| Date | May 2016 | Marks available | 1 | Reference code | 16M.3.SL.TZ0.12 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 0 |
| Command term | Describe | Question number | 12 | Adapted from | N/A |
Question
Describe one key characteristic of a nebula.
[1]
a.
Beta Centauri is a star in the southern skies with a parallax angle of 8.32×10−3 arc-seconds. Calculate, in metres, the distance of this star from Earth.
[2]
b.
Outline why astrophysicists use non-SI units for the measurement of astronomical distance.
[1]
c.
Markscheme
made of dust and/or gas
formed from supernova
can form new stars
some radiate light from enclosed stars
some absorb light from distant stars
a.
\(d = \frac{1}{{8.32 \times {{10}^{ - 3}}}}\) OR 120pc
120×3.26×9.46×1015=3.70×1018m
Answer must be in metres, watch for POT.
b.
distances are so big/large OR to avoid using large powers of 10 OR they are based on convenient definitions
c.
Examiners report
[N/A]
a.
[N/A]
b.
[N/A]
c.
