{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.687","julian_year":2026.687,"time":"2026-09-08T18:05:08.070Z","years_from_j2000":26.687,"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-177723","name":"HD 177723","class":"f8iv_yellow_white_subgiant","category":"star","object_type":"F8IV yellow-white subgiant","mag":9.09,"mag_band":"V","abs_mag":2.926,"abs_mag_band":"V","distance_ly":557.5323643817567,"distance_method":"parallax","ra_deg":285.93804,"dec_deg":45.608385,"epoch_ra_deg":286.134975,"epoch_dec_deg":45.647436,"epoch_moved_arcsec":0.657,"pm_ra_mas_yr":23.69,"pm_dec_mas_yr":-6.67,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Lyra","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-177723","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"19038+4537","age_years":2473752300,"companions":[{"measured":2015,"magnitude":14.9,"components":"AB","discoverer_code":"RAO  93","separation_arcsec":3.7,"position_angle_deg":21}],"mass_solar":1.319,"radius_solar":1.568,"spectral_type":"F8IV","uncertainties":{"metallicity_fe_h":[0.123,0.123]},"color_index_bv":0.498,"luminosity_solar":5.8830155998888225,"metallicity_fe_h":0.23,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (2013MNRAS.434.1422M, quality C)","surface_gravity_log_g":4.161,"surface_temperature_k":6494,"metallicity_fe_h_source":"Median of 5 spectroscopic determinations in 4 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":23.69,"proper_motion_dec_mas_yr":-6.67,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":3.934},"designations":[{"catalog":"HD","designation":"HD 177723"},{"catalog":"HIP","designation":"HIP 93607"}],"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."}