Great question! When stars age, hydrogen at their core is fused into helium. This releases huge amounts of energy and changes the composition of the star.
Hi Paige! What we should have said is that the Orion nebula is visible to the unaided aye, not that it is ONLY visible to the unaided eye. This is unique because there are very few celestial objects visible to the unaided eye. The Orion Nebula is around 20 light years away from Earth.
Earth does not have a position on the HR diagram because it is not considered a star. Also, the HR diagram is used to track temperature and luminosity as it is viewed from Earth.
Stars are measured using parallax. This can be done by observing "parallax shift" of stars when nears stars seem to shift against the background of more distant stars. Astronomers can use this shift and the diameter of Earth's orbit to calculate the distance of stars.
When you were talking about the HR disgram, you said that stars change over time. What happens that makes them change?
ReplyDeleteGreat question! When stars age, hydrogen at their core is fused into helium. This releases huge amounts of energy and changes the composition of the star.
ReplyDeleteYou said the Orion nebula is only visible to the unaided eye. How far away is it?
ReplyDeleteHi Paige! What we should have said is that the Orion nebula is visible to the unaided aye, not that it is ONLY visible to the unaided eye. This is unique because there are very few celestial objects visible to the unaided eye. The Orion Nebula is around 20 light years away from Earth.
Deletewhere would earth be on the HR diagram?
ReplyDeleteEarth does not have a position on the HR diagram because it is not considered a star. Also, the HR diagram is used to track temperature and luminosity as it is viewed from Earth.
DeleteWhat is the most common type of non-main sequence star? White dwarf, Red Giants, or Super Giants?
ReplyDeleteHow do they measure the distances of stars from Earth?
ReplyDeleteStars are measured using parallax. This can be done by observing "parallax shift" of stars when nears stars seem to shift against the background of more distant stars. Astronomers can use this shift and the diameter of Earth's orbit to calculate the distance of stars.
DeleteDo you know the percentage of stars that make up the main sequence?
ReplyDeleteAbout 90% of the stars in the universe are main-sequence stars.
DeleteHow do you know the distance of stars from each other (non-binary stars)?
ReplyDelete