Topic 14 - Stellar evolution Flashcards
1
Q
How many objects are in the Messier Catalogue?
A
110
2
Q
What type of objects are in the Messier Catalogue?
A
Galaxies, nebulae, clusters
3
Q
What is special about the objects in the Messier Catalogue?
A
All observed from the Northern Hemisphere.
4
Q
What is the NGC?
A
New General Catalogue
5
Q
How does the Bayer system work?
A
Stars are labelled according to their brightness within a constellation, using Greek letters.
6
Q
What is the balance in a white dwarf star?
A
Electron degeneracy pressure and gravity.
7
Q
What is the balance in a neutron star?
A
Neutron degeneracy pressure and gravity.
8
Q
What is the Chandrasekhar Limit
A
- Maximum mass of a stable white dwarf star
- 1.4 solar masses
9
Q
What is the difference between emission and absorption nebula?
A
- Emission nebula indícate newly born formed stars, Orion Nebula
- Absorption nebula is a dark nebula. It is so dense that it obscures visible wavelengths of light from objects behind it
10
Q
How can we detect black holes?
A
- If a binary star is close to a black hole, matter is pulled in, heated, and emits X-rays
- Black holes bend space-time so light from stars behind them appear as several images of stars
