Tuesday, September 2, 2014

NTT Observing Trip - Video Blog

Day One

Traveling from London - Madrid - Santiago - ESO Guesthouse

Having a look around Santiago on the first day out. It was raining quite a bit but I manged to find my way into town and back.

To boldly go where no Wakeford has gone before; Leaving on a jet plane; EvilRegal Hard Rock Cafe Santiago;
Polinesia Pisco; Santiago in the gloom

Day Two

Travel from Santiago heading north to La Serena followed by a bus trip up to the summit of La Silla

Morning coffee at ESO Guesthouse, Santiago; Desert fox up on La Silla; The NTT in the sunshine;
Looking down the mountain to the control room; The southern stars shining above the domes.

Day Three

Taking a little walk around the summit of La Silla

Over looking La Silla and all of the telescopes on the summit.
We also managed to find a physics gnome on the way up.

The 3.6m telescope at the very summit of La Silla

Sunset over the Atacama desert from the summit of La Silla with the 0.5m Danish telescope and the 0.6m in the foreground

Day Four

Our first night of observations at the NTT, While we were able to open up the dome and observe for the whole night the data may be a little difficult due to large fluctuations in the Earth's atmosphere which are more prominent at the wavelengths we are using.

Day Five

The wind has died down, the sky has cleared and observations are about to begin. Tonight we are monitoring a brown dwarf similar to Beta Pic to see if it is variable, followed by multi-wavelength observations of a faint brown dwarf until sunrise.

The second night of observing with NTT started with a trip up to the 3.6m telescope to open the dome and watch the sunset and get some pictures.
View from the walkway of the 3.6m telescope during sunset at the summit of La Silla.

Day Six

It is the 3rd night of observing with the NTT and the sky is covered in consistent thin cloud which is not necessarily a bad thing.

Tonight I am running the show to get an idea of how everything works and gain some experience to run solo observing in the future.

Day Seven

Today we got to take a trip up to the NTT to see the instruments and the opening of the dome.

View of Las Campanas from La Silla, The NTT dome opening, View over La Silla,
Inside the NTT dome; closed and open,
EFOSC instrument, astronomers under the NTT, SOFI instrument.

Cutting some shapes!

It is the last night of observing at the NTT and we have been getting some great data. Now all that is left to do is stay awake.

Day Eight

The night merges into the day when you re-shift from night observing to the land of the living. We took the afternoon to go in search of the famous La Silla Petroglyphs.

A word of warning for all who wish to pass into the desert, Down the mountain looking up at the telescopes,
This ancient petroglyph that we found does not appear to be on any "map" of the site.

A panoramic view of the mountain desert from La Silla,
Having fun with a shadow show,
The view of our walk while searching for petroglyphs.

SUNSET on the final night at La Silla Observatory 

The clouds make for a beautiful sunset but generally bad for observations. No green flash tonight.

Day Nine

Las day at La Silla Observatory. It has been a great learning experience and at times a great adventure. Thanks to all who were here and made it a great observing run - including at times mother nature taking pity on us.

One last selfie trip around La Silla Observatory

Day Ten

Last full day in Chile hanging around Santiago. I spent the morning at the National Air and Space Museum before heading back to the ESO Guesthouse for a dip in the pool.

It has been a great trip and thanks to all those who contributed to it with their hospitality.

Museo Aeronautical y del Espacio Santiago (National Air and Space Museum)

Tuesday, July 8, 2014

Hannah Wakeford IOP '3 Minute Wonder'

What can you do?

The National Institute of Physics '3 Minute Wonder' competition held at the Royal Institute in London followed a series of Regional competitions across the UK. The event itself was not recorded but I was asked to film my winning talk for a number of different things so it was recreated (kinda) at the University with the help of some friends from XTV Online.

For the competition I talked about how to search for water in the atmospheres of alien worlds using fruit and cuddly toys to help me out. Enjoy!

Sunday, February 16, 2014

What I learnt at Exoclimes III

Over the past week I attened the biannual planetary and exoplanetary climates conference Exoclimes. This year it was held in Davos in the east of Switzerland.

The conference itself brings together experts in the field of planetary atmospheres from our own system and beyond, to exoplanets and brown dwarfs. It also importantly brings together both theorists and observers in an effot to share knowledge, promote understanding, and grow collaborations. 

But as I have done with previous conferences I attened I thought I would share some of the 
"Things I learnt fro Exoclimes III" with you now.

