{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T19:58:40.800Z","years_from_j2000":26.654,"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-29645","name":"HD 29645","class":"f9iv_v_yellow_white_subgiant","category":"star","object_type":"F9IV-V yellow-white subgiant","mag":5.97,"mag_band":"V","abs_mag":3.453,"abs_mag_band":"V","distance_ly":103.93755751250549,"distance_method":"parallax","ra_deg":70.459245,"dec_deg":38.280182,"epoch_ra_deg":70.916269,"epoch_dec_deg":38.331061,"epoch_moved_arcsec":6.946,"pm_ra_mas_yr":241.54,"pm_dec_mas_yr":-97.88,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Perseus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-29645","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":5693540000,"mass_solar":1.164,"radius_solar":1.738,"spectral_type":"F9IV-V","uncertainties":{"metallicity_fe_h":[0.044,0.044]},"color_index_bv":0.593,"luminosity_solar":3.620762177566731,"metallicity_fe_h":0.05,"radial_velocity_km_s":47,"spectral_type_source":"SIMBAD (2003AJ....126.2048G, quality C)","surface_gravity_log_g":3.962,"surface_temperature_k":6003,"metallicity_fe_h_source":"Median of 7 spectroscopic determinations in 11 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":241.54,"proper_motion_dec_mas_yr":-97.88,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star","bolometric_luminosity_solar":3.4364},"designations":[{"catalog":"HD","designation":"HD 29645"},{"catalog":"HIP","designation":"HIP 21847"},{"catalog":"HR","designation":"HR 1489"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T19:16:43.430Z","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."}