AAS

Our inaugural meeting was on the 8th November 2010 and we officially formed in February 2011.
AAS holds monthly meetings with guest speakers.

All guests are welcome!
No knowledge necessary, just a curious mind.

We are able to provide assistance with setting up your telescope or just helping to find your way around the night sky.

AAS is able to host discussions on subjects as varied as Dark Energy through to 'How dark is your sky'.

Come along and get a new perspective on the universe in which you live!

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Next Meeting – Monday 27th November

The next meeting will be a talk by Martin Griffiths entitled
      “The Moon in the Western Imagination”  :  A history of lunar observation & how we regard the moon in science & culture
Martin has taught astronomy for over 30 years, developed adult education programmes for Swansea University and taught undergraduate Astronomy at the University of South Wales.  Currently he is the Director of the Brecon Beacons Observatory, a public educational resource in the BBNP, and an Astronomer and Science Presenter for Dark Sky Wales. He is also a Dark Sky Ambassador for the BBNP.

Usual place and time: The Kings Head, Abergavenny, at 7:30pm
All welcome  :  See you there.

 

Last Meeting 13th November

A good session last Monday, when Nick highlighted key facts about our nearest star, the Sun.  The “News of the Month” presentation has been put on the “Downloads” page. HERE

Artist impression of the dust clouds around Proxima Centauri  :  credit ESO/M Kommesser

One question that generated discussion but no definitive answer related to the travel time for a probe sent to our next nearest star, Proxima Centauri, around 4.2 light years distant.  The question arose from the concept proposal by “Breakthrough Starshot” ( HERE & HERE ) to send a swarm of small space craft at 15/20% of c, the speed of light, to collect data and image the Proxima system, including the exo-planet Proxima b.  Travel time would be of the order of 20/30 years. 
Specifically the question was what effect would travelling at 0.2c have on the different time frames of Earth and the probe.
I have put a graph of time dilation vs speed on the “General Items” page.  The conclusion is that at 0.2c the time dilation is such that the time on the probe would be running 2% slower than time on Earth, so 20 years on earth will be equivalent to 19.6 years on the probe.

Note:- Maximum speed reached by the Cassini probe on its way to Saturn was 44 km/s, or 0.00015 c.  At that speed it would take 29 thousand years to reach Proxima!

However, it would seem that we wouldn’t want to go to Proxima b anyway due to the significant radiation from its host star, a red dwarf.  It now seems that a better bet would be Ross 128 b, which is only 11 light years away, or 55 years at 0.2c.  OK for our younger members but a bit too long for me to see any results!!

Meetings in November 2017

This month we have a bit of a solar system theme:

On Monday the 13th November the meeting will look at our nearest and dearest star – the Sun- in detail. Despite being so prominent it has been poorly understood until research in the past few decades has gradually unraveled many of its mysteries – what is in the core? how does it keep going? how will it evolve? what is solar weather and sunspots?  In this session will discuss the latest findings that help to explain the most important object in our solar system.

On Monday the 27th November – Martin Griffiths, Director of the Brecon Beacons Observatory, Astronomer & Science Presenter for Dark Skies-Wales returns to the Society and continues the theme of the solar system with a look at Observing the Moon and how we regard the Moon in science and culture.   We see it in the sky each month and it has intrigued societies and cultures since prehistoric times.  It is critical to the astronomical stability of the Earth and therefore crucial to our very existence.  Martin has a very great knowledge of both observational astronomy and also the myths and legends associated with heavenly bodies, it promises to be a fascinating talk. 

As usual the meetings start at 19:30 upstairs in the King’s Head, next to the Borough Theatre, Abergavenny.  All welcome whether members or not.

Neutron Star Collisions – Where Gold, Platinum & other heavy elements are made

The LIGO-Virgo Collaboration plus leaders of telescope project teams gave an interesting press conference today in Washington.

