▁outer ▁structure . ▁" The ▁Ch andra ▁image ▁contains ▁some ▁puzz les ▁for ▁existing ▁ideas ▁of ▁how ▁a ▁star ▁can ▁produce ▁such ▁hot ▁and ▁inten se ▁X - ray s ," ▁says ▁Prof . ▁K ris ▁David son ▁of ▁the ▁University ▁of ▁Minnesota . ▁David son ▁is ▁principal ▁investig ator ▁for ▁the ▁E ta ▁Car ina ▁observations ▁by ▁the ▁Hub ble ▁Space ▁teles cope . ▁" In ▁the ▁most ▁popular ▁theory , ▁X - ray s ▁are ▁made ▁by ▁coll iding ▁gas ▁streams ▁from ▁two ▁stars ▁so ▁close ▁together ▁that ▁they ' d ▁look ▁like ▁a ▁point ▁source ▁to ▁us . ▁But ▁what ▁happens ▁to ▁gas ▁streams ▁that ▁escape ▁to ▁farther ▁distances ? ▁The ▁extended ▁hot ▁stuff ▁in ▁the ▁middle ▁of ▁the ▁new ▁image ▁gives ▁demand ing ▁new ▁conditions ▁for ▁any ▁theory ▁to ▁meet ." ▁ ▁Am ateur ▁X - ray ▁astronom y ▁ ▁Collect ively , ▁amateur ▁astronom ers ▁observe ▁a ▁variety ▁of ▁cel est ial ▁objects ▁and ▁phen omena ▁sometimes ▁with ▁equipment ▁that ▁they ▁build ▁themselves . ▁The ▁United ▁States ▁Air ▁Force ▁Academy ▁( USA FA ) ▁is ▁the ▁home ▁of ▁the ▁US ' s ▁only ▁under grad uate ▁satellite ▁program , ▁and ▁has ▁and ▁continues ▁to ▁develop ▁the ▁Fal con Launch ▁sound ing ▁rock ets . ▁In ▁addition ▁to ▁any ▁direct ▁amateur ▁efforts ▁to ▁put ▁X - ray ▁astronom y ▁pay loads ▁into ▁space , ▁there ▁are ▁opportun ities ▁that ▁allow ▁student - develop ed ▁experimental ▁pay loads ▁to ▁be ▁put ▁on ▁board ▁commercial ▁sound ing ▁rock ets ▁as ▁a