Astonomers study space and all that is in it. so yes, they study the sun.
Jesus sewed it together from sun-string and fairy dust.
because people would die
Astronomers measure it by predicting with the stars and using scientific tools
The surface temperature and the absolute magnitude, which is the brightness of the star when viewed from a standard distance of 10 parsecs.
Astronomers use the unit of measure "Light Years" to calculate the distance between pretty much anything in the Universe.
Earliest is an adjective.
Yes. But earliest is also an adjective, the superlative of early (most early). adjective - the earliest time adverb - he arrived earliest
Astonomers, like all scientists, dont have one single method ,or "The Scientific Method". They have a wide variey of ways to solve problems.
Raster.
Earliest, it is spelled correctly.
I think the earliest form is poem, because The Book of Songs is the earliest poetry anthology and the earliest literature.