Not pink and not that super!

The full moon at this time of year looks a bit bigger than at other times, because it coincides with the perigee of the moon's rather elliptical orbit. Hence the usual 'Supermoon' stuff in the media. Worth noting, but not really all that spectacular an event.

This year we've been hearing about the 'pink moon'. That's a new angle. Well it isn't pink either. Pink moon is apparently a North American term for the full moon at this time of year, because it coincides there with the blooming of a pink flower, the creeping flox. 

I had a look anyway, just in case.

 

Bound for South Australia - 8: Aroona camping

 

I spent a happy two nights at the rather idyllic Aroona campsite, near the Heysen Range in the Flinders Ranges. Tent sites were spacious, the toilets were clean and odourless, and each site had its own tap supplying spring water. Emus came wandering through, with their teenage families, and the night sky was of course magnificent.

A star runs out of juice? Explodes?

The bushfire smoke has pretty well cleared,  and sometimes we're even getting clear night skies. It was time to take a look at poor old Betelgeuse.



Betelgeuse, nowadays usually pronounced 'Beetle Juice' for some reason, is in trouble. It's well known to be a variable star, with its magnitude fluctuating typically between 0.0 and 1.3. It's an orange-red colour, and it's usually the second brightest star in Orion, the Hunter.

Top left is my picture from last night. Betelgeuse is not even a first magnitude star.

Here's a picture I took in March 2016. That's the Betelgeuse we knew and loved!

It's known that this sort of behaviour in a variable star can be indicative of an imminent supernova explosion. Watch out for this. It would be the brightest thing in the sky apart from the sun. It's fortunately about 700 light years distant. If it was one of the closer stars it could fry us along with all other life on the planet!

'Imminent' in this context means any time in the next 100,000 years, but you never know. It could be tomorrow! Here's a piece from Forbes magazine about a Betelgeuse explosion: Forbes Betelgeuse explosion article

Three 'Evening Stars' tonight

The view to the west just after sunset this evening. From my roof. I like my roof.

Spica's a real star, and it's only just visible in the twilight.

Starry starry night

The last few nights have been wet and overcast here in Sydney, but the previous few dozen were totally clear-sky astro-friendly ones. Here's a shot I took of the Milky Way's inner suburbs, a couple of weeks ago.

I'm still in awe of the picture quality I get from my mobile phone.

More on photography too easy!

As I said the other day (earlier post) you're not supposed to be able to do astronomical photography without telescopes, tripods, cable releases etc. You're not supposed to just hold your phone in the air, point it at the moon while it's set on fully auto, and touch the shutter button. Or if you do, you don't expect an image like this one.

But this is what my high-end Huawei phone gave me!

No wonder the Americans (and Google) are worried about them!

The planets are aligned.........

Every few years there's an alignment of the naked-eye planets, whereby you get to see all of them at the same time (if you know where to look). There are of course six of them, when you include the one beneath your feet.

Mercury was an easy evening object a few weeks ago, but it's done its dash again now. The others are all still out and proud.

For a while I've been seeking an ideal observing location within Sydney. You won't get anything like a perfect dark sky without travelling hundreds of kilometres, but some metropolitan areas should be more suitable than others. And I hit on Terry Hills the other night as a good option to try out.

Right & below: The galactic centre is right overhead, with the dark 'Emu in the Sky' stretching horizontally from near the Cross in the south.









Right & below: Looking more or less straight up here. A very red Mars, Saturn, and always-bright Jupiter are in a line. Brilliant Venus set in the west a while ago.

A dilly-bag in the sky

I was all geared up last week to photograph the blue blood monster purple super moon eclipse thing, but clouds got in the way. I had  my camera set up and ready though, so when the sky cleared again a few nights later, I pointed it up at the Southern Cross, where a new star had been born.

That's a lie of course. No new star, but a new name for one of the existing ones. Epsilon Crucis, the fifth brightest star of the constellation, had been reborn as Ginan, courtesy of the International Astronomical Union, as part of their programme to recognise the names used by indigenous peoples around the world. Ginan is the name used for the star for thousands of years by the Wardaman people of the Northern Territory. It represents a red dilly-bag full of special songs of knowledge.

Under the Southern Cross I stand

Apparently, it's the Australian cricket team's victory song ("with a sprig of wattle in my hand" etc). But that's not the Southern Cross' fault.

Here it is, complete with Pointers, power pylon, and a hint of Milky Way, taken from Sydney's northern suburbs, and suffering inevitably from a fair bit of light pollution. Compare the Milky Way's visibility with that from a few weeks ago out in the bush, here: http://sydneysapiential.blogspot.com.au/2017/04/kanangra-skies.html 

Kanangra skies

I spent the Easter long weekend in the Kanangra-Boyd National Park, doing an unexpectedly gruelling (but ultimately satisfying) 3-day bushwalk. More on that in subsequent posts, but here are some night sky shots from the Boyd River camping area.

We amazingly had an Easter of excellent weather, both bushwalking-wise, and astronomy-wise. And with reports of a possible nuclear winter to come, it was very much time to put my wide
angle lens to good use on the clear dark sky.

An exposure of a few seconds (first picture) yields the brighter stars (Southern Cross, Pointers etc) plus a hint of Milky Way. Click on the picture to see it a bit better.

