B/sbx The eXtended Catalogue of Spectroscopic Binary Orbits (Merle+, 2026-)
The eXtended Catalogue of Spectroscopic Binary Orbits
Merle, T., Jorissen, A., Alexandre, S., Desuter, J., Loup, C., Tokovinin, A.,
Traven, G., Van der Swaelmen, M., Van Eck, S., Van de Steene, G.,
Southworth, J., Sadowski, G.
<MNRAS, 547, 2, 28 pp. (2026)>
=2026MNRAS.547ag351M
ADC_Keywords: Binaries, orbits ; Binaries, spectroscopic
Description:
SBX originated from the migration of the SB9 catalogue, a project undertaken
as part of Simon Alexandre's Master's thesis in Data Science at ULB in
2024/2025. This effort involved transferring the catalogue into a robust
relational SQL database with well-defined constraints to guarantee data
consistency and facilitate advanced querying capabilities. Enriched with
high-precision astrometric data from Gaia DR3 and other external sources,
SBX offers significantly improved completeness and accuracy in the positions
and motions of astronomical objects. Today, the database is maintained by
Simon Alexandre and Thibault Merle.
A modern web interface, featuring intuitive search functions, orbital
visualisations, and comprehensive data download options, has been developed
to enhance accessibility and usability. The first release of SBX is online
since 2025-06-24.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
alias.dat 49 102459 List of other designations
systems.dat 489 4080 Position, magnitudes and spectral types
orbits.dat 6269 5169 Orbital parameters
velocities.dat 140 224148 Velocities parameters
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See also:
B/sb9 : Catalogue of Spectroscopic Binary Orbits
https://www.astro.ulb.ac.be/sbx/ : The eXtended Catalogue of Spectroscopic
Binary Orbits
Byte-by-byte Description of file: alias.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/4079] System Number (sn)
6-15 A10 --- Catalog Name of the astronomical catalog (catalog)
17-19 A3 --- Version ? Version of the astronomical catalog (version)
21-49 A29 --- Ident Identifier within the catalog (identifier)
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Byte-by-byte Description of file: systems.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/4080] System Number (sn)
6- 26 F21.17 deg RAdeg [0.01/359.72] Right Ascension at Epoch "Epoch"
(ICRS) (ra)
28- 41 F14.10 deg e_RAdeg [0.0/72.36]? Error on RA (ra_error)
43- 64 F22.18 deg DEdeg [-87.06/89.27] Declination at Epoch "Epoch"
(ICRS) (dec)
66- 79 F14.10 deg e_DEdeg [0.0/38.69]? Error on DE (dec_error)
81- 87 F7.2 yr Epoch [1991.25/2016.0] Epoch of position measurement
(position_epoch)
89-107 A19 --- RefPos Source of position data (position_source)
109-115 A7 --- Comp ? Component identifier for the system
(component)
117-127 F11.7 mag mag1 [-1.46/22.77]? Magnitude 1 (mag1)
129-147 A19 --- r_mag1 ? Source of Magnitude 1 data (mag1_source)
149-149 A1 --- band1 ? Photometric band for Magnitude 1 (band1)
151-178 A28 --- SpType1 ? Spectral type 1 (st1)
180-198 A19 --- r_SpType1 ? Bibliographic reference for spectral type 1
(st1_bibcode)
200-206 F7.3 mag mag2 [1.33/19.7]? Magnitude 2 (mag2)
208-226 A19 --- r_mag2 ? Source of Magnitude 2 data (mag2_source)
228-228 A1 --- band2 ? Photometric band for Magnitude 2 (band2)
230-237 A8 --- SpType2 ? Spectral type 2 (st2)
239-257 A19 --- r_SpType2 ? Bibliographic reference for spectral type 2
(st2_bibcode)
259-273 F15.10 mas Plx [-1.33/743.0]? Stellar parallax (parallax)
275-287 F13.10 mas e_Plx [0.0/4.85]? Error on parallax (parallax_error)
289-307 A19 --- r_Plx ? Source of parallax data (parallax_source)
309-324 F16.10 mas/yr pmRA [-3678.19/3468.26]? Proper motion in Right
Ascension (pmra)
326-340 F15.10 mas/yr e_pmRA [0.0/100.0]? Error in proper motion in Right
Ascension (pmra_error)
342-357 F16.10 mas/yr pmDE [-1677.83/1180.98]? Proper motion in Right
Ascension (pmdec)
359-373 F15.10 mas/yr e_pmDE [0.0/100.0]? Error in proper motion in
Declination (pmdec_error)
375-382 F8.2 yr EpochPm [1991.25/2016.0]? Epoch of proper motion
measurement (pm_epoch)
384-402 A19 --- RefPM ? Source of proper motion data (pm_source)
404-413 A10 --- Pos1900 ? Legacy coordinates for epoch 1900
(coordinates1900legacy)
415-446 A32 --- Pos2000 ? Legacy coordinates for epoch 2000
(coordinates2000legacy)
448-463 A16 --- familiy ? Array of system family members (family)
465-468 I4 --- parent [123/4078]? Parent SBX system number (parent)
470-473 I4 --- child1 [27/4076]? First child SBX system number
(child1)
475-478 I4 --- child2 [373/4077]? Second child SBX system number
(child2)
480-480 I1 --- truiple ? 'True' if SBX system is part of a triple
configuration (in_triple)
