{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T05:41:32.662Z","years_from_j2000":26.671,"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":"k2-37-d","name":"K2-37 d","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":586.8955707548397,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":243.4509662,"dec_deg":-24.7870527,"epoch_ra_deg":243.856491,"epoch_dec_deg":-24.855453,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-37","semi_major_axis_km":16485685.35114,"periapsis_km":null,"mass_kg":7.465209834739224e+25,"mass_msun":0.0000375436,"constellation":"Scorpius","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/k2-37-d","radius_km":14733.411000000002,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-37","host_v_mag":12.573,"uncertainties":{"mass_kg":[3.643022399352741e+25,3.702744078030655e+25],"radius_km":[446.46700000000004,1339.401],"distance_ly":[5.1369629490387085,5.228286734799397],"host_mass_solar":[0.03,0.03],"inclination_deg":[1.20594,0.60232],"host_radius_solar":[0.032,0.032],"host_temperature_k":[100,100],"semi_major_axis_km":[239356.59312,239356.59312],"orbital_period_days":[0.00055,0.00055]},"host_mass_solar":0.84,"inclination_deg":89.16344,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.809,"planets_in_system":3,"discovery_facility":"K2","host_spectral_type":"G3 V","host_temperature_k":5352,"orbital_period_days":14.09229,"transit_midpoint_bjd":2456907.2331,"equilibrium_temperature_k":646},"designations":[{"catalog":"Exoplanet","designation":"K2-37 d"}],"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."}