{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.680","julian_year":2026.68,"time":"2026-09-06T04:41:03.309Z","years_from_j2000":26.68,"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":"ross-128-b","name":"Ross 128 b","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":11.006277428602594,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":176.9376036,"dec_deg":0.7992898,"epoch_ra_deg":177.281918,"epoch_dec_deg":0.650044,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Ross 128","semi_major_axis_km":7420054.386719999,"periapsis_km":null,"mass_kg":8.361035014907931e+24,"mass_msun":0.00000420489,"constellation":"Virgo","discovered":"2017","featured":false,"url":"https://spacecatalog.org/object/ross-128-b","radius_km":7079.691000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Ross 128","host_v_mag":11.12,"eccentricity":0.116,"uncertainties":{"mass_kg":[1.2541552522361896e+24,1.2541552522361896e+24],"distance_ly":[0.0026255588406197848,0.0026255588406197848],"eccentricity":[0.097,0.097],"host_mass_solar":[0.017,0.017],"host_radius_solar":[0.0077,0.0077],"host_temperature_k":[60,60],"semi_major_axis_km":[254316.38018999997,254316.38018999997],"orbital_period_days":[0.007,0.007]},"host_mass_solar":0.168,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.1967,"planets_in_system":1,"discovery_facility":"La Silla Observatory","host_spectral_type":"M4","host_temperature_k":3192,"orbital_period_days":9.8658,"equilibrium_temperature_k":301},"designations":[{"catalog":"Exoplanet","designation":"Ross 128 b"},{"catalog":"Host star","designation":"Ross 128"}],"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."}