Test #3

Question 1

Chandrasekhar

Answer 1

Chandrasekhar’s limit: White dwarfs must be 1.4 M

Question 2

Annie Cannon

Answer 2

Designed OBAFGKM

Question 3

Henrietta Leavitte

Answer 3

Longer a Cepheid period, greater its luminosity.

Question 4

Zwicky & Baade

Answer 4

Predicted neutron stars. 30yrs no one believed

Question 5

Hertsprung & Russell

Answer 5

Independently noticed main-stair sequence

Question 6

Stellar parallax

Answer 6

only direct measurement of distances of stars

Question 7

 Parallax angle

Answer 7

half the maximum angle that a star appears to be displaced due to the Earthís motion around the Sun.

Question 8

A parsec is:
How many AU?
How many ly?

Answer 8

the distance of an object that has a parallax angle of one arc second.
One parsec is equal to 3.3 ly or about
200,000 AU

Question 9

Parallax distance formula in parsecs:

Answer 9

Distance to star (pc)=1/parallax angle in arcsec

Question 10

Parallax distance formula in ly:

Answer 10

Distance to star (pc)=3.3/parallax angle in arcsec

Question 11

Absolute magnitude distance:

Answer 11

32.6ly or 10 parsecs

Question 12

Order of spectral class:

Answer 12

OBAFGKM

Question 13

ISM:

Answer 13

Interstellar medium: thin gas laced with microscopic dust particles between stars

Question 14

Stars life cycle:

Answer 14

Born in molecular cloud (GMC’s) mostly H

Question 15

Stars most easily form where interstellar material is (dense/spacious) and (warm/cool)

Answer 15

Dense; cool

Question 16

size required to form star

Answer 16

.08 to 150 M

Question 17

White dwarf limit

Answer 17

1.4 M (biggest)

Question 18

Core

Answer 18

H,He,C,O,Ne,Mg,Si,Fe

Question 19

<.08

Answer 19

Brown dwarf

Question 20

.08-.4

Answer 20

red dwarf

Question 21

.4-8

Answer 21

giant-super giant-planetary nebula-white dwarf

Question 22

8-25

Answer 22

giant-super giant-supernova-neutron star or black hole.

Question 23

25

Answer 23

super giant-supernova-black hole

Question 24

Cepheid variable

Answer 24

pulsating stars that vary periodically in brightness.