2005 YU55 animation

Asteroid 2005 YU55 passed the Earth on the night of the 8/9th. Astronomer BJ Fulton used an LCOGT telescope in California to make an animation of the 400 metre diameter asteroid over the hours as it went by. The fly-by is compressed into less than 30 seconds for this animation.

The asteroid has also been observed by ESA's Herschel Space Observatory even though it was moving pretty fast through the field of view. They haven't released the data yet but I'm sure they will in due course.

Posted in astro blog by Stuart on Friday 11th Nov 2011 (10:51 GMT) | Permalink

The e-MERLIN road trip

In summer 2010, during my mini retirement, someone at the Jodcast had the idea to do a road trip of e-MERLIN. e-MERLIN is a network of radio telescopes spread around England and the Welsh borders with the headquarters at Jodrell Bank in Cheshire. The array is 217 km in diameter which would mean hundreds of miles of driving and there was a suggestion to do the whole array in one day. A few of us Jodcasters were up for the challenge and we took along some students from the University of Salford to be the camera crew. In the end we had two cars full of people.

The e-MERLIN network CREDIT: Stuart (yes, really)

The day arrived and we convened in central Manchester outside the Jodrell Bank Centre for Astrophysics bright and early. Well, early if not bright. Here is the result:

Being split between two cars we took along some walkie-talkies so we could stay in touch (yes we had phones but walkie-talkies are more fun) and gave the two cars the call-signs "pulsar" and "quasar". At one point, leaving Defford, we overheard two kids who happened to be on the same channel pretending to be pilots landing a plane. If you were those kids we are sorry that we freaked you out by pretending to be air-traffic control. It was very funny though.

The road trip was a lot of fun but also exhausting - more so for Jen who was driving and presenting. Having used the telescopes it was great to visit them all and it helped me appreciate the size a bit more. Plus, we got to do the science documentary cliché of "going on a journey".

Posted in astro blog by Stuart on Thursday 10th Nov 2011 (22:37 GMT) | Permalink

/observations version 2

Last year I wrote about the /observations project I worked on at LCOGT. The aim was to provide a web page for every public observation taken using the LCOGT network of telescopes and also provide ways to browse the images. It worked well but I knew there were improvements to be made. This week we've released version 2.

The first improvement is to allow you to browse by type of astronomical object. That is really easy as an idea but isn't so straight-forward to make work. Every observation needs to be classified. With 2 telescopes that would already be a big task for a person to do but would become a full-time job as the network expands next year. So, it had to be something that could be done automatically. Thankfully, one of my other projects - LookUP - came in useful.

When a page is created for an observation, LookUP tries to work out what the object is by querying a range of astronomical databases. If it detects an object type it stores the AVM category code for it. Once that works, it's relatively easy to make the categories browseable. The result is that you can get observations of globular clusters, emission nebulae, galaxies etc.

There are some objects that get misclassified or don't get identified and that is mostly down to the names assigned to them by the observers. Unfortunately, I can't insist that the observers use recognizable names. Nevertheless, my auto-categorization seems to work fairly well.

The second improvement was to the advanced search form. As well as being able to search by title, telescope, wavelength filter, and date, it is now possible to search by object type, by observer and by position. The position search took a bit of effort as I had to find an efficient cone search algorithm so that comparing against 60,000+ observations didn't make the results slow. Aside from some issues around the input formats (declination has to be in decimal degrees at the moment), this seems to work.

Heat map
Heat map of recent observations with the Faulkes Telescope North and Faulkes Telescope South CREDIT: Stuart/LCOGT
As a fun extra I created a heat map that shows roughly where all the telescopes have been observing during the past month. Reassuringly, it shows that nobody has observed too near to the Sun*.

I have some ideas for more improvements but they'll have to wait a while.

* Which they shouldn't be able to do anyway as the control interface shouldn't allow it

Posted in astro blog by Stuart on Thursday 10th Nov 2011 (16:07 GMT) | Permalink

Asteroid 2005 YU55

Asteroid 2005 YU55 will pass the Earth and Moon over the next 24 hours or so. It is roughly 400 metres in diameter and the closest it gets to us is something like 300,000 km. The closest it will get to the Moon is roughly 240,000 km. That is a long, long way away from either despite what an excited person in my blog comments insists. It won't hit the Earth and it won't hit the Moon.

Although 2005 YU55 passes within the orbital distance of the Moon, it doesn't actually get between the Earth and Moon at any point. It goes past them both. Also, space has a third dimension and 2005 YU55 actually goes quite a bit above the Earth and Moon plane when you look at it from the side. I still don't understand why some people are insisting it could hit the Earth or the Moon. It couldn't. It isn't in the right place or heading in the right direction.

Most asteroids are too far away to be able to measure their sizes directly or see detail on their surfaces from Earth. 2005 YU55 is now close enough for some Earth-based telescopes to get a good look. The Goldstone radio telescope has already produced radar images of it and plenty of others will be ogling as it goes by. In a couple of days ESA's Herschel Space Observatory (~1.5 million km away from Earth in the opposite direction than the Sun) will also have a look. Herschel has to wait that long because until then Herschel would have to look in the direction of the Earth and Sun to see it and that wouldn't do its instruments much good at all.

Can you observe it?

The asteroid is moving pretty quickly and its apparent position varies depending on where you are on Earth due to parallax. As 2005 YU55 is only about 400m across, it'll be roughly 11th magnitude. That means it'll be about 100 times fainter than the limit of the unaided eye. Nevertheless, I think I'll look up and wave goodbye as it carries on its merry way.

Posted in astro blog by Stuart on Tuesday 08th Nov 2011 (00:51 GMT) | Permalink
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