Groombridge 34

Coordinates: Sky map 00h 18m 22.8850s, +44° 01′ 22.6373″
Source: Wikipedia, the free encyclopedia.
Groombridge 34

Ultraviolet band light curves for GX Andromedae, with flares marked by red arrows. Adapted from Pettersen and Griffin (1980)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Groombridge 34 A
Right ascension 00h 18m 22.88498s[2]
Declination +44° 01′ 22.6380″[2]
Apparent magnitude (V) 8.119[3]
Groombridge 34 B
Right ascension 00h 18m 25.82514s[4]
Declination +44° 01′ 38.0924″[4]
Apparent magnitude (V) 11.007[3]
Characteristics
Spectral type M1.4V + M4.1V[3]
U−B color index +1.24/+1.40[5]
B−V color index +1.56/+1.80[5]
Variable type Flare stars
Distance
11.620 ± 0.001 ly
(3.5626 ± 0.0004 pc)
Periastron epoch
(T)		7140+560
−140
Details
Groombridge 34 A
Gyr
LHS 3/4, LTT 10108/10109, SAO 36248, PPM 42798[10]
Database references
SIMBADGJ 15 A
GJ 15 Ab
GJ 15 B
ARICNSGJ 15 A
GJ 15 B
Groombridge 34 is located in the constellation Andromeda.
Groombridge 34 is located in the constellation Andromeda.
Groombridge 34
Location of Groombridge 34 in the constellation Andromeda

Groombridge 34 is a

nearest stars
to the Solar System.

Both components are small, dim

variable star designations: the brighter member Groombridge 34 A is designated GX And, while the smaller component is designated GQ And.[12]

The star system has a relatively high proper motion of 2.9 

perihelion some 15,000 years ago when it came within 11 ly (3.5 pc) of the Sun.[13]

GX Andromedae

The more massive and luminous component of the pair has the

stellar flares. Gaia observations suggest a rotation period of 44 days and a magnetic activity cycle of roughly 9 years.[14]

GQ Andromedae

The smaller companion bears the variable star name GQ Andromedae. It is a red dwarf main sequence star that undergoes flare events like the primary; it has a spectral type M4.1,[3] so it also has a lower effective temperature.

Planetary system

In August 2014, a planet orbiting around Groombridge 34 A was reported.

Keck Observatory. At the time of its discovery, it was the sixth-nearest-known exoplanet
.

Using the

HARPS and HIRES spectrographs, researchers failed to detect the purported Groombridge 34 Ab. However, they did propose that another planet (Groombridge 34 Ac, GJ 15 Ac) could be orbiting the parent star.[16]

This discrepancy was later reconciled with new HIRES observations, covering a longer span of time, where both planets were recovered, constraining their minimum mass to 3.03 ME for Groombridge 34 Ab and 36 ME for Groombridge Ac. Their orbital periods are 11.4 and approximately 7,600 days, respectively. To date, this is the fourth-closest confirmed multi-planet system to the Sun, hosting the longest-period Neptune-mass exoplanet discovered so far.[7]

The Groombridge 34 A planetary system[7]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b ≥3.03+0.46
−0.44 M🜨 		0.072+0.003
−0.004 		11.4407+0.0017
−0.0016 		0.094+0.091
−0.065 		— —
c ≥36+25
−18 M🜨 		5.4+1.0
−0.9 		~7,600 0.27+0.28
−0.19 		— —

See also

  • List of nearest stars and brown dwarfs

References

  1. Bibcode:1980Obs...100..198P
    . Retrieved 30 October 2022.
  2. ^
    S2CID 244398875
    . Gaia DR3 record for this source at VizieR.
  3. ^
    S2CID 19269312
    , 64.
  4. ^
    S2CID 244398875
    . Gaia DR3 record for this source at VizieR.
  5. ^
    Bibcode:1986EgUBV........0M
    .
  6. ^
    S2CID 51814894
    .
  7. ^
    S2CID 54990041
    .
  8. ^
    S2CID 235435757
    . 40.
  9. ^
    S2CID 44208180
    .
  10. ^ "V* GX And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-02-09.{{cite web}}: CS1 maint: postscript (link)
  11. ^ Groombridge, Stephen (1838), Airy, George Biddell (ed.), A Catalogue of Circumpolar Stars, J. Murray, p. 2.
  12. Bibcode:1990A&AS...85..971P
    .
  13. ^
    S2CID 59039482
    . A35.
  14. S2CID 73564680
    .
  15. S2CID 17361592
    , 51.
  16. S2CID 119340839
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Groombridge_34&oldid=1229406504"