L 1159-16

L 1159-16 is a red dwarf in the northern constellation of Aries. With a normal apparent visual magnitude of 12.3, it is too faint to be seen by the naked eye, although it lies relatively close to the Sun at a distance of about 14.6 light-years (4.5 parsecs). It is a flare star, which means it can suddenly increase in brightness for short periods of time.

L 1159-16
Observation data
Epoch J2000      Equinox J2000
Constellation Aries
Right ascension 02h 00m 12.959s[1]
Declination +13° 03′ 07.01″[1]
Apparent magnitude (V) 12.298[2]
Characteristics
Spectral type M4.5 V[3]
U−B color index +1.37[4]
B−V color index +1.80[4]
R−I color index 1.39[3]
Variable type Flare star
Astrometry
Proper motion (μ) RA: +1092.0[1] mas/yr
Dec.: –1772.9[1] mas/yr
Parallax (π)223.7321 ± 0.0699 mas[5]
Distance14.578 ± 0.005 ly
(4.470 ± 0.001 pc)
Absolute magnitude (MV)14.03[6]
Details
Mass0.14[7] M☉
Radius0.161[8] R☉
Luminosity0.00135[9] L☉
Surface gravity (log g)5.05[7] cgs
Temperature3,158[8] K
Metallicity [Fe/H]−0.14[8] dex
Rotational velocity (v sin i)3.8[9] km/s
Age4.8[7] Gyr
Other designations
TZ Ari, 2MASS J02001278+1303112, GCTP 412.02, GJ 83.1, GJ 9066, G 003-033, LFT 171, LHS 11[10]
Database references
SIMBADdata
L 1159-16
Location of L 1159-16 in the constellation Aries

Variability

L 1159-16 is a variable star. It is a flare star, showing brief increases in brightness due to eruptions from its surface. In the ultraviolet, flares of over a magnitude have been observed. In addition it shows longterm variations in brightness which may be due to starspots and rotation, possibly classifying it as a BY Draconis variable.[11] It was given the variable star designation TZ Arietis in 1970.[12]

Planetary system

In June 2019 three candidate planets were reported in orbit around L 1159-16 (GJ 83.1),[13] and two were confirmed in August 2020.[14]

The L 1159-16 (as of 2020)[15] planetary system[14]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
d (unconfirmed) ≥4.0+1.9
−1.8 M🜨		 0.016+0.001
−0.002		 1.93177+0.00016
−0.00020		 0.09+0.26
−0.09		 — —
b[15] ≥27.9+19
−11 M🜨		 0.403+0.039
−0.047		 241.590+4.6
−4.0		 0.16+0.32
−0.16		 — —
c ≥70.7+26.3
−21.5 M🜨		 0.871+0.087
−0.100		 766.954+16.710
−19.237		 0.39+0.18
−0.32		 — —

In March 2022, astronomers using the Calar Alto Observatory in Spain, as part of the CARMENES survey project, reported they had found no evidence for the planet L 1159-16 b at a period of 241.59 days, and confidently defined candidate L 1159-16 d as nothing more than a spurious chromatic effect of the star, linked to its rotation. They did confirm L 1159-16 c, re-designated it as L 1159-16 b, and updated its parameters.[16]

The L 1159-16 (as of 2022)[17] planetary system[16]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b[17] ≥0.23±0.02 MJ 0.88±0.02 772.05+2.41
−1.84		 0.49+0.06
−0.07		 — —

