{"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":"2026-09-05T01:59:28.402Z","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":"hip-28618","name":"HIP 28618","class":"b2_iii_blue_white_giant","category":"star","object_type":"B2(III) blue-white giant","mag":12.31,"mag_band":"V","abs_mag":3.869,"abs_mag_band":"V","distance_ly":1591.0067921647824,"distance_method":"parallax","ra_deg":90.61615499999999,"dec_deg":-66.791294,"epoch_ra_deg":90.611509,"epoch_dec_deg":-66.790537,"epoch_moved_arcsec":0.256,"pm_ra_mas_yr":-1.26,"pm_dec_mas_yr":9.5,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Dorado","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hip-28618","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"radius_solar":5.725,"spectral_type":"B2(III)","color_index_bv":-0.102,"luminosity_solar":2.4683116896973445,"variable_mag_max":12.153,"variable_mag_min":12.453,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (1974A&AS...16..277C, quality D)","surface_gravity_log_g":3.676,"surface_temperature_k":15712,"proper_motion_ra_mas_yr":-1.26,"proper_motion_dec_mas_yr":9.5,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: above 7,500 K GSP-Phot's temperature and extinction are degenerate"},"designations":[{"catalog":"HIP","designation":"HIP 28618"}],"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."}