{"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":"2026-09-04T18:02:26.167Z","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":"hd-109577","name":"HD 109577","class":"g3_5v_yellow_main_sequence_star","category":"star","object_type":"G3/5V yellow main-sequence star","mag":9.51,"mag_band":"V","abs_mag":4.645,"abs_mag_band":"V","distance_ly":306.5380715970813,"distance_method":"parallax","ra_deg":189.052485,"dec_deg":-56.870019,"epoch_ra_deg":189.428872,"epoch_dec_deg":-57.018144,"epoch_moved_arcsec":2.342,"pm_ra_mas_yr":-84.35,"pm_dec_mas_yr":-24.38,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Crux","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-109577","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"12362-5652","age_years":9945904000,"companions":[{"measured":2016,"magnitude":10.84,"components":null,"discoverer_code":"HDS1768","separation_arcsec":8.1,"position_angle_deg":2}],"mass_solar":0.92,"radius_solar":1.008,"spectral_type":"G3/5V","color_index_bv":0.796,"luminosity_solar":1.2078138351067802,"variable_mag_max":9.45,"variable_mag_min":9.58,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1975MSS...C01....0H, quality D)","surface_gravity_log_g":4.375,"surface_temperature_k":5600,"proper_motion_ra_mas_yr":-84.35,"proper_motion_dec_mas_yr":-24.38,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.9028},"designations":[{"catalog":"HD","designation":"HD 109577"},{"catalog":"HIP","designation":"HIP 61516"}],"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."}