{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.818","julian_year":2026.818,"time":"2026-10-26T22:02:14.453Z","years_from_j2000":26.818,"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-1887","name":"HD 1887","class":"g8_k1v_yellow_main_sequence_star","category":"star","object_type":"G8/K1V yellow main-sequence star","mag":9.91,"mag_band":"V","abs_mag":5.963,"abs_mag_band":"V","distance_ly":200.83535576837278,"distance_method":"parallax","ra_deg":5.82552,"dec_deg":0.163704,"epoch_ra_deg":6.173497,"epoch_dec_deg":0.313403,"epoch_moved_arcsec":8.425,"pm_ra_mas_yr":313.61,"pm_dec_mas_yr":18.59,"position_epoch_jyear":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Pisces","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-1887","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":10470156000,"mass_solar":0.775,"radius_solar":0.762,"spectral_type":"G8/K1V","color_index_bv":0.914,"luminosity_solar":0.3587566830392615,"radial_velocity_km_s":-3.6,"spectral_type_source":"SIMBAD (1999MSS...C05....0H, quality D)","surface_gravity_log_g":4.553,"surface_temperature_k":4876,"proper_motion_ra_mas_yr":313.61,"proper_motion_dec_mas_yr":18.59,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":0.2951},"designations":[{"catalog":"HD","designation":"HD 1887"},{"catalog":"HIP","designation":"HIP 1841"}],"updated_at":"2026-10-01T09:42:28.932Z","citation":{"plain":"SpaceCatalog. HD 1887 [catalogue entry]. Data release DR1 (2026-08-21). https://spacecatalog.org/object/hd-1887","bibtex":"@misc{spacecatalog_hd-1887,\n  author       = {{SpaceCatalog}},\n  title        = {{HD 1887}},\n  howpublished = {SpaceCatalog, data release DR1 (2026-08-21)},\n  year         = {2026},\n  url          = {https://spacecatalog.org/object/hd-1887},\n  note         = {Catalogue entry, data release DR1 (2026-08-21). Values from HYG Database v4.1.}\n}","url":"https://spacecatalog.org/object/hd-1887","release":"DR1","doi":null},"references":[{"bibcode":"1999MSS...C05....0H","ads_url":"https://ui.adsabs.harvard.edu/abs/1999MSS...C05....0H/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."}