A Night of Observing With Friends and Neighbours

In the week I was stopped by my next door neighbour, while on my way in from work, with the starting sentence  “that’s a large telescope you were using last night, is it yours?”

“It is” I replied “It’s actually one of two that I have.”

“Ah I see, my son saw you out there with it the other night, but was too shy to come over and ask for a look”

“That’s no problem at all” I said “He’s welcome to come and have a look at any time. Assuming the skies are clear over the weekend, I”ll get them both out and set up, and we can do a bit of viewing”

So, Sunday evening arrives and the skies are perfectly clear. I have a group of friends with me (who also wanted to see what was going on in the skies). I set up both of my scopes, the 8″ Skywatcher 200 and the 3″ Skywatcher 102. The 102 is computer driven and this would be the first time I had used it in such a configuration since having it.

I started the evening with a small sky orientation, using the same reference points, that I use to align the 102. Vega (located in East), Arcturus (in the South West) and then pointed out Saturn (also in the South West) and Polaris (in the North) These are the main objects that I use, when I am out, as they are most familiar to me in relation to my surroundings (i.e. my garden)

The first object of interest we looked at, was Saturn. Fairly low in the South-West, just peaking above the roof top of the adjoining houses. It was particularly clear and crisp. I had the 8″ on it, with a 25mm eyepiece and 2x Barlow, so the view of the rings was pretty spectacular. The Cassini division was clearly visible, as at the current time, the rings are tilted down towards us. Saturn was the first of the planets that I ever saw through a telescope, and I am pretty sure it is what got me hooked on astronomy. It’s always a good reliable object to view for first timers, as it has that WOW factor. (Plus, at this point the Moon hadn’t risen above the horizon)

Next we moved on to play a game that I call “Red Star, Blue Star” I use this to show that stars have different colours and how this relates to physical parameters of stars. We used Vega and Arcturus for this as the colour difference between the two. I explained that blue stars, are generally large very hot yet short lived (in star terms) and that red stars are cooler, and yet live a lot longer. This then led on to the talk about stellar distances, the light year, and how astronomy is basically time travel.

After all looking at both stars, I then used the 102 to point to a number of different star clusters (M13, M92 and M5) and had a discussion about them and what they are.

The hardest question of the night, was trying to explain what would happen if gravity between binary stars stopped. Tricky because its hard to explain to a 10 year old the answer to this question, and not go into too much detail about general relativity. However I think we managed.

Finally, around 11pm the Moon made a spectacular appearance from below the horizon. Bright vibrant orange. Attention to this then took up the rest of the night. Both the 200 and the 105 were slewed to it. The 102 using a 35mm camera projection wide angle eyepiece, and the 200 the same 25mm with 2x barlow. The craters were lovely in the orange light, and made for great viewing. There were lots of images taken using iPhones by the members of the group.

 

Hopefully the evening of astronomy helped inspire a new generation of amateurs, and as the year goes on, hopefully I can hold another evening, when there are different objects visible.

“BX442” –The First Spiral Galaxy in the Universe?

It seems that, so far, it is: In July of 2012, astronomers observed a spiral galaxy in the early universe, billions of years before many other spiral galaxies formed while using the Hubble Space Telescope. They were taking pictures of about 300 very distant galaxies in the early universe to study their properties. This distant spiral galaxy they discovered  existed roughly three billion years after the Big Bang, and light from this part of the universe has been traveling to Earth for about 10.7 billion years.

“As you go back in time to the early universe, galaxies look really strange, clumpy and irregular, not symmetric,” said Alice Shapley, a UCLA associate professor of physics and astronomy, and co-author of the study. “The vast majority of old galaxies look like train wrecks. Our first thought was, why is this one so different, and so beautiful?”

“BX442 looks like a nearby galaxy, but in the early universe, galaxies were colliding together much more frequently,” she said. “Gas was raining in from the intergalactic medium and feeding stars that were being formed at a much more rapid rate than they are today; black holes grew at a much more rapid rate as well. The universe today is boring compared to this early time.”

