Extracts from the Old Blog

I began the first version of this blog soon after I decided that I would take early retirement, but while I was still working. Looking through the archive showed lots of broken links and lost images, but I thought I would share some of the posts that might still be of interest. 

18 Jun 2017

Apologies for the long gap in posts. We have been trying to move house, so lots of things have gone on hold, including this blog. It is all taking longer than we expected, but the blog will be re-launched, and probably redesigned, when we are finally in our new home. Thanks for your patience.

20 Sep 2015 -- Chi Cygnids

A new meteor shower has been (provisionally) recognised and my meteor camera is playing a small part. Firstly, meteor observers around the world received a request that we should carefully check our data following a report of an “outburst”. This is not as spectacular as it sounds, simply that observers had noticed a number of meteors from the same part of the sky – too many to occur by chance.

P. Jenniskens, SETI Institute, reports the detection of an outburst from a new Jupiter-family comet shower, the chi Cygnids (given IAU number 757 and
abbreviation CCY). Martin Breukers and Carl Johannink first noticed five
nearly identical orbits in multi-station video observations of the CAMS
BeNeLux network in the observing interval Sept. 14d19h23m-15d03h35m UT.
Partial results from the CAMS California network add four meteors in the
observing interval Sept. 15d03h10m-15d12h45m. The nine meteors detected
appeared between Sept. 14d21h and 15d11h UT (solar longitude 171.54-172.08
deg). The geocentric radiant is at R.A. = 301.0 +/- 2.2 deg, Decl. =
+32.6 +/- 1.6 deg (equinox 2000.0), with velocity v_g = 15.1 +/- 0.9 km/s.
The median orbital elements are (N = 9): q = 0.949 +/- 0.003 AU, a = 2.75
+/- 0.40 AU, e = 0.655 +/- 0.041, i = 18.6 +/- 1.6 deg, Peri. = 209.9 +/-
1.9 deg, Node = 171.64 +/- 0.23 deg (equinox 2000.0).

Confirmation of the outburst was found in the near-real time CMOR radar
observations (P. Brown et al., University of Western Ontario), which are
posted at website URL http://fireballs.ndc.nasa.gov/cmor-radiants/. The
24-hr averaged maps showed a small concentration of radiants at this
position during the observing period 15d05h15m-15d20h15m UT.

We were asked to analyse and send in video observations from around 15 September. I had already sent mine. Jakub Koukal (from the Czech Republic, who co-ordinates EDMOND the European database of meteor observations) then sent an email to Richard, another member of UKMON:

 … now i have one orbit of 757CCY (20150914_202235) between your east camera (Wilcot E) and Horley SE. After collecting all data, it will be time for recalculating elements. I found overall 51 orbits in EDMOND database from year 2007, with another outburst in 2010. This means that this shower is annual, with low activity between returns of potential parent body (comet from Jupiter´s family), and with outburst during perihelion passage of potential parent body (~5 years) – something like Draconids or Leonids. In attachment is confirmation (provisional) of this shower, based on current data, which i have.

It looks as if the Chi Cygnids is a small meteor shower which peaks every five years to coincide with the return of an (as yet unidentified) comet which leaves debris in its orbit. If this is eventually confirmed, one meteor observation from my camera will be among a hundred or so which were used to identify the shower.

New meteor showers are being recognised all the time, partly as a result of good data from observations made with simple video equipment. It is a minor discovery. It will not change the world, but in a tiny way, has changed our understanding of it. I am pleased to have been part of real science, with lots of other amateurs and a few professionals co-operating around the world. That’s quite a good feeling!

9 Aug 2015

I stepped outside to watch the International Space Station pass over. I love to watch it. Its stately movement across the sky is beautiful, and thinking about what it means is important, I think. As it moved away eastwards I saw the sudden flash of a bright perseid meteor below it. This was a classic perseid. Blue colour and with a little explosion at the end. All over in a moment, but lovely.

