Gliese 221
From Infogalactic: the planetary knowledge core
Observation data Epoch J2000.0 Equinox J2000.0 |
|
---|---|
Constellation | Orion |
Right ascension | 05h 53m 00.0s |
Declination | −05° 59′ 41″ |
Apparent magnitude (V) | 9.69 ± 0.01 |
Characteristics | |
Spectral type | K7V/M0V |
Astrometry | |
Parallax (π) | 49.23±1.65 mas |
Distance | 66 ly (20 ± 1 pc) |
Details | |
Mass | 0.7 M☉ |
Radius | ? R☉ |
Luminosity | 0.095 ± 0.01 L☉ |
Surface gravity (log g) | 4.74 ± 0.02 cgs |
Temperature | 4324 ± 100 K |
Metallicity | -0.14 ± 0.17 |
Age | 4.4 ± 4 × 109 years |
Other designations | |
BD-061339, HIP 27803, LTT 2396
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|
Database references | |
SIMBAD | data |
Exoplanet Archive | data |
Extrasolar Planets Encyclopaedia |
data |
Gliese 221 is an orange-red dwarf star.
Planetary system
From 2003 to 2012, the star was under observance from HARPS. It is becoming less active and this reduced activity allowed for lower-mass planetary measurements to be made.
In 2012, a super-Venus planet, and an eccentric Neptune / Saturn in the habitable zone,[1] were deduced by radial velocity. They were published in January 2013. In January 2014, a new, sub-Saturn planet candidate was reported.[2]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >0.027 ± 0.004 MJ | 0.0428 ± 0.0007 | 3.8728 ± 0.0004 | - | — | — |
c | >0.17 ± 0.03 MJ | 0.435 ± 0.007 | 125.94 ± 0.44 | 0.31 ± 0.11 | — | — |
d (unconfirmed) | >0.07 MJ | 1.0947 | 500 | — | — | — |
References
- ↑ The preprint defined the star's HZ to 0.5-0.9 AU. Square root of luminosity would put an Earth analogue at 0.31 AU. The planet's semimajor is 0.435 AU.
- ↑ A new cold sub-Saturnian candidate planet orbiting GJ 221: Mikko Tuomi, January 16, 2014
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
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