{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T21:27:22.642Z","years_from_j2000":26.67,"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-18449","name":"24 Per","class":"k2iii_orange_giant","category":"star","object_type":"K2III orange giant","mag":4.94,"mag_band":"V","abs_mag":-0.323,"abs_mag_band":"V","distance_ly":368.1222665248014,"distance_method":"parallax","ra_deg":44.76534,"dec_deg":35.183128,"epoch_ra_deg":45.182423,"epoch_dec_deg":35.290544,"epoch_moved_arcsec":1.25,"pm_ra_mas_yr":-46.49,"pm_dec_mas_yr":5.81,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Perseus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-18449","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"mass_solar":3.901,"radius_solar":22.6,"spectral_type":"K2III","uncertainties":{"metallicity_fe_h":[0.06,0.06]},"color_index_bv":1.235,"luminosity_solar":117.27353057793782,"metallicity_fe_h":-0.13,"radial_velocity_km_s":-36,"spectral_type_source":"SIMBAD (1952ApJ...116..122R, quality C)","surface_gravity_log_g":2.24,"surface_temperature_k":4758,"metallicity_fe_h_source":"Median of 2 spectroscopic determinations in 2 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-46.49,"proper_motion_dec_mas_yr":5.81,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":213.7671},"designations":[{"catalog":"Bayer/Flamsteed","designation":"24 Per"},{"catalog":"HD","designation":"HD 18449"},{"catalog":"HIP","designation":"HIP 13905"},{"catalog":"HR","designation":"HR 882"}],"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."}