A) Show that the surface temperature of a star can be inferred from measurements of blackbodyfluxes at two different frequencies, even if the stellar radius and distance are unknown. b) Explain why in practice this method does not work well if both frequencies are on theRayleigh-Jeans side of the spectrum, hνkT.
c) Derive a simple, approximate expression for the temperature when both measurements areon the Wien tail, hνkT.
d) Derive an expression for the star’s radius if a distance measurement is also available (e. g.,from parallax).

Asubject in a clinical research trial experiences a serious, unanticipated adverse drug experience. how should the investigator proceed, with respect to the irb, after the discovery of the adverse event occurrence? a. do not report the adverse drug experience to the irb since it is a common adverse experience.b. report the adverse drug experience to the irb only if there are several other occurrences.c. report the adverse drug experience as part of the continuing review report.d. report the adverse drug experience in a timely manner, in keeping with the irb's policies and procedures, using the forms or the mechanism provided by the irb.