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

« Previous BHT   Next BHT »

ID# 15

GS 2023+338

V404 Cyg

(Miller-Jones2009)

RA     (ICRS)     DEC

[hh:mm:ss.ss]          [dd:mm:ss.ss]

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]
[keV]		 2.59E-07
[2-10]		 Zycki1999
Outburst magnitude (AB) R∼10.7 Casares1991
Quiescent magnitude (AB) R=16.58±0.01 Casares1993Zurita2004
E(B-V) [mag] 1.3 Casares1993

Dynamically confirmed BH


NOTES
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 Casares1993Khargharia2010
Star's radial velocity amplitude (K2) [km/s] 208.4±0.5 Casares2019
Mass function 'f(M1)' [M☉] 6.08±0.06 Casares1992Casares1994
BH mass (M1) [M☉] 9+0.2-0.6 Khargharia2010
Mass ratio (q=M2/M1) 0.067±0.005 Casares1994Casares1996
Inclination angle (i) [deg] 67+3-1 Khargharia2010
Rot. broadening (v sini) [km/s] 39±1 Casares1996



Optical/NIR magnitudes
Mag. Outburst (AB)
Casares1991
V∼11.7 R∼10.7
Mag. Quiescent (AB)
Casares1993Zurita2004
B=20.47±0.05 V=18.38±0.02 R=16.58±0.01
I=16.07±0.05
J=14.59±0.08 H=14.21±0.06 Ks=14.39±0.05
Aladin finding chart
Scroll to zoom. Set survey image in "Manage layers"
Default image: DSS2 Red
GS 2023+338 in Simbad

Pan-STARRS1 finding chart

Click to enlarge in new tab/window

PS1 Finding chart PS1 Finding chart

Finding charts

Orientation: North up, East left. Object marked
Click to enlarge in new tab/window

Finding chart
Finding chart
Finding chart
Finding chart

This research has made use of NASA's Astrophysics Data System (ADS), the SIMBAD database operated at CDS (Strasbourg, France) and APLpy
Please acknowledge the use of this catalogue in any published work you derive from it.
Last modified: 02 February 2025.