14 Feb 2015

Songs allow birds to mark out a territory, which protects the resources they need to breed. The song is a challenge to other birds of the same species, but also prevents conflict because birds who do not wish to challenge for the territory can avoid it. Peak activity for birdsong in our climate is crepuscular – in the time around and after dawn and again in the evening. The dawn (and dusk) chorus, where birds of many species sing, is one of the glories of nature and one of the most powerful signs of spring.

It is rather difficult to pinpoint when birdsong begins again. Robins, for example, sing a little all through winter. It is a sound of hope in the darkness and also reflects that Robins maintain a territory through the winter. Some species will begin to sing in mild weather, but stop again if the weather worsens.

This year, the first day I heard a substantial amount of bird song was on 27 January. I noted that not only did I hear a Robin, but that there was a great tit (whose song is very monotonous) and several blackbirds singing in the dusk.  In 2014, I experienced something similar on 8th January – weeks earlier. It was much milder in 2014, of course.

Last week, here and at College on the South Downs, there were a couple of days with lots of birdsong, which I am hearing much better now I have hearing aids to help with high frequencies. There were lots of thrushes singing at College – quite wonderful.

8 Nov 2014

My meteor video system captured sprites early on the morning of 8 November 2014.

Sprites are one form of transient luminous event or upper atmospheric lightning. In the upper atmosphere, very high above active thunderstorms, there are various forms of electrical discharge (sprites, elves, blue jets and even gnomes and pixies!) that are poorly understood and which were not even recognised until the last 20 years or so. In the last few years, it has been realised that video systems designed to capture meteors may also capture these fleeting phenomena which seem to occur at similar heights to meteors. Early this morning, my meteor camera caught two (and possibly three) sprites associated with thunderstorms that were over Northern France and the English Channel (120 – 150km away from here) at the time. I am thrilled to have video of one of the atmosphere’s most elusive sights.

Jet

At 03:20 the system captured a “columnar sprite” or possibly a “blue jet” (Clearly visible in the lower centre of the image captured from the video). As I look at the video in detail (frame by frame) I can see a very faint general flash along the lower right of the screen one frame (125 second) before the sprite appears. I think this was the very distant lightning reflected in clouds that were just below the horizon here and possibly from some clouds that are just visible in the image, between here and the storm. (The video camera is extremely sensitive, so this seems possible. Lightning is easily bright enough to be seen from 150km away at night if you are high enough. I was once thrilled to watch from the window of an airliner at night as lightning coursed backwards and forwards through a line of towering African thunderstorms. The captain reassured us that we were over 100miles away from them). The sprite lasts three video frames or 3/25th second, with only one frame being bright as shown in the image. A blue jet is emitted from the top of the thunderstorm cloud, so this is more likely to be a column sprite – an emission high in the upper atmosphere (perhaps up to 100km) above the storm.

The video shows a very much fainter sprite happening about 15 second before this one, to its left and lower down.

At 03:37 (see main image) the system captured a classic “carrot” sprite – very clear and bright. Again, it is possible to see a brightening along the horizon, which I assume to be from lightning, about 125 second before the sprite appears. This sprite appears on four video frames (425 second in total). The central column appears first then the “carrot”. Like lightning, sprites are a very short lived phenomenon.

Such sensitive video systems are very noisy – the backgrounds look like snowstorms, and trying to convert the video to web format makes it even worse. I will try to process a viewable video and share it. On my computer, it is possible to work through frame by frame to see the details. The sprites are fairly bright. If you had been looking in exactly the right place (and had you eyes open and focused at the split second the sprites occurred) you could have seen them with the naked eye.

I have reported the sprites to researchers at Bath University, as well as to the UK meteor network.

15 Aug 2014

I am now running a video meteor observation system and am proud to contribute the data to the UK Meteor Observation Network (ukmon). There is a basic cctv camera, fixed so that it is pointed SSE and up towards the sky, housed in a proper weatherproof case. The video is fed to a cheap usb video capture card and then to the same PC that runs the weather station. This runs software from the sonotaco group in Japan. The software receives the video and records it continuously, discarding it continuously 30 seconds or so later unless it has detected specific kinds of change in the shot – i.e. a meteor travelling across the frame. When this happens, the recording is sent to a file and details of the time are logged. Later, other software is used to analyse the meteor trail to calculate its exact position against the sky. When the data is shared, software is used to match observations of the same meteor from more that one site. This allows highly accurate positions to be calculated for the meteor and even allows its orbit to be determined.

