Monthly Archives: December 2009

Cold winter draws in on UK physics

The Science and Technology Facilities Council (STFC) was created in haste. A sudden transfer of the management structure of the Particle Physics and Astronomy Research Council (PPARC) onto an entirely new budget and a new set of responsibilities formed by a merger of PPARC and the Council for the Central Laboratory of the Research Councils (CCLRC). Due to an accounting error, the source of which remains contentious to this day, the budget of nearly two and a half billion pounds came in £80 million short. The result was carnage for various research grants, most notably in Solar Terrestrial Physics (STP). STFC came under pressure from international partners as it reneged on deals at a whim, the government, whose Investing in People report signaled severe structural problems inside the council, parliament whose science and innovation committee branded the STP massacre and attitude towards the field as ‘bizarre’ and of course scientists in the affected fields who felt STFC were working to their own agenda. STFC said this was a necessary painful step in balancing the books of the new council and that it would not happen again.

Fast forward from then to the end of 2009, now. STFC is in a cash crisis of at least similar magnitude. It had been rumoured that around £70 million would be needed to be found due to a loan taken out during the previous crisis (which apparently STFC forgot it had to repay) and fluctuations in exchange rates relating to subscriptions to international facilities (which Lord Drayson said had been fully funded, but the Science and Technology Committee suggests had not been). The cuts announced today amounted to around £115 million.

It would appear that some small progress had been made in making the decisions on where the axe falls more accountable, but they started from a pretty low base. STFC appears to still be making the mistake of following the boss’s (Professor Keith Mason’s) mantra of “we must look like winners or we won’t be funded”, by which he means having only jazzy looking fresh science on the table. Looking at present funding levels and the dire state of physics as a result, it is clear this hasn’t at all worked – either now or during the first round of cuts.

The research council, although responsible for where the axe fell and repaying its own loans, needn’t take the entirety of the blame. Questions are now being asked about the Science Minister, Lord Drayson. Through his twitter account, he continuously spoke with honeyed words about being on the side of scientists. His genuine enthusiasm for the brief and apparent willingness to let STFC know when he was unhappy at preparations to pull out of successful collaborations (in this case the European Southern Observatory and CERN) convinced a few that he was working to salvage something. However, his assurances turned out to be a little toothless as beyond twittering platitudes such as “don’t let stfc do this”, he seemed to forget he was the man in government charged with making sure STFC is run appropriately. The Haldane principle, which is the convention by which politicians don’t interfere in the allocations of funds to science, also applies to administration. This means that if Drayson were to dictate where every penny went, he would be rightly ignored, but if STFC were to make a hash of running the budget, or, more crucially, if they decided to set out a ‘coherent plan’ for the allocation of their budget that went against the advice of scientists, they too would be in contravention of the convention. This latter point seems the case. Whereas 2008 saw STFC at loggerheads with international partners, who referred to the UK as incompetent and unreliable in their handling of subscriptions, this time we see the Government’s Science Minister at loggerheads with his own Quango, each blaming the other for the deficit.

Drayson has today responded by announcing another structural review of the council, rightly noting that a council looking after huge subscriptions and smaller research grants might be tempted to apply cuts to the latter more appropriately sized for the former. But Drayson has also announced a new UK Space Agency, which will be taking over from STFC. Does he intend to create this agency by transplanting a bit of STFC like STFC was created by transplanting a bit of PPARC? Or is he a little cooler on the idea of an agency than has otherwise been suggested? Additionally, with a proposed quarter of new funding earmarked for Government directed research only from 2013, it may be a little silly to waste a lot of time and money examining a structure whose time may be more limited than that of the review.

The response to the cuts has been as swift and savage as the prioritisation itself. A stream of tweets using the #stfc hashtag continues to pass comments around. The Royal Astronomical Society notes that UK scientists have no subscriptions to research grade optical telescopes in the northern hemisphere, plus we’re pulling out of many high impact and very successful space missions. The Institute of Physics has bemoaned the 25% cut to funding for PhD students and Post Doctoral Researchers (ie first jobs for PhD students after qualification) at a time when every other industrialised nation put up their funding (6.7% in the case of the USA). The papers have also focused on this with the Guardian additionally pointing out that nuclear physics faces more than 50% total cuts to funding at a time when Government policy is on creating new nuclear power stations. The Times Higher Education highlights a few flagship programs now down the drain and breaks down the cuts into £42 million off space projects, £39 million off astronomy, £32 million off particle physics and £12 million off nuclear physics.

