▁the ▁lack ▁of ▁dark ▁matter ▁is ▁unknown . ▁ ▁In ▁the ▁ 1 9 5 0 s , ▁strong ▁radio ▁sources ▁were ▁found ▁to ▁be ▁associated ▁with ▁very ▁dim , ▁very ▁red ▁objects . ▁ ▁When ▁the ▁first ▁spectrum ▁of ▁one ▁of ▁these ▁objects ▁was ▁taken ▁there ▁were ▁absor ption ▁lines ▁at ▁w avel ength s ▁where ▁none ▁were ▁expected . ▁ ▁It ▁was ▁soon ▁real ised ▁that ▁what ▁was ▁observed ▁was ▁a ▁normal ▁gal actic ▁spectrum , ▁but ▁highly ▁red ▁shift ed . ▁ ▁These ▁were ▁named ▁quasi - stell ar ▁radio ▁sources , ▁or ▁qu as ars , ▁by ▁ ▁Hong - Y ee ▁Ch iu ▁in ▁ 1 9 6 4 . ▁ ▁Qu as ars ▁are ▁now ▁thought ▁to ▁be ▁galaxies ▁formed ▁in ▁the ▁early ▁years ▁of ▁our ▁universe , ▁with ▁their ▁extreme ▁energy ▁output ▁power ed ▁by ▁super - mass ive ▁black ▁holes . ▁ ▁The ▁properties ▁of ▁a ▁galax y ▁can ▁also ▁be ▁determined ▁by ▁analyz ing ▁the ▁stars ▁found ▁within ▁them . ▁ ▁NGC ▁ 4 5 5 0 , ▁a ▁galax y ▁in ▁the ▁Vir go ▁Cl uster , ▁has ▁a ▁large ▁portion ▁of ▁its ▁stars ▁rot ating ▁in ▁the ▁opposite ▁direction ▁as ▁the ▁other ▁portion . ▁It ▁is ▁believed ▁that ▁the ▁galax y ▁is ▁the ▁combination ▁of ▁two ▁smaller ▁galaxies ▁that ▁were ▁rot ating ▁in ▁opposite ▁directions ▁to ▁each ▁other . ▁Bright ▁stars ▁in ▁galaxies ▁can ▁also ▁help ▁determine ▁the ▁distance ▁to ▁a ▁galax y , ▁which ▁may ▁be ▁a ▁more ▁accurate ▁method ▁than