{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T19:00:42.163Z","years_from_j2000":26.681,"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-15906-b","name":"HD 15906 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":148.60369497168037,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":38.2712534,"dec_deg":-10.352178,"epoch_ra_deg":38.598917,"epoch_dec_deg":-10.233596,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 15906","semi_major_axis_km":13463808.362999998,"periapsis_km":null,"mass_kg":3.3742748453021296e+25,"mass_msun":0.0000169697,"constellation":"Cetus","discovered":"2023","featured":false,"url":"https://spacecatalog.org/object/hd-15906-b","radius_km":14286.944000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 15906","host_v_mag":9.78,"eccentricity":0.11,"uncertainties":{"radius_km":[510.24800000000005,510.24800000000005],"distance_ly":[0.2870176123907342,0.28799608152388445],"eccentricity":[0.03,0.04],"host_mass_solar":[0.036,0.02],"inclination_deg":[0.12,0.16],"host_radius_solar":[0.005,0.005],"host_temperature_k":[89,89],"semi_major_axis_km":[149597.8707,149597.8707],"orbital_period_days":[0.000032,0.000032],"argument_of_periastron_deg":[75.7,76.9]},"host_mass_solar":0.79,"inclination_deg":87.98,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.762,"planets_in_system":2,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_spectral_type":"K V","host_temperature_k":4757,"orbital_period_days":10.924709,"transit_midpoint_bjd":2458416.3453,"equilibrium_temperature_k":668,"argument_of_periastron_deg":160.5},"designations":[{"catalog":"Exoplanet","designation":"HD 15906 b"},{"catalog":"Host star","designation":"HD 15906"}],"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."}