination 61.4 °
Argument of the node 45.3 °
Epoch of the periastron 1745
Individual data
Names A; B.
Observation data:
Apparent brightness

A. 8.13 mag
B. 11.04 mag
Typing:
Spectral class A. M2 V
B. M3.5 Ve
B − V color index A. (1.99)
B. (1.80)
U − B color index A. 1.24
B. 1.24
Physical Properties:
Dimensions A. 0.40 M ☉
B. 0.16 M ☉
radius A. 0.3863 ± 0.0021 R ☉
B. 0.19 R ☉
Luminosity A. 0.026 L ☉
B. ~ 0.003 L ☉
Effective temperature A. 3730 ± 49 K
B. ~ 3000 K
Metallicity [Fe / H] A. −0.32
B.
Other names
and catalog entries
Bonn survey BD + 43 ° 44
Henry Draper Catalog HD 1326 [1]
SAO catalog SAO 36248 [2]
Tycho catalog TYC 2794-157-1 [3]
Hipparcos catalog HIP 1475 [4]
WDS catalog WDS J00184 + 4401
Further designations: GCTP 49,
  GX And, GJ 15 A, Gl 171-047, LHS 3, LTT 10108, LFT 31, Vys 085 A GQ And, GJ 15 B, Gl 171-048, LHS 4, LTT 10109, LFT 32, Vys 085 B

Template: Infobox double star / maintenance / RekDekSizeLeer

Groombridge 34 is a binary star system 11.7  light years from the Sun in the constellation Andromeda . It consists of two red dwarfs in a nearly circular orbit around their common barycentre with a separation of over 147 AU . Both stars are variable and show random flares , which is why they have been given variable names . In this case, the brighter star Groombridge 34 A is called GX Andromedae , the weaker star Groombridge 34 B is called GQ Andromedae .

distance

Determining the distance for Groombridge 34

source Parallax (mas) Distance (pc) Distance (Lj) Distance ( Pm )
Woolley et al. (1970) 282 ± 7 3.55 ± 0.09 11.57 +0.29−0.28 109.4 +2.8−2.7
Gliese & Jahreiß (1991) 289.5 ± 4.9 3.56 ± 0.06 11.27 ± 0.19 106.6 ± 1.8
van Altena et al. (1995) 282.0 ± 2.2 3.546   +0.28−0.27 1.57 ± 0.09 109.4   +0.9−0.8
Perryman et al. (1997) (Hipparcos) 280.27 ± 1.05 3.568 ± 0.013 11.64 ± 0.04 110.1 ± 0.4
Perryman et al. (1997) (Tycho) 320.70 ± 24.40 3.12   +0.26−0.22 10.2   +0.8−0.7 96.2   +7.9−6.8
van Leeuwen (2007) 278.76 ± 0.77 3.587 ± 0.01 11.7 ± 0.03 110.69   +0.31−0.30
Gatewood (2008) (MAP-based study) 281.45 ± 1.05 3.553 ± 0.013 11.59 ± 0.04 109.6 ± 0.4
RECONS TOP100 (2012) 279.87 ± 0.60 3.573 ± 0.008 11.654 ± 0.025 110.25 ± 0.24
Dittmann et al. (2014) (A) 279.30 ± 5.40 3.58 ± 0.07 11.68   +0.23−0.22 10.5   +2.2−2.1
Dittmann et al. (2014) (B) 313.90 ± 9.30 3.19   +0.10−0.09 10.39   +0.32−0.30 98.3   +3.0−2.8
Gaia DR2 (2018) 280.69 ± 0.04
280.79 ± 0.05 		3.56 ± 0.01 11.61 ± 0.01 109.84 ± 0.04

Non-trigonometric distance determinations are marked in italics . The most precise determination is marked in bold .

Planetary system

In August 2014, the discovery of an exoplanet around Groombridge 34 A was announced. The existence of the planet was from analyzes of the radial velocities of the parent star at Eta-Earth Survey with the HIRES - spectrograph at the Keck Observatory on Mauna Kea ( Hawaii derived).

The planet ( Groombridge 34 Ab ) is believed to have a mass of at least 5.35 ± 0.75 Earth masses. It orbits its parent star in 11.4433 ± 0.0017 days with a semi-major axis of 0.0717 ± 0.0034 AU. At the time of its discovery, Groombridge 34 Ab was the sixth nearest known exoplanet.

Web links

Individual evidence

  1. ↑ a b c VizieR: HIP 1475. Accessed March 28, 2015 .
  2. ↑ a b c Andrew W. Howard, Geoffrey W. Marcy, Debra A. Fischer, Howard Isaacson, Philip S. Muirhead, Gregory W. Henry, Tabetha S. Boyajian, Kaspar von Braun, Juliette C. Becker, Jason T. Wright , John Asher Johnson: The NASA-UC-UH Eta-Earth Program: IV. A Low-mass Planet Orbiting an M Dwarf 3.6 PC from Earth . arxiv : 1408.5645 .
  3. ↑ GX am. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed November 8, 2018 .
  4. ↑ GQ am. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed November 8, 2018 .
  5. ↑ a b D. H. Berger, DR Gies, HA McAlister, TA ten Brummelaar, TJ Henry, J. Sturmann, L. Sturmann, NH Turner, ST Ridgway, JP Aufdenberg, A. Merand: First Results from the CHARA Array. IV. The Interferometric Radii of Low-Mass Stars . arxiv : astro-ph / 0602105 .
  6. ^ Woolley R., Epps EA, Penston MJ, Pocock SB: GJ 1111. Retrieved March 28, 2015 .
  7. ↑ Gliese, W. and Jahreiß, H .: Gl 15. Accessed on March 28, 2015 .
  8. ^ Van Altena WF, Lee JT, Hoffleit ED: GCTP 49. Retrieved March 28, 2015 .
  9. ↑ a b Perryman et al .: HIP 1475. Retrieved March 28, 2015 .
  10. ↑ George Gatewood: Astrometric Studies of Aldebaran, Arcturus, Vega, the Hyades, and Other Regions. Retrieved March 28, 2015 .
  11. ↑ RECONS: THE ONE HUNDRED NEAREST STAR SYSTEMS. Retrieved March 28, 2015 .
  12. ↑ a b Dittmann, Jason A .; Irwin, Jonathan M .; Charbonneau, David; Berta-Thompson, Zachory K .: Trigonometric Parallaxes for 1,507 Nearby Mid-to-Late M-dwarfs . arxiv : 1312.3241 .
  13. ↑ Andrew W. Howard, Geoffrey W. Marcy, Debra A. Fischer, Howard Isaacson, Philip S. Muirhead, Gregory W. Henry, Tabetha S. Boyajian, Kaspar von Braun, Juliette C. Becker, Jason T. Wright, John Asher Johnson: The NASA-UC-UH Eta-Earth Program: IV. A Low-mass Planet Orbiting an M Dwarf 3.6 pc from Earth . arxiv : 1408.5645 .