{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.674","julian_year":2026.674,"time":"2026-09-04T03:36:12.480Z","years_from_j2000":26.674,"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":"k2-312-c","name":"K2-312 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":358.3153965596143,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":140.3390845,"dec_deg":14.3678691,"epoch_ra_deg":140.707863,"epoch_dec_deg":14.253926,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 80653","semi_major_axis_km":281543192.65739995,"periapsis_km":null,"mass_kg":1.0041079132713052e+28,"mass_msun":0.0050498,"constellation":"Cancer","discovered":"2023","featured":false,"url":"https://spacecatalog.org/object/k2-312-c","radius_km":81639.68000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 80653","host_v_mag":9.452,"eccentricity":0.8435,"uncertainties":{"mass_kg":[4.1758741194647855e+26,3.7962491995134415e+26],"distance_ly":[2.6092510217339475,2.6451282232827893],"eccentricity":[0.0013,0.0013],"host_mass_solar":[0.069,0.063],"host_radius_solar":[0.033,0.033],"host_temperature_k":[61,61],"semi_major_axis_km":[12117427.5267,11967829.656],"orbital_period_days":[0.13,0.13],"argument_of_periastron_deg":[0.5,0.5]},"host_mass_solar":1.15,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.199,"planets_in_system":2,"discovery_facility":"Roque de los Muchachos Observatory","host_spectral_type":"G0 V","host_temperature_k":5959,"orbital_period_days":871.32,"transit_midpoint_bjd":2458968.72,"equilibrium_temperature_k":229,"argument_of_periastron_deg":41.3},"designations":[{"catalog":"Exoplanet","designation":"K2-312 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."}