????????????????????????
??????2????????????21?????? (???????????????? ???)?????,??????????????????,??????????????
??
?????????????????????????????????????????????2??????21?????,?????????????,???????“??????????????”(??????????????)???,???“????”?????

?(Gaia)???????(????,LAMOST)??????????,?????,??????J0731+3717?2000????????????????,??550????????????? M15?????????????????????????????????????????“??”,????? M15?????????????
??/??????????????????????????????,???????«????»???????
????????????????,??????????????????????????????????,??????????J0731+3717????????????,??“??????????”????
????????
???????????????????????,????????????(?‘?????????’??????????X-1)?????????????????????????(??Sgr A*)????????????????????,????????????????,??????????????,????????????????????????????

????????,???????????????????????????,???????:????(???????????????)????,??????????(???);??,???????????????????(???)?
?????????????
??????21???????,????????????????(HST)????M15??????????????????????????,?M15????????1700???????????3200????,??????????,?????????,???
?,??????????????????????500????????????????,??????????7?????????????,?????????
??????????,???
????
????,??????????????????????????????????????????“????????????????”,?????????????????????,??????J0731+3717???????????????2000??550??M15??????????????????,?????????????M15??

??????????????????,?,??,???????,???????????????????????????“???????????????”???????????????????????????????,??????/????????,?????,???M15????????????????
??????????????,?????“?????????????????????????????????”??????????????????? J0731+3717,???????????????????????(????????)

??