The Signature Of The Stars Worksheet (Page 2 of 6) in pdf

The Signature Of The Stars Worksheet Page 2

The Expanding Universe

Part 2 : T he L ight f rom S tars C ontains I nformation.

The c ore o f a s tar i s v ery h ot ( ~15 × 1 0

K ), a nd v ery h ot o bjects g low. T he l ight p roduced b y a s tar’s c ore c ontains a ll t he c olours i n t he

spectrum. A stronomers c an l earn m any t hings a bout a s tar’s m otion, t emperature, a nd c omposition b y a nalyzing t he s tarlight t hat r eaches

Earth. A s pectroscope i s a n i nstrument t hat s eparates l ight i nto i ts s pectrum. O ne o f t he e arliest u ses o f t he s pectroscope w as t o a nalyze

light c oming f rom a stronomical o bjects. T he l ight d irected f rom a t elescope t hrough a s pectroscope p roduces a n i mage c alled a

spectrograph.

F igure 3

s hows a s pectrograph o f t he S un.

Wavelength ( nm)

Figure 3

A s pectrograph o f t he S un. N ote: T he l ettered l ines r epresent d ifferent e lements. L ines A a nd B a re d ue t o t errestrial o xygen a nd a re n ot d ue t o t he S un.

What d o t he d ark l ines i n

F igure 3

i ndicate?

Predict w hat h appens t o l ight a s i t t ravels f rom t he c ore o f t he S un t o t he s urface?

Where d o y ou t hink t he e lements i n t he o uter l ayers o f t he S un c ome f rom?

Activity 2