{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.688","julian_year":2026.688,"time":"2026-09-09T05:57:07.052Z","years_from_j2000":26.688,"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-177830-c","name":"HD 177830 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":204.7198782269792,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":286.3363574,"dec_deg":25.9204327,"epoch_ra_deg":286.610565,"epoch_dec_deg":25.960628,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 177830","semi_major_axis_km":76848426.17859,"periapsis_km":null,"mass_kg":2.8470817267728453e+26,"mass_msun":0.000143184,"constellation":"Lyra","discovered":"2010","featured":false,"url":"https://spacecatalog.org/object/hd-177830-c","radius_km":50195.647000000004,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 177830","host_v_mag":7.18,"eccentricity":0.3,"uncertainties":{"mass_kg":[3.7961069783078374e+25,3.7961069783078374e+25],"distance_ly":[0.4057385338796288,0.4057385338796288],"eccentricity":[0.1,0.1],"host_radius_solar":[0.06,0.06],"semi_major_axis_km":[44879.361209999995,44879.361209999995],"orbital_period_days":[0.1,0.1],"argument_of_periastron_deg":[29,29]},"host_mass_solar":1.47,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":2.62,"planets_in_system":2,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"K0","host_temperature_k":4949,"orbital_period_days":110.9,"periastron_epoch_bjd":2450179,"transit_midpoint_bjd":2455177,"equilibrium_temperature_k":538.95,"argument_of_periastron_deg":110},"designations":[{"catalog":"Exoplanet","designation":"HD 177830 c"},{"catalog":"Host star","designation":"HD 177830"}],"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."}