Scientists on twitter have been active with Brian Cox fighting the particle physics corner and Chris Lintott batting for astronomy. Chris is of the opinion that STFC seem happy to have a finger in each pie, but not to actually sample the taste – we can build or run a facility, but not have the money to use it or store the data derived from it.

But onto the cuts themselves.

In astronomy, the projects Advanced LIGO, KMOS, VISTA, Dark Energy Survey, E-ELT R&D, SKA R&D, SuperWASP, e-Merlin, Zeplin III will be funded throughout the period reviewed, JCMT, Gemini and ING will carry on until 2012 when Gemini loses funding. This group will need to lose £16 million. Projects to lose stfc funding include:

  • Auger –  Cosmic Ray observatory (at a time when new knowledge about the heliosphere is coming in).
  • Inverse Square Law Experiment in Space – looking at deviations from Newtonian descriptions of gravity
  • ROSA – Robotic teaching telescope at Sheffield
  • ALMA – Atacama Large Millimetre/submillimetre Array, a powerful telescope exploring a neglected part of the electromagnetic spectrum
  • JIVE – Joint Institute for VLBI (Very Long Baseline Interferometry – a telescope) in Europe. See above, but for longer wavelengths
  • Liverpool Telescope – robotic 2m telescope on La Palma, used for schools and research
  • UKIRT – UK Infrared Telescope in Hawaii, very important for the researchers in my own group, looking at the planets.

Particle physics sees the following projects funded, but collectively saving £25 Million; ATLAS, CMS, GridPP, nEDM, Cockroft Institute, IPPP, LHCb, MICE, SuperNEMO, T2K and the John Adams Institute. STFC funding has been removed for the following:

  • Boulby Underground Laboratory – observes particles that don’t often interact with ordinary matter, recently in the news over the search for Dark Matter. That program was called “Missing” as now is Boulby.
  • CDF – Collider Detector at Fermilab, which detects high energy collisions in a particle collider
  • D0 – international collaboration (including CDF) looking at the fundamental nature of matter
  • eEDM – electron-electron dipole moment experiment in space, making advance measurements to search for neutrino absolute masses, dark matter particles and matter: antimatter assymatries
  • LowMass – Generic detector
  • MINOS – Main Injector Neutrino Oscillation Search at FermiLab, looking at how neutrinos interfere with one another
  • Particle Calorimeter – discriminates between particles
  • Spider – silicon detector
  • The Neutrino Factory – experiment to create and study neutrinos

Nuclear physics keeps NUSTAR with £2 million reductions, but loses STFC funding for:

  • AGATA – advanced gamma-ray tracking array, looking at high energy photons for nuclear spectroscopy
  • ALICE – one of six experiments at CERN
  • PANDA – an antiproton collider

In space, the probes still being funded are: Aurora, GAIA, Herschel, JWST-MIRI, LISA Pathfinder, Rosetta, Planck, ExoMars, Hinode, Cosmic Vision, Solar Orbiter, Stereo, Swift and Bepi-Colombo. Many high profile and successful probes have lost STFC funding, including:

  • Cassini – the Equinox mission, presently giving us movies of the aurorae of Saturn in visible, infrared and UV light amongst many, many other things. Vital to research interests at Imperial… an STP field experiment.
  • Cluster – set of satellites looking into Earth’s interaction with the solar wind and the magnetic environment an STP field experiment.
  • SoHO – Solar and Heliospheric Observatory, watches the Sun in a variety of ways an STP field experiment.
  • Venus Express – satellite based on Mars Express technology observing the second planet from the Sun. We help pay to build it and get it there, now someone else takes the data. An STP field experiment.
  • XMM-Newton – space based x-ray telescope. Has been used in STP before…

Other facilities funded include the Diamond Synchrotron, Astra / Astra-Gemini, ESRF, ILL, ISIS, Vulcan 10 PetaWatt, with STFC funding withdrawn for:

  • NLS – the New Light Source; producing highly controlled x-ray pulses
  • The Photon Science Institute – focuses on interdisciplinary use of photon science
  • XFEL – The European X-ray Laser project

These cuts do not take into account any programs that may lose money due to the £14 million loan from other research councils to STFC, are dependent on £11 million of internal savings being found and financial predictions being met. They also ignore the impending £600 million cuts to the Universities budget announced in the PreBudget Report (which oddly enough started with the same “We begin in a position of strength” hollow rubric as the STFC announcement on the cuts).

I guess we’ll save that for the 2010 crisis…

For full details on the cuts, Paul Crowther runs a rolling blog.


