| Date | May 2012 | Marks available | 3 | Reference code | 12M.3.SL.TZ1.13 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | Draw and Outline | Question number | 13 | Adapted from | N/A |
Question
This question is about the star Naos (Zeta Puppis).
The following data are available for the star Naos.
Surface temperature = 4.24×104K
Radius = 7.70×109m
Apparent magnitude = +2.21
Parallax angle = 3.36×10–3 arcseconds
The distance to Naos may be determined by the method of stellar parallax. The diagram shows the star Naos and the Earth in its orbit around the Sun.
(i) Draw lines on the diagram above in order to indicate the parallax angle of Naos.
(ii) Outline how the parallax angle of Naos may be measured.
Markscheme
(i) either angle p as shown;
(ii) the star’s position is observed at two times, six months apart;
the shift in the star’s position relative to the distant stars is (twice) the parallax angle;
Accept correct answers which are clear from annotations on the diagram.
