{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.788","julian_year":2026.788,"time":"2026-10-15T20:12:17.178Z","years_from_j2000":26.788,"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":"hd-2751","name":"HD 2751","class":"a4iv_v_white_subgiant","category":"star","object_type":"A4IV/V white subgiant","mag":7.54,"mag_band":"V","abs_mag":1.793,"abs_mag_band":"V","distance_ly":460.02302291767046,"distance_method":"parallax","ra_deg":7.665374999999999,"dec_deg":-54.970223,"epoch_ra_deg":7.985312,"epoch_dec_deg":-54.821125,"epoch_moved_arcsec":1.434,"pm_ra_mas_yr":47.88,"pm_dec_mas_yr":23.93,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Phoenix","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-2751","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":{"age_years":222740770,"mass_solar":2.461,"radius_solar":2.051,"spectral_type":"A4IV/V","color_index_bv":0.203,"luminosity_solar":16.70321225815042,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1975MSS...C01....0H, quality D)","surface_gravity_log_g":4.231,"surface_temperature_k":10308,"proper_motion_ra_mas_yr":47.88,"proper_motion_dec_mas_yr":23.93,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate; Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star","bolometric_luminosity_solar":43.2834},"designations":[{"catalog":"HD","designation":"HD 2751"},{"catalog":"HIP","designation":"HIP 2406"}],"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."}