Galaxies in today’s universe divide into various types, including spiral galaxies like our own Milky Way, which are rotating disks of stars and gas in which new stars form, and elliptical galaxies, which include older, redder stars moving in random directions. The mix of galaxy structures in the early universe is quite different, with a much greater diversity and larger fraction of irregular galaxies, Shapley said.

“The fact that this galaxy exists is astounding,” said David Law, lead author of the study and Dunlap Institute postdoctoral fellow at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics. “Current wisdom holds that such ‘grand-design’ spiral galaxies simply didn’t exist at such an early time in the history of the universe.” A ‘grand design’ galaxy has prominent, well-formed spiral arms.

The galaxy, which goes by the not very glamorous name of BX442, is quite large compared with other galaxies from this early time in the universe; only about 30 of the galaxies that Law and Shapley analyzed are as massive as this galaxy.

To gain deeper insight into their unique image of BX442, Law and Shapley went to the W.M. Keck Observatory atop Hawaii’s dormant Mauna Kea volcano and used a unique state-of-the-science instrument called the OSIRIS spectrograph, which was built by James Larkin, a UCLA professor of physics and astronomy. They studied spectra from some 3,600 locations in and around BX442, which provided valuable information that enabled them to determine that it actually is a rotating spiral galaxy — and not, for example, two galaxies that happened to line up in the image.

“We first thought this could just be an illusion, and that perhaps we were being led astray by the picture,” Shapley said. “What we found when we took the spectral image of this galaxy is that the spiral arms do belong to this galaxy. It wasn’t an illusion. We were blown away.” Law and Shapley also see some evidence of an enormous black hole at the center of the galaxy, which may play a role in the evolution of BX442.

Why does BX442 look like galaxies that are so common today but were so rare back then?

Law and Shapley say the answer may have to do with a companion dwarf galaxy, which the OSIRIS spectrograph reveals as a blob in the upper left portion of the image, and the gravitational interaction between them. Support for this idea is provided by a numerical simulation conducted by Charlotte Christensen, a postdoctoral scholar at the University of Arizona and a co-author of the research in Nature. Eventually the small galaxy is likely to merge into BX442, Shapley said.

Law, a former Hubble postdoctoral fellow at UCLA, and Shapley will continue to study BX442.

“We want to take pictures of this galaxy at other wavelengths,” Shapley said. “That will tell us what type of stars are in every location in the galaxy. We want to map the mixture of stars and gas in BX442.”

Shapley said that BX442 represents a link between early galaxies that are much more turbulent and the rotating spiral galaxies that we see around us. “Indeed, this galaxy may highlight the importance of merger interactions at any cosmic epoch in creating grand design spiral structure,” she said.

Studying BX442 is likely to help astronomers understand how spiral galaxies like the Milky Way form, Shapley concluded.

The image at the top of the page ian an artist’s conception of the farthest spiral galaxy ever seen; in a Hubble/Keck image (inset), the blob at upper left is a companion galaxy whose gravity may have sparked the spiral structure. Credit: (left) David Law; (right) Joe Bergeron, Dunlap Institute for Astronomy and Astrophysics

The Daily Galaxy via UCLA News and Nature.com

via “BX442” –The First Spiral Galaxy in the Universe?.

Heart on fire: Our galaxy’s black hole is set to blow!

THE centre of our galaxy is a place of extremes. “It has the highest density of stars, the fastest-moving stars, the most concentrated reservoir of gas and the strongest magnetic fields in the galaxy,” says Mark Morris, an astronomer at the University of California, Los Angeles. And lurking at its very heart is the most enigmatic object of all: our galaxy’s very own supermassive black hole.

via Heart on fire: Our galaxy’s black hole is set to blow – space – 02 May 2013 – New Scientist.

Marco Tempest: The magic of truth and lies (and iPods)

Marco Tempest: The magic of truth and lies

This is a TED video that I came across some months ago now, and even sat here watching it, I get goosebumps.

Now I recognise that this isn’t specifically an Astronomical or Physic related post, but it is totally worth sharing. As it happens, I frequently use the “Distant Suns” app on my iPhone, which utilises augmented reality for locating astronomical objects, so I guess there is a link.

via Marco Tempest: The magic of truth and lies (and iPods) | Video on TED.com.