| Date | May 2018 | Marks available | 2 | Reference code | 18M.3.HL.TZ1.18 |
| Level | Higher level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | Show that | Question number | 18 | Adapted from | N/A |
Question
Type Ia supernovae typically have a peak luminosity of around 5 × 105 Ls, where Ls is the luminosity of the Sun (3.8 × 1026 W). A type Ia supernova is observed with an apparent peak brightness of 1.6 × 10–6 W m–2.
Describe the formation of a type Ia supernova.
Show that the distance to the supernova is approximately 3.1 × 1018 m.
State one assumption made in your calculation.
Markscheme
a white dwarf accretes mass «from a binary partner»
when the mass becomes more than the Chandrasekhar limit (1.4Ms) «then asupernova explosion takes place»
[2 marks]
d = \(\sqrt {\frac{{\text{L}}}{{4\pi {\text{b}}}}} = \sqrt {\frac{{5 \times {{10}^5} \times 3.8 \times {{10}^{26}}}}{{4\pi \times 1.6 \times {{10}^{ - 6}}}}} \)
d = 3.07 × 1018 «m»
At least 3 sig fig required for MP2.
[2 marks]
type Ia supernova can be used as standard candles
there is no dust absorbing light between Earth and supernova
their supernova is a typical type Ia
[1 mark]
