{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.676","julian_year":2026.676,"time":"2026-09-05T00:40:34.868Z","years_from_j2000":26.676,"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-207330","name":"81 π² Cyg","class":"b2_5iii_blue_white_giant","category":"star","object_type":"B2.5III blue-white giant","mag":4.23,"mag_band":"V","abs_mag":-3.421,"abs_mag_band":"V","distance_ly":1105.615000031926,"distance_method":"parallax","ra_deg":326.69836499999997,"dec_deg":49.30957,"epoch_ra_deg":326.944928,"epoch_dec_deg":49.433451,"epoch_moved_arcsec":0.108,"pm_ra_mas_yr":3.61,"pm_dec_mas_yr":-1.86,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cygnus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-207330","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"21468+4919","companions":[{"measured":1997,"magnitude":5.98,"components":null,"discoverer_code":"MIU   3","separation_arcsec":0.1,"position_angle_deg":131}],"spectral_type":"B2.5III","color_index_bv":-0.12,"luminosity_solar":2034.2297432117314,"metallicity_fe_h":-0.1,"radial_velocity_km_s":-12,"spectral_type_source":"SIMBAD (2024A&A...690A.176N, quality C)","surface_gravity_log_g":3.49,"surface_temperature_k":18680,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":3.61,"proper_motion_dec_mas_yr":-1.86,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"81 Pi2 Cyg"},{"catalog":"HD","designation":"HD 207330"},{"catalog":"HIP","designation":"HIP 107533"},{"catalog":"HR","designation":"HR 8335"}],"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."}