KX Andromedae

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KX Andromedae

Bipolar jets ejected from KX Andromedae, imaged in light[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 23h 07m 06.21216s[2]
Declination +50° 11′ 32.4886″[2]
Apparent magnitude (V) 6.88 – 7.28 variable[3]
Characteristics
Spectral type B3pe+K1III[4]
Apparent magnitude (U) 6.79[5]
Apparent magnitude (B) 7.25[5]
Apparent magnitude (V) 6.92[5]
Apparent magnitude (G) 6.852[2]
Apparent magnitude (J) 5.845[6]
Apparent magnitude (H) 5.33[5]
Apparent magnitude (K) 5.19[5]
Variable type Be star
Astrometry
Radial velocity (Rv)−7.8±0.9[7] km/s
Proper motion (μ) RA: +1.625(19) mas/yr[2]
Dec.: −0.761(17) mas/yr[2]
Parallax (π)1.3172±0.0207 mas[2]
Distance2,480 ± 40 ly
(760 ± 10 pc)
Orbit[8]
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[9] M
Age22.4±3.1[9] Myr
Secondary
Radius19±4[8] R
Surface gravity (log g)2.0±0.5[8] cgs
Temperature5000±400[8] K
Rotational velocity (v sin i)25±5[8] km/s
Other designations
KX And, AAVSO 2302+49, BD+49 4045, HD 218393, HIP 114154, SAO 52701, TYC 3631-1533-1, 2MASS J23070621+5011324
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.[3] It is at a distance of 2,480 light-years (760 parsecs).[2]

A light curve for KX Andromedae, plotted from Hipparcos data,[10] folded with the period published by Koen and Eyer (2002)[11]

The primary component of the KX Andromedae system is a Be star with a spectral classification B3pe as of 2017,[3] although in historical records it has varied from B1 to B7.[12]

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, transferring mass to the primary star.[8]

The system is only about 25 million years old. The pair complete a circular orbit every 38.919 days at an inclination of 50°.[8]

KX Andromedae is surrounded by bipolar jets of ejected material, that extend 19 light-years (5.8 parsecs) out from it in each direction (angular size 20). These faint jets, visible in hydrogen-alpha, were discovered in 2024 by astronomer Stefan Ziegenbalg.[1]

References

[edit | edit source]
  1. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  2. ^ a b c d e f Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Gaia DR3 record for this source at VizieR.
  3. ^ a b c 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.
  4. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  5. ^ a b c d e 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.
  6. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  7. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  8. ^ a b c d e f g Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  9. ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  10. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  11. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
  12. ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
[edit | edit source]
  • Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).