{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T18:23:34.193Z","years_from_j2000":26.684,"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-156279-b","name":"HD 156279 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":118.05067013268669,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":258.0966686,"dec_deg":63.3527828,"epoch_ra_deg":258.150371,"epoch_dec_deg":63.319743,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 156279","semi_major_axis_km":75098131.0914,"periapsis_km":null,"mass_kg":1.79031112248815e+28,"mass_msun":0.00900373,"constellation":"Draco","discovered":"2011","featured":false,"url":"https://spacecatalog.org/object/hd-156279-b","radius_km":79726.25,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 156279","host_v_mag":8.07,"eccentricity":0.647,"uncertainties":{"mass_kg":[1.5203978044230497e+27,1.4463709449907323e+27],"distance_ly":[0.1170901396003109,0.11774245235574438],"eccentricity":[0.0007,0.0008],"host_mass_solar":[0.117,0.117],"inclination_deg":[28,32],"host_radius_solar":[0.02,0.02],"host_temperature_k":[40,40],"semi_major_axis_km":[3291153.1553999996,2991957.414],"orbital_period_days":[0.00405,0.00417],"argument_of_periastron_deg":[0.118,0.117]},"host_mass_solar":0.94,"inclination_deg":87,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.95,"planets_in_system":2,"discovery_facility":"Haute-Provence Observatory","host_spectral_type":"G6","host_temperature_k":5453,"orbital_period_days":133.40355,"periastron_epoch_bjd":2452724.507,"transit_midpoint_bjd":2455464.94,"equilibrium_temperature_k":361.73,"argument_of_periastron_deg":265.742},"designations":[{"catalog":"Exoplanet","designation":"HD 156279 b"}],"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."}