{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T21:58:20.735Z","years_from_j2000":26.665,"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":"fafnir","name":"Fafnir","class":"k1_5iiife_1_orange_giant","category":"star","object_type":"K1.5IIIFe-1 orange giant","mag":4.82,"mag_band":"V","abs_mag":-0.103,"abs_mag_band":"V","distance_ly":314.8227697474643,"distance_method":"parallax","ra_deg":276.496035,"dec_deg":65.56348,"epoch_ra_deg":276.514428,"epoch_dec_deg":65.577909,"epoch_moved_arcsec":2.931,"pm_ra_mas_yr":106.52,"pm_dec_mas_yr":-27.07,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Draco","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/fafnir","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18260+6534","companions":[{"measured":2016,"magnitude":13,"components":null,"discoverer_code":"UC 3580","separation_arcsec":24.4,"position_angle_deg":208}],"spectral_type":"K1.5IIIFe-1","uncertainties":{"metallicity_fe_h":[0.077,0.077]},"color_index_bv":1.179,"luminosity_solar":95.76349769692685,"metallicity_fe_h":-0.43,"radial_velocity_km_s":32,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality B)","surface_gravity_log_g":2.11,"surface_temperature_k":4430,"metallicity_fe_h_source":"Median of 11 spectroscopic determinations in 12 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":106.52,"proper_motion_dec_mas_yr":-27.07,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"42 Dra"},{"catalog":"Common name","designation":"Fafnir"},{"catalog":"HD","designation":"HD 170693"},{"catalog":"HIP","designation":"HIP 90344"},{"catalog":"HR","designation":"HR 6945"}],"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."}