{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T06:19:31.990Z","years_from_j2000":26.677,"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":"hd-163607-c","name":"HD 163607 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":221.0867314171831,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":268.4181383,"dec_deg":56.3924701,"epoch_ra_deg":268.53748,"epoch_dec_deg":56.386211,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 163607","semi_major_axis_km":357538910.973,"periapsis_km":null,"mass_kg":4.177793183637715e+27,"mass_msun":0.00210107,"constellation":"Draco","discovered":"2012","featured":false,"url":"https://spacecatalog.org/object/hd-163607-c","radius_km":84828.73000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 163607","host_v_mag":8,"eccentricity":0.08,"uncertainties":{"mass_kg":[7.023096219654496e+25,7.023096219654496e+25],"distance_ly":[0.5322872084337253,0.5345703030777424],"eccentricity":[0.014,0.014],"semi_major_axis_km":[16455765.776999999,16455765.776999999],"orbital_period_days":[4.4,4.4],"argument_of_periastron_deg":[12,12]},"host_mass_solar":1.12,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.76,"planets_in_system":2,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"G5","host_temperature_k":5522,"orbital_period_days":1272,"periastron_epoch_bjd":2455111,"equilibrium_temperature_k":228.5,"argument_of_periastron_deg":274},"designations":[{"catalog":"Exoplanet","designation":"HD 163607 c"}],"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."}