Give it a full minute, and enhance it a little, and we get a very bright Milky Way indeed, though you have to work a little to distinguish that Cross. You see the Coalsack dark nebula well. It's otherwise known as the head of the Emu constellation - the enormous dark-patch constellation of indigenous astronomy. More of that in a few weeks time hopefully, when it's fully visible, nuclear winters permitting.







Here are my fellow campers, enjoying a nice warm campfire.

Last chance to see.....

..... the six naked eye planets.

Every few years the five naked-eye planets align themselves such that you can see them all in the sky at the same time. Right now is just such a time, and there's a few more days of this before the most timid of them - Mercury

- drops back out of sight below the pre-dawn horizon. I recommend 5:00am to 5:20am in Sydney latitudes.



So get up early, get out there, and enjoy the spectacle.


In the eastern sky, from bottom to top, there's Mercury and Venus, close together, then there's Saturn, and pretty high up there's Mars. Venus is the brightest thing in the sky, and Mars is one of the reddest. Scorpius, the curly-tailed scorpion, helps you locate them all.

Over in the north-west is the second brightest planet in the night sky: Jupiter. It's a bit away from the others, and I couldn't get it into the same frame, despite lashing out on a new $370 super-wide angle lens! It's in the constellation Leo the Lion.

So what's this sixth naked-eye planet? Just look down at the one below beneath your feet! *

'Last Chance to See', by the way, is the title of a book co-authored by Douglas Adams (of Hitch Hiker's Guide to the Galaxy fame). It was about several endangered species of animal around the globe. It could almost refer to the clear skies still sometimes available above planet Earth, or indeed to a liveable Planet Earth itself.


* With thanks to Perry Vlahos and the Sydney Morning Herald

Astronomy dominates

Twice a year astronomy dominates the Macquarie University nighttime campus, when they hold their legendary astronomy open nights.

They've always been good, but I found last night that they've grown into quite sizeable and multi-faceted events.

The relevant car park had more telescopes than you could point a laser pointer at. They were trained on various star clusters, planets, and the moon. The many visiting stargazers never had to queue too long, so good was the array of viewing instruments on offer.

The (massive) laser pointer itself was trained on I'm not sure what, but anyway served as an excellent beacon to guide us in to the astronomical zone.

There were planetariums to visit, and information stands on astronomical societies and equipment. There were small scale space rockets seemingly for sale, the lot.

There were kids' activities involving robots and laser mazes. There were also talks about black holes, giant telescopes, and aboriginal astronomy.

We went to the main feature talk on cosmology ('A Long Time Ago in Galaxies Far, Far Away'), and it was excellent. It was delivered by Amanda Bauer, who's an astronomer and outreach officer at the Australian Astronomical Observatory at Coonabarabran. She did a fine job, so enthusiastically explaining her work on galaxy formation and evolution. She can't wait for Betelgeuse to explode and light up the daytime sky, or for the Andromeda Galaxy to finally get here, smash its way through our galaxy, and shake it all up for us a bit. She talked a lot about the red shift and how it was a marker for galactic speeds and distances. I noticed she was a bit into purple shift herself, with a purple astrogirl hairstyle.

I wanted to tell her afterwards about how I'm a bit of a red shift sceptic, but thought better of it. This doesn't go down well in gatherings of astronomers - I've tried before! Red shift is accepted as being due to motion away from us, and the more distant are objects from us, the bigger the red shifts, and therefore the bigger the speeds. As we're seeing the distant objects as they were billions of years ago, the relationship between red shift and apparent distance can be used to decide whether the expansion of the universe is increasing or decreasing or whatever. Nobel prizes were awarded a few years back when it was pronounced that the universe was expanding at an accelerating rate. It all depended on those studies, and the assumption that that red shift relationship held up at the very great distances, speeds, and times involved. To explain this accelerating expansion, a thing called 'dark energy' had to be invented, and astronomers have no idea what this dark energy is, nor indeed what dark matter is.  Between them they now need to make up most of the stuff of the universe. It's all getting uncomfortably complicated.

I think the next big Macquarie astronomy open night  is in October.

We are stardust (billion year old carbon)

So said Joni Mitchell in her classic 1970 song 'Woodstock' ( https://www.youtube.com/watch?v=cRjQCvfcXn0 ) and of course she was right. Here's a 2014 interview with a somewhat older Joni Mitchell, in case you're a fan: https://www.youtube.com/watch?v=HajWhhXkfYQ

Joni was taken ill a few weeks ago and the reporting suggested she was about to leave us. Thankfully she came good again.

But this wasn't supposed to be a post about Joni Mitchell. It was supposed to be about a current astronomical phenomenon I've been following: the nova ('new star') in Sagittarius. Here's my picture, as of early morning on 14 April. There's a star there that wasn't visible before, and it's been fluctuating noticeably in brightness for a few weeks now. Sure, it's not all that bright, but there was nothing at all to see there before!

Novas are thought to be massive nuclear ignitions of material pulled out of red giants by their white dwarf companion stars. The star consequently becomes tens of thousands of times brighter for a while. It'll probably fizzle out again soon. It's actually supernovas, which are vastly brighter still, which blow themselves to bits and spread their stardust around. Only extremely massive stars become supernovas, and there's only one in our galaxy every few hundred years. (I remember seeing the 1987 one in a neighbouring galaxy though.) All matter, other than hydrogen, is made in stars, and it's mainly through supernovas that all this stuff gets spread around. So 93% of the matter inside us is stardust from supernovas, as I understand it. More on this at: http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/supernovae.htm