{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T13:30:58.611Z","years_from_j2000":26.681,"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":"hip-55507-b","name":"HIP 55507 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":83.13497758535388,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":170.5227246,"dec_deg":46.907803,"epoch_ra_deg":170.895091,"epoch_dec_deg":46.760576,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HIP 55507","semi_major_axis_km":757264421.4834,"periapsis_km":null,"mass_kg":1.5441243619050784e+28,"mass_msun":0.00776562,"constellation":"Ursa Major","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/hip-55507-b","radius_km":80364.06,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HIP 55507","host_v_mag":9.8,"eccentricity":0.362,"uncertainties":{"mass_kg":[3.262876186963886e+27,4.7301265025698596e+27],"distance_ly":[0.08349603269548632,0.08382218907320306],"eccentricity":[0.195,0.124],"host_mass_solar":[0.079,0.079],"inclination_deg":[22.37,15.693],"host_radius_solar":[0.048602,0.084061],"host_temperature_k":[149.45,93.16],"semi_major_axis_km":[69862205.6169,89160330.9372],"orbital_period_days":[529.24741,887.26948],"argument_of_periastron_deg":[27.7,15.166]},"host_mass_solar":0.65,"inclination_deg":135.022,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.723643,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"M0","host_temperature_k":4171,"orbital_period_days":5138.43727,"periastron_epoch_bjd":2452398.476,"equilibrium_temperature_k":76.05,"argument_of_periastron_deg":65.571},"designations":[{"catalog":"Exoplanet","designation":"HIP 55507 b"},{"catalog":"Host star","designation":"HIP 55507"}],"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."}