{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.664","julian_year":2026.664,"time":"2026-08-31T13:09:53.366Z","years_from_j2000":26.664,"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-78366","name":"HD 78366","class":"g0iv_v_yellow_subgiant","category":"star","object_type":"G0IV-V yellow subgiant","mag":5.95,"mag_band":"V","abs_mag":4.535,"abs_mag_band":"V","distance_ly":62.5900611965985,"distance_method":"parallax","ra_deg":137.21289,"dec_deg":33.882217,"epoch_ra_deg":137.624069,"epoch_dec_deg":33.77289,"epoch_moved_arcsec":5.952,"pm_ra_mas_yr":-191.06,"pm_dec_mas_yr":-115.4,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Lynx","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-78366","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":5212025600,"mass_solar":1.027,"radius_solar":1.084,"spectral_type":"G0IV-V","uncertainties":{"metallicity_fe_h":[0.038,0.038]},"color_index_bv":0.585,"luminosity_solar":1.3365955165464416,"metallicity_fe_h":0.03,"radial_velocity_km_s":26.8,"spectral_type_source":"SIMBAD (2003AJ....126.2048G, quality C)","surface_gravity_log_g":4.306,"surface_temperature_k":5877,"metallicity_fe_h_source":"Median of 6 spectroscopic determinations in 8 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-191.06,"proper_motion_dec_mas_yr":-115.4,"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":1.2543},"designations":[{"catalog":"Gliese","designation":"Gl 334.2"},{"catalog":"HD","designation":"HD 78366"},{"catalog":"HIP","designation":"HIP 44897"},{"catalog":"HR","designation":"HR 3625"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-30T09:56:50.739Z","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."}