|Designation|| GX/GQ Andromedae|
|Right ascension||00h 18m 22.9s|
|Declination||+44o 01' 22"|
|Type of object||Binary star|
|Magnitude|| Absolute Mag: 10.33|
Apparent Mag: 8.09(A)/11.06(B)
|Distance from Earth||11.62 ±0.04 ly|
|Radial velocity||+12.0 km/s|
|Proper motion|| RA: 2888.92 mas/yr|
Dec.: 410.58 mas/yr
|Parallax||280.59 ± 0.95 mas|
Groombridge 34 is a binary star system located around 11.6 light years from our Sun. The system is located in the constellation Andromeda, northwest of the Andromeda galaxy. Neither star is visible in the night sky to the unaided eye, with Groombridge 34 A having an apparent magnitude of 8.09 and Groombridge 34 B an apparent magnitude of only 11.06. Both stars of the Groombridge 34 AB system are flare stars and therefore also have the variable star designation of GX Andromedae and GQ Andromedae respectively.
The binary star system was first mentioned in "A Catalog of Circumpolar Stars" by Stephen Groombridge, published after his death in 1838. In 1860 it was discovered the system has a large proper motion relative to our own solar system.
Groombridge 34 A
Groombridge 34 A is the more massive of the pair and is a main sequence red dwarf of the spectral class M1.5 Vne. The star has around 48.6 percent of the Sun's mass and 34 percent of its diameter. The star is very dim, with only 64/10,000th of the Sun's visual luminosity. It is estimated that Groombridge 34 A is, on average, some 157 AU from its companion, with an orbital period of around 3,000 years.
Groombridge 34 B
Groombridge 34 B is cooler and dimmer then its companion with a spectral class of M3.5 Vne. It has some 16.3 percent of our Sun's mass and 19 percent of its diameter. The star is only some 42/10,000th as visually luminous as our Sun.
Thus far no substellar companions have been located around either star of the Groombridge 34 system. For an Earth-like world to be comfortable with liquid water on the surface, it would have to be around 0.25 AU from Groombridge 34 A and 0.13 from Groombridge 34 B when taking into account infrared radiation. However, if such a world exists, it would be very difficult for life to exist there as both stars in the Groombridge 34 system are flare stars. At the distance needed for liquid water to exist, the world would be exposed up to 10,000 times the normal X-ray output during a flare, which would be deadly to life as we know it.
- Groombridge 34 AB