{"id":2634992,"slug":"hat-p-21-5415777","name":"HAT-P-21","domain":"deep-sky","class":"star","otype":"Em*","otype_label":"EmLine*","ra":171.27494133064,"dec":41.02796248256,"coo_err_mas":0.0136,"coo_bibcode":"2020yCat.1350....0G","plx_mas":3.519,"pmra":-1.142,"pmdec":13.523,"rv_kms":-51.87,"redshift":-0.00017300474,"dist_pc":null,"vmag":11.46,"bmag":12.56,"gmag":11.557181,"jmag":10.503,"kmag":10.111,"sp_type":"G3","morph_type":null,"size_maj":null,"size_min":null,"size_angle":null,"nbref":49,"simbad_oid":5415777,"gaia_dr3":null,"jpl_spkid":null,"ned_name":null,"exo_name":null,"host_object_id":null,"depth":0,"deep_at":null,"views":1,"first_seen":"2026-08-14T16:51:56.328251+00:00","updated_at":"2026-09-06T03:30:06.079676+00:00","identifiers":["HAT-P-21"],"measurements":[{"parameter":"effective_temperature","value":5695.0,"value_text":null,"unit":"K","err_plus":45.0,"err_minus":45.0,"band":null,"method":null,"source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"effective_temperature","value":5588.0,"value_text":null,"unit":"K","err_plus":80.0,"err_minus":80.0,"band":null,"method":null,"source":"nasa-exo","reference":"Stassun et al. 2017","ref_year":2017},{"parameter":"effective_temperature","value":5588.0,"value_text":null,"unit":"K","err_plus":80.0,"err_minus":80.0,"band":null,"method":null,"source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"effective_temperature","value":5634.0,"value_text":null,"unit":"K","err_plus":125.03,"err_minus":125.03,"band":null,"method":null,"source":"nasa-exo","reference":"ExoFOP","ref_year":2010},{"parameter":"effective_temperature","value":5588.0,"value_text":null,"unit":"K","err_plus":80.0,"err_minus":80.0,"band":null,"method":null,"source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"mass","value":0.998,"value_text":null,"unit":"M_sun","err_plus":0.04,"err_minus":0.04,"band":null,"method":null,"source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"mass","value":0.947,"value_text":null,"unit":"M_sun","err_plus":0.042,"err_minus":0.042,"band":null,"method":null,"source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"mass","value":1.24,"value_text":null,"unit":"M_sun","err_plus":0.6,"err_minus":0.6,"band":null,"method":null,"source":"nasa-exo","reference":"Stassun et al. 2017","ref_year":2017},{"parameter":"mass","value":0.947,"value_text":null,"unit":"M_sun","err_plus":0.042,"err_minus":0.042,"band":null,"method":null,"source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"radius","value":1.248,"value_text":null,"unit":"R_sun","err_plus":0.05,"err_minus":0.05,"band":null,"method":null,"source":"nasa-exo","reference":"Mancini et al. 2022","ref_year":2022},{"parameter":"radius","value":1.21,"value_text":null,"unit":"R_sun","err_plus":0.17,"err_minus":0.17,"band":null,"method":null,"source":"nasa-exo","reference":"Stassun et al. 2017","ref_year":2017},{"parameter":"radius","value":1.105,"value_text":null,"unit":"R_sun","err_plus":0.083,"err_minus":0.083,"band":null,"method":null,"source":"nasa-exo","reference":"Bonomo et al. 2017","ref_year":2017},{"parameter":"radius","value":1.105,"value_text":null,"unit":"R_sun","err_plus":0.083,"err_minus":0.083,"band":null,"method":null,"source":"nasa-exo","reference":"Bakos et al. 2010","ref_year":2010},{"parameter":"radius","value":1.26,"value_text":null,"unit":"R_sun","err_plus":0.07,"err_minus":0.07,"band":null,"method":null,"source":"nasa-exo","reference":"ExoFOP","ref_year":2010}],"orbit":null,"exoplanet":null,"sources":[]}