A scientist claims that all red main-sequence stars are 1 billion years old. Which of the following, if true, would prove that this claim is false?
A) The discovery of a red main-sequence star in a star cluster where the main sequence turnoff is about that of the Sun
B) The discovery of a red main-sequence star in a star cluster where all the other stars are red giants or red supergiants
C) Stellar evolution theory predicts that the main-sequence lifetime of red stars can be as long as 100 billion years.
D) The minimum lifespan of a red main-sequence star is estimated to be 10 billion years.
Question 2
Most of the mass of the Milky Way is located in the halo of the galaxy in the form of dark matter.
Indicate whether the statement is true or false
The two bright stars are (left) Alpha Centauri and (right) Beta Centauri.
Deciduous and permanent teeth. (A) The deciduous teeth, with the age of eruption given in months; (B
The declining age of menarche over the past 150 years has been measured in many European countries,
William Kentridge, History of the Main Complaint.
School age (late childhood): 6–12 years, or to puberty.
Nick buys a $25 000, 5.4% bond with quarterly interest coupons, 3 years before maturity, to ...