The warm glow of an alien night

The transit method of detecting extrasolar planets has been a well used and successful tool, yielding many a planet around other stars. Recent years have seen better equipment recording higher quality transits, and with them far more detail that take us beyond the original ideas of transit theory. In a paper now on arXiv, David Kipping discusses how the depths of transit curves in the infrared can vary due to atmospheric effects complicating the original theory of transits.

The original theory is quite simple, the planet blocks quite a bit of light from the host star as it passes between us and it. The light blocked is determined by the apparent size of the disc of the planet blocking it, which depends on the planet’s radius and it’s distance from the star. The result was a graph of light emitted from the star against time that showed a line interrupted by regular flat bottomed, sloping sided dips as the planet got in the way.

Initial results from Kepler showed that the line wasn’t quite as flat as originally believed. As the planet moved round the star it exhibited phases as the dayside reflected light. The phase went from ‘new Moon’ when the planet was doing its blocking, through crescent and gibbous close to ‘Full Moon’, but not quite as the planet would then vanish behind the star. This means the flat line actually exhibits a rise in recorded light, followed by a drop whilst the planet is behind the Sun, then a return to the pre-drop amount and a decline before the main dip.

The planet itself also doesn’t present a solid black disc. Any space based imagery of the curve of the Earth will show a thin layer of translucent gas – our atmosphere – glowing as light is transmitted through it. The type of planets that are most readily visible through the transit method are ‘Hot Jupiters’ – large gas planets close in to the star. Their size means they block a lot of light relative to others, their proximity means they swing round the star quickly, meaning astronomers don’t have to wait years to record their repeated dips. Being gas, their atmospheres are rather larger than ours, and they are translucent for a larger fraction of their radius. This also affects the transit curve graph.

Information can be got from light reflected by or transmitted through a gas. Spectroscopy is the study of the amount of light emitted at different wavelengths of light (blue has a different wavelength to red etc) and other electromagnetic radiation photons – gamma rays, x-rays, ultraviolet, infrared, microwaves, submilimetre and radio waves. The full electromagnetic spectrum (including the visible rainbow of light between UV and IR) extends from the highly energetic and short wavelength gamma rays to the longer wavelength and low energy radio waves. Each and every material – gas, liquid, solid – has the capability to emit or absorb a selection of lines cut out from this spectrum. This is referred to as the spectrum of that material, or it’s spectral signature or fingerprint. It’s one of the many things astronomers look for in data recorded by their telescopes. Looking at the reflected light or the light transmitted through the atmosphere has allowed astronomers to pick out individual gases in a planet’s atmosphere (both exoplanets and planets in our own solar system).

The spectroscopic principle however dictates that there are two types of radiation that can be emitted by objects – that corresponding to the spectral signature and continuum, or in this case black body, emission caused by thermal emission. Old style streetlights produce a yellow glow as the sodium inside it is heated enough to emit the colours associated with its spectral signature – yellow. But newer streetlights, high pressure sodium lamps, emit white light – all the various colours together – due to continuum emission. In fact, they both emit spectral and continuum light, but by altering the properties of the gas inside the lamp, the preferred method of emission can be altered (in this case because the energy that would go into the spectral emissions gets lost due to collisions in the higher pressure mixture).

Turning away from the streetlights and back to planets, what does this mean? Well a planet in orbit of a star will receive light emitted by that star. The light will pass through the atmosphere and strike the surface. Some will be absorbed by the atmosphere or the surface, some will be reflected. The radiation absorbed carries with it energy, meaning the absorption heats up the planet. Now as the Earth hasn’t burnt to a crisp or turned into a small star, the planet must then be able to get rid of the energy it absorbs. It does this through ‘black body’ radiation. This refers to a thought experiment involving an ideal absorber, which is also an ideal emitter of radiation. This creates a characteristic smooth emission curve (measure of energy emitted at each wavelength) known as a black body emission profile, to which thermal emission profiles such as stars, planets and even light bulbs can be compared to. The peak of the curve is determined by temperature and allows us to determine the ‘black body temperature’ of an object, one of several ways to determine temperature using an object’s emission spectrum. The peak emission of the Sun, for example, is in visible light. The colours of other stars are also determined by the peaks of their emissions, with blue stars representing bodies with higher black body temperatures than red stars. For planets close in to their host stars, the black body emission peaks in the infrared.

Taking these sources of emission together, it becomes possible to see that in some parts of the spectrum, an exoplanet will be brighter than others. As the star itself varies in emission rates across the spectrum, this means the ratio of planet to starlight radiation varies considerably.