See also

References
  1. Zacharias, N.; et al. (2003), "The Second U.S. Naval Observatory CCD Astrograph Catalog (UCAC2)", CDS/ADC Collection of Electronic Catalogues, vol. 1289, Bibcode:2003yCat.1289....0Z.
  2. Landolt, Arlo U. (July 1992), "UBVRI photometric standard stars in the magnitude range 11.5-16.0 around the celestial equator", Astronomical Journal, 104 (1): 340–371, 436–491, Bibcode:1992AJ....104..340L, doi:10.1086/116242.
  3. Riaz, Basmah; Gizis, John E.; Harvin, James (August 2006), "Identification of New M Dwarfs in the Solar Neighborhood", The Astronomical Journal, 132 (2): 866–872, arXiv:astro-ph/0606617, Bibcode:2006AJ....132..866R, doi:10.1086/505632.
  4. Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
  5. Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. Gaia EDR3 record for this source at VizieR.
  6. Boro Saikia, S.; et al. (2018), "Chromospheric activity catalogue of 4454 cool stars. Questioning the active branch of stellar activity cycles", Astronomy and Astrophysics, 616: A108, arXiv:1803.11123, Bibcode:2018A&A...616A.108B, doi:10.1051/0004-6361/201629518, S2CID 118915212.
  7. Yee, Samuel W.; Petigura, Erik A.; von Braun, Kaspar (2017), "Precision Stellar Characterization of FGKM Stars using an Empirical Spectral Library", The Astrophysical Journal, 836 (1): 77, arXiv:1701.00922, Bibcode:2017ApJ...836...77Y, doi:10.3847/1538-4357/836/1/77, S2CID 6302522.
  8. Houdebine, Éric R.; Mullan, D. J.; Doyle, J. G.; de la Vieuville, Geoffroy; Butler, C. J.; Paletou, F. (2019), "The Mass–Activity Relationships in M and K Dwarfs. I. Stellar Parameters of Our Sample of M and K Dwarfs", The Astronomical Journal, 158 (2): 56, arXiv:1905.07921, Bibcode:2019AJ....158...56H, doi:10.3847/1538-3881/ab23fe, S2CID 159041104.
  9. McLean, M.; Berger, E.; Reiners, Ansgar (February 2012), "The Radio Activity-Rotation Relation of Ultracool Dwarfs", The Astrophysical Journal, 746 (1): 23, arXiv:1108.0415, Bibcode:2012ApJ...746...23M, doi:10.1088/0004-637X/746/1/23, S2CID 119159519.
  10. "TZ Ari -- Flare Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-08-18.
  11. Gershberg, R. E.; Katsova, M. M.; Lovkaya, M. N.; Terebizh, A. V.; Shakhovskaya, N. I. (1999), "Catalogue and bibliography of the UV Cet-type flare stars and related objects in the solar vicinity", Astronomy and Astrophysics Supplement Series, 139 (3): 555–558, Bibcode:1999A&AS..139..555G, doi:10.1051/aas:1999407.
  12. Kukarkin, B. V.; Kholopov, P. N.; Perova, N. B. (October 1970), "57th Name-List of Variable Stars", Information Bulletin on Variable Stars, 480 (1): 1, Bibcode:1970IBVS..480....1K.
  13. Barnes, J. R.; et al. (2019-06-11), Frequency of planets orbiting M dwarfs in the Solar neighbourhood, arXiv:1906.04644v1, Bibcode:2019arXiv190604644T.
  14. Feng, Fabo; et al. (2020). "Search for Nearby Earth Analogs. III. Detection of ten new planets, three planet candidates, and confirmation of three planets around eleven nearby M dwarfs". arXiv:2008.07998. doi:10.3847/1538-4365/abb139. S2CID 221150644. {{cite journal}}: Cite journal requires |journal= (help)
  15. Planet GJ 9066 b, Extrasolar Planets Encyclopaedia, retrieved 31 March 2022, Planet Status: Confirmed
  16. Quirrenbach, A.; et al. (2022). "The CARMENES search for exoplanets around M dwarfs: Two Saturn-mass planets orbiting active stars". arXiv:2203.16504 [astro-ph.EP].
  17. Planet TZ Ari b, Extrasolar Planets Encyclopaedia, retrieved 31 March 2022, Planet Status: Confirmed

Further reading
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