astronomy

HR diagram, diagram of comet orbit

what is the order of planets from the sun?

(sun) → mercury → venus → earth → mars → jupiter → saturn → uranus → neptune

describe the orbit of planets in the solar system

slightly elliptical

what is a natural satellite?

objects that orbit a planet and aren’t man made

what happens to planet temperature and orbital speed as distance from the sun increases?

both decrease

what are Jupiter’s 4 largest satellites?

Ganymede

Callisto

Io

Europa

what is the sun made from?

hydrogen and helium

how does the sun release energy?

the fusion of hydrogen to form helium

what is the solar system?

our sun and planets together

what is the solar system part of?

the milky way galaxy

what is a galaxy?

a collection of billions of stars

what is the universe made up of?

billions of galaxies

how does the moon stay in orbit?

the pull of gravity from the earth

how do planets stay in orbit?

the pull of gravity from stars

how do stars orbit around galaxies?

pull of gravity from black hole causes stars to orbit the centre of their galaxies

what is a geostationary orbit?

a satellite that’s orbit takes exactly 24 hours

name 3 uses of geostationary orbits

satellite communication

GPS

TV

describe the orbit of a commet

very elongated elliptical orbits

when do commets travel slower?

when further away from the sun due to the difference in gravitational field strength

what is the surface temperature of a blue star?

>11000 K

what is the surface temperature of a blue-white star?

7500-11000 K

what is the surface temperature of a white star?

6000-7500 K

what is the surface temperature of a yellow-white star?

5000-6000 K

what is the surface temperature of an orange star?

3500-5000 K

what is the surface temperature of a red star?

<3500 K

what are the two factors which affect how bright a star appears to us?

size

how far away from us a star is

what is the brightest on the apparent magnitude scale?

first brightest

sixth - dullest seen by eye

what is absolute magnitude?

measure of how bright a star would appear at a set distance (10 parsecs = 32.6 light years)

describe the life cycle of a star

nebula (cloud of gas and dust)

protostar (collapsing under its own gravity)’

main sequence stars (nuclear fusion H→He)

then it goes to EITHER

red giants (low mass or approx mass of sun) → white dwarfs (THE END OF SMALL MASS)

OR

red supergiant (if high mass)

supernova

THEN EITHER

neutron star

OR

if very high mass, black hole