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

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ID# 63

MAXI J1820+070

ASASSN-18ey = V3721 Oph

( Bahramian2018 Gandhi2019 )

RA     [J2000]     DEC

[]          []

18:20:21.94  +07:11:07.19

ℓ                      b

[deg]                            [deg]

035.8535506  +10.1591562

Year of discovery: 2018  
( Tucker2018 Kawamuro2018 )

# of outbursts after discovery:

Basic data

Distance [kpc] 3.46+2.18-1.03/
Gandhi2019 Atri2020
Distance to the plane (z) [kpc] 0.61±0.380.18 / 0.52 Gandhi2019 Atri2020
Orbital period (Porb) [h] 16.4518±0.0002 Torres2019
Peak X-ray flux [erg s-1 cm-2]
Outburst magnitude (AB) V∼14 Tucker2018
Quiescent magnitude (AB) V=18.3 Hambsch2019
E(B-V) [mag] 0.18 Tucker2018

Dynamically confirmed BH


MAXI J1820+070: Kojiguchi2019 identified historic outburst in 1898 and 1934 through the analysis of photographic plates (suggesting a recurrence of 40 yr) and it showed rebrightenings in Jan 2019 ( Russell2019c ), Aug 2019 ( Hambsch2019 ), Feb 2020 ( Adachi2020 ) and Mar 2021 ( Baglio2021 )

Dynamical parameters

Orbital period [h] 16.4518±0.0002 Torres2019
Star's spectral type K3 – 5 Torres2019
Star's radial velocity amplitude (K2) [km/s] 418±4 Torres2019
Mass function 'f(M1)' [M] 5.2±0.2 Torres2019
BH mass (M1) [M] 5.71 – 8.10 (8.40±0.770.70 if adopted i=63º) Torres2020
Mass ratio (q=M2/M1) 0.07±0.01 Torres2020
Inclination angle (i) [deg] >67 – 81 (or 63±3 for the orientation angle of the radio jet) Torres2020 Atri2020
Rot. broadening (v sini) [km/s] 84±5 Torres2020

Optical/NIR magnitudes

Mag. Outburst (AB)
V∼14 g’=13.14±0.03 i’=13.08±0.05
Mag. Quiescent (AB)
Aladin finding chart
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MAXI J1820+070 in Simbad

Pan-STARRS1 finding chart

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PS1 Finding chart PS1 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.