{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T02:27:56.050Z","years_from_j2000":26.671,"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-26722","name":"47 Tau","class":"g5iii_a7v_yellow_giant","category":"star","object_type":"G5III+A7V: yellow giant","mag":4.84,"mag_band":"V","abs_mag":-0.197,"abs_mag_band":"V","distance_ly":331.7969261129768,"distance_method":"parallax","ra_deg":63.484935,"dec_deg":9.263824,"epoch_ra_deg":63.850664,"epoch_dec_deg":9.331965,"epoch_moved_arcsec":0.854,"pm_ra_mas_yr":-9.42,"pm_dec_mas_yr":-30.6,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Taurus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-26722","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"04139+0916","age_years":232967360,"companions":[{"measured":2016,"magnitude":7.32,"components":"AB","discoverer_code":"BU  547","separation_arcsec":1.3,"position_angle_deg":339},{"measured":2015,"magnitude":13.2,"components":"AC","discoverer_code":"BU  547","separation_arcsec":28.2,"position_angle_deg":228}],"mass_solar":3.594,"radius_solar":18.451,"spectral_type":"G5III+A7V:","uncertainties":{"metallicity_fe_h":[0.07,0.07]},"color_index_bv":0.799,"luminosity_solar":104.42392185431747,"metallicity_fe_h":-0.1,"radial_velocity_km_s":-7,"spectral_type_source":"SIMBAD (1969AJ.....74..689S, quality C)","surface_gravity_log_g":2.361,"surface_temperature_k":5303,"metallicity_fe_h_source":"Median of 2 spectroscopic determinations in 2 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-9.42,"proper_motion_dec_mas_yr":-30.6,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":203.3881},"designations":[{"catalog":"Bayer/Flamsteed","designation":"47 Tau"},{"catalog":"HD","designation":"HD 26722"},{"catalog":"HIP","designation":"HIP 19740"},{"catalog":"HR","designation":"HR 1311"}],"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."}