{"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":"2026-09-04T18:10:22.738Z","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-190406","name":"15 Sge","class":"g0v_yellow_main_sequence_star","category":"star","object_type":"G0V yellow main-sequence star","mag":5.8,"mag_band":"V","abs_mag":4.552,"abs_mag_band":"V","distance_ly":57.95244366184412,"distance_method":"parallax","ra_deg":301.025985,"dec_deg":17.070173,"epoch_ra_deg":301.327311,"epoch_dec_deg":17.142602,"epoch_moved_arcsec":15.101,"pm_ra_mas_yr":-394.07,"pm_dec_mas_yr":-406.42,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Sagitta","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-190406","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"20041+1704","age_years":6342633000,"companions":[{"measured":2015,"magnitude":11.34,"components":"AD","discoverer_code":"BUP 202","separation_arcsec":89.1,"position_angle_deg":3},{"measured":2015,"magnitude":11.14,"components":"AI","discoverer_code":"SMR  20","separation_arcsec":132.1,"position_angle_deg":129},{"measured":2015,"magnitude":12.31,"components":"AF","discoverer_code":"BUP 202","separation_arcsec":142.4,"position_angle_deg":315},{"measured":2015,"magnitude":9.5,"components":"AB","discoverer_code":"STT 592","separation_arcsec":163.2,"position_angle_deg":291},{"measured":2013,"magnitude":11.77,"components":"AE","discoverer_code":"BUP 202","separation_arcsec":175,"position_angle_deg":51},{"measured":2015,"magnitude":6.92,"components":"AC","discoverer_code":"STT 592","separation_arcsec":217,"position_angle_deg":335}],"mass_solar":1.011,"radius_solar":1.098,"spectral_type":"G0V","uncertainties":{"metallicity_fe_h":[0.04,0.04]},"color_index_bv":0.6,"luminosity_solar":1.3158306550959187,"metallicity_fe_h":0.05,"radial_velocity_km_s":4.8,"spectral_type_source":"SIMBAD (2006AJ....132..161G, quality C)","surface_gravity_log_g":4.367,"surface_temperature_k":5853,"metallicity_fe_h_source":"Median of 11 spectroscopic determinations in 13 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-394.07,"proper_motion_dec_mas_yr":-406.42,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":1.2731},"designations":[{"catalog":"Bayer/Flamsteed","designation":"15 Sge"},{"catalog":"Gliese","designation":"Gl 779"},{"catalog":"HD","designation":"HD 190406"},{"catalog":"HIP","designation":"HIP 98819"},{"catalog":"HR","designation":"HR 7672"}],"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."}