482-482 I1 --- quadruple ? 'True' if SBX system is part of a quadruple
configuration (in_quadruple)
484-484 I1 --- highOrder ? 'True' if SBX system is part of a high-order
multiple configuration (inhighorder)
486-489 I4 --- SB9Dup [2169/3779]? SB9 system number of the
duplicate entry (sn_duplicate)
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Byte-by-byte Description of file: orbits.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/4080] SBX system number (sn)
6- 6 I1 --- O [1/6] Orbit number (on)
8- 25 F18.11 d Per [0.05/116675.0] Orbital period
(period)
27- 43 E17.15 d e_Per ? Error in orbital period
(period_error)
45- 61 F17.8 d T0 ? Time of periastron passage
(periastron_time)
63- 76 E14.12 d e_T0 ? Error in time of periastron passage
(periastrontimeerror)
78- 82 F5.1 --- f_T0 ? Flag for periastron time
(periastrontimeflag)
84- 94 E11.10 --- ecc Orbital eccentricity (eccentricity)
96- 103 E8.6 --- e_ecc ? Error in orbital eccentricity
(eccentricity_error)
105- 114 F10.5 deg Periastron [-134.31/360.0]? Argument of
periastron (periastron_argument)
116- 125 F10.5 deg e_Periastron ? Error in argument of periastron
(periastronargumenterror)
127- 137 F11.6 km/s K1 ? Velocity semi-amplitude of component
1 (K1)
139- 146 F8.4 km/s e_K1 ? Error in velocity semi-amplitude of
component 1 (K1_error)
148- 158 F11.6 km/s K2 ? Velocity semi-amplitude of component
2 (K2)
160- 167 F8.4 km/s e_K2 ? Error in velocity semi-amplitude of
component 2 (K2_error)
169- 180 F12.7 km/s velocity [-460.0/617.0]? Systemic velocity
(systemic_velocity)
182- 189 F8.4 km/s e_velocity ? Error in systemic velocity
(systemicvelocityerror)
191- 210 F20.15 km/s rms1 ? Root Mean Square of Radial
Velocities for component 1 (rms_RV1)
212- 218 F7.1 --- o_rms1 ? Number of Radial Velocity
measurements for component 1 (num_RV1)
220- 239 F20.16 km/s rms2 ? Root Mean Square of Radial
Velocities for component 2 (rms_RV2)
241- 247 F7.1 --- o_rms2 ? Number of Radial Velocity
measurements for component 2 (num_RV2)
249- 252 I4 --- Grade ? Grade of the orbit solution (grade)
254- 257 F4.1 --- GradeLeg ? Legacy grade of the orbit solution
(grade_legacy)
259- 309 A51 --- BibCode Bibliographic reference for the orbit
(bibcode)
311- 320 A10 --- Contr ? Contributor of the orbit solution
(contributor)
322- 324 A3 --- accessLeg ? Legacy accessibility information
(accessibility_legacy)
326- 328 A3 --- epoch_reference Reference adopted for the times (JD
or MJD) (epoch_reference)
330- 334 F5.1 km/s SystVel1 [-21.8/23.6]? Apparent systemic
velocity for component 1
(apparentsystemicvelocity_1)
336- 339 F4.1 km/s e_SystVel1 [0.4/1.11]? Error in apparent systemic
velocity for component 1
(apparentsystemicvelocityerror1)
341- 345 F5.1 km/s SystVel2 [-21.8/27.0]? Apparent systemic
velocity for component 2
(apparentsystemicvelocity_2)
347- 350 F4.1 km/s e_SystVel2 [0.5/1.7]? Error in apparent systemic
velocity for component 2
(apparentsystemicvelocityerror2)
352-6269 A5918 --- N Notes or comments about the orbit
(note)
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Byte-by-byte Description of file: velocities.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/4080] SBX system number (sn)
6- 6 I1 --- O [1/5] Orbit number (on)
8- 25 F18.10 d Epoch [13742.8/2457836.38] Epoch of velocity
measurement (epoch)
27- 37 F11.6 km/s RV [-879.0/868.0] Radial velocity
(radial_velocity)
39- 58 F20.8 km/s e_RV [-303.64/9990000000.0]? Error in radial
velocity (radialvelocityerror)
60- 75 E16.14 --- Weight [-1.5/206611.56]? Weight of the velocity
measurement (weight)
77- 82 A6 --- Comp Component identifier for the velocity
measurement (component)
84-102 A19 --- VelRef ? Source of velocity data (velocity_source)
104-117 F14.9 --- offLegacy [-362.6/383.3]? Legacy offset for velocity
(offset_legacy)
119-140 A22 --- comment ? Legacy comment for velocity (comment_legacy)
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Acknowledgements:
If SB9 or SBX helped you in your published work, we would appreciate it if you
could cite one of the following references:
SBX: Merle, T., Jorissen, A., Alexandre, S., Desuter, J., Loup, C.,
Tokovinin, A., Traven, G., Van der Swaelmen, M., Van Eck, S.,
Van de Steene, G., Southworth, J., Sadowski, G., 2026, MNRAS, 547, 2, 28 pp.
The SB9 catalogue: status, comparison with non-single stars from Gaia DR3 and
evolution to SBX.
SB9: Pourbaix D., Tokovinin A.A., Batten A.H., Fekel F.C., Hartkopf W.I.,
Levato H., Morrell N.I., Torres G., Udry S., 2004,
Astronomy and Astrophysics, 424, 727-732
The ninth catalogue of spectroscopic binary orbits.
License: CC-BY-4.0
* 2026-08-07: from https://astro.ulb.ac.be/sbx/tap/
(End) G.Landais, I.Brossard, T.Merle 17-Jul-2026