{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T23:44:22.385Z","years_from_j2000":26.679,"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-156846","name":"HD 156846","class":"g1v_yellow_main_sequence_star","category":"star","object_type":"G1V yellow main-sequence star","mag":6.5,"mag_band":"V","abs_mag":3.111,"abs_mag_band":"V","distance_ly":155.31240550493604,"distance_method":"parallax","ra_deg":260.142975,"dec_deg":-19.333746,"epoch_ra_deg":260.537698,"epoch_dec_deg":-19.362156,"epoch_moved_arcsec":5.31,"pm_ra_mas_yr":-138.67,"pm_dec_mas_yr":-142.8,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Ophiuchus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-156846","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"17206-1920","age_years":4677111000,"companions":[{"measured":2015,"magnitude":14.1,"components":"AB","discoverer_code":"A  2241","separation_arcsec":5.3,"position_angle_deg":70}],"mass_solar":1.247,"radius_solar":2.066,"spectral_type":"G1V","uncertainties":{"metallicity_fe_h":[0.044,0.044]},"color_index_bv":0.578,"luminosity_solar":4.961351535855693,"metallicity_fe_h":0.17,"radial_velocity_km_s":-69,"spectral_type_source":"SIMBAD (1988MSS...C04....0H, quality C)","surface_gravity_log_g":3.995,"surface_temperature_k":5927,"metallicity_fe_h_source":"Median of 7 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":-138.67,"proper_motion_dec_mas_yr":-142.8,"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":4.7257},"designations":[{"catalog":"HD","designation":"HD 156846"},{"catalog":"HIP","designation":"HIP 84856"},{"catalog":"HR","designation":"HR 6441"}],"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."}