{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.672","julian_year":2026.672,"time":"2026-09-03T13:35:34.525Z","years_from_j2000":26.672,"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-173540","name":"μ CrA","class":"g5_6iii_yellow_giant","category":"star","object_type":"G5/6III yellow giant","mag":5.2,"mag_band":"V","abs_mag":-0.22,"abs_mag_band":"V","distance_ly":395.82077074601807,"distance_method":"parallax","ra_deg":281.93589,"dec_deg":-40.406167,"epoch_ra_deg":282.404925,"epoch_dec_deg":-40.377032,"epoch_moved_arcsec":0.823,"pm_ra_mas_yr":24.64,"pm_dec_mas_yr":-18.57,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Corona Australis","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-173540","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":317759720,"mass_solar":3.196,"radius_solar":10.972,"spectral_type":"G5/6III","uncertainties":{"metallicity_fe_h":[0.04,0.04]},"color_index_bv":0.781,"luminosity_solar":106.6596121230258,"metallicity_fe_h":-0.15,"radial_velocity_km_s":-18,"spectral_type_source":"SIMBAD (1978MSS...C02....0H, quality D)","surface_gravity_log_g":2.818,"surface_temperature_k":5972,"metallicity_fe_h_source":"One spectroscopic determination, compiled from the literature (PASTEL, Soubiran+ 2016)","proper_motion_ra_mas_yr":24.64,"proper_motion_dec_mas_yr":-18.57,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":114.3779},"designations":[{"catalog":"Bayer/Flamsteed","designation":"Mu CrA"},{"catalog":"HD","designation":"HD 173540"},{"catalog":"HIP","designation":"HIP 92226"},{"catalog":"HR","designation":"HR 7050"}],"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."}