Gravitational Waves – Lecture, University of Birmingham- Tuesday 30 October 2012

Went to a lecture at the University of Birmingham this evening. It was part of their outreach programme. There are further events coming up.

The lecture was supposed to be about the Square Kilometre Array (SKA) but the visiting lecturer was ill, so Dr Andreas Freise from University of Birmingham stepped in and delivered a lecture on Gravitational Waves and a Proposed Einstein Telescope(ET).

Below are my scribbled notes pretty much as is, purely for my own purposes as a reminder.

Gravitational waves stretch and squash on different axes
LIGO – Laser Interferometer Gravitational wave Observatory
Gravitational waves are a prediction of general relativity
Ripples in space-time
Sources – binary systems, pulsars, accreting stars, supernovae
Everything actually generates them but needs to be really large to be measurable

Detected using an Interferometer
Was impressed to see Processing being used to demonstrate a Michelson interferometer
(aside – Sky at Night Magazine November 2012 has an article about Michelson and Morley and the theory of the aether as a medium for propagation of light.  They used an interferometer to attempt to prove the existence of the aether – the failure ended up disproving it)
The interferometer acts as a detector.  A laser is fired into it.   If output changes – then either the mirror moved or it’s a gravitational wave.  In the interferometer photon is not affected by the the GW but the mirror is.  A lot of the tech seems to be about ensuring the mirrors don’t move so therefore anything that get’s detected is a gravitational wave.
LIGO is a big version of The interferometer.
Mirrors are decoupled and hanging on wires so they don’t move. Have to invent stuff.
Need very clean glass to eliminate thermal lensing

It didn’t work though so now they upgrade to the advanced LIGO.
This will be ready in 2015.
If it doesn’t see Gravitational waves though – does that mean prediction is wrong or mean it didn’t work?Have developed more For the advanced LIGO they have developed a more complex interferometer.
More information in the LIGO magazine – PDF download available.

Ground vibration seems to be the biggest problem – keeping that mirror as still as possible is essential. – (I’d wondered about that) so the next stage would be to go underground.  Also suggested going into space.

Questions from the audience:
Graviton got mentioned – particle equivalent of gravity. There is a field for each particle – quantum physics. Can behave as a field. Can behave as a particle.  Cf photon and em field.

Practical implications?
Hope to see something different in the sky. Perhaps. Add to cosmological models.

My question:  Why go to space?
Ground vibrations. Gravitational pull to centre of earth distorts the geoometry of the mirrors and puts a limit on length of about 3m

There was an excellent question from one of the school students.   She asked if the ET telescope is intended to be underground and in a triangle so there are two sets of 3 detectors picking up from multiple directions, why not take it from a two dimensional arrangement, ie a triangle, to a 3 dimension one – a tetrahedron?
Brilliant question.  Lecturer seemed surprised by it.  Comes down to financing and that would be the 4th generation.  They need to fund the 3rd generation, the ET first.

More info about detection of gravitational waves at http://www.gwoptics.org/

A bit of further reading about Gravitational Waves from Wikipedia.  I see that the Astronomy Cast podcast has an episode about them.  I should take a listen.

A final thought, having read the article about Michelson and Morley’s experiments with interferometers to attempt to detect the aether and the subsequent failure of this that led to a move away from that model of understanding.   So far Gravitation Waves have not been detected, only predicted and inferred.  What if using similar methods to the Michelson-Morley experiment ultimately fails to detect them?

Observation Plans

Every month I seem to accumulate several lists of things I should be looking for in the coming month. These come from a variety of sources, newsletters like Walsall Astro’s “What’s Up”, Sky at Night Magazine, the Jodrell Bank Jodcast and probably a few more besides.
I’ve decided to try to collate these into a single handy calendar so that on any given night, if it’s clear, I’ve a ready source of inspiration for my observations.
There will be other highlights for a month that aren’t date specific and probably some more longer term, general things I wish to see when the opportunity presents, which are listed separately.
So I’ve made and embedded a Google Calendar into a new Observation Planning page.

