{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T14:35:31.428Z","years_from_j2000":26.681,"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-165634","name":"HD 165634","class":"g7_iiibcn_1ch_3_5hk_1_yellow_giant","category":"star","object_type":"G7:IIIbCN-1CH-3.5HK+1 yellow giant","mag":4.55,"mag_band":"V","abs_mag":-0.534,"abs_mag_band":"V","distance_ly":339.03988079293254,"distance_method":"parallax","ra_deg":272.02074,"dec_deg":-28.457093,"epoch_ra_deg":272.446202,"epoch_dec_deg":-28.45379,"epoch_moved_arcsec":1.071,"pm_ra_mas_yr":24.77,"pm_dec_mas_yr":-31.59,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Sagittarius","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-165634","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"mass_solar":3.892,"radius_solar":18.924,"spectral_type":"G7:IIIbCN-1CH-3.5HK+1","uncertainties":{"metallicity_fe_h":[0.074,0.074]},"color_index_bv":0.938,"luminosity_solar":142.42951649732905,"metallicity_fe_h":-0.15,"radial_velocity_km_s":-5,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality C)","surface_gravity_log_g":2.4,"surface_temperature_k":5374,"metallicity_fe_h_source":"Median of 7 spectroscopic determinations in 7 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":24.77,"proper_motion_dec_mas_yr":-31.59,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":240.4131},"designations":[{"catalog":"HD","designation":"HD 165634"},{"catalog":"HIP","designation":"HIP 88839"},{"catalog":"HR","designation":"HR 6766"}],"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."}