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🡕 Source: Akras, S., Guzman-Ramirez, L., Leal-Ferreira, M. L., et al., 2019, ApJS, 240, 21, 2019ApJS..240…21A Spectral Type Carbon star Magnitude range (V)   Outbursts No

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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 –

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Position

Right ascension (°)	296.224498 ± 0.958948refGaia Collaboration, Brown, A. G. A., Vallenari, A., et al., 2018, A&A, 616, A1, 2018A&A…616A…1G	Parallax (mas)	–	Reddening E(B-V) (mag)	0.215 ± 0.009refSchlafly, E. F., Finkbeiner, D. P., 2011, ApJ, 737, 103, 2011ApJ…737..103S
Declination (°)	-14.863099 ± 0.987261refGaia Collaboration, Brown, A. G. A., Vallenari, A., et al., 2018, A&A, 616, A1, 2018A&A…616A…1G	Distance (kpc)	500.00 ± 10.00refKarachentsev, I. D., Kashibadze, O. G., 2006, Astrophysics, 49, 3, 2006Ap…..49….3K
Galactic longitude (°)	25.275570 ± 0.987261refGaia Collaboration, Brown, A. G. A., Vallenari, A., et al., 2018, A&A, 616, A1, 2018A&A…616A…1G	Proper motion in α (mas/yr)	–
Galactic latitude (°)	-18.409390 ± 0.958948refGaia Collaboration, Brown, A. G. A., Vallenari, A., et al., 2018, A&A, 616, A1, 2018A&A…616A…1G	Proper motion in δ (mas/yr)	–

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Observations

U (mag)	22.64refMassey, P., McNeill, R. T., Olsen, K. A. G., et al., 2007, AJ, 134, 2474, 2007AJ….134.2474M	X-Ray		Flickering
B (mag)	22.82refMassey, P., McNeill, R. T., Olsen, K. A. G., et al., 2007, AJ, 134, 2474, 2007AJ….134.2474M	X-Ray type		Outbursts	No
V (mag)	21.62refMassey, P., McNeill, R. T., Olsen, K. A. G., et al., 2007, AJ, 134, 2474, 2007AJ….134.2474M	IUE	No	Type
R (mag)		IRAS flux at 12 μm (Jy)		IPmax (eV)	114.0refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K
I (mag)		IRAS flux at 25 μm (Jy)		OVI lines	YesrefKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K
G (mag)	20.39refGaia Collaboration, Brown, A. G. A., Vallenari, A., et al., 2018, A&A, 616, A1, 2018A&A…616A…1G	IRAS flux at 60 μm (Jy)
J (mag)	17.34refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K	IRAS flux at 100 μm (Jy)
H (mag)	16.37refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K	WISE W1 (mag)
K (mag)	15.82refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K	WISE W2 (mag)
L (mag)		WISE W3 (mag)
		WISE W4 (mag)
		Radio
		Radio flux (mJy)

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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 T0 (JD)

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Cool component

Spectral type	CrefKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K	Mass (M⊙)		Pulsation	YesrefKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K
Eff. temperature (K)	3318refAkras, S., Guzman-Ramirez, L., Leal-Ferreira, M. L., et al., 2019, ApJS, 240, 21, 2019ApJS..240…21A	Radius (R⊙)		Type	SR pulsationsrefKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K
IR type	S🡕 Source: Akras, S., Guzman-Ramirez, L., Leal-Ferreira, M. L., et al., 2019, ApJS, 240, 21, 2019ApJS..240…21A, refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K	Luminosity (L⊙)		Pulsation period (days)	142 ± 3refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K
Metallicity [Fe/H]				Ephemeris type
				Ephemeris T0 (JD)

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Hot component

Type/Spectra	WD?refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K	Mass (M⊙)		Spin period (min)
Eff. temperature (K)		Radius (R⊙)		Accretion disk
Lower limit (K)		Luminosity (L⊙)
Upper limit (K)	130000refKniazev, A. Y., Väisänen, P., Whitelock, P. A., et al., 2009, MNRAS, 395, 1121, 2009MNRAS.395.1121K

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Links

SIMBAD     CDS Portal

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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).

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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