The Moon, Observations – Friday 26 October 2012

Location: Home, top and middle of drive.
Conditions: thin cloud, amost full moon.
Equipment: Skywatcher 130, asdacam, 7×15 binoculars
Highlights: Moon, Jupiter

The nights are closing in.  Good news for observing.  Clear early on this evening but by the time I got the scope out and set up about 20:30 it was getting cloudy.  It was OK observing the moon through the cloud although at times there was too much reflection into the clouds causing something of a halo effect that meant there was no definition to be found on the edges. Moon was about 3 days from being full so there was still a terminator.
The crater Bailey was just into the darkness. The rays around Tycho were bright white.
Cloud was moving quite quickly so was variable in thickness. Decided to have a go at imaging so popped a cheap 640 x480 webcam (£3 from Asda) that I’d previously modified, removing the lens and IR filter, into the eyepiece holder.   Shot a few AVIs to try some processing later….
Cloud cover was at about 90% by 22:00 so I packed up. Of course by the time I was taking the last of the kit in, about 20 minutes later it was clearing up again.
Jupiter was just clearing the front gates so I took a quick look through the binoculars.  Looking forward to getting the ‘scope on this and seeing the banding in coming weeks.  Walsall Astro’s What’s Up Newsletter for November helpfully includes transit times for the Galilean Moons and the Great Red Spot (GRS) which I’ve added to the Observation Plans page so I’m looking forward to observing those events.

Seven Ages of Starlight

Just watched a brilliant BBC programme called Seven Ages of Starlight on BBC Four. All about the life of stars. I made notes for my own purposes as I watched it. These are below. Purely for my own purposes. So if it don’t make sense then tough. I didn’t write it as a blog post for anybody else. (this is the problem with putting a blog somewhere public perhaps.)

1 Birth of a star
Pleiades as a star forming region. apparently mentioned by Homer in Odessey

Plasma – soup of unattached particles. Proton and electron of Hydrogen particles in atom become separated. Fusion is where the proton that are repelling occasionally collide. 4 protons make Helium atom.E=mc^2 comes into play. Mass becomes energy. C is big so small mass gives lot of energy.

Copernicus – heliocentric model.

Planets forming – blank out star in Pegasus and you see the white spots of planets forming.

2 Adulthood
Sunspot sketching by projection. Galileo showed that over days they moved and showed rotation of sun.
Solar wind – causes aurora where planets have magnetic field. Runs out of momentum at the outer limit of the solar system – the Heliosphere. Provides protection against galactic radiation and cosmic rays.

Talked of the sun running out of fuel. We didn’t know when it would come. I remember being at infant school and being told that. Only young but genuinely scared. Remember going home at lunchtime being very worried about it. It’s ok. We’re about 1/2 way through. 5 billion years left.

Sun is balanced – fusion balances gravity.

Lifecycle of stars – colour and luminosity. – the Hertzsprung Russell diagram
Main sequence. Central diagonal line.
2 outcrops. Fate of sun is to head off main sequence to red giant.

3 Red Giant
Eg Betelgeuse, Arcturus
Stars fuse H to He. When hydrogen runs out, core collapses, heats up and starts hydrogen fusion to helium in a shell around core. This overcomes gravity. Expands further. Expansion leads to cooling.
Next stage is helium fusion – carbon and oxygen created.

4 White Dwarf
come next.
Sirius in Canis Major has a faint companion, Sirius B, a white dwarf.
Very dense.
Burnt out remains of star where fusion has stopped-fuel run out. Why does it even shine?
Gravity wins over fusion – collapses under it’s own weight. Very small.
Quantum mechanics comes into play – don’t collapse completely – pressure of electrons trying not to be in same place is what keeps it from collapsing. Still shines because of this – cools and fades over time.
Slow and quiet death.

