{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T22:34:24.455Z","years_from_j2000":26.679,"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-154633","name":"HD 154633","class":"g5v_yellow_main_sequence_star","category":"star","object_type":"G5V yellow main-sequence star","mag":6.11,"mag_band":"V","abs_mag":0.793,"abs_mag_band":"V","distance_ly":377.4956746640029,"distance_method":"parallax","ra_deg":255.56568,"dec_deg":64.600739,"epoch_ra_deg":255.605934,"epoch_dec_deg":64.561549,"epoch_moved_arcsec":1.065,"pm_ra_mas_yr":-20.32,"pm_dec_mas_yr":34.34,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Draco","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-154633","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"17023+6436","age_years":502386500,"companions":[{"measured":2020,"magnitude":10.3,"components":"Aa,Ab","discoverer_code":"TOI1487","separation_arcsec":0.1,"position_angle_deg":46}],"mass_solar":2.702,"radius_solar":8.994,"spectral_type":"G5V","uncertainties":{"metallicity_fe_h":[0.1,0.1]},"color_index_bv":0.96,"luminosity_solar":41.95657223387252,"metallicity_fe_h":0.18,"radial_velocity_km_s":-25,"spectral_type_source":"SIMBAD (quality D)","surface_gravity_log_g":2.808,"surface_temperature_k":4988,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":-20.32,"proper_motion_dec_mas_yr":34.34,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":44.9767},"designations":[{"catalog":"HD","designation":"HD 154633"},{"catalog":"HIP","designation":"HIP 83359"},{"catalog":"HR","designation":"HR 6360"}],"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."}