This is the Fourth Edition of the Catalog of Low-mass X-ray Binaries (LMXBs) in the Galaxy and the Magellanic Clouds. The catalog has a companion catalog of high-mass X-ray binaries (HMXBs) which is called HMXBCAT in the HEASARC database system). The catalog contains source name(s), coordinates, X-ray flux, system parameters, and stellar parameters of the components and other characteristic properties of 187 low-mass X-ray binaries, together with references to a comprehensive selection of the relevant literature. The aim of this catalog is to provide some basic information on the X-ray sources and their counterparts in other wavelength ranges (gamma-rays, UV, optical, IR, and radio). Some sources, however, are only tentatively identified as low-mass X-ray binaries on the basis of their X-ray properties being similar to the known low-mass X-ray binaries. Further identification in other wavelength bands is needed to finally determine the nature of these sources. In cases where there is some doubt about the low-mass nature of the X-ray binary, this is mentioned. Literature published before 1 October 2006 has, as far as possible, been taken into account. This online catalog was created by the HEASARC in September 2007 based on machine-readable tables obtained from the ADC/CDS data centers (their catalog J/A+A/469/807, tables lmxb.dat and lmxbnote.dat). This is a service provided by NASA HEASARC .

This database table is a revised and updated version of the published General Gamma-Ray Source Catalog (Macomb & Gehrels 1999, ApJS, 120, 335). It contains all 309 gamma-ray point sources listed in Table 1 of the published version of this catalog; 4 gamma-ray point sources (2CG 054+01, A0620-00, GX 340+0, and H1822-000) added by the HEASARC that were listed in Table 2 of the published catalog but were (presumably accidentally) omitted from Table 1 of the published catalog; and 107 sources (106 sources from the 3rd Egret (3EG) catalog of Hartman et al. (1999, ApJS, 123, 79) and GEV J1732-3130) that were compiled by Macomb and Gehrels subsequent to their original publication (Macomb and Gehrels 2001, unpublished). Thus, the present database table is essentially a summary master list of all detected gamma-ray point sources as of circa 2000. There is another HEASARC database table called the Gamma-Ray Source Detailed Catalog (Macomb & Gehrels 1999 & 2001) or MGGAMMADET that contains detailed information on the gamma-ray properties of these sources such as fluxes and spectral indices and that is based on Tables 2A-2G of the Macomb & Gehrels paper. This database table was created by the HEASARC in March 2001 based on tables supplied to the HEASARC by the catalog authors which contained an updated version of Table 1 from the published paper. This is a service provided by NASA HEASARC .

XRBCAT is a catalog of X-ray binaries, based on the van Paradijs (1996) compilation, and updated by Nick White to include all the new (mostly transient) systems discovered since then up until the last update (see below). The information in XRBCAT is basic and does not attempt to be complete. It includes the name of the source, the position, the pulse or orbital period (if one is known), the object class, a flux (a maximum and, if available, a minimum), and an optical V magnitude (if available). To reference XRBCAT, please use the following acknowledgment: "This paper utilized the HEASARC XRBCAT X-ray Binary catalog". Since it is a very time consuming task to keep track of all the new sources and discoveries, there may be incomplete or missing sources. This catalog was last updated on April 22, 1998. This is a service provided by NASA HEASARC .

This database table contains the slightly revised contents of the detailed Tables 2A - 2G from the General Gamma-Ray Source Catalog of Macomb & Gehrels (1999). It lists details of all known gamma-ray observations within the energy range from 50 keV to ~1 TeV for 314 discrete gamma-ray sources that were listed in Tables 2A - 2G of the published version of this catalog, including all 310 sources listed in the published Summary Table 1, together with 4 sources (2CG 054+01, A0620-00, GX 340+0, and H1822-000) that were listed only in Table 2 of the published catalog but were (presumably accidentally) omitted from Table 1. The positions for the sources in the present database were taken from Table 1 of the General Gamma-Ray Source Catalog. Thus, this table is essentially a compilation of gamma-ray observations of discrete sources as known to the authors as of early 1999. There is another HEASARC database table called the Gamma-Ray Source Summary Catalog (Macomb & Gehrels 1999) or MGGAMMACAT that contains the summary information on these sources that was given in Table 1 of the General Gamma-Ray Source Catalog. As noted above, this is a slightly revised version compared to the published Tables 2A - 2G. The known differences between the HEASARC and published versions are discussed in the HEASARC_Version section of the help documentation. This database table was created by the HEASARC in March 2002 based upon machine-readable versions of Tables 2A-2G of the Macomb & Gehrels (1999) General Gamma-Ray Source Catalog that were supplied by the authors. One duplicate entry was removed from this table in June 2019. This is a service provided by NASA HEASARC .

The CatWISE Preliminary catalog contains positions and brightnesses for 900,849,014 sources selected from combined WISE and NEOWISE all-sky survey data collected from 2010 to 2016 at 3.4 and 4.6 microns (W1 and W2). CatWISE adapts AllWISE software to measure the sources in co-added images created from six month subsets of these data, each representing one coverage of the inertial sky, or epoch. The catalog includes the measured motion of sources in 8 epochs over the 6 year span of the data.