# Tagged: astronomy

Already looking forward to this year’s summer holiday – in a relatively Moon-free fortnight – and a chance to get the telescope out.

Last year I shocked myself with this:

Jupiter, 9 August 2012

- produced by just pointing the second-hand DSLR at the eyepiece. This year I want to go better but don’t want to spend a fortune either (ie., I am not buying a thousand quid camera).

I have read webcams are the way to go – can anyone offer some advice on how this all should work?

# Gamma ray bursts are not that rare

Map of gamma ray bursts observed by BATSE mission: public domain

Yesterday it was reported that scientists have suggested that an anomalous peak in radioactive materials discovered in antarctic ice sediments and in ancient Japanese cedar trees could be explained by a gamma ray burst hitting the Earth in the 8th century CE.

The BBC radio report I head described gamma ray bursts as “extremely rare” and the website article – and much other coverage – repeats the idea that they are rare events.

But they are not.

There are an estimated $1.25\times10^{11}$ galaxies in the universe. It is estimated that a gamma ray burst happens at least once every million years in any galaxy – or approximately every $3\times10^8$ days. That means that today there will be approximately 1000 gamma ray bursts. Now, let’s assume that due to relativistic effects  we can at most only observe one-tenth of the universe, that still means 100 events in the observable part of the universe (how big the observable universe is in comparison to the universe is another matter however).

Of gamma ray bursts are narrowly beamed so even with this high rate of production not many get seen on Earth (probably a good thing given the energies involved), but they are far from rare.

Of course, events in our galaxy are rare (the fact that we are here at all is testament to that), but on the universal scale that is drawing a very tight boundary on the region being tested.

# Infrared astronomy on the cheap?

When I was an undergraduate infrared astronomy was a relatively new area of study and was generating much excitement and seeing this project on Kickstarter I wonder if there could be some amateur action available – www.kickstarter.com/projects/andyrawson/ir-blue-thermal-imaging-smartphone-accessory.

Any views, anyone?

# Death of Sir Patrick Moore

Patrick Moore (Photo credit: aesop)

Patrick Moore‘s death should surely be marked globally, because it is the passing of a man who as an amateur had a greater impact in his field – specifically planetary astronomy – than many professionals. Are there any others left in pure science who can claim that?

Patrick Moore is most likely to be remembered in Britain as an eccentric populariser of astronomy, and as the presenter of the world’s longest running television programme, the monthly “The Sky at Night”. And he certainly achieved greatness as a populariser.

But his contributions to science should not be forgotten. His earlier claim to be the discoverer of Mare Orientale was mistaken – as Moore himself appeared to recognise later in life – but his contribution to the mapping and understanding of the Moon in the pre-space flight age was a real one. Indeed NASA are reported to have used his charts.

Anyone who has ever viewed the Moon through a telescope will understand the fascination for astronomers – especially in the days before space travel. It is surely the most beautiful thing that can be seen except for Earth from the the air or space itself. My only photos from this summer don’t really do it justice, but the deep valleys and wide basalt plains are still enticing.

Many of Moore’s ideas on the Moon – such as the idea that the craters were the result of vulcanism (discussed at length in V. A. Firsoff’s 1969 classic The Old Moon And The New) have now been decisively refuted by the scientific results of the Apollo programme, but they retained their credibility even after Neil Armstrong‘s giant leap because they were based on serious observation and thought (I saw Moore defend them as late as 1979 even though by then he was isolated in his view).

Moore was a prolific writer and while many recent works bearing his name appear to be attempts to cash-in on his recognition (for which we should bear him no ill-will), books such as Guide to the Planetsrepresented the pinnacle of accessible writing at the very moment long-range space travel was to transform our view of the Solar System permanently. (This has been subsequently been republished as New Guide to the Planetswhich, presumably, includes much of the new information that came from the Voyager and other probes.

His death is a sad moment.

• I met Moore several times in 1979 when John Shutler, Finchley Catholic High School‘s legend of the physics lab, took a small group of us to several lectures he delivered at Queen Mary College at Mile End. Moore was charm himself and on our second meeting gave each of us a copy of his map of the Moon – then the amateur’s standard chart – and delivered some brilliant lectures. Mr Shutler’s embarrassment on having greasy hands (we’d all just been eating chips) at the first meeting was a source of much amusement, but did not trouble Moore.

