Gliese 221
Gliese 221 is an orange-red dwarf star 66 light years from Earth. It is depleted in heavy elements, containing just 46% of solar abundance of iron.[2]
| 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 | |
| Radial velocity (Rv) | 22.9±0.4[1] km/s |
| Proper motion (μ) | RA: -1.170[1] mas/yr Dec.: -346.762[1] mas/yr |
| Parallax (π) | 49.2485 ± 0.0185[1] mas |
| Distance | 66.23 ± 0.02 ly (20.305 ± 0.008 pc) |
| Details[2] | |
| Mass | 0.72±0.21 M☉ |
| Radius | ? R☉ |
| Luminosity | 0.095 ± 0.01 L☉ |
| Surface gravity (log g) | 4.74 ± 0.02 cgs |
| Temperature | 4324 ± 100 K |
| Metallicity | -0.34±0.08 |
| Age | 4.4±4 Gyr |
| Other designations | |
BD-061339, HIP 27803, LTT 2396, 2MASS J05530028-0559410, Gaia EDR3 3022099969137163904 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
Planetary system
From 2003 to 2012, the star was under observance from the High Accuracy Radial Velocity Planet Searcher (HARPS). It is becoming less active and this reduced activity allowed for lower-mass planetary measurements to be made.
A super-Venus planet, and an eccentric Neptune / Saturn in the habitable zone, were deduced by radial velocity in January 2013.[3] They were confirmed in May 2013.[4] In January 2014, a candidate planet d was proposed.[5]
The planet Gliese 221b is not transiting the disk of the parent star.[6]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | >8.5806 ± 1.2712 M⊕ | 0.0428 ± 0.0007 | 3.8728 ± 0.0004 | - | — | — |
| c | >54.026 ± 9.534 M⊕ | 0.435 ± 0.007 | 125.94 ± 0.44 | 0.31 ± 0.11 | — | — |
| d (unconfirmed) | 22.246 M⊕ | 1.0947 | 500 | — | — | — |
References
- Brown, A. G. A.; et al. (Gaia collaboration). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics (in press). arXiv:2012.01533. doi:10.1051/0004-6361/202039657. S2CID 227254300. Gaia EDR3 record for this source at VizieR.
- SWEET-Cat updated New homogenous spectroscopic parameters, 2018, arXiv:1810.08108
- G. Lo Curto; et al. (2013). "The HARPS search for southern extrasolar planets: XXXVI. New multi-planet systems in the HARPS volume limited sample: a super-Earth and a Neptune in the habitable zone". Astronomy & Astrophysics. 551: A59. arXiv:1301.2741. Bibcode:2013A&A...551A..59L. doi:10.1051/0004-6361/201220415.
- Two planetary companions around the K7 dwarf GJ 221 : a hot super-Earth and a candidate in the sub-Saturn desert range, 2013, arXiv:1305.2203
- A new cold sub-Saturnian candidate planet orbiting GJ 221, 2014, arXiv:1401.4000
- The Spitzer search for the transits of HARPS low-mass planets -II. Null results for 19 planets, 2017, arXiv:1701.01303
- "Planet BD-061339b".
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.