HR 5553

HR 5553 is a binary star system located thirty-eight light-years away from the Sun, in the northern constellation Boötes. It has the variable star designation DE Boötis, and is classified as an RS Canum Venaticorum variable that ranges in apparent visual magnitude from 5.97 down to 6.04,[3] which is bright enough to be dimly visible to the naked eye. The system is drifting closer to the Sun with a radial velocity of −30 km/s,[5] and is expected to come as close as 26.9 light-years in 210,000 years.[11]

HR 5553
Observation data
Epoch 2000      Equinox 2000
Constellation Boötes
Right ascension  14h 53m 23.76674s[1]
Declination +19° 09′ 10.0813″[1]
Apparent magnitude (V) 6.00[2] (5.97 to 6.04)[3]
Spectral type K0 V[4]
U−B color index +0.49[4]
B−V color index +0.84[4]
Variable type RS CVn[3]
Radial velocity (Rv)−29.82±0.15[5] km/s
Proper motion (μ) RA: −442.23[1] mas/yr
Dec.: +217.61[1] mas/yr
Parallax (π)86.88 ± 0.46[1] mas
Distance37.5 ± 0.2 ly
(11.51 ± 0.06 pc)
Absolute magnitude (MV)5.69[6]
Period (P)125.396±0.001 d
Semi-major axis (a)≥0.52±0.03 AU
Eccentricity (e)0.51±0.001
Inclination (i)93.4±4.2°
Longitude of the node (Ω)248.3±3.6°
Argument of periastron (ω)
HR 5553 A
Mass0.84[7] M
Radius0.86[7] R
Luminosity0.498[7] L
Surface gravity (log g)4.57[8] cgs
Temperature5,313[8] K
Metallicity [Fe/H]0.10[8] dex
Rotational velocity (v sin i)4.0[8] km/s
Age0.7–1.3[9] Gyr
HR 5553 B
Mass0.45[4] M
Other designations
DE Boo, BD+19°2881, GJ 567, HD 131511, HIP 72848, LHS 5279[10]
Database references

Orbital elements for this single-lined spectroscopic binary was first calculated in 1981 using radial velocity measurements from David Dunlap Observatory combined with older measurements from Mount Wilson Observatory and Dominion Astrophysical Observatory.[12] The two stars orbit each other with a period of 125 days and a large eccentricity of 0.51.[4]

The primary, designated component A, is a K-type main sequence star with a stellar classification of K0 V. It is around one[9] billion years old and is spinning with a projected rotational velocity of 4 km/s.[8]The star has 84% of the mass of the Sun and 86% of the Sun's radius.[7] It is radiating 50%[7] of the luminosity of the Sun from its photosphere at an effective temperature of 5,313 K.[8] Component B has an estimated 45% of the mass of the Sun.[4]

An infrared excess has been detected around this system, most likely indicating the presence of a circumstellar disk at a radius of 34.2 AU. The temperature of this dust is 40 K.[8] The estimated mass of the dust is 0.0002 times the mass of the Earth. It is aligned to within 10° of the plane of the binary system.[7]


  1. ^ a b c d e van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
  2. ^ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ a b c Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085.
  4. ^ a b c d e f g Kennedy, Grant M. (February 2015), "Nature or nurture of coplanar Tatooines: the aligned circumbinary Kuiper belt analogue around HD 131511", Monthly Notices of the Royal Astronomical Society: Letters, 447 (1): L75–L79, arXiv:1412.0674, Bibcode:2015MNRAS.447L..75K, doi:10.1093/mnrasl/slu190.
  5. ^ a b Karataş, Y.; et al. (April 2004), "Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution", Monthly Notices of the Royal Astronomical Society, 349 (3): 1069–1092, arXiv:astro-ph/0404219, Bibcode:2004MNRAS.349.1069K, doi:10.1111/j.1365-2966.2004.07588.x.
  6. ^ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
  7. ^ a b c d e f Marshall, J. P.; et al. (October 2014), "Interpreting the extended emission around three nearby debris disc host stars", Astronomy & Astrophysics, 570: 13, arXiv:1408.5649, Bibcode:2014A&A...570A.114M, doi:10.1051/0004-6361/201424517, A114.
  8. ^ a b c d e f g h Eiroa, C.; et al. (July 2013), "DUst around NEarby Stars. The survey observational results", Astronomy & Astrophysics, 555: A11, arXiv:1305.0155, Bibcode:2013A&A...555A..11E, doi:10.1051/0004-6361/201321050.
  9. ^ a b Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, arXiv:0807.1686, Bibcode:2008ApJ...687.1264M, doi:10.1086/591785.
  10. ^ "DE Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-12-07.
  11. ^ Bailer-Jones, C.A.L.; et al. (2018). "New stellar encounters discovered in the second Gaia data release". Astronomy & Astrophysics. 616: A37. arXiv:1805.07581. Bibcode:2018A&A...616A..37B. doi:10.1051/0004-6361/201833456.
  12. ^ Kamper, K. W.; Lyons, R. W. (1981). "The Spectroscopic Orbits of HD131511". Journal of the Royal Astronomical Society of Canada. 75: 56–58. Bibcode:1981JRASC..75...56K.

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