RA (ICRS) DEC
|
ℓ b
|
Distance [kpc] | ∼25 | Casares2009 |
---|---|---|
Distance to the plane (z) [kpc] | ∼-1.21 | Casares2009 |
Orbital period (Porb) [h] | 61.068±0.002 | Casares2009 |
Peak X-ray flux [erg s-1 cm-2] [keV] |
2.38E-09 [2-10] |
Kitamoto1990 |
Outburst magnitude (AB) | V=16.9 | Kitamoto1990 |
Quiescent magnitude (AB) | i'∼20.2 | Casares2009Russell2015a |
E(B-V) [mag] | 1 | Kitamoto1990 |
Dynamically confirmed BH
GS 1354-64 (BW Cir) is associated with MX 1353-64 which showed an outburst in 1971-1972. It showed another outburst in 1997 (Remillard1997a) and in 2015 (Miller2015). Gandhi2019 obtained a distance of 0.7+3.4-0.3 kpc from Gaia DR2 which is unconsistent with the lower limit derived in Casares2009. If the Gaia distance were correct, it would open the possibility for Cen X-2 being BW Cir since its 1967 outburst would no longer be super-Eddington. |
Orbital period [h] | 61.068±0.002 | Casares2009 |
---|---|---|
Star's spectral type | G0 – 5III | Casares2004 |
Star's radial velocity amplitude (K2) [km/s] | 279±5 | Casares2004Casares2009 |
Mass function 'f(M1)' [M☉] | 5.7±0.3 | Casares2009 |
BH mass (M1) [M☉] | ≥7.6±0.7 | Casares2009 |
Mass ratio (q=M2/M1) | 0.12+0.03-0.04 | Casares2009 |
Inclination angle (i) [deg] | ≤79 | Casares2009 |
Rot. broadening (v sini) [km/s] | 69±8 | Casares2009 |
|
|||
---|---|---|---|
V=16.9 | |||
Casares2009Russell2015a |
|||
V∼21.5 | R=20.71±0.03 | ||
i'∼20.2 | |||
Orientation: North up, East left.
Object marked
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Finding chart reference: Casares2009
BA=20.10±0.04 | VA=18.44±0.02 | RA=17.60±0.03 | IA=17.03±0.03 |
BB=19.65±0.04 | VB=18.60±0.02 | RB=17.99±0.04 | IB=17.62±0.04 |
BC=20.38±0.05 | VC=18.95±0.02 | RC=18.17±0.04 | IC=17.68±0.03 |
BD=19.94±0.03 | VD=18.28±0.01 | RD=17.42±0.02 | ID=16.74±0.02 |
BE=19.37±0.02 | VE=18.24±0.01 | RE=17.63±0.02 | IE=17.21±0.02 |