Table 2 shows some properties of four stars in the constellation Triangulum.
| Name | Apparent magnitude | Absolute magnitude | Spectral class |
|---|---|---|---|
| Beta Trianguli | 3.00 | 1.35 | A |
| Alpha Trianguli | 3.42 | 1.95 | F |
| Gamma Trianguli | 4.01 | 1.20 | K |
| HD 13182 | 5.30 | 0.90 | K |
Discuss, with reference to the Hipparcos scale, why many star maps show only two stars in the constellation Triangulum.
State and explain which star in Table 2 has the most prominent Hydrogen Balmer absorption lines.
Deduce which star, Gamma Trianguli or HD 13182, has the larger diameter.
Astronomers recently used the radial velocity method to discover an exoplanet orbiting HD 13182. Describe the main features of the radial velocity method in the detection of planets.
Calculate the distance from the Earth to Beta Trianguli. Give an appropriate unit for your answer.
