{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T17:05:53.352Z","years_from_j2000":26.654,"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-166182","name":"102 Her","class":"b2iv_blue_white_subgiant","category":"star","object_type":"B2IV blue-white subgiant","mag":4.37,"mag_band":"V","abs_mag":-2.873,"abs_mag_band":"V","distance_ly":916.1696772861775,"distance_method":"parallax","ra_deg":272.18955,"dec_deg":20.814557,"epoch_ra_deg":272.476666,"epoch_dec_deg":20.818286,"epoch_moved_arcsec":0.18,"pm_ra_mas_yr":-2.71,"pm_dec_mas_yr":-6.2,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Hercules","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-166182","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"18088+2049","companions":[{"measured":2023,"magnitude":11.8,"components":null,"discoverer_code":"AGC   8","separation_arcsec":23.1,"position_angle_deg":137}],"spectral_type":"B2IV","color_index_bv":-0.164,"luminosity_solar":1228.0046179887881,"radial_velocity_km_s":-15,"spectral_type_source":"SIMBAD (quality C)","surface_temperature_k":22420,"proper_motion_ra_mas_yr":-2.71,"proper_motion_dec_mas_yr":-6.2,"stellar_parameters_method":"Spectroscopic determinations compiled from the literature (PASTEL, Soubiran+ 2016)"},"designations":[{"catalog":"Bayer/Flamsteed","designation":"102 Her"},{"catalog":"HD","designation":"HD 166182"},{"catalog":"HIP","designation":"HIP 88886"},{"catalog":"HR","designation":"HR 6787"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-08-27T16:03:54.983Z","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."}