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

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ID# 15

GS 2023+338

V404 Cyg

( Miller-Jones2009 )

RA     [J2000]     DEC

[]          []

20:24:03.82  +33:52:01.90

ℓ                      b

[deg]                            [deg]

073.1187114  -02.09132512

Year of discovery: 1989  
( Makino1989 )

# of outbursts after discovery: 2

Basic data

Distance [kpc] 2.39±0.14 Miller-Jones2009
Distance to the plane (z) [kpc] -0.09±0.01 Miller-Jones2009
Orbital period (Porb) [h] 155.30803±5E-05 Casares2019
Peak X-ray flux [erg s-1 cm-2]
Outburst magnitude (AB) R∼10.7 Casares1991
Quiescent magnitude (AB) R=16.58±0.01 Casares1993 Zurita2004
E(B-V) [mag] 1.3 Casares1993

Dynamically confirmed BH


GS 2023+338 (V404 Cyg) showed two outbursts detected in plate scales (1938 and 1956) prior to its detection in X-rays in 1989 ( Wachmann1948 , Richter1989 ). It has shown two new outbursts in 2015: June ( Barthelmy2015 ) and December ( Barthelmy2015a ).
Gandhi2019 obtained a distance of 2.40+0.95-0.53 from Gaia DR2.

Dynamical parameters

Orbital period [h] 155.30803±5E-05 Casares2019
Star's spectral type K3III Casares1993 Khargharia2010
Star's radial velocity amplitude (K2) [km/s] 208.4±0.5 Casares2019
Mass function 'f(M1)' [M] 6.08±0.06 Casares1992 Casares1994
BH mass (M1) [M] 9+0.2-0.6 Khargharia2010
Mass ratio (q=M2/M1) 0.067±0.005 Casares1994 Casares1996
Inclination angle (i) [deg] 67+3-1 Khargharia2010
Rot. broadening (v sini) [km/s] 39±1 Casares1996

Optical/NIR magnitudes

Mag. Outburst (AB)
V∼11.7 R∼10.7
Mag. Quiescent (AB)
Casares1993 Zurita2004
B=20.47±0.05 V=18.38±0.02 R=16.58±0.01
J=14.59±0.08 H=14.21±0.06 Ks=14.39±0.05
Aladin finding chart
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GS 2023+338 in Simbad

Pan-STARRS1 finding chart

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PS1 Finding chart PS1 Finding chart

Finding charts

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Finding chart
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.