{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T20:55:43.700Z","years_from_j2000":26.684,"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-164922-c","name":"HD 164922 c","class":"neptune_like_planet","category":"exoplanet","object_type":"Neptune-like planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":71.75962159972701,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":270.6304652,"dec_deg":26.3104077,"epoch_ra_deg":270.900764,"epoch_dec_deg":26.310101,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 164922","semi_major_axis_km":51012873.9087,"periapsis_km":null,"mass_kg":7.763818228128793e+25,"mass_msun":0.0000390454,"constellation":"Hercules","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/hd-164922-c","radius_km":23343.846,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 164922","host_v_mag":7.01227,"eccentricity":0.12,"uncertainties":{"mass_kg":[1.1944335735582758e+25,1.7916503603374138e+25],"distance_ly":[0.049249613035228255,0.049575769412944996],"eccentricity":[0.09,0.11],"host_mass_solar":[0.035,0.029],"host_radius_solar":[0.021,0.014],"host_temperature_k":[30,30],"semi_major_axis_km":[598391.4828,598391.4828],"orbital_period_days":[0.05,0.06],"argument_of_periastron_deg":[77,110]},"host_mass_solar":0.926,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.946,"planets_in_system":4,"discovery_facility":"Multiple Observatories","host_spectral_type":"G9 V","host_temperature_k":5390,"orbital_period_days":75.74,"periastron_epoch_bjd":2457564.7,"transit_midpoint_bjd":2455221.1,"equilibrium_temperature_k":400.5,"argument_of_periastron_deg":-29},"designations":[{"catalog":"Exoplanet","designation":"HD 164922 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."}