5 Supernova
This is the alternative to Red Giant-White Dwarf for larger stars. Is what happens to large star when it dies. Huge explosion. Leave behind remnants.
Alex Filipenko – supernovae hunter.
Different elements give off different colours. We can tell what a star is by the colour.
Colours of elements in the supernova remnants.
Look at supernova with spectrograph.
Where did elements come from? Fred Hoyle had answer.
Red giants not hot enough to create all elements. Supernovas were.
All about final stage in fight against gravity. Fusion occurs time and time again with heavier and heavier elements forming each time in similar way to the Hydrogen to Helium to Oxygen and Carbon cycles until we get to iron. When ball of iron reaches critical mass size of earth, collapses to size of city, rebounds and goes supernova explosion. That creates even heavier elements and throws them out. This would be where the famous Sagan quote from Cosmos arises “We are made of star stuff” – we are stardust.
And so it starts again. This dust collides under gravity, clouds collapse, stars are born. Next generation.

6. Neutron Stars
Calculations of Zwicky predicted neutron stars. Solidity is an illusion. Lot of empty space in atom.
Zwicky predicted that implosion of iron core squeezes protons and electrons together so closely to form neutrons. Intense Magnetic field generated.
Supernova leaves behind dense kernel.
Dismissed as until radio astronomy when in 1967 picked up strange signal – exact and predictable. – Pulsar.
Then found Crab Pulsar within Crab Nebula in Taurus.

Pulses come from the intense magnetic field. As it spins these are thrown out from n and s poles.

7 Black Holes
Also predicted by taking relativity to it’s logical conclusion.
Event horizon – literally that.
Happens when super massive star goes nova.
Infinite density, zero volume.
Language and imagery of big bang is always misleading – fireball – well not really.
Get’s into the whole , where did the first H atoms come from?

Epilogue – Nebulae
NASA have made one in the Ames lab. Have seen organic molecules in nebulae. This is where life comes from? Ties into podcast I listened to on abiogenesis the other day?
And how did the amino acids get here? They’ve found meteorites containing them.
One of those what if? epilogues you get in documentaries.

FAIL Observations, Tuesday 16 October 2012

Location: Home, outside back door
Conditions: Seeing good, clear but gathering cloud.
Equipment: Skywatcher 130, 25mm eyepiece.
Highlights: none

A mixed evening. Caught up earlier on writing up my logs from Oman so that’s a WIN.
However my observations with the scope as a FAIL. Didn’t find any of the targets I was looking for, although it was useful as starhopping practice. These notes are for completeness and for potential future comparison for when I do manage to observe these targets.
Clear skies outside with some cloud so I set up outside the back door. My plan was to have a crack at he September Sky at Night magazine Deep Sky Tour around Cygnus. Cygnus was to the west, close to the zenith just above the fir trees. That’s why I set up there. Tried for both the Pelican Nebula, IC5070, and North American Nebula with no joy. Below is the notes I put into SkySafari+ as I was working on them.

Pelican Nebula – IC 5070 Bright Nebula in Cygnus 16 Oct 2012 21:15
Did not find. From Sept S@N DST. Located the area between sars Cyg 56 and 57 by starhopping from Deneb. No sign of nebula though. Seeing is good tonight. Moved away and came back to confirm my hop and tried again to discern the thicker patch between 56 and 57. FAIL

North America Nebula – NGC 7000 Bright Nebula in Cygnus 16 Oct 2012 21:29
Another DNF from Sept S@N DST. I fancy i can make out some nebulosity but probably not. This is a big spread out nebula so using 25mm eyepiece. In the right area. Have referred to star charts several times to confirm. Too much grey and not enough black in sky. Tried to use Gulf of Mexico and Mexico areas as recognisable features and again FAIL

I’m about to give up on the Sky at Night Sept 2012 Deep Sky Tour. I just don’t think it’s possible in these skies.

Bromsgrove Astro Open Evening – Monday 15 October 2012

I went across to an open evening at Bromsgrove Astro this evening. It’s a bit out of a distance about half an hour away but that’s a good thing. They hold their meetings at Bromsgrove Rugby Club. Seemed quite dark there, once they have the floodlights off and they also have access to a dark site.
I’ve been to a few Walsall Astro events but they meet on a Thursday which clashes with my ukulele activities so whilst I have an affinity for Walsall, having grown up round there, that’s out.
Spoke to a couple of members who were friendly and gave me some good advice on stacking and processing the imaging data I collected in Oman (astronomer talk for photos what I took).
I’m seriously thinking of joining due to the combination of a dark place to observe safely and access to people with experience I can learn from.

