{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T17:05:56.657Z","years_from_j2000":26.654,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued J2000 position is carried along the great circle the object's own published motion puts it on, at a constant velocity, and the result is referred to the true equator and equinox of this instant. Those are separate things: the motion moves the object, and the rotation turns the grid under it by about fifty arcseconds a year, with nutation adding up to another seventeen.","excluded":"Parallax, the radial-velocity perspective term, aberration and refraction; each is below the accuracy of the catalogued positions themselves. An object with no published proper motion comes back where the catalogue has it rather than at a fabricated zero, and says so with a null pm_ra_mas_yr. A body with no fixed position is not propagated at all — its place comes from an ephemeris, which is what /api/v1/visible answers with."},"slug":"barnard-c","name":"Barnard c","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":5.957409317185177,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":269.4486144,"dec_deg":4.7379808,"epoch_ra_deg":269.780177,"epoch_dec_deg":4.734664,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Barnard's star","semi_major_axis_km":4098981.6571799996,"periapsis_km":null,"mass_kg":2.000676235710112e+24,"mass_msun":0.00000100617,"constellation":"Ophiuchus","discovered":"2025","featured":false,"url":"https://spacecatalog.org/object/barnard-c","radius_km":4738.9283000000005,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Barnard's star","host_v_mag":9.54,"eccentricity":0.08,"uncertainties":{"mass_kg":[1.7916503603374138e+23,1.7916503603374138e+23],"distance_ly":[0.0031800246827382484,0.0031800246827382484],"eccentricity":[0.05,0.06],"host_mass_solar":[0.007,0.007],"host_radius_solar":[0.006,0.006],"host_temperature_k":[28,28],"semi_major_axis_km":[59839.14828,59839.14828],"orbital_period_days":[0.0006,0.0006],"argument_of_periastron_deg":[48.1,38.9]},"host_mass_solar":0.162,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.185,"planets_in_system":4,"discovery_facility":"Gemini Observatory","host_spectral_type":"M3.5-4 V","host_temperature_k":3195,"orbital_period_days":4.1244,"periastron_epoch_bjd":2460242.92,"equilibrium_temperature_k":400,"argument_of_periastron_deg":90.8},"designations":[{"catalog":"Exoplanet","designation":"Barnard c"},{"catalog":"Host star","designation":"Barnard's star"}],"source":{"id":"exoplanet_archive","name":"NASA Exoplanet Archive (Planetary Systems Composite Parameters)","url":"https://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=PSCompPars","license":"Public domain (NASA)"},"updated_at":"2026-08-27T16:03:54.983Z","attribution":"Data from SpaceCatalog.org. Individual records carry their source and license in `source`; attribution is required for CC-BY and CC-BY-SA rows."}