{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.674","julian_year":2026.674,"time":"2026-09-04T03:36:15.190Z","years_from_j2000":26.674,"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-108561","name":"HD 108561","class":"a0_1v_white_main_sequence_star","category":"star","object_type":"A0/1V white main-sequence star","mag":6.72,"mag_band":"V","abs_mag":1.06,"abs_mag_band":"V","distance_ly":441.9464579954753,"distance_method":"parallax","ra_deg":187.07673,"dec_deg":4.396559,"epoch_ra_deg":187.419214,"epoch_dec_deg":4.24783,"epoch_moved_arcsec":1.317,"pm_ra_mas_yr":-46.08,"pm_dec_mas_yr":-17.72,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Virgo","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-108561","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"12283+0424","age_years":265891800,"companions":[{"measured":2016,"magnitude":13.5,"components":"AB","discoverer_code":"BU  923","separation_arcsec":3,"position_angle_deg":56},{"measured":2015,"magnitude":13.4,"components":"AC","discoverer_code":"FOX 176","separation_arcsec":66.5,"position_angle_deg":76}],"mass_solar":2.841,"radius_solar":2.628,"spectral_type":"A0/1V","color_index_bv":0.15,"luminosity_solar":32.809529311311906,"radial_velocity_km_s":16,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality D)","surface_gravity_log_g":4.074,"surface_temperature_k":10749,"proper_motion_ra_mas_yr":-46.08,"proper_motion_dec_mas_yr":-17.72,"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":89.6783},"designations":[{"catalog":"HD","designation":"HD 108561"},{"catalog":"HIP","designation":"HIP 60850"}],"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."}