{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T15:50:37.461Z","years_from_j2000":26.686,"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":"mascara-1-b","name":"MASCARA-1 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":594.4950143556397,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":317.5515264,"dec_deg":10.7388967,"epoch_ra_deg":317.876311,"epoch_dec_deg":10.848011,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"MASCARA-1","semi_major_axis_km":6036573.278486399,"periapsis_km":null,"mass_kg":7.023096219654496e+27,"mass_msun":0.00353202,"constellation":"Equuleus","discovered":"2017","featured":false,"url":"https://spacecatalog.org/object/mascara-1-b","radius_km":114172.72369825802,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"MASCARA-1","host_v_mag":8.28,"eccentricity":0.00034,"uncertainties":{"mass_kg":[1.7083207020781207e+27,1.7083207020781207e+27],"radius_km":[1358.347975203,1286.8559798649999],"distance_ly":[6.268725579715809,6.402449694579674],"eccentricity":[0.00023,0.00034],"host_mass_solar":[0.068,0.063],"inclination_deg":[0.17,0.17],"host_radius_solar":[0.024,0.022],"host_temperature_k":[150,150],"semi_major_axis_km":[7330.295664299999,6881.5020521999995],"orbital_period_days":[8.7e-7,8.8e-7],"argument_of_periastron_deg":[52,67]},"host_mass_solar":1.9,"inclination_deg":88.45,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":2.082,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"A8","host_temperature_k":7490,"orbital_period_days":2.14877381,"transit_midpoint_bjd":2458833.488151,"equilibrium_temperature_k":2594.3,"argument_of_periastron_deg":-16},"designations":[{"catalog":"Exoplanet","designation":"MASCARA-1 b"},{"catalog":"Host star","designation":"MASCARA-1"}],"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":"2026-09-02T19:50:56.720Z","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."}