Groombridge 34

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
Astrometry
Groombridge 34 A
Radial velocity (Rv)+11.62±0.08[6] km/s
Proper motion (μ) RA: 2,891.518 mas/yr[2]
Dec.: 411.832 mas/yr[2]
Parallax (π)280.7068 ± 0.0203 mas[2]
Distance11.6191 ± 0.0008 ly
(3.5624 ± 0.0003 pc)
Absolute magnitude (MV)10.32[citation needed]
Groombridge 34 B
Radial velocity (Rv)10.60±0.15[4] km/s
Proper motion (μ) RA: 2,862.796 mas/yr[4]
Dec.: 336.432 mas/yr[4]
Parallax (π)280.6947 ± 0.0278 mas[4]
Distance11.620 ± 0.001 ly
(3.5626 ± 0.0004 pc)
Absolute magnitude (MV)13.3[citation needed]
Orbit[7]
Period (P)1230+930
−110 yr
Semi-major axis (a)93+42
−6 AU
Eccentricity (e)0.53+0.23
−0.28
Inclination (i)54+11
−16°
Longitude of the node (Ω)2+35
−43°
Periastron epoch (T)7140+560
−140
Details
Groombridge 34 A
Mass0.393+0.009
−0.008[8] M☉
Radius0.385±0.002[8] R☉
Luminosity0.02249±0.00019[8] L☉
Habitable zone inner limit0.112[9] AU
Habitable zone outer limit0.239[9] AU
Surface gravity (log g)4.87±0.04[7] cgs
Temperature3,601+12
−11[8] K
Metallicity [Fe/H]−0.34±0.09[7] dex
Rotation43.86±0.56 days[7]
Rotational velocity (v sin i)1.09±0.79[7] km/s
Age~3.02[3] Gyr
Groombridge 34 B
Mass0.15±0.02[7] M☉
Radius0.18±0.03[7] R☉
Luminosity~8.5×10−4[7] L☉
Habitable zone inner limit0.048[9] AU
Habitable zone outer limit0.103[9] AU
Surface gravity (log g)5.08±0.15[7] cgs
Temperature3304±70[7] K
Metallicity [Fe/H]−0.37±0.10[3] dex
Age~2.754[3] Gyr
Other designations
GX/GQ Andromedae, BD+43° 44, GCTP 49, GJ 15 A/B, G 171-047/171-048, HD 1326, HIP 1475, 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 binary star system in the northern constellation of Andromeda. It was listed as entry number 34 in A Catalogue of Circumpolar Stars, published posthumously in 1838 by British astronomer Stephen Groombridge.[11] Based upon parallax measurements taken by the Gaia spacecraft, the system is located about 11.6 light-years (3.6 parsecs) from the Sun. This positions the pair among the nearest stars to the Solar System.

Both components are small, dim red dwarf stars that are too faint to be seen with the naked eye. They orbit around their common barycenter in a fairly eccentric orbit with a separation of about 93 AU and a period of around 1,230 years.[7] Both stars exhibit random variation in luminosity due to flares and they have been given 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 arc seconds per year,[13] and is moving away from the Solar System at a velocity of 11.6 km/s.[6] It achieved perihelion some 15,000 years ago when it came within 11 ly (3.5 pc) of the Sun.[13]

  1. ^ Cite error: The named reference Pettersen was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Gaia DR3 A was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference apj804_1_64 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference Gaia DR3 B was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference MERMILLIOD was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Nidever2002 was invoked but never defined (see the help page).
  7. ^ a b c d e f g h i j k Cite error: The named reference Pinamonti2018 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Pineda2021 was invoked but never defined (see the help page).
  9. ^ a b c d Cite error: The named reference aaa555_A104 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference groombridge1838 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference petit1990 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference aa575_A35 was invoked but never defined (see the help page).