This is already well known; part of the field of exoplanet research has been the search for spectral windows where a given planet is easiest to see. But in this new paper, Dave and Giovanna Tinetti look at how the emissions can affect how the transit curve looks when recorded in different wavelengths, specifically, does the black disc glow a little providing a slightly incorrect transit depth, in turn affecting the derived radius of the planet?

The paper begins by noting the emissions from the night side can be directly observed. As mentioned earlier, light due to the phases of an orbiting exoplanet has been observed. This light includes both light reflected from the star on the dayside and light emitted directly from the planet on both the day and nightside. Studying the emissions over the course of an orbit and knowing the accurate phase of the planet should work, allowing anisotropic emission profiles to be uncovered (eg more thermal emissions on the dusk side than predawn etc). The planet HD 189733b is examined in this way in the next section. The results show that the transit depth in the infrared is altered enough to be detected by the Spitzer space telescope (meaning it will be very measurable in the upcoming James Webb Space Telescope).

The next section is theoretical. It starts off by noting that variations in the dayside flux over time could be mapped to nightside variations and seeing what effect this has on the results. Then it moves onto potential sources of pollution from nightside emissions on other observables. Transmission spectra looks at light shining through the translucent atmosphere surrounding the main body of the planet. That planet, like our own, will be emitting thermal radiation. That atmosphere, like our own, will be emitting radiation due to photochemical reactions (recombination of ionised gas) and chemical reactions, as well as heat transported by winds (ions like H3+ can act as thermostats, radiating heat from the planet spectroscopically). For this, some knowledge of the atmospheric composition is required in order to know what spectral lines will be radiating (this is the opposite to the method used to discover the composition – fit various modelled gas spectra to observations). The authors plot a spectrum that neglects nightside pollution, one that includes it and one that notes the difference between the two in order to determine where the effect is greatest. They determine the effect is large enough to be measured by Spitzer.

Next, they look back at work done previously and as whether the determination of the composition of the atmosphere of HD 189733b was affected by this. Modelling the star and the planet as black bodies, they determine the thermal profile of the planet and note that just from this first order approximation, they discover a measurable deviation at 8.0 microns. A future paper will include the atomic and molecular lines and determine how each is affected in greater detail.

Finally, they note that a similar effect will lead to underestimation of the secondary eclipse depth (the slight drop in light due to the reflecting planet going behind the star).

They conclude by noting we’re moving into an era of higher precision measurements, meaning stricter definitions on what is being measured are required and considerations of atmospheric composition will become more important.

This field is maturing.

The UK eyes the skies

There have been two recent interesting developments in the space industry. The first is the arrival onto the world stage of Space Ship 2, which will be taking those willing to stump up £120,000 above all three cloud layers for a glimpse of the Earth’s curve and the feeling of weightlessness before returning to the ground. Virgin Galactic’s baby (presently under the scrutiny of the US security forces due to backing from the middle east) represents the first foot in the door of private sector space experiences.

The second development was the announcement of a British Space Agency to promote UK space science and replace the British National Space Centre, a consortium of research councils and government departments that presently coordinates UK space science and engineering. Whilst the announcement has been welcomed, there are concerns about the practicalities. STFC has moved to try and impose its present structure on space science within the new agency (apparently “it works” despite an apparently unexpected but entirely predictable £40 million shortfall for the second time in three years and international disgrace within twelve months of founding), and voices within the space industry are concerned about politicisation of the agency from one side or the other in the impending election campaign as well as dangers of the funding vanishing as the Treasury claws back the national debt. A British space agency would put us on a par with Russia, China, India, France, Canada and the USA, all of which have their own agencies.

But the announcement did focus attention on one thing, which was the £6.5 billion the UK space industry puts into the economy, compared to the £270 million spent on it (mostly – £180 million – going to ESA, the European Space Agency). The Times ran a special on the industry, including articles on an overview of the industry (or two), a link to a pdf on Lloyd’s predictions for the sector in 2010, a focus on satellite communication, an interview with the head of EADS Astrium and a comment by Colin Pillinger on why the sector should receive additional investment.