It was to announce the results of the Gravitational Wave that was detected on the 17th August (GW170917).  This latest detection was noted at our meeting last Monday. 
It turns out that this event was the merger of 2 neutron stars, called a kilonova, and, as it was also detected by the Virgo array, it allowed the location of the source to be estimated.  As a result telescopes, both earth and space based, were able to identify the precise event and examine it from radio waves, through visible light to X rays.
It is some 130 M light years away in the galaxy NGC4993, an elliptical galaxy in the southern constellation Hydra.  Data analysis to date indicates that the neutron stars were formed when the universe was 2 M years old, and after orbiting each other for 11 B years collided 130 M years ago.  One speaker also estimated that the amount of gold, platinum and other heavy elements was 16,000 times the mass of the earth; one panel member then referred to the merger as a “Bling Event”

This is the start of what the press conference termed multi-messenger astronomy, ie EMR (inc visible light) + Neutrino + Gravitational waves.

If there is interest then we could use this event as the topic for the next Discussion Group meeting on the 13th November and look at the preliminary results.  If you would like for that then email me at  cosmology@AbergavennyAS.org.uk 

More info at the LIGO website HERE and many news sites.

Next Meeting – Monday 23rd Oct. “The Dynamic Universe”

Andy Newsam, (Prof of Astronomy Education & Engagement, Astrophysics Research Institute, Liverpool; Director of National Schools’ Observatory; ESERO-UK Space Ambassador) will give a talk about “The Dynamic Universe”

The Universe is a dynamic, ever-changing place full of extremes. From black holes to asteroids, massive exploding stars to elusive distant planets, every part of the Universe poses its own questions. So, how are astronomers trying to find the answers and how can you help?

Usual time & Place : The Kings Head, Abergavenny, at 7:30pm.

Come and learn about our universe, all welcome.

Matters from the Discussion Group 9th Oct.

There weren’t many who could make Monday evening’s session but it was very lively none the less.

The “News of the Month” that was presented at the meeting  has been posted on the “Downloads” page HERE

One question that came up, but wasn’t answered, concerned the analysis of the LIGO data.  Basically “How do we know that black holes were involved and how do we know what the before and after masses of the objects was?”
I have had a quick look on the web and came across information on this very question.  The results for the first detection are summarised in the graph below.  I have posted the LIGO Flyer that this graph is from on the “Downloads” page HERE
However, if you want to look at the matter in more detail there is a paper, by B. P. Abbott et al of the LIGO Scientific Collaboration and Virgo Collaboration, on the web at this ADDRESS and you can access the data set at this ADDRESS

Notes for Meeting Monday 9th Oct. : Black Holes and Dark Matter

I have posted brief notes for tomorrow’s meeting on the downloads page  HERE 
Feel free to expand/correct these thoughts.  I won’t be upset!

I have just checked the Links on the Notes and they don’t appear to be working.  So, as I haven’t got time to check them out now they are repeated below:


SOME LINKS:-
Dark Matter                               :           Top 5 candidates for Dark Matter
Black Holes & Dark Matter          :           NASA     :     AAAS     :      The Guardian


I look forward to an interesting discussion.

Meeting Monday 25th September, The Kuiper belt and beyond, Keith Moseley

 

This Monday we welcome back Keith Moseley who will give a talk entitled “The Kuiper Belt and Beyond”. The Kuiper belt is named after Gerard Kuiper and is the region of the solar system beyond Neptune where the short period comets come from.  It is also the home to the so-called Trans-Neptunian Objects (TNOs) that are attracting increasing interest from astronomers; particulary since the New Horizons mission produced stunning pictures of Pluto, itself a TNO.  What is becoming increasingly clear is that much of what astronomers believed about the solar system and its formation is being turned on its head as its outer regions are explored.

Meeting as usual starts at 7:30 pm upstairs in the Kings Arms and all are warmly welcome.

The Sun – Next meeting this coming Monday 11th Sep @ 7:30pm

Every thing you wanted to know about our Sun but were afraid to ask (well maybe!).

5 Day Solar Show video from NASA

Nick will talk about our sun, the source of all life on Earth.  He will deal with the basics and no doubt will have photos taken with his solar scope.
Topics covered will include:-
–  Where does it come from;
–  What makes in shine;
–  What it’s structure;
–  What are solar storms and should we worry;
–  When will it go out?

