NGC 6822 SySt-1

CONFIRMED NGC 6822  

Equatorial coordinates
α =  296.224498 ± 0.958948 | 19 44 53.880000
δ =  -14.863099 ± 0.987261 | -14 51 46.600000
 
Constellation Sagittarius
Symbiotic IR Type S🡕
Spectral Type Carbon star
Magnitude range (V)  
Outbursts No

Identifiers

NGC 6822 SySt-1 GSC TYC WRAY
SIMBAD LGGS J194453.88-145146.6 HIP SAO Hen
BD – IRAS  GAIA DR2 4182446338325490816? ESO
HD 2MASS  WISE  AAVSO

Position

Right ascension (°) 296.224498 ± 0.958948ref Parallax (mas) Reddening E(B-V) (mag) 0.215 ± 0.009ref
Declination (°) -14.863099 ± 0.987261ref Distance (kpc) 500.00 ± 10.00ref    
Galactic longitude (°) 25.275570 ± 0.987261ref Proper motion in α (mas/yr)    
Galactic latitude (°) -18.409390 ± 0.958948ref Proper motion in δ (mas/yr)    

Observations

U (mag) 22.64ref X-Ray   Flickering  
B (mag) 22.82ref X-Ray type   Outbursts No
V (mag) 21.62ref IUE No Type  
R (mag)   IRAS flux at 12 μm (Jy)   IPmax (eV) 114.0ref
I (mag)   IRAS flux at 25 μm (Jy)   OVI lines Yesref
G (mag) 20.39ref IRAS flux at 60 μm (Jy)      
J (mag) 17.34ref IRAS flux at 100 μm (Jy)      
H (mag) 16.37ref WISE W1 (mag)      
K (mag) 15.82ref WISE W2 (mag)      
L (mag)   WISE W3 (mag)      
    WISE W4 (mag)      
    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 Cref Mass (M)   Pulsation Yesref
Eff. temperature (K) 3318ref Radius (R)   Type SR pulsationsref
IR type S🡕, ref Luminosity (L)   Pulsation period (days) 142 ± 3ref
Metallicity [Fe/H]       Ephemeris type  
        Ephemeris T(JD)  

Hot component

Type/Spectra WD?ref Mass (M)   Spin period (min)  
Eff. temperature (K)   Radius (R)   Accretion disk  
Lower limit (K)   Luminosity (L)      
Upper limit (K) 130000ref        

Links

SIMBAD     CDS Portal


Notes

It is an S-type symbiotic star, comprising a red giant losing mass to a compact companion, which is most probably a white dwarf. The red giant is an asymptotic giant branch (AGB) carbon star, and a semiregular variable, pulsating in the first overtone with a period of 142 d (Kniazev et al., 2009).


References

  • Akras, S., Guzman-Ramirez, L., Leal-Ferreira, M. L., et al., 2019, ApJS, 240, 21, 2019ApJS..240…21A
  • Massey, P., McNeill, R. T., Olsen, K. A. G., et al., 2007, AJ, 134, 2474, 2007AJ….134.2474M
  • Kniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K

Last updated: May 2, 2019 @ 11:15 am