Another Night Out, Another Clear Sky – Saturday 13-Sunday 14 October 2012

Location: Walking home
Conditions: 4 or 5 pints, 1/2 pint pork scratchings, chicken tikka in a naan
Highlights: Oxjam, Moselele, beer, friends, pork scratchings, music, Jupiter, Orion, M45 Pleiades

Had a gig this evening playing at the OxjamBrum festival with my uke band Moselele. Afterward I stayed out around town with friends taking in some of the other bands. I had a great time. I got the taxi to drop me at the kebab shop and I walked home from there. Once again, as previously commented whenever I go out, it turns out to be a nice clear night.

I had had a couple of beers so I’ve pieced these observations together from my tweets at the time.

01:30 Walking home I noticed Jupiter shining bright and Orion was up and nearby the Pleiades open cluster, M45 was very noticable as a blueish fuzz.
Arriving home, I popped back out quickly with the bins for a closer look. Standing in the street with a pair of binoculars at 1am – that’s not odd behavior is it?

Observations from the Back Garden – Friday 12 October 2012

Location: Garden, Home, Top of drive – had started down in middle of the so-called lawn.
Conditions: cloud gathering through evening.
Equipment: Skywatcher 130 scope, assorted eyepieces, new streetlight baffle.
Highlights: Andromeda Galaxy, M31

22:00 Andromeda Galaxy – Messier 31
First time out in the garden in a while. Was a clear night when heading home so I was hopeful to get some decent observing in. It’s also dark a lot earlier now. That’s how long it’s been since I’ve been out here. Not as dark or warm as Oman though.
I recognised constellation of Andromeda high to The East. I starhopped from Mirach through u and v to find M31, the Andromeda Galaxy which was distinct in the RACI view finder. Switching to the 25mm eyepiece on the scope Andromeda was very obvious. No detail but an expansive smudge of light from 2.5 light years away. I moved up to the 17mm plossl and it was OK-ish, a bit disappointing. I was starting to battle against gathering and drifting clouds though and the 6mm superwide was just useless. At this point I gave up. Cloud stops play.
It’s a start on the Sky At Night Magazine Oct 2012 Deep Sky Tour anyway. That’s Just as well as my November subscription arrived today. Also got the Moore Winter Marathon to try. I saw it on this month’s TV show. I never did get anywhere with the September Deep Sky Tour around Cygnus. It’s dark earlier though so maybe I’ll get a last chance early one evening in the next week.
I think I’ll set up a page to keep track of my observing objectives or plans. At the moment I feel like I’ve a lot of catching up to do.

I also pressed a new bit of kit into service tonight and it seems to have been a success. I mounted a large sheet of plywood on uprights that I can move around the garden to shield me from the street lights. It was very helpful in keeping the light out my eyes and stop it reducing my dark adaptation.
Only cost about £4 to make too.

Observing programs
Messier: 8/110
Lunar 100 observed: 8/100
Lunar 100 imaged: 8/100

Shangri La, Muscat, Oman Observations – Thursday 4 October 2012

Location: Barr Al Jissa Shangri La Hotel, Muscat, Oman
Conditions: Clear
Equipment: Naked eye, Celestron Skymaster 15×50 binoculars
Highlights: Mars,

18:00-ish watched the sunset from the sea having a bob. Best way to watch the sun go down. The resort had a Lazy River running through it – a long loop styled on a falaj (Omani irrigation system used to bring water from the pools in the upper reaches of the wadis to the villages) with water jets to keep it flowing. We had one last float around on a rubber ring round this from where I could see a few stars coming out and in particular Mars high to the West.
We returned to our room via the pool where I had a moment lying on my back in the empty pool looking up at the stars at the zenith. The moon was not yet up. Once again Cygnus was at the zenith and I could just make out a faint fuzz of the Milky Way across to Cassiopeia. That’s quite a way to see it I suppose and in some ways summed up the great day we’d had doing very little around the resort, just reading and messing about in the water.

