Help

What is the MSC?

The Multiple Star Catalog (MSC) is a catalogue of physical multiple stars (multiplicity ≥ 3) compiled by Andrei Tokovinin. It contains data on stellar systems of multiplicity 3 to 7, including orbital periods, separations, component magnitudes, spectral types, and estimated masses. The present version is the 2018 update (2018ApJS..235....6T) of the original 1997 publication.

Grades

• Grade 1–2: Refuted or unconfirmed hierarchies (given for reference)
• Grade 3: Confirmed hierarchy, some periods unknown
• Grade 4: Confirmed, periods known or estimated
• Grade 5: Confirmed, well-characterised orbital elements

Observing Technique Codes

• V / v — Visual / interferometric binary
• A / a — Astrometric orbit / candidate
• S1 / S2 — Spectroscopic SB1 / SB2
• E / E* — Eclipsing / eclipse timing
• C / c — Common proper motion
• o — Occultation binary

Mass Estimation Methods

• r — From original publication
• v — From absolute V magnitude
• k — From absolute K/H magnitude
• a — From spectral type or B-V
• s — Sum of sub-system masses
• q — From mass ratio (SB2/astrometric)
• m — Minimum secondary mass (SB1)

Navigating the Catalog

• Use the Search page to find systems by WDS identifier, HIP, or HD number.
• Click a Triples / Quadruples / … card on the home page to browse all systems of that multiplicity.
• On a system page, click any node in the Mobile Diagram to reveal its orbital parameters.
• Use ← Prev / Next → to step through systems of the same multiplicity.
• Use the Simbad button to cross-match the system in CDS/SIMBAD.
• Use the Gaia button to query the Gaia archive.

References and Data Access

• Original catalogue: Tokovinin 2018, ApJS, 235, 6
• VizieR entry: J/ApJS/235/6
• TAP access: MSC TAP service

Reporting Bugs

If you encounter any technical issues, bugs, or data inconsistencies while using the MSC Navigator, please contact the maintainers: