{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T12:53:18.625Z","years_from_j2000":26.683,"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":"lalande-21185","name":"Lalande 21185","class":"m2_v_red_star","category":"star","object_type":"M2+V red star","mag":7.49,"mag_band":"V","abs_mag":10.46,"abs_mag_band":"V","distance_ly":8.306876784067738,"distance_method":"parallax","ra_deg":165.83447999999999,"dec_deg":35.969877,"epoch_ra_deg":166.201171,"epoch_dec_deg":35.789953,"epoch_moved_arcsec":128.14,"pm_ra_mas_yr":-580.2,"pm_dec_mas_yr":-4767.09,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Ursa Major","discovered":"1801","featured":false,"url":"https://spacecatalog.org/object/lalande-21185","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wikidata_id":"Q683605","radius_solar":0.417,"also_known_as":["Argelander's second star"],"discovered_by":"Jérôme Lalande","spectral_type":"M2+V","uncertainties":{"metallicity_fe_h":[0.172,0.172]},"color_index_bv":1.502,"luminosity_solar":0.0057016427228074665,"metallicity_fe_h":-0.2,"wikipedia_article":"Lalande 21185","radial_velocity_km_s":-84.3,"spectral_type_source":"SIMBAD (1989ApJS...71..245K, quality B)","surface_gravity_log_g":4.832,"surface_temperature_k":3511,"metallicity_fe_h_source":"Median of 4 spectroscopic determinations in 7 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-580.2,"proper_motion_dec_mas_yr":-4767.09,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4) — low confidence: Gaia's classifier calls the source a binary, which GSP-Phot fitted as one star","bolometric_luminosity_solar":0.0239},"designations":[{"catalog":"Common name","designation":"Lalande 21185"},{"catalog":"Gliese","designation":"GJ 411"},{"catalog":"Gliese","designation":"Gl 411"},{"catalog":"HD","designation":"HD 95735"},{"catalog":"HIP","designation":"HIP 54035"},{"catalog":"IRAS","designation":"IRAS 11005+3615"}],"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."}