YY Her

CONFIRMED MILKY WAY

Constellation
Hercules

Equatorial coordinates
α = 18 14 34.191
δ = +20 59 21.195

Galactic coordinates
l = 48.1438°
b = 17.2430°

Suspected	1950^Ref
Confirmed	1950^Ref
Symbiotic IR type	S^Ref
Hot component type	shell-burning^Ref
Outbursts	Yes^Ref - Z And^Ref

Identifiers

YY Her	IRAS -	GSC2.4.2 N28F000256	AAVSO 000-BCB-707
SIMBAD EM* AS 297	Pan-STARRS 133182736425447670	SAO -	VSX 14863
GAIA DR3 4528063078197198848	SkyMapper -	WRAY -	GCVS YY Her
2MASS J18143419+2059213	HIP -	Hen -	BD -
WISE J181434.18+205921.2	TYC -	ESO -	HD -

Symbiotic Catalogs

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

Position

Right ascension (°)	273.6425^Ref	Parallax (mas)	0.122±0.024^Ref	Reddening E(B-V) (mag)	0.08±0.0^Ref ^{, Note}
Declination (°)	20.9892^Ref	Distance (kpc)	3.2^Ref, 10±3^Ref 6.94^Ref ^{, Note}, 5.74^Ref ^{, Note}
Galactic longitude (°)	48.1438^Ref	Proper motion in α (mas/yr)	-1.16±0.02^Ref
Galactic latitude (°)	17.2430^Ref	Proper motion in δ (mas/yr)	0.31±0.02^Ref

Observations

X-Ray	No^Ref	IR type	S^Ref	Radio	No^Ref
X-Ray type	-	J (mag)	9.04^Ref	Flickering	No^Ref
GALEX FUV (mag)	-	H (mag)	8.13^Ref	Outbursts	Yes^Ref
GALEX NUV (mag)	-	K (mag)	7.86^Ref	Outburst type	Z And^Ref
IUE	Yes^Ref	WISE W1 (mag)	7.73^Ref	Jets	-
FUSE	No^Ref	WISE W2 (mag)	7.81^Ref	Resolved nebula	No^Ref
U (mag)	-	WISE W3 (mag)	7.44^Ref	IPmax (eV)	109.3 (UV)^Ref, 54.4^Ref
B (mag)	13.90^Ref	WISE W4 (mag)	6.84^Ref	[O III] lines	No^Ref
V (mag)	12.88^Ref	IRAS 12μm (Jy)	-	He II lines	Yes^Ref
R (mag)	-	IRAS 25μm (Jy)	-	[Fe VII] lines	No^Ref
I (mag)	-	IRAS 60μm (Jy)	-	O VI lines	No^Ref
BP (mag)	12.96^Ref	IRAS 100μm (Jy)	-
G (mag)	11.82^Ref	AKARI S09 (Jy)	-
RP (mag)	10.69^Ref	AKARI S18 (Jy)	-

Orbit

Orbital period (days)	590±3^Ref, 589.5±0.3^Ref	γ velocity (km/h)	-11.32±1.21^Ref	Size of giant’s orbit (AU)	-
Eccentricity	0.15±0.03^Ref	RV of giant (km/h)	-	Separation (AU)	-
Inclination (°)	-	Inferior conj. of giant (JD)	-	Mass function	-
Eclipses	Yes^Ref			Mass ratio	2^Ref
Orbital ephemeris	Min (V) = 2448945±10 + 590±3 x E^Ref, Min (VRI) = 2450686.2±2.1 + 589.5±0.3 x E^Ref

Cool component

Spectral type	M2 III^Ref, M3 III^Ref, M4 III^Ref	Mass (M_⊙)	-	Pulsation	-
Eff. temperature (K)	3600^Ref, 3500^Ref	Radius (R_⊙)	170^Ref	Type	-
IR type	S^Ref	Luminosity (L_⊙)	3600^Ref	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)	100000^Ref	Luminosity (L_⊙)	2000^Ref
Lower limit (K)	-
Upper limit (K)	-

Links

SIMBAD CDS Portal ARAS Database

Notes

Michalitsianos et al. (1982) detected Mg IV in the UV. The long-term light curve of the star is documented in Munari et al. (1997). Additionally, Mikołajewska et al. (2002) claimed that the giant is tidally distorted.

References

Allen, D. A., 1984, PASA, 5, 3, 369, 1984PASA....5..369A
Herbig, G. H., 1950, PASP, 62, 367, 211, 1950PASP...62..211H
Hric, L., Gális, R., Niarchos, P. et al., 2006, CoSka, 36, 1, 26, 2006CoSka..36...26H
Huang, C. C., 1984, A&A, 135, 410, 1984A&A...135..410H
Kenyon, S. J., Gallagher, J. S., 1983, AJ, 88, 666, 1983AJ.....88..666K
Luna, G. J. M., Sokoloski, J. L., Mukai, K. et al., 2013, A&A, 559, A6, 2013A&A...559A...6L
Merc, J., Beck, P. G., Mathur, S. et al., 2023, arXiv, arXiv:2312.16126, 2023arXiv231216126M
Michalitsianos, A. G., Kafatos, M., Feibelman, W. A. et al., 1982, ApJ, 253, 735, 1982ApJ...253..735M
Mikołajewska, J., Kolotilov, E. A., Shugarov, S. Y. et al., 2002, A&A, 392, 197, 2002A&A...392..197M
Munari, U., Rejkuba, M., Hazen, M. et al., 1997, A&A, 323, 113, 1997A&A...323..113M
Mürset, U., Nussbaumer, H., Schmid, H. M. et al., 1991, A&A, 248, 458, 1991A&A...248..458M
Mürset, U., Schmid, H. M., 1999, A&AS, 137, 473, 1999A&AS..137..473M
Sokoloski, J. L., Bildsten, L., Ho, W. C. G., 2001, MNRAS, 326, 2, 553, 2001MNRAS.326..553S

Last updated: January 12, 2024