BlackCAT A Catalog of Stellar-Mass Black Holes in X-ray Binaries

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ID# 13

GS 2000+251

QZ Vul

( Okamura1988 Hjellming1988 )

RA     [J2000]     DEC

[]          []

20:02:49.48  +25:14:11.36

ℓ                      b

[deg]                            [deg]

063.3663891  -02.99847575

Year of discovery: 1988  
( Makino1988 )

# of outbursts after discovery:

Basic data

Distance [kpc] 2.7±0.7 Jonker2004
Distance to the plane (z) [kpc] -0.14±0.04 Jonker2004
Orbital period (Porb) [h] 8.258095±0.000005 Charles1991 Casares1995a Ioannou2004
Peak X-ray flux [erg s-1 cm-2]
Outburst magnitude (AB) V=16.4 Wagner1988 Charles1988
Quiescent magnitude (AB) R=21.3±0.2 Callanan1991 Beekman1996
E(B-V) [mag] 1.1 – 1.7 Charles1991 Casares1995a

Dynamically confirmed BH


Dynamical parameters

Orbital period [h] 8.258095±0.000005 Charles1991 Casares1995a Ioannou2004
Star's spectral type K3 – 7V Casares1995a Harlaftis1996
Star's radial velocity amplitude (K2) [km/s] 520±5 Casares1995a Harlaftis1996
Mass function 'f(M1)' [M] 5±0.1 Casares1995a Harlaftis1996
BH mass (M1) [M] 5.5 – 8.8 Ioannou2004
Mass ratio (q=M2/M1) 0.04±0.01 Harlaftis1996
Inclination angle (i) [deg] 54 – 60 Ioannou2004
Rot. broadening (v sini) [km/s] 86±8 Casares1995a Harlaftis1996

Optical/NIR magnitudes

Mag. Outburst (AB)
Wagner1988 Charles1988
Mag. Quiescent (AB)
Callanan1991 Beekman1996
J=19.0±0.2 H=18.37±0.03 Ks=18.9±0.2
Aladin finding chart
Scroll to zoom. Set survey image in "Manage layers"
Default image: DSS2 Red
GS 2000+251 in Simbad

Pan-STARRS1 finding chart

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PS1 Finding chart PS1 Finding chart

Finding charts

Orientation: North up, East left. Object marked
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Finding chart reference: Callanan1991

Finding chart
Finding chart
Finding chart

This research has made use of NASA's Astrophysics Data System (ADS) and the SIMBAD database operated at CDS (Strasbourg, France)
Please acknowledge the use of this catalogue in any published work you derive from it.

Last modified: 27 August 2021.