{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.676","julian_year":2026.676,"time":"2026-09-04T20:09:15.259Z","years_from_j2000":26.676,"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":"hip-15911","name":"HIP 15911","class":"f4v_yellow_white_main_sequence_star","category":"star","object_type":"F4V yellow-white main-sequence star","mag":9.74,"mag_band":"V","abs_mag":3.531,"abs_mag_band":"V","distance_ly":569.2084365476384,"distance_method":"parallax","ra_deg":51.229635,"dec_deg":47.415019,"epoch_ra_deg":51.699938,"epoch_dec_deg":47.509775,"epoch_moved_arcsec":0.936,"pm_ra_mas_yr":24.86,"pm_dec_mas_yr":-24.76,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Perseus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hip-15911","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":2572430800,"mass_solar":1.285,"radius_solar":1.494,"spectral_type":"F4V","color_index_bv":0.473,"luminosity_solar":3.369767985844035,"metallicity_fe_h":0.08,"variable_mag_max":9.682,"variable_mag_min":9.782,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (2012ApJ...752...58Z, quality C)","surface_gravity_log_g":4.112,"surface_temperature_k":6454,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":24.86,"proper_motion_dec_mas_yr":-24.76,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":3.4814},"designations":[{"catalog":"HIP","designation":"HIP 15911"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"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."}