  • In a small community that has a relatively new biannual conference for those in the field some people automatically assume everyone else was at the previous events and remembers exactly what your talk was on 2 years ago
  • Paleoclimatology is a fascinating subject for instance did you know that the spikiness of a leafs edge can tell you what latitude of the earth you are at due to a temperature correlation.
  • If you spend all of your money on a massive conference room then you cut back on the amount spent on coffee, which is not the greatest idea when dealine with over 150 astrophysicists.
  • The exoclimes drinking game this year required you to take a drink each time someone mentioned 'clouds' or 'WFC3'. Let's just say that if we were actually doing this Tuesdays talks would have been liver destroying.
  • The amount of notes that you take during each talk seriously diminishes as the week goes on. Unless you know they are specific to you or broad enough so that you know what they are talking about (generally rare but appreciated).
  • Venus is the biggest problem we have in planetary science. She is also the queen of super-rotation.
  • From the observers: It is important to constrain the C-O ratio. Hot Jupiters with high albedos probably have high reflective clouds. The smaller the star the smaller the planet we can observe. You need as much data as possible; transit+eclipse+RV+phase curve. WE NEED MORE TELESCOPE TIME!
  • Half of known exoplanet atmospheres are cloudy. (Both a bold and unnerving statement)
  • We need models complex enough to fit the data but not so much as to introduce degeneracies.
  • Many enshrouded exoplanetary systems, like WASP-12, may have disintegrating close-in rocky planets leaving a metallic diffuse haze surrounding the inner system.
  • Both Juno (2016) and JUICE (2030) are going to tell us a lot about the atmosphere of Jupiter.
  • There are knowns, known unknowns, and unknown unknowns.
  • If we want to detect the transmission spectrum of an Earth analogue transiting a sun-like star within 40 light years it would take 77 years and a very good telescope.
  • There are many and varied atmospheric retrieval  techniques and all of those involved will happily sit on stage and argue about them with an audience desperately wishing they would stop eating into the one and only coffee break they get in the day.
  • There are still a huge number of questions to both ask and answer - but hey, that's not a bad thing or we would all be out of a job.
  • And finally if you want to wake everybody up at the end of a very long week make sure that the last talk is by Charbonneau. I mean we all still desperately needed a drink at the end, but it helped. 

Overall it was a really great week and I can honestly say I learnt a lot more than just the highlights I have shared above. As my first international conference it was also a fantastic opportunity to meet some collaborators and hopefully make a few more and I am looking forward to being able to go to Exoclimes IV in 2016 (if I can get a post-doc).

I thought I would also leave you with this trailer and feature I made of myself and friends in what I have called the Exoclimes Olympics

Also check out the website for links to most of the talks and the posters http://www.exoclimes.org.

This is mine :D

email hannah@astro.ex.ac.uk for more details.

Saturday, January 25, 2014

Some of the weirdest and most wonderful facts of the universe

Gravitationally speaking the super-massive black hole at the centre of our galaxy has no idea that it is surrounded by over 300,000 stars and those 300,000 stars have no idea that the surround a super-massive black hole with the mass of 10 billion suns

The stars in the centre of our galaxy orbiting the invisible super-massive black hole

Light exists all around us, but in its own frame it is not there at all. If you travel at the speed of light it takes no time at all to get from one side of the universe to the other, even though it would take over 13 billion years from our point of view. To itself, in its own frame, light does not exist.

The cold gas and dust coming together to
form stars and galaxies

    When stars are forming they drop to temperatures close to absolute zero as the gas becomes essentially transparent to radiation before becoming opaque again and heating up to soaring temperatures as the gravitational pressure increases and ignites hydrogen burning.

    A cartoon of GJ 436b's interior

    Just 33 light years away from the Earth there is a planet called GJ 436b which is made of hot ice. This Neptune sized planet sits 50 times closer to its star than the Earth does to the Sun heating up its atmosphere to over 700 degrees. Yet compressed lower down in the planet is a shell of solid water ice at temperatures well above freezing but under so much pressure that it has no choice but to maintain a solid state. 

    The Andromeda nebula - the only naked eye
    galaxy in the northern hemisphere

    The universe is so big that reasonably we do not yet understand it all with the matter that makes up you, me and all the planets, stars, and galaxies we observe taking up just 4% of what we know. The rest occupied by dark matter and dark energy of which we know very little. It wasn't until 1923 when Edwin Hubble discovered that a small fuzzy blob called the Andromeda Nebula could not be part of our galaxy the milky way. Revealing for the first time that the universe is actually much, much bigger than our own little collection of stars. 
    And that the Andromeda nebula was not a nebula at all but another distinct collection of stars forming a vast galaxy separate from our own, just one of billions that occupy our universe. 
    The cosmic web of galaxies and dark matter that forms our universe from the millennium simulation


    Let me know what weird and wonderful facts I have missed in the comments box below

    Top to bottom: ESO; http://thequantumlife.tumblr.com/; ESA–AOES Medialab; exoplanets.org; NASA; Millenium Simulation, MPA Garching, V. Springel, S. White et al.

