A presentation I gave to the Brighton Astronomy Society in Jan 2016 - http://brightonastro.com/ , https://www.facebook.com/brightonastro/ Annoyingly that's removed the videos from the slides, so here are links to those: https://www.youtube.com/watch?v=e-P5IFTqB98&t=18s (This Youtube channel "In a nutshell" is absolutely fantastic by the way and I highly recommend a look through their other videos!) https://www.youtube.com/watch?v=duoHtJpo4GY https://vimeo.com/8723702 I've also made my notes from preparing the slides available here as well: https://docs.google.com/document/d/1gqgsAbvoCB_7-_gPToqOuSixc02YnU-ajf-uT60R1vc/edit?usp=sharing -- there are LOTS of further links to interesting videos in there as well, that I didn't use on the night so worth a scan through. Any further questions, feel free to ask in comments on here

1. BLACK HOLES &
NEUTRON STARS

2. BLACK HOLES IN
POPULAR CULTURE

7. THE LIFE AND DEATH
OF STARS

9. SMALLER STARS (LIKE OUR SUN)
( Don’t worry, we have around 5
billions years left yet … )

11. CHANDRASEKHAR LIMIT
• Discovered by Subrahmanyan Chandrasekhar
• Awarded Nobel Prize for Physics 1983
• Maximum mass of stable white dwarf
• 1.4 x mass of our Sun
• Above that – Neutron star or Black Hole

12. TOLMAN–OPPENHEIMER–VOLKOFF LIMIT
• Calculated in 1939, derived from similar
equations to the Chandrasekhar limit
• Maximum mass of neutron star
• 2 - 3 x mass of our Sun ( from core remnant )
• Original star mass 15 – 20 solar masses
• Above that – Black Hole

13. ALL ABOUT MASS OF CORE REMNANT
< 1.4 Solar Masses = White dwarf
1.4 - ~3 Solar Masses = Neutron star
> 3 Solar Masses = Black hole

14. MASS OF ORIGINAL STAR
< 10 Solar masses = White dwarf
10 – 29 Solar masses = Neutron star
> 29 Solar masses = Black hole

15. SOME OTHER SCENARIOS….
• Some stars may just vanish to black hole instantly
• Some huge stars blow up entirely, leaving NOTHING
• Some may form Quark Stars

16. NEUTRON STAR
• All empty space of atoms squeezed away
• Density of an atom core
• Tight structure of neutrons
• Matchbox of material = 13m tonnes
• Cube of Earth 135m square

17. BLACK HOLE
• Core completely collapses in on itself
• Mass compacts down to singularity
• Infinite density
• 1 dimension only
• More on this soon…
• Event Horizon – giving black hole its name

18. VERY DENSE MASS…..

19. NON ROTATING BLACK HOLE
• “Schwarzschild Black Hole”
• No spin, no electric charge

20. SINGULARITY
• Infinite density
• 1 dimension – no real “size”
• Space-time curves infinitely
• Physics (esp relativity) breaks down entirely
• Combined quantum & relatively MAY explain one day
• No information can ever escape from singularity

21. EVENT HORIZON
• Shwarzschild radius – light can’t escape
• = Event Horizon
• No information can ever escape
• ( Except Hawking radiation! )
• Past this boundary, space time curves inwards
ONLY

22. GRAVITY – SPACETIME CURVATURE

23. GRAVITY – SPACETIME CURVATURE

24. GRAVITY – SPACETIME CURVATURE

25. GRAVITY – SPACETIME CURVATURE

26. NON ROTATING BLACK HOLE
• “Schwarzschild Black Hole”
• No spin, no electric charge

27. ROTATING BLACK HOLE

28. • Inner / outer horizon
• Static Limit
• ”Location at which space-time is flowing at
the speed of light, making stationary
particles that would be travelling at the
speed of light”
• Ergosphere – region between the two
ROTATING BLACK HOLE

29. ACCRETION DISK & JETS

30. • Strong gravity bends light
• Large scales, gravitational
lensing of distant galaxies
• Similar around black holes
• Interstellar
GRAVITATIONAL LIGHT DISTORTION

31. • Too close to event horizon, yes
• At more distance, same pull as
original star
• Replacing Sun with black hole
NOT VORACIOUS VACUUM CLEANERS!

32. • Micro
• Solar Mass
• Intermediate Mass
• Super Massive
TYPES OF BLACK HOLE

33. • Micro:
TYPES OF BLACK HOLE
• Theoretical, never observed
• May have been created shortly after Big Bang
• May be created in particle accelerators
• Exist for 10th of trillionth of trillionth seconds

34. • Solar Mass:
TYPES OF BLACK HOLE
• Ghost of massive stars
• Size range approx 5 – 64 solar masses
• ~ 100m within our galaxy, mostly invisible
• Observable when in binary pair with star
• Nearest 1600 light years away

35. TYPES OF BLACK HOLE

36. • Intermediate Mass:
TYPES OF BLACK HOLE
• Thought at center of some globular clusters

37. • Supermassive:
TYPES OF BLACK HOLE
• The true monsters!
• Centre of all spiral
& elliptical galaxies
• Largest 30bn –
40bn solar masses!

38. MILKY WAY CENTRE – SAGITTARIUS A*

41. • 2 ly = 51Bn Km
• Nearest star is 37 tr Km
• Fits in 730 times!
MILKY WAY CENTRE – SAGITTARIUS A*

42. • Event horizon estimate 44 M km
• 75% of distance of Mercury to Sun
• Mass 4m Solar masses
• Event Horizon Telescope – imminent!!
MILKY WAY CENTRE – SAGITTARIUS A*

43. • Avg – 0.1% mass of galaxy
• Largest in relation to galaxy 4% – 14%!
SUPERMASSIVE BLACK HOLES

47. • Scientists not yet sure
• Early galaxy gas clouds collapse
• Stellar black hole eats and enlarge
• Clusters of stellar holes combine
• Merging of galaxies combines cores
• Mystery how so big so early!
HOW FORMED?

48. • Ancient and distant
• 12 billion light years away
• Universe 1.8 bn years old
• But ENORMOUSLY bright!
• Dust/Gas rich early galaxies,
accretion disks
• > 200,000 known
• Blasars are where jets point
at us!
QUASARS & BLASARS

49. GRAVITATIONAL WAVES
• Orbiting and merging of
black holes
• Proposed by Einsten 1916
• Detected LIGO 2015
• Two 30 solar mass black
holes merging

50. GRAVITATIONAL WAVES
• eLISA – coming 2030!
maybe…..
• Pathfinder sent 2015
• Detect supermassive BH
mergers in early Universe
• Observe 25k compact
binaries in Milky Way

51. WHAT HAPPENS TO YOU
IF YOU GET CLOSE TO BLACK HOLE?

53. https://vimeo.com/8723702

55. Hawking Radiation
Something CAN escape the
Event Horizon! .. maybe ……
DEATH OF A BLACK HOLE?

57. To come….
NEUTRON STARS?
Future talk 
( There was so much to talk
about black holes! )
Ran out of time…..

58. QUESTIONS?