It is surprising how many meteors the system captures: well over 200 in the six nights it has been running (which have included quite long periods of cloud). It helps that this is the peak of the perseids meteor shower. Although the full moon has interfered, I have been delighted to see how many meteors have been captured and down to about magnitude 2.

As well as video, the system captures a snapshot of the meteor. All snapshots, and details of all the meteors captured, are at ukmon

1 Aug 2014

July has been an almost perfect summer month this year. We had lots of sunny, warm and dry weather but also a few thundery breakdowns, which included a few classic summer thunderstorms here. We avoided the flash flooding and other nasty consequences that hit others and so were happy to see them go past. It now looks as if things are going to change as we go into August, though we are unlikely to be too wet here.

Southern England can be oppressively humid in the summer, but this has been fairly manageable in the last few weeks.

The weather station is fully set up, calibrated and operational. I cleared all the data at midnight to remove false readings (e.g. “rainfall” recorded by jiggling the sensor when putting the weather station in place) and so that the data is genuinely comparable from day to day. The weather station is in proper operation from 1 August 2014.

16 Apr 2014

After more than a week of very hard work, there is real progress in the garden.

The greenhouse is fully fixed and functioning, with tomatoes, aubergines, cucumbers and a melon all growing nicely, along with some mixed salad leaves.

Outside, the deep beds are in position and filled with lovely soil that I bought in. I planted out cabbages, beans, peans and sweet peas, courgettes and shallots. There are raspberry canes growing well. About a quarter of the garden now looks like a cared for and proactive area. Much more to do, but a good start has been made.

5 Apr 2014

I spent about an hour and a half in the garden, beginning the long process of bringing it under control again. Things have been much too busy at work for a long time for me to do much more than cut the lawn, so there is much to do.

Today, I cut back the grape vine that had taken over the greenhouse and turned the cuttings into mulch. I think I am about half way to getting the greenhouse back into a useable state, but I will have to replace some glass and do some other repairs as well as clear out the weeds. Even if we only have some tomatoes in grow bags, that will be pleasant, and then the greenhouse can be there for the winter.

As I was clearing, I discovered a blackbird nest, sadly complete with four eggs.

2 Mar 2014

For the first time in a very long time, I decided to set up the telescope and try to image the supernova in the galaxy M82 before it fades into invisibility. It took me a while to remember how to set things up, and this was the first time I was using a mac for astrophotography, so all the software was new to me. Even so, I managed to get everything working, though not particularly well.  I am pleased that you can actually see the supernova, although the image I made is poor. It is approximately magnitude 11.7 right now – fading away. The explosion of a supernova is almost beyond imagination. It usually outshines the whole of the rest of the galaxy at the peak. The star has exploded, which is why a supernova does not last long in the sky.

16 Feb 2014

The internet has quite a lot of discussion about the meteor I saw. It seems to have fallen above the English Channel and so was probably about 50 miles away from me.  It also seems to have been brighter than I thought: just showing how light polluted this town has become.

15 Feb 2014

I saw a very bright meteor this evening, at about 6:30pm. The sky was clear and it was dark, but with just a ghost of light left in the sky. At first, I thought I was seeing a firework, but I soon realised what it must be.

It was significantly brighter than Jupiter, but certainly did not light the sky or cast a shadow, and it appeared as a thin streak, coming down almost vertically and growing quickly in apparent size. It is hard to judge how large it became – still small but definitely an object and leaving sparks behind it. The whole thing lasted less than a second and just disappeared – no explosion or final flare up though it was becoming brighter until then.  I was standing at the Brighton road, Vicarage Lane junction in Horley and the meteor seemed to be coming down over the building nearby so to my south-west, with the end of the trail slightly to the left (east) of the beginning. When I first noticed, it was high – perhaps 80 degrees or so in altitude and it was still at least 60 degrees when it disappeared. I suspect this all means it was relatively close, but impossible to tell.

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