The Belt (called Gould’s Belt in North America, and named for Benjamin Gould, who identified it in 1879.) is actually a fragmented ring of of star-forming clouds, young stars and nebulae that comes in at around 3000 light years in diameter. Containing lots of bright, young O- and B-type stars, in sits neatly inside the local spiral arm of our own galaxy the Milky Way. The Sun appears to be situated roughly in the middle of it – but it is not know where it came from or what it really is. To study the star-forming regions does not necessitate any understanding of the belt itself, but it is curious to wonder how it came to be.

The image below (from galaxymap.org) shows approximately where in our Milky Way galaxy the Gould Belt lies. You have to image the entire Solar System as an invisible speck near the middle of the white ring, denoting the Gould Belt.

One common theory is that there was some ancient supernova that exploded and sent radiation and material outward. Like a ripple from a stone dropped in a pond, this caused an ever-growing ring of activity in the surrounding interstellar medium. This model works fairly well, since the local bubble – a region of low density in which the Sun and a few other stars sit – fits reasonably well inside the Gould Belt. Perhaps both of these structural features could have resulted from an ancient explosion.

It is also possible that some much larger scale interaction has taken place. A recent paper on arXiv suggests that the belt originated 30 million years ago when a giant dark matter clump collided with a giant molecular cloud in the Milky Way’s spiral arm.

Maybe there is no Gould Belt! It could be that we only think we can see a ring-shaped pattern in the layout of our local region. After all when it comes to detailed structure in the galaxy, we cannot see much further out than our own spiral arm. Maybe these kinds of shapes are merely coincidental from our viewpoint.

The image at the top of this post was created by my office-mate Jason Kirk and it shows the star-forming clouds within the Gould Belt. The belt itself is marked as a blue ring and the local bubble is shown as a shaded area. The size of the star-forming regions is proportional to their mass, assuming a uniform density. This image was created for the Spitzer Gould Belt Survey and I have always found it handy when thinking about the Gould Belt.

The problem is that the detector arrays for the device are currently at the NIST (National Institute of Standards and Technology) lab in Boulder, Colorado where a ‘radiation incident’ has taken place. Contamination from plutonium means that no one can enter the lab and the detectors are currently inside.

The incident is described on the NIST website, which says that “a small plutonium spill occurred on June 9″. The sample that is thought to have caused the leak would have contained just one-quarter of a gram of plutonium. This seemingly tiny portion of radioactive material was accidentally spread around by a lab worker who also used a sink to wash his hands while contaminated.

The lab has since been inspected and many surfaces are contaminated including “the floor [and] various tabletops and surfaces, consistent with a spread of material by hands and shoes”. NIST are working with experts and hope to have the situation resolved soon.

Meanwhile, SCUBA-2 has to wait. It has now been two weeks and as soon as the science team can get their hands on the arrays they hope to begin the next phase of work and try to bring to life a device which many have been waiting for with anticipation.

SCUBA-2, and its orbital cousin Herschel, will begin a new era for the science of star formation and submillimetre observing. You’ll hopefully be hearing a lot more about both these instruments right here in the weeks and months to come.

SCUBA-2 can scan the sky much faster than SCUBA and will allow researchers to measure the properties of protoplanetary disks around young stars, amongst other things. Exciting stuff. It is however very big.

Whereas SCUBA was comparable to a hefty water-heater, SCUBA-2 is more like a minivan. Mostly this is because of the cryostat that is required to keep the technology inside SCUBA-2 at a very low temperature. This technology has been developed principally in Edinburgh but also in Cardiff as well a few other places.

I saw SCUBA-2 in Edinburgh in 2006 and noted its large size at the time. When I observed at the JCMT last November (2007) I asked how on Earth they intended to get the the very expensive SCUBA-2 inside the very expensive JCMT without damaging either. The answer gave was that it would be tricky, and now thanks to a series of photos from April 2nd and 3rd I know what they meant.

The full gallery of 600 photos can be found on the Joint Astronomy Centre‘s JCMT pages. There is also a fairly large animated GIF file (22MB) if you would like to see the installation in action.

Although rare, altitude sickness is not unheard of on Mauna Kea. The conditions at the summit are below 40% the normal oxygen levels, and under half the usual atmospheric pressure. The fluids in your body tend to ‘leak’ as I understand it. Your blood’s ability to convey oxygen around the body is greatly impaired and your reactions are often sluggish and unusual.

Tourists have been known to simply keel over after reaching the top because they didn’t spend enough time getting used to the altitude on the way up. Astronomers have also been known to be carried down, despite days of preparation at 9,000 feet. Altitude in rare cases induces people to heart attacks and hypothermia in extreme cases.

