LIN 250

SUSPECTED SMC  

Equatorial coordinates
α =  13.539757 ± 0.014800 | 00 54 09.541560
δ =  -72.695359 ± 0.012900| -72 41 43.291671
 
Constellation Tucana
Symbiotic IR Type D’🡕
Spectral Type B0 I [e]
Magnitude range (V) 13.0 – 14.3ref
Outbursts No

Identifiers

LIN 250 GSC TYC WRAY
SIMBAD LHA 115-S 18 HIP SAO Hen
BD – IRAS  GAIA DR2 4688986534938381184 ESO
HD 2MASS J00540955-7241431 WISE J005409.55-724143.2 AAVSO 000-BLL-502

Position

Right ascension (°) 13.539757 ± 0.014800ref   Parallax (mas) Reddening E(B-V) (mag) 0.367 ± 0.028ref
Declination (°) -72.695359 ± 0.012900ref  Distance (kpc) 62.10 ± 1.90ref    
Galactic longitude (°) 302.648558 ± 0.014800ref  Proper motion in α (mas/yr) 0.591 ± 0.031ref     
Galactic latitude (°) -44.431394 ± 0.012900ref  Proper motion in δ (mas/yr) -1.173 ± 0.025ref     

Observations

U (mag) 12.94ref X-Ray Noref Flickering  
B (mag) 13.48ref X-Ray type   Outbursts No
V (mag) 13.82ref IUE Yes Type  
R (mag) 12.79ref IRAS flux at 12 μm (Jy)   IPmax (eV) 114ref
I (mag) 12.55ref IRAS flux at 25 μm (Jy)   OVI lines Yesref
G (mag) 13.18ref  IRAS flux at 60 μm (Jy)      
J (mag) 12.35ref IRAS flux at 100 μm (Jy)      
H (mag) 11.93ref WISE W1 (mag) 9.38ref    
K (mag) 11.11ref WISE W2 (mag) 8.36ref    
L (mag) 9.45ref WISE W3 (mag) 6.28ref    
    WISE W4 (mag) 4.88ref    
    Radio      
    Radio flux (mJy)      

Orbit

Orbital period (days)   γ velocity (km/h)   Size of giant’s orbit (AU)  
Eccentricity   RV of giant (km/h)   Separation (AU)  
Inclination (°)   Inferior conj. of giant (JD)   Mass function  
Ephemeris type       Mass ratio  
Ephemeris T(JD)          

Cool component

Spectral type B0 I [e]ref Mass (M) 35-40ref Pulsation  
Eff. temperature (K) 25000ref
4015ref
Radius (R) 33-36ref Type  
IR type D’🡕, ref Luminosity (L) 300000-460000ref Pulsation period (days)  
Metallicity [Fe/H]       Ephemeris type  
        Ephemeris T(JD)  

Hot component

Type/Spectra   Mass (M)   Spin period (min)  
Eff. temperature (K)   Radius (R)   Accretion disk  
Lower limit (K)   Luminosity (L)      
Upper limit (K)          

Links

SIMBAD     CDS Portal     VSX


Notes

LHA 115-S 18 is a very peculiar emission-line star exhibiting the B[e] phenomenon. Its spectrum shows features of an extremely wide range of excitation and ionization stages, extending from highly ionized atomic lines (Si IV, C IV, He II) in the ultraviolet and optical regions to molecular emission bands of CO and TiO in the optical and infrared regions (Torres et al., 2012). They also observed Raman-scattered O VI lines in the spectra of the star but according to their analysis, a symbiotic B[e] scenario seems not to be the most plausible. Therefore we classified this object only as a suspected symbiotic star. On the other hand, Akras et al. (2019) list this star as confirmed one. 


References

Last updated: May 2, 2019 @ 11:02 am