{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T15:46:45.107Z","years_from_j2000":26.67,"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-66948","name":"HD 66948","class":"g3vgg6mg2_yellow_main_sequence_star","category":"star","object_type":"G3VgG6mG2 yellow main-sequence star","mag":7.2,"mag_band":"V","abs_mag":3.272,"abs_mag_band":"V","distance_ly":199.1187947524496,"distance_method":"parallax","ra_deg":121.64341499999999,"dec_deg":22.456737,"epoch_ra_deg":122.039287,"epoch_dec_deg":22.379475,"epoch_moved_arcsec":3.666,"pm_ra_mas_yr":-128.52,"pm_dec_mas_yr":-48.8,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cancer","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-66948","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"G3VgG6mG2","uncertainties":{"metallicity_fe_h":[0.01,0.01]},"color_index_bv":0.769,"luminosity_solar":4.277598314820376,"metallicity_fe_h":-0.4,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1986ApJ...309..260A, quality C)","surface_gravity_log_g":3.61,"surface_temperature_k":5291,"metallicity_fe_h_source":"Median of 2 spectroscopic determinations in 3 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-128.52,"proper_motion_dec_mas_yr":-48.8,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"HD","designation":"HD 66948"},{"catalog":"HIP","designation":"HIP 39681"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-01T22:58:55.274Z","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."}