    Tuesday, January 7, 2014

    The smallest things make the biggest differences

    It has been a long time since I have written a scientific post but I was intrigued by a discussion we were having the other day about the Deuterium to Hydrogen ratio (D/H) in exoplanet atmospheres and it got me thinking about Venus and its escaping atmosphere and how little attention is paid to its significance in the exoplanet community. 

    Let me expand on my train of thought by first explaining what the D/H ratio is and why we care. 

    Deuterium (D) is an isotope of Hydrogen (H) defined by the addition of 1 neutron to Hydrogen's original 1 proton + 1 electron configuration. Deuterium acts in the same way that Hydrogen does but is more massive or heavier than its original counterpart. Additionally there is a second isotope of Hydrogen called Tritium, which has two additional neutrons in its nucleus. 

    Deuterium can also form water molecules, called heavy water, because it has the same chemical properties of Hydrogen. There is in fact one deuterium atom for every 10,000 Hydrogen atoms, and as there are two isotopes of Hydrogen we can then assume that one in every 5,000 water molecules should have Deuterium in place of Hydrogen. 

    Consider then that all Hydrogen (and its isotopes) that exist in the universe today were created at the very moment of the Big Bang, because while Hydrogen is turned into other elements through nuclear fusion in stars, no new hydrogen or deuterium has been created since the beginning of the universe. This can be seen all around us by the D/H ratio in the Earth, Moon, comets, and even the space between stars which all have very similar D/H ratios ~ 1/1000.

    But here is the puzzling thing, and this is where Venus comes in, Venus has a D/H ratio 100 times that found on the Earth.

    This is not to say that Venus has more Deuterium than the Earth but that it in fact has less Hydrogen. 

    Which takes me onto the escaping atmosphere part. 

    Hydrogen is about half as massive as a Deuterium atom and on average will therefor sit higher up in a planet's atmosphere. This makes the Hydrogen gas, higher up in the atmosphere, more prone to escape than gasses found lower down. 

    But Hydrogen and Deuterium have a natural affinity to form water molecules and would not be prone to escape; and this is where Venus gets interesting.

    While Venus is about 95% the size of the Earth and 82% of its mass, with an iron-nickel core and a rocky crust, it is noting like our fair planet. Venus has a very thick atmosphere almost entirely comprised of Carbon Dioxide. Its cloud filled sky is a bath of sulphuric acid moving at speeds over 200 km/h.

    From a distance the Earth and Venus are remarkably similar, but as always it is the smallest of difference which produce the most potent affects. The small difference in their distance from the sun, the lack of a magnetic field or ozone layer, the tinniest decrease in mass between the two planets, acted as a catalyst for the dramatic differences we see today. 

    Artists impression of Venus' escaping atmosphere
    The smaller mass would result in less radioactive heat sources inside the planet causing the formation of a hard solid crust with little to no tectonic activity after the heat of radioactive decay ran out. The increased temperature due to is closer proximity to our host star leaves more water in the atmosphere as vapor than is locked up in rocks and oceans causing further solidification and drying out of the surface. This evaporation of liquid water releases the Carbon Dioxide dissolved in its depths locking more heat in to the planets atmosphere via the greenhouse effect until no water can survive as liquid on the surface. 

    Venus' water was hot enough to remain a vapor in the upper atmosphere and without the protection of a magnetic field or ozone layer it was subject to harsh radiation from the Sun. Energetic Ultraviolet light bomb-barded the water molecules causing it to dissociate into Hydrogen and Oxygen, or 1/5000th of the time into Deuterium and Oxygen. These would then be prone to escape through further heating of the gas in the planets upper atmosphere. 

    The thermal escape velocity of Venus' atmosphere is around 10.4 km/s, with Hydrogen's escape velocity at half that and Deuterium's around a third, it would not take much to cause either of them to escape. But again it is the small difference that make everything. Just 1.5 km/s difference in escape velocity means that Venus would loose 99.9% of its hydrogen atoms while only 90% of its Deuterium atoms escaped producing the abnormally high D/H ratio observed by the Pioneer spacecraft.

    So there really is a lesson to learn from the Earth and Venus, while from a distance they are unsuspecting twin rocky worlds in our inner solar system, they are vastly different worlds with many different intricate stories to tell. 

    That and the smallest things can make the biggest difference.

    What's Next?

    There were some great resources that I used for this article and they can be found in the links below so please have a browse.

    IMAGE CREDIT: Earth and Venus - ESA; Hydrogen and Deuterium - Nick Strobel; Venus' escaping atmosphere - ESA