{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T14:51:14.224Z","years_from_j2000":26.672,"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-218356","name":"56 Peg","class":"k0_5ii_ba1cn_2ch_0_5_orange_bright_giant","category":"star","object_type":"K0.5II:Ba1CN-2CH-0.5 orange bright giant","mag":4.76,"mag_band":"V","abs_mag":-1.534,"abs_mag_band":"V","distance_ly":591.9353391033187,"distance_method":"parallax","ra_deg":346.778085,"dec_deg":25.468259,"epoch_ra_deg":347.104934,"epoch_dec_deg":25.61312,"epoch_moved_arcsec":0.888,"pm_ra_mas_yr":0.26,"pm_dec_mas_yr":-33.31,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Pegasus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-218356","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"spectral_type":"K0.5II:Ba1CN-2CH-0.5","uncertainties":{"metallicity_fe_h":[0.088,0.088]},"color_index_bv":1.285,"luminosity_solar":357.7667699361107,"metallicity_fe_h":-0.175,"radial_velocity_km_s":-27,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality C)","surface_gravity_log_g":1.3,"surface_temperature_k":4500,"metallicity_fe_h_source":"Median of 6 spectroscopic determinations in 6 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":0.26,"proper_motion_dec_mas_yr":-33.31,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"56 Peg"},{"catalog":"HD","designation":"HD 218356"},{"catalog":"HIP","designation":"HIP 114155"},{"catalog":"HR","designation":"HR 8796"}],"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."}