Imagine you have imaged an exoplanet which is in a face-on circular orbit around a star 12.31 parsecs from the Earth. The apparent radius of the orbit is 0.78 arcseconds.
How far (in astronomical units) is the planet from the centre of its star?
You may assume that a parsec is 3.086e16m and an astronomical unit is 1.496e11m
Explanation
The distance is given by the equation r=Dθ. You need to convert the angle from arcseconds into radians (multiply by π/(180×60×60) ), and also convert the distance from parsecs to metres, and the answer from metres to astronomical units.
VASTAUS ON 9.602 AU
Eli tämä mielestäni pitäisi laskea D=r/θ.
r=12.31*3.086e16
θ=0.78*π/(180×60×60)
Sitten vastaus AU:na (12.31*3.086e16)/(0.78*pi/(180×60×60))/1.496e11 = 6.71511e11 eli väärin menee. Olen koittanut ratkaista tätä jo monta tuntia.
How far (in astronomical units) is the planet from the centre of its star?
You may assume that a parsec is 3.086e16m and an astronomical unit is 1.496e11m
Explanation
The distance is given by the equation r=Dθ. You need to convert the angle from arcseconds into radians (multiply by π/(180×60×60) ), and also convert the distance from parsecs to metres, and the answer from metres to astronomical units.
VASTAUS ON 9.602 AU
Eli tämä mielestäni pitäisi laskea D=r/θ.
r=12.31*3.086e16
θ=0.78*π/(180×60×60)
Sitten vastaus AU:na (12.31*3.086e16)/(0.78*pi/(180×60×60))/1.496e11 = 6.71511e11 eli väärin menee. Olen koittanut ratkaista tätä jo monta tuntia.
Vastaukset 1
Vanhimmat
r=Dθ eli 12.31*3.086e16*0.78*pi/(180*60*60)/1.496e11 eli antaa oikean vastauksen