Come along and make it a good start to our autumn series – Everyone is welcome
Usual Venue : The Kings Head, 59 Cross St., Abergavenny

September is on the way

3 items in this post:-

1) The schedule of meetings for the Autumn
2) The final fling of Cassini
3) An invitation to a GW lecture in Cardiff University


1) The schedule of meetings for the Autumn
The “Meetings” page has been updated for the period September to December.
Meanwhile, the September meetings are:-
11th September – Nick Busby, AAS  :  Basics – The Sun – what is it’s Structure and how does it work.

25th September – Keith Moseley, MARS (Monmouth Astronomy Research Society), ex Head of Physics, Monmouth School  :  Subject to be confirmed


2) The final fling of Cassini

 

A portrait of Saturn created by layering together 12 different images taken using different filters from
Cassini’s imaging instruments. Credit: NASA/JPL-Caltech/Space Science Institute/G. Ugarkovic

An extract from the BBC news site, 14th August, 2017.  HERE

The Cassini probe has begun the final phase of its mission to Saturn.

The satellite has executed the first of five ultra-close passes of the giant world, dipping down far enough to brush through the top of the atmosphere.

It promises unprecedented data on the chemical composition of Saturn.

It also sets the stage for the probe’s dramatic end-manoeuvre next month when it will plunge to destruction in the planet’s atmosphere.

Cassini is currently flying a series of loops around Saturn that thread the gap between its atmosphere and its rings.

The 14th August swing-by saw the spacecraft go closer than ever before to the cloud tops – skimming just 1,600km (1,000 miles) above them.

This low pass was designed to allow the probe to directly sample the gases of the extended upper-atmosphere.

Saturn’s bulk composition is thought to be about 75% hydrogen with the rest being mostly helium, explains Nicolas Altobelli, the ESA’s Cassini project scientist.

“It’s expected that the heavier helium is sinking down,” he told BBC News. “Saturn radiates more energy than it’s absorbing from the Sun, meaning there’s gravitational energy which is being lost. And so getting a precise measure of the hydrogen and helium in the upper layers sets a constraint on the overall distribution of the material in the interior.”

Dipping down into the atmosphere should create a drag on the spacecraft, requiring Cassini to use its thrusters to maintain a stable flight configuration and stop itself from tumbling. But the mission’s scientists think any buffeting effects ought to be manageable.

They are hopeful that when the post-pass analysis is done, the probe will be permitted to go even lower on the remaining four dip-downs before 15 September’s goodbye plunge.

Cassini is a joint venture between the US, European and Italian space agencies. They are ending the probe’s operations after 20 years because it is running low on fuel and will soon become uncontrollable.

Scientists want to avoid the possibility of a future collision with Saturn’s moons Titan and Enceladus, which could conceivably support simple microbial life. And the only way to prevent that is to deliberately drive the probe to destruction in the atmosphere of the giant planet.

Eos article “Saturn Unveiled: Ten Notable Findings from Cassini-Huygens”  HERE


 3) An invitation to a GW lecture in Cardiff University

What  :  Gravitational Waves: Natures biggest explosions
When  :  6th September, 2017  :  Time 17:00 – 20:00
Where  :  Cardiff University, Main Building, Park Place, CF10 3AT
Entry  :  Free entry – but you need to book a place
Open to all
More details  :  Website and Booking Page HERE

Gravitational waves — ripples in the fabric of space-time — were one of the first major predictions of Einstein’s theory of gravity, and are the last to be directly measured. These waves are produced by some of the most violent phenomena in the universe, such as collisions of black holes, the explosive deaths of massive stars, and the big bang itself. But they are so fantastically weak that they have only recently been observed, following decades of effort by a worldwide collaboration.

In this inaugural lecture, Professor Patrick Sutton from the School of Physics and Astronomy will discuss Cardiff University’s role in the discovery of gravitational waves, and how the team are using them as a new probe of Nature and its most extreme environments.

Registration and refreshments (VJ Gallery) from 5pm, with the Lecture (Large Chemistry Lecture Theatre) at 6pm. A drinks reception will take place after the lecture in the VJ Gallery.