Astr 181 - Study guides, Class notes & Summaries

How many stars are in our galaxy? - correct answer 4 x 10^11 What is our cosmic address? - correct answer Earth Solar System Interstellar Neighborhood Milky Way Lanieakea Observable Universe Infinite Universe What is an astronomical unit? - correct answer The average distance between the Sun and the Earth As a blackbody becomes hotter, it also becomes ______ and ______. - correct answer More luminous, bluer. If an electromagnetic wave's frequency increased, then - correct ...

________ allow gasses and to escape the sun, creating solar wind. - ️️Open field lines A planet in orbit around the Sun is accelerating toward the Sun because ______ . - ️️Its direction is constantly changing A star is 230 light years away. Therefore, the light we see tonight left the star _______ years ago. - ️️230 A star's luminosity describes ______ . - ️️How much energy the star gives off each second Absolute magnitude is _______ . - ️️How bright a star appears at 10...

A hydrogen atom that has been photoionized is _____. - ️️An ion, a proton, and positively charged. A main sequence O star will have a ___ temperature, a ____ radius, a ____ luminosity and a ____ absolute magnitude than a main sequence G star like the Sun. - ️️larger, larger, larger, smaller A star that is 50 pc away will show a parallax of _____. - ️️.02 arc secs A star with T=10,000 K (spectral type A) shows strong absorption lines from _______. - ️️neutral hydrogen (H I) ac...