Hu 2-1

SUSPECTED MILKY WAY

Constellation
Hercules

Equatorial coordinates
α = 18 49 47.560
δ = +20 50 39.272

Galactic coordinates
l = 51.4835°
b = 9.6845°

Suspected	2001^Ref
Confirmed	-
Symbiotic IR type	D?^Ref
Hot component type	shell-burning?^Ref
Outbursts	-

Identifiers

Hu 2-1	IRAS 18476+2047	GSC2.4.2 N299000809	AAVSO -
SIMBAD PN Hu 2-1	Pan-STARRS 133012824482953680	SAO -	VSX 63047
GAIA DR3 4530814090658118656	SkyMapper -	WRAY -	GCVS -
2MASS J18494756+2050394	HIP 92400	Hen -	BD -
WISE J184947.56+205039.2	TYC 1596-2485-1	ESO -	HD 349423

Symbiotic Catalogs

Bidelman (1954)	-	Allen (1984)	-	Belzcyński et al. (2001)	-
Gaposchkin (1957)	-	Kenyon (1986)	-	Akras et al. (2019)	-
Boyarchuk (1969)	-	Vaidis (1988, 1991)	-

Position

Right ascension (°)	282.4482^Ref	Parallax (mas)	0.419±0.066^Ref	Reddening E(B-V) (mag)	0.27±0.01^Ref ^{, Note}
Declination (°)	20.8442^Ref	Distance (kpc)	2.37^Ref ^{, Note}, 2.18^Ref ^{, Note}
Galactic longitude (°)	51.4835^Ref	Proper motion in α (mas/yr)	-0.89±0.04^Ref
Galactic latitude (°)	9.6845^Ref	Proper motion in δ (mas/yr)	-7.84±0.05^Ref

Observations

X-Ray	-	IR type	D?^Ref	Radio	Yes^Ref
X-Ray type	-	J (mag)	11.16^Ref	Flickering	-
GALEX FUV (mag)	-	H (mag)	11.20^Ref	Outbursts	-
GALEX NUV (mag)	-	K (mag)	10.43^Ref	Outburst type	-
IUE	Yes^Ref	WISE W1 (mag)	9.37^Ref	Jets	-
FUSE	No^Ref	WISE W2 (mag)	8.34^Ref	Resolved nebula	-
U (mag)	-	WISE W3 (mag)	3.11^Ref	IPmax (eV)	-
B (mag)	12.37^Ref	WISE W4 (mag)	-0.06^Ref	[O III] lines	-
V (mag)	13.30^Ref	IRAS 12μm (Jy)	2.09^Ref	He II lines	-
R (mag)	12.30^Ref	IRAS 25μm (Jy)	12.20^Ref	[Fe VII] lines	-
I (mag)	-	IRAS 60μm (Jy)	6.99^Ref	O VI lines	-
BP (mag)	11.42^Ref	IRAS 100μm (Jy)	4.38^Ref
G (mag)	12.82^Ref	AKARI S09 (Jy)	0.78^Ref
RP (mag)	11.13^Ref	AKARI S18 (Jy)	5.68^Ref

Orbit

Orbital period (days)	9125-29200^Ref	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	-
Eclipses	-			Mass ratio	-
Orbital ephemeris	-

Cool component

Spectral type	-	Mass (M_⊙)	-	Pulsation	-
Eff. temperature (K)	-	Radius (R_⊙)	-	Type	-
IR type	D?^Ref	Luminosity (L_⊙)	-	Pulsation period (days)	-
Metallicity [Fe/H]	-			Pulsation ephemeris	-

Hot component

Type/Spectral type	-	Mass (M_⊙)	-	Spin period (min)	-
Shell-burning/Accreting-only	shell-burning?^Ref	Radius (R_⊙)	-	Accretion disk	-
Eff. temperature (K)	-	Luminosity (L_⊙)	-
Lower limit (K)	-
Upper limit (K)	-

Links

SIMBAD CDS Portal

Notes

A possible link to symbiotic binaries was suggested by Miranda et al. (2001), related to a possible symbiotic outflow.

References

Miranda, L. F., Torrelles, J. M., Guerrero, M. A. et al., 2001, MNRAS, 321, 3, 487, 2001MNRAS.321..487M

Last updated: August 20, 2021