Something to remember as there appears to be a flurry of tweets on twitter about impending STFC cuts announcements…

(I keep my thoughts on that on the rolling coverage post here)

The three enclosures of the Zooniverse

Over the years, Galaxy Zoo, the citizen science project where people log onto a website and classify galaxies by shape, has undergone a series of evolutions. First out came Galaxy Zoo 2, which enhanced the classifications in which the galaxies, all snapped with the Sloan Digital Sky Survey 2 could be put. The Galaxy Zoo Supernovae then looked at a particular strip of SDSS data, which had been reimaged several times, possibly catching supernovae. The results of the trial showed that users could in fact identify exploding stars. Then came Galaxy Zoo Mergers, which gave users computer simulations of merging galaxies and asked them to run the simulations to classify interacting galaxies.

Now all three of the later projects are back. The Zooniverse has been launched and waits willing users from across the world. Training is provided and fame (though not fortune) could be round the corner should you be someone who spots a new feature in the firmament or identifies a new class of galaxy, both things that have happened in the projects so far.

The new eyes on infrared skies launched

There was an article in the Times this weekend on the new VISTA infrared telescope – the Visible and Infrared Survey Telescope for Astronomy. This new telescope operates on the European Southern Observatory’s Paranal Observatory in Chile and was built by a consortium of eighteen UK universities at a cost of £37 million. This week saw it being handed over for operations.

Meanwhile, earlier today, a different kind of infrared survey telescope was launched, quite literally. WISE is a space telescope that will slowly build up an image of the entire sky in infrared light from orbit. With UKIRT in Hawaii also turning to survey operations (as part of STFC’s cuts program, which will then lead to the closure of that facility), I begin to wonder where the more target specific operations are to take place…

If you want an idea of the difference in the night sky when viewed in infrared as opposed to visible light (or x-ray, microwave, radio and hydrogen alpha (red)) then the Chromoscope is here to help. The two telescopes above will look a little deeper at better resolution than the chromoscope image and will also be searching for things that change in the night through repeated surveys.

Drink in the Dark Skies

Watching the local news, I noticed an item on an unusual way to celebrate the granting of Galloway Forest Park’s status as a Dark Sky Park, granted by the International Dark Skies Association. This was the promotion of a real ale called Galloway Stargazers, sold in the Selkirk Arms, but brewed in Cumbria. More on this way of passing the time before a Dark Sky becomes a Clear Sky here.

The Geminids are coming…

From the 6th to the 19th of December, there will be a few more shooting stars in the sky than normal. This is the Geminids meteor shower, this year peaking at about 5am on the 14th of December, and much to it’s honour, the star of the next twitter #MeteorWatch.

The Geminids are so called as if the paths of the various meteors of the shower are traced back to their apparent point of origin, known as the radiant, then this radiant is seen to be within the area of the constellation of Gemini, just above the ‘heads’ of the twins Castor and Pollux. Gemini lies up above and slightly to the left of the upright Orion, and as this constellation is rising relatively early, due East, the meteors should be visible here in the UK.

The meteors of this shower are bits of dust from the extinct comet 3200 Phaethon, which has lost all of its internal ices over its many journeys around the Sun and now pretends to be a 5.10km diameter asteroid crossing the orbits of the inner four planets. These big bits of dust burn brightly and often different colours, usually greens or blues, sometimes yellows. They’re medium velocity meteors, making them easier to see and good candidates for photography (brighter and slower moving, so produce brighter trails on 30 second exposures).

The meteors are expected to rain down at around 100 meteors an hour or more, that’s about a couple every minute, during the peak time. The new Moon is only two days after this year’s peak, meaning little light pollution from the Moon. The best time to observe the Geminids from the UK would therefore be after midnight until dawn on the 14th, though the peak of activity is very stretched out in this shower compared to sharper rises in activity in others, meaning the whole evening of the 13th should be a relatively good time to watch out. Meteors are naked eye objects, so observers can just wrap up warm and sit out with a flask of tea (like watching distant fireworks). The best views tend to be at an angle of fifty or so degrees away from the radiant in any direction, but keep an eye on the whole sky for the best chance of catching meteors, which can appear from anywhere.

Of course, you needn’t be alone when looking for meteors. The Twitter meteorwatch, run by NewburyAS (who tweet here) will be up and running for the shower. Cameras from around the planet will be pointing into the skies looking for, photographing and videoing the meteors for live and recorded playbacks. As ever, there will be discussion about how it’s looking, astronomy in general and what other sights are out there (Mars should be a hot topic). But as ever, we will be subject to the vagaries of the weather, which will be dependant on the mercy of an English Lake District winter here in Kendal… The #meteorwatch will run from the 12th-14th of December. The trailer for the event (from their youtube channel) is below, as is an example of a Perseid meteor recording from an earlier #MeteorWatch (imaged using a camera and UFOCapture software):