The best story I have heard is of a telescope engineer who had been up many times but on one occasion called back to base to complain of a cable that was too short. He stressed that despite cutting it three times already, the cable still would not reach the desired spot. He was told to return immediately and was right as rain upon his return.

Descent is the only cure for altitude sickness, and in most instances a short while at lower altitude will correct the problem entirely. Alas this wasn’t to be the case for me. After a time at the observer’s station I still could not breathe normally and so James di Francesco, my mentor on the summit, took me down to the town of Hilo to the Medical Center.

They administered a series of tests, an injection and a lot of oxygen; and got me better. The doctor also informed me that if I needed, I could return to the station at 9,000 feet that very same day after collecting my prescription.

Jollied by this prognosis I did indeed return to the station where I began struggling to breathe again almost right away. I was swiftly returned to the medical center at sea level where a longer wait and a different doctor told me I had a pulmonary oedema. This time I did not return to the station. I was instead restricted to lower climbs for 48 hours. Over that time, my breathing gradually returned to normal.

I have since flown to San Francisco and today walked a fair away across the city. It’s good that my lungs are almost mended, but a shame that I apparently picked up a nasty cold during that time. I never get colds and so I’m pissed about it.

On the plus side, I got to see more of Hawaii than I would have done and San Francisco is a brilliant city which everyone should visit if you haven’t already.

A great many people from home have sent their kind thoughts via email and phone and I am very touched. The hardest thing about getting ill is doing it on your own. I am very grateful to those who have been here with me. James di Francesco, Henry Matthews, Antonio Chrysostomou, Sarah Sadavoy, Ben the Telescope operator, the rangers of Mauna Kea and the Jason and Co. at the HP station have all at some point kept me company. Thanks guys!

It is only days until I get home and truthfully I can’t wait. Until then San Francisco is a very good place to spend time that needs to be served.

1820: Just got back from a tour of the W.M. Keck Telescopes, which one of the operators was kind enough to give us – that is one big scope!

Every five minutes our webcam updates. I’m the one in the black hat!

1830: Just arrived, dewars refilled and thankfully last night’s ice and snow has melted. We have pretty good grade 2 weather and may even be able to do some Gould Belt observing (which is why we came). To start though it looks like we’ll be looking for some observations in the nearby galaxies survey. Dave Clements is here to oversee that project.

1842: Having some mechanical problems with the telescope’s braking at the moment. I am familiarising myself with some of the data reduction techniques and the JAC’s weather pages. Below you’ll see the CSO’s Tau graph. This is an indication of the weather conditions, in a sense. What it actually measures is the opacity of the sky. The lower the bars, the better the weather.

1903: Hubble is about to pass overhead so I may and have a look. Its only magnitude 2.8 but up here that ought to look quite nice.

1920: Hubble was a let down. The lack of oxygen preventing us from seeing much dimmer than mag 2. That and the Moon, which is almost full tonight. Just getting the first data in from HARP. Our calibration source has a lovely C0 spike, but it’s the wrong kind, C¹⁸0 instead of ¹²CO.

1945: Calibrating using Uranus at the moment then onto the real science. we may even be in Grade 1 weather soon (That’s good).

2000: Have just starting taking our first science data of the evening. It’s an MSB than will take an hour to run. Since I think I’ve exhausted looking at ‘pictures’ of Uranus, I think thumb-twiddling has begun.

2018: We are currently using HARP to image M74 in CO. Here’s an APOD picture of the same object in optical wavelengths takne by Gemini North over the road.

2148: We waved at my parents…

… and sent secret messages…

2228: Our galaxy is giving me plenty to do with data reduction while James and Sarah are trying to find an off position for the first Taurus measurements for the Gould Belt Survey. I may have drunk too much Gatoraid by now.

0014: Yay! Have actually found something of interest: a structure in ¹³CO in Taurus. Brilliant.

0133: Okay so now I’m just bored. Turns out cutting edge science can be cutting edge boring too. Waiting for some more data to come in. La la la la.

0308: The datasets from Taurus are so large that I can leave the room for ages and come back to find them still incomplete. They are good though; even in these rough reductions the data is showing structure and velocity spread.

0347: Just reduced the most incredible map of Orion!

0447: Yeah those Orion maps are really amazing. We’ve got spectral lines galore!

0454: Going to wrap this entry up now. We’re going to pop outside the dome shortly to try and snap some sunrise shots of the summit. I also want to make a nice cup of tea before then!