We ate on the Corniche in Muttrach at Fast Food and Juice Centre cafe again, which serves great shawarma, felafel, hummus and a really refreshing lemon mint drink. A Tunisian family at the next table struck up conversation in a mix of French and English. They lived and worked in Oman and were very hospitable, inviting us to their home, which we had to decline as we were flying onto Dubai the next day. When we came to settle our bill we found they had very kindly paid it. “Welcome to Oman!”. This friendliness and generosity seems to be very much part of the culture and having travelled and been hassled in other countries was very surprising and refreshing. All too often you think that somebody has an angle. Whilst you should never be naive, people in Oman and generally and genuinely nice.

11:20 Back at the room, another observation of Jupiter through the bins. Didn’t sketch this time but did take a screenshot with SkySafari+ just to track the Galilean moons again.
screenshot from SkySafari+ Where is Io though?

Having sketched and tracked the positions of Jupiter’s moons nearly every evening I ought to make a chart of my observations to show the day to day movements. I know there is one printed in Sky at Night magazine each month but it would be interesting to compare and confirm my observations.

I also took some photos of Orion. I’ll have a go a stacking and processing them later, when I’m back home and it’s a cloudy night.

This was my last night of stargazing on this holiday. After this we had a couple of days in Dubai before returning home. This had been an incredible holiday. It was very much a holiday and all the stargazing I did was a bonus extra. I tried not to let it dominate but at the same time took the opportunity where I could.

Observing programs
Messier: 8/110
Lunar 100 observed: 8/100
Lunar 100 imaged: 8/100

Shangri La, Muscat, Oman Observations – Wednesday 3 October into Thursday 4 October, 2012

Location: Barr Al Jissa Shangri La Hotel, Muscat, Oman
Conditions: Clear
Equipment: Celestron Skymaster 15×50 binoculars
Highlights: Jupiter, Orion, M42 Orion Nebula, Trapezium

We left the desert and spent a day exploring Wadi Bani Khalid. We swam in the clear freshwater pools of the canyon up in the mountains. We wouldn’t need to visit Wild Wadi back in Dubai after this. I crawled down into the Mukhal cave with my headtorch and before long was quite deep within the cave where it was very hot and dark. Turning a corner and taking care to be able to trace my route back, I could hear running water. I headed towards it for a few minutes and it got louder but I never saw the waterfall that’s supposedly in there. I was conscious that A was waiting for me outside and didn’t want her worrying so I headed back.
It was over a three hour drive back to Muscat and with some fun stress with the traffic we finally arrived at the Shangri La, Barr Al Jissah well after dark.
I had high hopes for this as a decent place for some stargazing. Before we’d headed out to Oman I’d had a discussion with somebody on Stargazers Lounge that suggested it was a good site. The resort is quite isolated, in it’s own grounds, some way South of Muscat. We had a seaview room so when we arrived there were dark skies out over the sea to the East.

12:48 After a late dinner I went out on the balcony and set the binoculars up on the tripod. The moon was out, about 3-4 days past full but very high so almost out of sight from the balcony. It did wash out the sky a bit but looking east there was no orange glow of light pollution. As I’ve done every evening I’ve been able to on this trip, I took a look at Jupiter and made a quick sketch of it’s moons.

It was interesting this evening and I needed to use SkySafari+ again to identify and locate moons. Io was in front and on the edge of the disk of Jupiter. I couldn’t make it out individually but there did appear to be a slight notch to the disk. It was hard to be sure if this was being caused by the shadow of Io on the disk or was just an artefact of the fact that the disk is very bright. It might have been due to a bit of flare or radial spiking. I get that sometimes due, I think, to my contact lenses.

12:55 Orion was up and on it’s side.

M42, the Orion Nebula was clearly visible as a smudge to the naked eye. It showed up well in the binoculars and seemed to surround a couple of the brighter stars. One of these brighter stars was actually the open cluster known as the Trapezium, although I was unable to resolve that to individual stars in the bins.
Observing M42, the Orion Nebula means another Messier Object spotted, taking my tally up to 8/110.

Observing programs
Messier: 8/110
Lunar 100 observed: 8/100
Lunar 100 imaged: 8/100