New Online Database of Symbiotic Variables: AS 281

Constellation
Sagittarius

Equatorial coordinates
α = 18 10 43.858
δ = -27 57 50.145

Galactic coordinates
l = 3.6002°
b = -4.2972°

Suspected	1969^Ref
Confirmed	1984^Ref
Symbiotic IR type	S^Ref
Hot component type	shell-burning^Ref
Outbursts	-

Identifiers

AS 281	IRAS -	GSC2.4.2 S9TL001042	AAVSO 000-BJT-854
SIMBAD EM* AS 281	Pan-STARRS 74442726827453643	SAO -	VSX 241081
GAIA DR3 4050929693788352384	SkyMapper 181043.88-275749.8	WRAY 16-378	GCVS -
2MASS J18104386-2757501	HIP -	Hen 2-357	BD -
WISE J181043.85-275750.0	TYC -	ESO 456-65	HD -

Symbiotic Catalogs

Bidelman (1954)	-	Allen (1984)	AS 281 (Conf.)	Belzcyński et al. (2001)	AS 281 (Conf.)
Gaposchkin (1957)	-	Kenyon (1986)	AS 281 (Conf.)	Akras et al. (2019)	AS 281 (Conf.)
Boyarchuk (1969)	-	Vaidis (1988, 1991)	Ap1-10 (Conf.)

Position

Right ascension (°)	272.6827^Ref	Parallax (mas)	0.209±0.041^Ref	Reddening E(B-V) (mag)	0.48±0.03^Ref ^{, Note}
Declination (°)	-27.9639^Ref	Distance (kpc)	7^Ref, 4.5^Ref 5.02^Ref ^{, Note}, 4.38^Ref ^{, Note}
Galactic longitude (°)	3.6002^Ref	Proper motion in α (mas/yr)	-3.47±0.04^Ref
Galactic latitude (°)	-4.2972^Ref	Proper motion in δ (mas/yr)	-2.53±0.03^Ref

Observations

X-Ray	No^Ref	IR type	S^Ref	Radio	Yes^Ref
X-Ray type	-	J (mag)	8.30^Ref	Flickering	-
GALEX FUV (mag)	-	H (mag)	7.28^Ref	Outbursts	-
GALEX NUV (mag)	-	K (mag)	6.92^Ref	Outburst type	-
IUE	No^Ref	WISE W1 (mag)	6.69^Ref	Jets	-
FUSE	No^Ref	WISE W2 (mag)	6.80^Ref	Resolved nebula	-
U (mag)	-	WISE W3 (mag)	6.50^Ref	IPmax (eV)	114^Ref
B (mag)	12.00^Ref	WISE W4 (mag)	6.09^Ref	[O III] lines	No^Ref
V (mag)	13.60^Ref	IRAS 12μm (Jy)	-	He II lines	Yes^Ref
R (mag)	-	IRAS 25μm (Jy)	-	[Fe VII] lines	Yes^Ref
I (mag)	-	IRAS 60μm (Jy)	-	O VI lines	Yes^Ref
BP (mag)	14.00^Ref	IRAS 100μm (Jy)	-
G (mag)	12.13^Ref	AKARI S09 (Jy)	-
RP (mag)	10.76^Ref	AKARI S18 (Jy)	-

Orbit

Orbital period (days)	533±30^Ref	γ velocity (km/h)	-137.23±1.01^Ref	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	Min (B) = 2449021 + 533±30 x E^Ref

Cool component

Spectral type	M5.5 III^Ref, M5 III^Ref, M3 III^Ref, M6 III^Ref	Mass (M_⊙)	-	Pulsation	Yes^Ref
Eff. temperature (K)	3430^Ref, 3300^Ref	Radius (R_⊙)	-	Type	SR^Ref
IR type	S^Ref	Luminosity (L_⊙)	-	Pulsation period (days)	65±1^Ref
Metallicity [Fe/H]	-0.36±0.08^Ref			Pulsation ephemeris	-

Hot component

Type/Spectral type	WD^Ref	Mass (M_⊙)	-	Spin period (min)	31.4^Ref
Shell-burning/Accreting-only	shell-burning^Ref	Radius (R_⊙)	-	Accretion disk	-
Eff. temperature (K)	-	Luminosity (L_⊙)	2800^Ref
Lower limit (K)	114000^Ref
Upper limit (K)	-

Links

SIMBAD CDS Portal

Notes

Herbig (1969) reported a strong continuous spectrum with intense Hβ and He II. Stenholm & Acker (1987) detected [Fe VII] and O VI lines. Toma et al. (2016) identified variability with a period of 31.4 minutes and an amplitude of 0.008 mag. It might represent a rotational period of a magnetic white dwarf, similar to Z And.

References

Allen, D. A., 1980, MNRAS, 192, 521, 1980MNRAS.192..521A
Allen, D. A., 1984, PASA, 5, 3, 369, 1984PASA....5..369A
Gałan, C., Mikołajewska, J., Hinkle, K. H. et al., 2017, MNRAS, 466, 2, 2194, 2017MNRAS.466.2194G
Gromadzki, M., Mikołajewska, J., Soszyński, I., 2013, AcA, 63, 4, 405, 2013AcA....63..405G
Herbig, G. H., 1969, PNAS, 63, 4, 1045, 1969PNAS...63.1045H
Medina Tanco, G. A., Steiner, J. E., 1995, AJ, 109, 1770, 1995AJ....109.1770M
Mikołajewska, J., Acker, A., Stenholm, B., 1997, A&A, 327, 191, 1997A&A...327..191M
Sanduleak, N., Stephenson, C. B., 1973, ApJ, 185, 899, 1973ApJ...185..899S
Stenholm, B., Acker, A., 1987, A&AS, 68, 51, 1987A&AS...68...51S
Toma, R., Ramsay, G., Macfarlane, S. et al., 2016, MNRAS, 463, 1, 1099, 2016MNRAS.463.1099T

AS 281