{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.785","julian_year":2026.785,"time":"2026-10-14T17:28:47.574Z","years_from_j2000":26.785,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued position is carried along the great circle the object's own published motion puts it on, at a constant velocity, from the epoch that position was measured at, 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. The motion runs from position_epoch_jyear where the upstream publishes one — a timed pulsar's position belongs to the year it was timed — and from J2000 where it does not. 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","name":"Ross 128","class":"dm4_red_dwarf","category":"star","object_type":"dM4 red dwarf","mag":11.12,"mag_band":"V","abs_mag":13.491,"abs_mag_band":"V","distance_ly":10.943524941529892,"distance_method":"parallax","ra_deg":176.93499,"dec_deg":0.804563,"epoch_ra_deg":177.28482,"epoch_dec_deg":0.645804,"epoch_moved_arcsec":36.464,"pm_ra_mas_yr":605.62,"pm_dec_mas_yr":-1219.23,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Virgo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/ross-128","source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0","attribution":"HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.","commercial_use":"allowed"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"radius_solar":0.215,"spectral_type":"dM4","color_index_bv":1.746,"luminosity_solar":0.0003496230040027,"variable_mag_max":11.041,"variable_mag_min":11.171,"radial_velocity_km_s":-31.1,"spectral_type_source":"SIMBAD (2019AJ....157...63K, quality C)","surface_gravity_log_g":5.055,"surface_temperature_k":3093,"proper_motion_ra_mas_yr":605.62,"proper_motion_dec_mas_yr":-1219.23,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.0038},"designations":[{"catalog":"Common name","designation":"Ross 128"},{"catalog":"Gliese","designation":"Gl 447"},{"catalog":"HIP","designation":"HIP 57548"}],"updated_at":"2026-10-01T09:42:28.932Z","attribution":"Data from SpaceCatalog.org. Each record names its upstream in `source`, with that producer's terms in `source.license`, the acknowledgement it asks for in `source.attribution`, and whether its terms allow commercial use in `source.commercial_use`; those terms govern the record, and citing SpaceCatalog does not discharge them."}