# Memo to self: fighting the Moon is a waste of time

Moon (Photo credit: penguinbush)

My telescope is getting its (sadly) annual run out but I need not have bothered this week – as despite clear skies the Moon is also about (full Moon is on 1 August) – and that makes even setting up the telescope difficult: you can pick out Vega as a bright star in your scope, but Deneb? Even it is being drowned in moonlight.

Maybe next week will be clear too and I can get a good run: maybe even getting to see Uranus (no sniggering at the back), which is viewable right now, though low. Or even, if luck holds, Neptune.

# The Moon (again)

Won’t be doing this every night, I promise, but here’s this evening’s photograph. Possibly the crater you see at the South (bottom) is Tycho, which as any lunar observer knows dominates the full Moon with its extensive ray system, but here is only just visible in the dawn light.

I suspect the (low) quality of these images is likely quite similar to the view of Galileo when he first turned a telescope skywards four centuries ago.

# Waited 32 years for this…

Moon at 21hrs BST, 27 May 2012

Ever since I did my Astronomy ‘O’ level in 1980 I have wanted to take a picture of craters on the Moon.

In those days it was all but impossible to get high street developers to make prints from my attempts and so it failed.

But now, at last, the digital age is with us, and with the aid of a telephoto lens, I have done it,

The Appennines (Mons Apenninus) can be seen very clearly as can several craters (I used to be able to name craters very easily, but I am long out of practice,but I’d guess Archimedes and Plato.)

Next step, get the camera to work with the telescope.

# Skywatcher-127 synch scan telescope

Image via Wikipedia

I used my Skywatcher-127 synch scan telescope for the second time last night – the sky was not as clear as before and the Moon was also a big interference and so I did not stay long at it – though as I was more familiar with how the set-up worked I was up and running much more quickly.

With this scope, which has an alt-az mount, you enter the time and geographic location, centre the scope on two selected bright stars and then the computer does the rest: moving the scope to match the Earth’s rotation, taking you to selected co-ordinates and so on: for someone used to mucking about with equatorial mounts and setting circles it can be a bit strange at first, but the advantages become obvious quickly.

That said the alignment process is not 100% accurate, but objects I was looking for were with one field of view (at x80) so were easy to find once the scope had pointed at where it thought they were.

Living close to the centre of London I am not going to get much use of it in the back garden, though the Moon and the planets may be options, so the fact that it is a Maksutov-Cassegrain and not a Newtonian is pretty important – as it is transportable. The computerised mount also helps in that it means there is no question of readjusting the axis or working out where north is (though if if you cannot find Polaris what do you want a telescope for?).

However, as this Amazon link for telescopes shows, Newtonians are about half the price of the compound optic reflectors, so if you live somewhere dark, bear that in mind.

Ultimately my aim is not to see the sights of the sky – I did a lot of that 25 years ago (though I still dream of seeing the southern skies) – so I need something more and that is likely to be another revived passion of my youth: photography. These days, though, decent cameras for astrophotography cost more than the telescopes, so I will have to see how that develops (no pun intended).

Update: The one thing I should have added was that powering the mount is a bit of a pain. Despite a battery cradle being supplied it is plain that run-of-the-mill batteries will not deliver sufficient power (perhaps more expensive ones might for at least a bit) and so I have been using an old IBM Thinkpad power supply to deliver the necessary 12 VA. That considerably limits flexibility in siting the telescope.

# Astronomy is still out of this world

Not since the summer before I went to university have I done this – turned a telescope to the skies.

But, and although the viewing site was less than ideal (looking north/north west only), I have just spent a very enjoyable two hours doing that again.

Sights taken in included M13 (Hercules globular cluster):

Ring Nebula (M57):

And the Helix Nebula:

(NB none of these are my photographs, but rather than put up images from Hubble or similar, I thought I use images that were closer to the real experience for me. If you think they look unimpressive that is your problem, not mine!)