{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.687","julian_year":2026.687,"time":"2026-09-09T01:45:04.611Z","years_from_j2000":26.687,"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-238090-b","name":"HD 238090 b","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":49.69122877065673,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":183.0886375,"dec_deg":54.486153,"epoch_ra_deg":183.424313,"epoch_dec_deg":54.336659,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 238090","semi_major_axis_km":13942521.54924,"periapsis_km":null,"mass_kg":4.11482366090826e+25,"mass_msun":0.000020694,"constellation":"Ursa Major","discovered":"2020","featured":false,"url":"https://spacecatalog.org/object/hd-238090-b","radius_km":16072.812000000002,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 238090","host_v_mag":9.71,"eccentricity":0.3,"uncertainties":{"mass_kg":[5.67355947440181e+24,5.494394438368069e+24],"distance_ly":[0.020384773607296465,0.020384773607296465],"eccentricity":[0.17,0.16],"host_mass_solar":[0.021,0.021],"host_radius_solar":[0.016,0.016],"host_temperature_k":[51,51],"semi_major_axis_km":[164557.65777,164557.65777],"orbital_period_days":[0.01,0.011],"argument_of_periastron_deg":[24.8,22.8]},"host_mass_solar":0.578,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.57,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"M0.0 V","host_temperature_k":3933,"orbital_period_days":13.671,"equilibrium_temperature_k":469.6,"argument_of_periastron_deg":119.3},"designations":[{"catalog":"Exoplanet","designation":"HD 238090 b"},{"catalog":"Host star","designation":"HD 238090"}],"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."}