So I assume you know where Hawaii is, and after that the following screen caps from Google Maps should show you where I’ll be this evening and the next few evenings.

In this image you can also see the city of Hilo, where the Joint Astronomy Centre that administers the JCMT and UKIRT is located. It is from here that observers drive up the mountain to get to a place called Hale Pohaku (HP). HP acts as a halfway station where people stay while they observe to keep them acclimatised to the altitude. It is from HP that I am typing right now.

This image clearly shows that Mauna Kea was a volcano. The cinder cones and caldera are visible.

These are the observatories of Mauna Kea. In order going clockwise from the bottom-left we have the CSO, the JCMT, the SMA, Subaru, the Keck telescopes, the NASA IR telescope, the Canadian-France-Hawaii telescope, Gemini North, UH 2.2m telescope and UKIRT.

The JCMT is the larger of the three in this image. Finally, here it is from the ground:

Since this will be my first professional expedition I will be taking lots of pictures and notes as I try to get to grips with using a real telescope to doing real science.

As much as possible I will blog here, though at this stage I really don’t know what will be possible.
So in case you suddenly notice an absence of blog posts in the next while, fear not – it is just me being all busy and such.

If you have any questions about my trip drop me a line via the comments thread here and I will get back to you.

V838 Monoceroti Expansion (Hubble)

It wasn’t anything interesting until it happened but the star V838 Monoceroti, which had simply sat in obscurity, flared up in 2002 to become 600,000 more luminous than our own Sun. It didn’t take long for the star to fade back into the darkness but the Hubble Space Telescope managed to get quite a few pictures of it during its active phase. (Click for animated version)

In this series of images you can see how the star’s outer layers were first expelled and then cut away by the powerful radiation from the star. The event was made even more interesting by the fact that a ‘light echo‘ was seen. During the expansion the object appeared to expand faster than the speed of light – the effect was however merely an astronomical optical illusion.

The Egg Nebula (Hubble)

Also known as CRL2688, the Egg Nebula shows a pair of mysterious ‘searchlights’ bursting out from a dense cocoon of dust surrounding a hidden, Sun-like star. We see the light escaping in the directions where the cocoon is thinner. Objects like CRL2688 are rare because they are in a phase of their evolution that is short-lived. Images like this one are very important to understanding how stars like our Sun will ultimately die.

The Sun in UV (SOHO)

[quicktime width="400" height="400"]http://www.orbitingfrog.com/blog/movies/SuninUV.mp4[/quicktime]

The surface of the Sun is far more active than most people would think. This ultraviolet video taken by NASA’s SOHO spacecraft gives brilliant detail. It allows us to see one full revolution of the Sun on its axis, which normally takes about 25 days. In this video you can make out large flares erupting from the surface and the striking magnetic loops that seem to whirl about them as they go. (Full 512×512 MPEG Here)
Red Square Nebula Nebula (Hale/Keck)

Discovered in 2007, this ruby-like nebula may be the result of two interacting stars. If one star is dying then the material from it may be dragged into a disc around the orbits of both objects. Material can then only escape from the system along the poles of the disc, resulting in two cones leading out of the stars. When viewed from the edge these cones seem like two triangles. Here the system is seen in the infrared. Structures like this are rarely seen in nebula but there is in fact a Red Rectangle Nebula which is less symmetric but still quite interesting to look at.

Abell 39 (NOAO)

Here we see an almost perfect planetary nebula that sits about 7,000 light years away in the constellation Hercules. The dot at the centre is the original star, which – as it died – released the expanding gas shell also seen clearly here. The ghostly appearance of the shell is due to the blue-green filter used to take the image, which picks out the oxygen emitted light at 500.7nm.

Saturn’s Rings (Cassini)

This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. Cassini was sheltered from the Sun’s glare by positioning itself behind Saturn. Ring structures are revealed here in detail as they brighten substantially at viewing angles where the Sun is almost directly behind the objects. These observations allowed Cassini to detected two new faint rings.

The Horsehead Nebula Swallowed Something (SCUBA)

Observers used the JCMT submillimetre telescope on Mauna Kea in Hawaii to take this image of the familiar Horsehead Nebula, who’s outline can be seen here. When observed at 850 microns, we are seeing the cold dust at temperatures close to absolute zero. This dust is deep inside the optical nebula normally seen, which is transparent at this wavelength. It seems from the image that the Horse has swallowed a ‘lozenge’ which is in fact a region of dense dust that may be collapsing under gravity. In fact this could be a star system in the making.

