{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.822","julian_year":2026.822,"time":"2026-10-28T01:32:12.682Z","years_from_j2000":26.822,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued position is carried along the great circle the object's own published motion puts it on, at a constant velocity, from the epoch that position was measured at, 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. The motion runs from position_epoch_jyear where the upstream publishes one — a timed pulsar's position belongs to the year it was timed — and from J2000 where it does not. 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-209253","name":"HD 209253","class":"f6_5v_yellow_white_main_sequence_star","category":"star","object_type":"F6.5V yellow-white main-sequence star","mag":6.63,"mag_band":"V","abs_mag":4.234,"abs_mag_band":"V","distance_ly":98.29896605453844,"distance_method":"parallax","ra_deg":330.637365,"dec_deg":-32.133748,"epoch_ra_deg":331.029858,"epoch_dec_deg":-32.003489,"epoch_moved_arcsec":0.801,"pm_ra_mas_yr":-19.49,"pm_dec_mas_yr":22.64,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Piscis Austrinus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-209253","source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0","attribution":"HYG Database v4.1, Astronexus (github.com/astronexus/HYG-Database). Fields derived from it stay under CC BY-SA 4.0.","commercial_use":"allowed"},"radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"age_years":2896681000,"mass_solar":1.14,"radius_solar":1.201,"spectral_type":"F6.5V","uncertainties":{"metallicity_fe_h":[0.096,0.096]},"color_index_bv":0.504,"luminosity_solar":1.7635996338979947,"metallicity_fe_h":-0.1,"radial_velocity_km_s":0,"spectral_type_source":"SIMBAD (2006AJ....132..161G, quality C)","surface_gravity_log_g":4.212,"surface_temperature_k":6157,"metallicity_fe_h_source":"Median of 5 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":-19.49,"proper_motion_dec_mas_yr":22.64,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":1.8532},"designations":[{"catalog":"HD","designation":"HD 209253"},{"catalog":"HIP","designation":"HIP 108809"}],"updated_at":"2026-10-01T09:42:28.932Z","citation":{"plain":"SpaceCatalog. HD 209253 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-209253","bibtex":"@misc{spacecatalog_hd-209253,\n  author       = {{SpaceCatalog}},\n  title        = {{HD 209253}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-209253},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-209253","release":"DR1","doi":null},"references":[{"bibcode":"2006AJ....132..161G","ads_url":"https://ui.adsabs.harvard.edu/abs/2006AJ....132..161G/abstract","quantity":"properties.spectral_type_source"}],"attribution":"Data from SpaceCatalog.org. Each record names its upstream in `source`, with that producer's terms in `source.license`, the acknowledgement it asks for in `source.attribution`, and whether its terms allow commercial use in `source.commercial_use`; those terms govern the record, and citing SpaceCatalog does not discharge them."}