Epoch J2000.0 Equinox J2000.0
|Right ascension||05h 53m 00.0s|
|Declination||−05° 59′ 41″|
|Apparent magnitude (V)||9.69 ± 0.01|
|Parallax (π)||49.23±1.65 mas|
(20 ± 1 pc)
|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|
BD-061339, HIP 27803, LTT 2396
Gliese 221 is an orange-red dwarf star.
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, were deduced by radial velocity. They were published in January 2013. In January 2014, a new, sub-Saturn planet candidate was reported.
(in order from star)
|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||—||—||—|
- 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
- "Planet BD-061339b".
- 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: . Bibcode:2013A&A...551A..59L. doi:10.1051/0004-6361/201220415.
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