Gomez’s Hamburger (Hubble)

Arturo Gomez found this odd object in 1985 and it became known as Gomez’s Hamburger for obvious reasons. It is actually a proto-planetary nebula, an earlier version of Abell 39 perhaps. The curves of light (the bun) are reflecting light from the star which is being obscured by a thick band of dust (the burger). The whole thing is only only a fraction of a light year across and located 10,000 light years away in Sagittarius.

The Solar Spectrum (NOAO)

If you could catch a rainbow and put it under a microscope you would see that it was not a continuous blend of colours. Along the width of it would be seen, scattered irregularly, dark patches. Atoms and molecules in the Sun’s atmosphere pick out specific frequencies of light and absorb them, diminishing their intensity by comparison. This images shows the spectrum of light from the Sun stretched out to make these absorption lines visible. We use the reverse of the idea (emission lines) when we make coloured lights. For instance, we excite sodium atoms to emit a signature orange light in street lamps. In this image you can see two prominent dark bands in the yellow-orange section which are the absorption due to sodium.

Update to This Entry

The Sombrero Galaxy in Infrared (Spitzer)

By looking at things in different wavelengths we can see much more than meets the eye. This image is a perfect example. Just as with the Horsehead image above we are seeing cooler material. This time it is dust in the Sombrero galaxy. The red ring is a thick band of dust encircling the whole galaxy. In the optical, this dust ring is what gives the Sombrero its distinctive black, obscuring line.

Oddities in the Orion Nebula (Hubble)

Deep within high resolution images of the Orion Nebula taken by Hubble we can see dark blobs. When you take a closer look you can see that these are like little flattened blobs. Some show a dim, red glow at their centres, others are just dark. These are proto solar-systems.

The red glowing is a protostars attempting to burst through and the dark disks are thick dust regions where one day planets may form. 6 billion years ago, this is what our Solar System may have looked from very far away.

HARP is the Heterodyne Array Reciever Programme and consists of a 4×4 grid of supercoducting detectors capable of detecting the submillimetre wavelgnths at which star formation seems to be best observed. ACSIS is the AutoCorrelation Spectrometer and Imaging System and is a scomples of electronics and processors which analyse the HARP data, as well as data from other instruments. When attached the 15m JCMT dish this enables researchers to study the motion of gas.

The instruments produce a 3D ‘cube’ of data. Essntially andi mage which has a third, wavelength, dimesion. Different molecules give off radiation at different wavelengths and also the motions of gas can slighty affect the precise wavelength valuesd as well. These two factors allow not only the chemical make up of the cloud to be determined but also the movements of those chemicals within the cloud to be traced.

HARP and ACSIS allow astronomers to see the motion of this gas with a clarity and precision not previously available at these wavelengths. Together they give the JCMT the powerful ability to record information in three dimensions. Unlike the previous generation of receiver systems, HARP/ACSIS can produce camera-like images of the sky across thousands of adjacent wavelengths simultaneously; forming a three-dimensional image set called a “spectral cube”. The wavelength dimension permits the telescope to sense molecular tracers as well as to detect the motions of the gas.

“HARP/ACSIS is revolutionising our view of star formation in the galaxy” – Dr. John Richer

The image shown below is of Orion in carbon monoxide. This is just one slice out of the data cube and all the slices together can be combined to form a movie. The gas in the south of the cloud is moving toward the observer, whilst in the north it is moving away. This is because the star forming region at the centre – the familar M42 Orion Nebula – is pushing the gas outward as the stars form inside.

The press release from the STFC also invluded some thoughts from astronomers i8nvolve din the field. Dr. Jane Buckle of the Cavendish Laboratory says: “Commissioning HARP and ACSIS took a lot of hard work and dedication, particularly from the JAC, the Cavendish Laboratory and UK ATC staff, but the new spectral imaging capabilities at the JCMT make this a very exciting time for star formation research.”

Dr. Bill Dent of the UK Astronomy Technology Centre in Edinburgh says:” We often find gas clouds many tens of light-years across containing hundreds of stars all forming simultaneously. With this new system, we can map the structure and measure the speed of the gas that’s forming all these new stars and, furthermore, do a chemical analysis, perhaps looking for regions rich in rare and exotic molecules. Before HARP/ACSIS arrived, it was just not possible to study and understand whole clouds in this way.”

Dr. John Richer has used the JCMT for 19 years to make spectroscopic observations of molecular clouds. “It used to be a painstaking and slow process. Now with HARP’s 16 sensitive detectors, we can take data at a much more rapid rate and begin to answer much more ambitious questions about the formation of new star systems.

You can see the mobie of the data via ths link from the STFC press release.