New Online Database of Symbiotic Variables: ER Del

Constellation
Delphinus

Equatorial coordinates
α = 20 42 46.503
δ = +08 41 13.613

Galactic coordinates
l = 54.4629°
b = -19.9934°

Suspected	1989^Ref
Confirmed	1989^Ref
Symbiotic IR type	S^Ref
Hot component type	accreting-only^Ref
Outbursts	-

Identifiers

ER Del	IRAS 20403+0830	GSC2.4.2 N2LJ000338	AAVSO 000-BCV-817
SIMBAD V* ER Del	Pan-STARRS 118423106934565109	SAO -	VSX 13448
GAIA DR3 1750795043999682304	SkyMapper -	WRAY -	GCVS ER Del
2MASS J20424649+0841135	HIP -	Hen -	BD +08 4506
WISE J204246.49+084113.4	TYC 1089-194-1	ESO -	HD -

Symbiotic Catalogs

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

Position

Right ascension (°)	310.6938^Ref	Parallax (mas)	0.483±0.025^Ref	Reddening E(B-V) (mag)	0.07±0.0^Ref ^{, Note}
Declination (°)	8.6871^Ref	Distance (kpc)	1.75-2.6^Ref 1.90^Ref ^{, Note}, 1.93^Ref ^{, Note}
Galactic longitude (°)	54.4629^Ref	Proper motion in α (mas/yr)	3.81±0.03^Ref
Galactic latitude (°)	-19.9934^Ref	Proper motion in δ (mas/yr)	4.51±0.02^Ref

Observations

X-Ray	Yes^Ref	IR type	S^Ref	Radio	Yes^Ref
X-Ray type	δ^Ref	J (mag)	6.19^Ref	Flickering	No^Ref
GALEX FUV (mag)	17.30^Ref	H (mag)	5.34^Ref	Outbursts	-
GALEX NUV (mag)	16.69^Ref	K (mag)	4.99^Ref	Outburst type	-
IUE	No^Ref	WISE W1 (mag)	4.93^Ref	Jets	-
FUSE	No^Ref	WISE W2 (mag)	4.89^Ref	Resolved nebula	-
U (mag)	-	WISE W3 (mag)	4.79^Ref	IPmax (eV)	47.9 (UV)^Ref, 13.6^Ref
B (mag)	12.17^Ref	WISE W4 (mag)	4.64^Ref	[O III] lines	No^Ref
V (mag)	10.41^Ref	IRAS 12μm (Jy)	0.62^Ref	He II lines	No^Ref
R (mag)	-	IRAS 25μm (Jy)	0.25^Ref	[Fe VII] lines	No^Ref
I (mag)	-	IRAS 60μm (Jy)	0.40^Ref	O VI lines	No^Ref
BP (mag)	10.54^Ref	IRAS 100μm (Jy)	1.00^Ref
G (mag)	9.04^Ref	AKARI S09 (Jy)	0.72^Ref
RP (mag)	7.86^Ref	AKARI S18 (Jy)	0.21^Ref

Orbit

Orbital period (days)	2089±6^Ref, 2094.2±4.4^Ref	γ velocity (km/h)	-51±0.5^Ref, -49.37±0.07^Ref, -48.18±1.02^Ref	Size of giant’s orbit (AU)	1.35^Ref, 1.36^Ref
Eccentricity	0.17±0.07^Ref, 0.228±0.016^Ref	RV of giant (km/h)	7.27±0.01^Ref	Separation (AU)	-
Inclination (°)	-	Inferior conj. of giant (JD)	2449659,2454465.3	Mass function	0.07^Ref, 0.077^Ref
Eclipses	-			Mass ratio	2.86-4.64^Ref
Orbital ephemeris	-

Cool component

Spectral type	S5.5/2.5^Ref	Mass (M_⊙)	2-3.25^Ref	Pulsation	Yes^Ref
Eff. temperature (K)	3470±160^Ref	Radius (R_⊙)	115^Ref	Type	SR^Ref
IR type	S^Ref	Luminosity (L_⊙)	-	Pulsation period (days)	59.028889^Ref
Metallicity [Fe/H]	-			Pulsation ephemeris	-

Hot component

Type/Spectral type	-	Mass (M_⊙)	0.7^Ref	Spin period (min)	-
Shell-burning/Accreting-only	accreting-only^Ref	Radius (R_⊙)	-	Accretion disk	-
Eff. temperature (K)	-	Luminosity (L_⊙)	-
Lower limit (K)	-
Upper limit (K)	-

Links

SIMBAD CDS Portal ARAS Database

Notes

Designated as an irregular variable star with a spectral type of S5.5/2.5 (Ake, 1979), this star exhibits a strong UV continuum and emission lines with an ionization potential up to 47.5 eV (Johnson & Ake, 1989). In the optical, no emission lines were reported by Munari & Zwitter (2002), but Hα in emission was detected by van Eck & Jorissen (2002). The orbital period of 2089 days was reported by Jorissen et al. (2012), and the star was also detected in X-rays by Luna et al. (2013).

References

Ake, T. B., 1979, ApJ, 234, 538, 1979ApJ...234..538A
Boffin, H. M. J., Hillen, M., Berger, J. P. et al., 2014, A&A, 564, A1, 2014A&A...564A...1B
Johnson, H. R., Ake, T. B., 1989, IAU Colloq. 106: Evolution of Peculiar Red Giant Stars, 371, 1989eprg.proc..371J
Jorissen, A., Boffin, H. M. J., Karinkuzhi, D. et al., 2019, A&A, 626, A127, 2019A&A...626A.127J
Jorissen, A., van Eck, S., Dermine, T. et al., 2012, BaltA, 21, 39, 2012BaltA..21...39J
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
Munari, U., Zwitter, T., 2002, A&A, 383, 188, 2002A&A...383..188M
van Eck, S., Jorissen, A., 2002, A&A, 396, 599, 2002A&A...396..599V

ER Del