Suppose you take images of star SBD 1256 in different filters and find that, by comparing the brightness of the star through the different filters, it's an F5 star.You assume the star is on the main sequence (F5V), and then use the H-R diagram and determine that it's at a distance of 120 parsecs.A few months later you take a spectrum of SBD 1256 and notice that its absorption lines are very narrow, indicating that it's not an F5V main-sequence star but rather a giant F5III star.Explain how this now affects the distance estimate and why.

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The Answer of Suppose you take images of star SBD 1256 in different filters and find that, by comparing the brightness of the star through the different filters, it's an F5 star.You assume the star is on the main sequence (F5V), and then use the H-R diagram and determine that it's at a distance of 120 parsecs.A few months later you take a spectrum of SBD 1256 and notice that its absorption lines are very narrow, indicating that it's not an F5V main-sequence star but rather a giant F5III star.Explain how this now affects the distance estimate and why.

Suppose You Take Images of Star SBD 1256 in Different