Astronomy:KX Andromedae

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Short description: Spectroscopic binary star in the constellation Andromeda
KX Andromedae
KXAndLightCurve.png
A light curve for KX Andromedae, plotted from Hipparcos data,[1] folded with the period published by Koen and Eyer (2002)[2]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Andromeda
Right ascension  23h 07m 06.2120s[3]
Declination +50° 11′ 32.4891″[3]
Apparent magnitude (V) 6.88 – 7.28 variable[4]
Characteristics
Spectral type B3pe+K1III[5]
Apparent magnitude (U) 6.79[6]
Apparent magnitude (B) 7.25[6]
Apparent magnitude (V) 6.92[6]
Apparent magnitude (G) 6.8227[3]
Apparent magnitude (J) 5.845[7]
Apparent magnitude (H) 5.33[6]
Apparent magnitude (K) 5.19[6]
Variable type Be star
Astrometry
Radial velocity (Rv)−7.8±0.9[8] km/s
Proper motion (μ) RA: 1.697±0.057 [3] mas/yr
Dec.: −0.788±0.048[3] mas/yr
Parallax (π)1.2444 ± 0.0328[3] mas
Distance2,620 ± 70 ly
(800 ± 20 pc)
Orbit[9]
Period (P)38.919 days
Eccentricity (e)0±0.03
Inclination (i)50±5°
Periastron epoch (T)HJD 2423220.25±0.09
Semi-amplitude (K2)
(secondary)
86.2±0.8 km/s
Details
Primary
Mass9.0±0.1[10] M
Age22.4±3.1[10] Myr
Secondary
Radius19±4[9] R
Surface gravity (log g)2.0±0.5[9] cgs
Temperature5000±400[9] K
Rotational velocity (v sin i)25±5[9] km/s
Other designations
2MASS J23070621+5011324, AAVSO 2302+49, BD+49 4045, HIP 114154, HD 218393, SAO 52701, TYC 3631-1533-1
Database references
SIMBADdata

KX Andromedae (often abbreviated to KX And) is a spectroscopic binary star in the constellation Andromeda. Its apparent visual magnitude varies between 6.88 and 7.28.[4]

The primary component of the KX Andromedae system is a Be star with a spectral classification B3pe as in 2017,[4] although on historical record it has varied from B1 to B7.[11]

The secondary star is difficult to detect in the spectrum, but has been given a K1III spectral type. It is likely to be an asymptotic giant branch star that fills its Roche lobe.[9]

The system is only about 25 million years old. The pair complete a circular orbit every 38.919 days at an inclination of 50°.[9]

References

  1. "/ftp/cats/more/HIP/cdroms/cats". Strasbourg astronomical Data Center. https://cdsarc.cds.unistra.fr/viz-bin/ftp-index?/ftp/cats/more/HIP/cdroms/cats. 
  2. Koen, Chris; Eyer, Laurent (March 2002). "New periodic variables from the Hipparcos epoch photometry". Monthly Notices of the Royal Astronomical Society 331 (1): 45–59. doi:10.1046/j.1365-8711.2002.05150.x. Bibcode2002MNRAS.331...45K. 
  3. Jump up to: 3.0 3.1 3.2 3.3 3.4 3.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  4. Jump up to: 4.0 4.1 4.2 KX And, database entry, Combined General Catalog of Variable Stars (GCVS5.1, 2017 Ed.), N. N. Samus, O. V. Durlevich, et al., CDS ID II/250 Accessed on line 2018-10-17.
  5. Shenavrin, V. I.; Taranova, O. G.; Nadzhip, A. E. (2011). "Search for and study of hot circumstellar dust envelopes". Astronomy Reports 55 (1): 31–81. doi:10.1134/S1063772911010070. Bibcode2011ARep...55...31S. 
  6. Jump up to: 6.0 6.1 6.2 6.3 6.4 Database entry, Catalogue of Stellar Photometry in Johnson's 11-color system (2002 Ed.), J. R. Ducati, CDS ID II/237 Accessed on line 2018-11-10.
  7. Cutri, Roc M.; Skrutskie, Michael F.; Van Dyk, Schuyler D.; Beichman, Charles A.; Carpenter, John M.; Chester, Thomas; Cambresy, Laurent; Evans, Tracey E. et al. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues 2246: II/246. Bibcode2003yCat.2246....0C. http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/246. 
  8. Pourbaix, D. et al. (September 2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy and Astrophysics 424 (2): 727–732, doi:10.1051/0004-6361:20041213, Bibcode2004A&A...424..727P. 
  9. Jump up to: 9.0 9.1 9.2 9.3 9.4 9.5 9.6 Tarasov, A. E.; Berdyugina, S. V.; Berdyugin, A. V. (May 1998), "The massive interacting binary KX And: The orbit and physical parameters of the secondary component", Astronomy Letters 24 (3): 316–320, Bibcode1998AstL...24..316T 
  10. Jump up to: 10.0 10.1 Tezlaff, N.; Neuhäuser, R.; Hohle, N. N. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode2011MNRAS.410..190T 
  11. Koubský, P.; Harmanec, P.; Brož, M.; Kotková, L.; Yang, S.; Božić, H.; Sudar, D.; Frémat, Y. et al. (2019), "Properties and nature of be stars", Astronomy & Astrophysics 629: A105, doi:10.1051/0004-6361/201834597