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Indeed. The speed of light is defined to be exactly 299,792,458 m/s but how much more fun it is to quote it in obscure units. I think it is around 1803 giga-furlongs/fortnight. At least a furlong is well defined (1/8 mile or approx 201m). The problem with NTUs is that they are so vague. How tall is a giraffe and what is the volume of a swimming pool? In most cases I don’t really think they help to visualise the object being described.
Owen, I guess the level of inconvenience depends on where you start from! The venue is a few minutes walk from the mainline railway station which is around 2.5 hours from either London or Edinburgh and tickets aren’t that expensive if booked well in advance. As others have pointed out there are several Park and Ride sites around York that would work for a day visit. York is a great city to visit too so you could make a weekend of it although best to stay some way outside the centre on a bus route if budget is limited.
Indeed. If there is an ISO standard giraffe then there aren’t many of them roaming the streets of Chelmsford for reference. At least I have a vague idea of how long a double decker bus is. I’m hoping that the journo that wrote this did it tongue in cheek but it is very difficult to tell…
Len. Good point. There are some good pubs within a few minutes walk. This being Yorkshire I’d have thought that you would be keen to save money by taking your own sandwiches into the pub and sneakily eating them whilst downing a (relatively inexpensive) beer. Perhaps York is too posh for that?
James, I think train bookings are possible three months in advance so they should be available for May 18 from next weekend.
Sorry you can’t make it. I hope to make videos of the talks but we had technical gremlins last time which meant that several of the talks weren’t recorded. Hopefully we’ll have a better run at it this time.
Automation of detection of transients is one of the things that even pros struggled with for a long time but they seem to have got it pretty well sorted now. I remember back in the late 90s helping Tom Boles with this and the main problem was that you had to accept a pretty high false alarm rate in order to avoid missing stuff. At that time it was just more efficient to blink manually.
I’ve got a large C library of image processing functions written over the years. One of them takes two images at the same scale, cross correlates them in the frequency domain to get alignment, attempts to blur the sharper one to get the same median PSF as the other one, normalises and then subtracts. I have to say that it is not brilliantly effective and that in the end I decided that I had more interesting things to do!
The human eye/brain combination takes some beating.
Robin, Impressive spectra given how faint this is. The sky is still getting dark here but the nova is considerably brighter than the 28th. I get 16.7 R tonight compared to 18.0 R two days ago.
There are at least four variable objects blinking on and off when I compare my median-subtracted frame from last night with one from early December. See if you can find them all here.
Tom – I was imaging the Moon during the eclipse, at this point with 5s exposures every 30s but I missed the impact at 04:41:38 by 8s. The timestamps in the attached half-scale images are the start of exposure (note the filenames are when the file was generated which is a few seconds after the shutter closed) and should be accurate to 0.1s or so. If there was another event at 04:42:01 I would have missed that by around 1s.
Clear in Chelmsford at the moment. Live images from my telescope appearing here.
That’s a fun observation. Perhaps it is a test for a subsequent Trump-centred edition where large parts of the world are erased.
I have to admit I let my S&T subscription lapse a few years ago. At the risk of sounding like a very old fogey it used to be a really good magazine that stood way above all of the others but now I think it is just one of many and I seldom found stuff of interest in it that I couldn’t get elsewhere.
As others have said 46P/Wirtanen is exactly where the orbit says it should be but diffuse comets are much more difficult to see than their magnitudes would suggest. Even though this one got to 4th magnitude at its brightest the light was spread over an area several times that of the Moon. I did see it a few times from my light polluted garden in Chelmsford using 11×80 bins but it wasn’t easy. Other people at dark sites did get a much better view. With these diffuse comets it is usually better to use binoculars than a telescope.
Yes, I’m using two 902H2s and I think the majority of other observers are using these cameras too. The 910HX is probably the best SD camera around at the moment but they are rather expensive.
Very nice radio results. As Alex said the weather this side of the Irish Sea has been pretty rubbish in January so far but I was lucky to get a few hours of clear sky a just the right time on the morning of Jan 4th so picked up quite a few Quads on video. It clouded over around 02:30 so, according to your plot, I picked up the strongly rising activity but not quite the peak.
Voyager-1 is currently 3.3 times further away (21.7 billion km vs 6.6 billion km) so the path loss is 10.3dB more. It has an 18W X-band transmitter (NH is 12W) and a larger HGA (3.7 m vs 2.1m). This gives an overall spacecraft EIRP increase of 6.7dB. On the negative side Voyager uses an old FEC code (rate 1/2 concatenated vs rate 1/6 Turbo) which loses around 2.5 dB. Overall the link is around 6 dB worse. I believe that Voyager 1 currently supports TM rates of up to 600 bps to the 70-m DSN stations so this would imply a margin of around 2dB for all losses in that case (it is currently far from solar conjunction).
