Gliese 521

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Gliese 521
Observation data
Epoch J2000      Equinox J2000
Constellation Canes Venatici
Right ascension 13h 29m 24.102s[1]
Declination +46° 11′ 11.36″[1]
Apparent magnitude (V) +10.26[2]
Characteristics
Spectral type M1V[3]
Apparent magnitude (J) 7.05[2]
Apparent magnitude (H) 6.51[2]
Apparent magnitude (K) 6.26[2]
Astrometry
Radial velocity (Rv)−65.55±0.62[4] km/s
Proper motion (μ) RA: −42.466[1] mas/yr
Dec.: 389.084[1] mas/yr
Parallax (π)74.8051 ± 0.0257[1] mas
Distance43.60 ± 0.01 ly
(13.368 ± 0.005 pc)
Absolute magnitude (MV)10.243[4]
Details
Mass0.506±0.021 M☉[2]
0.47±0.05[5] M☉
Radius0.619±0.030 R☉[4]
0.47±0.05[5] R☉
Luminosity0.033+0.008
−0.007[5] L☉
Surface gravity (log g)4.79±0.04[5] cgs
Temperature3,493±50[4] K
Metallicity [Fe/H]−0.34 dex[2]
−0.09±0.09[5] dex
Rotation49.5±3.5 d[6]
Rotational velocity (v sin i)0.85[4] km/s
Other designations
BD+46 1889, GJ 521, HIP 66625, SAO 44697, WDS 13394+4611, LTT 13979, TYC 3463-00063-1, 2MASS J13392410+4611114[7]
Database references
SIMBADdata

Gliese 521 is a double star in the northern constellation of Canes Venatici. The primary is suspected to host a substellar companion yet unconfirmed. The system is located at a distance of 43.6 light-years from the Sun based on parallax measurements, but is drawing closer with a radial velocity of −65.6 km/s.[4] It is predicted to come as close as 15.70 light-years from the Sun in 176,900 years.[8] This star is too faint to be visible to the naked eye, having an apparent visual magnitude of +10.26[2] and an absolute magnitude of 10.24.[4]

The primary is an M-type main-sequence star with a stellar classification of M1V.[3] It is only about half the size and mass of the Sun. The star is rotating slowly with a projected rotational velocity of 0.85 km/s[4] and a rotation period of roughly 49.5 days.[6] The star has a lower metal-content compared to the Sun. It is radiating just 3%[5] of the luminosity of the Sun from its photosphere at an effective temperature of 3,493 K.[4]

A faint stellar companion was announced by E. Jódar and associates in 2013. The companion has an angular separation of 521 mas along a position angle of 352.1°±1.4° from the primary. This is equivalent to a projected separation of 7.24±0.14 AU.[9]

A planetary companion?[]

According to Marcy & Benitz (1989)[10] detected a possible periodicity of 510 days, inferring possible presence of a massive planetary object with minimum mass of 12 times that of Jupiter in highly eccentric orbit (e=0.6). So far the planet has not been confirmed. A radial velocity study of the star during the period 2013–2017 initially found a promising signal, but this disappeared when additional data was collected and was instead attributed to magnetic activity.[11]

The Gliese 521 planetary system[10]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b (unconfirmed) ≥12 MJ 1.038 510 0.6 — —

See also[]

References[]

  1. ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e f g Jenkins, J. S.; et al. (2009). "Rotational Velocities for M Dwarfs". The Astrophysical Journal. 704 (2): 975. arXiv:0908.4092. Bibcode:2009ApJ...704..975J. doi:10.1088/0004-637X/704/2/975. S2CID 119203469.
  3. ^ a b Alonso-Floriano, F. J.; et al. (May 2015). "CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS". Astronomy & Astrophysics. 577: 19. arXiv:1502.07580. Bibcode:2015A&A...577A.128A. doi:10.1051/0004-6361/201525803. A128.
  4. ^ a b c d e f g h i Houdebine, E. R. (September 2010). "Observation and modelling of main-sequence star chromospheres - XIV. Rotation of dM1 stars". Monthly Notices of the Royal Astronomical Society. 407 (3): 1657–1673. Bibcode:2010MNRAS.407.1657H. doi:10.1111/j.1365-2966.2010.16827.x.
  5. ^ a b c d e f Maldonado, J.; et al. (February 2017). "HADES RV Programme with HARPS-N at TNG . III. Flux-flux and activity-rotation relationships of early-M dwarfs". Astronomy & Astrophysics. 598: 19. arXiv:1610.05906. Bibcode:2017A&A...598A..27M. doi:10.1051/0004-6361/201629223. A27.
  6. ^ a b Suárez Mascareño, A.; et al. (April 2018). "HADES RV programme with HARPS-N at TNG. VII. Rotation and activity of M-dwarfs from time-series high-resolution spectroscopy of chromospheric indicators". Astronomy & Astrophysics. 612: 17. arXiv:1712.07375. Bibcode:2018A&A...612A..89S. doi:10.1051/0004-6361/201732143. A89.
  7. ^ "BD+46 1889". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-11-21.
  8. ^ Bailer-Jones, C. A. L. (January 2018). "The completeness-corrected rate of stellar encounters with the Sun from the first Gaia data release". Astronomy & Astrophysics. 609: 16. arXiv:1708.08595. Bibcode:2018A&A...609A...8B. doi:10.1051/0004-6361/201731453. S2CID 119462489. A8.
  9. ^ Jódar, Esther; et al. (February 2013). "New companions to nearby low-mass stars". Monthly Notices of the Royal Astronomical Society. 429 (1): 859–867. Bibcode:2013MNRAS.429..859J. doi:10.1093/mnras/sts382.
  10. ^ a b Marcy, Geoffrey W.; Benitz, Karsten J. (September 1989). "A search for substellar companions to low-mass stars". Astrophysical Journal, Part 1. 344 (1): 441–453. Bibcode:1989ApJ...344..441M. doi:10.1086/167812.
  11. ^ Gonzalez Alvarez, Ester (2018). Planets around low-mass stars and stellar activity effects. Doctoral Thesis. Università degli Studi di Palermo. Retrieved 2021-11-21.
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