Sunday, 22 December 2013

20131221 - ISON Not Found + the start of a theory

Over the past few days two famous telescopes have been looking for C/2012 S1 ISON.

The Arecibo (the world's largest Radio Telescope in Puerto Rico) reported yesterday that they had found nothing. 

The Hubble Telescope reported late yesterday that they had found no trace of it. Here is a link to their results.

There may be a few bits around, but they would be less than 150 meters in size.

So there is no need to throw any life rafts, Just wreaths :( 

Why and when ISON started to break up is now the question that is being asked and various theories, which need to be tested, are being put forward. My personal theory - unproven - is that sometime in the lead up to the 13th November (perhaps a day or two before) the nucleus of the comet started to become unstable, whether a chunk broke away or it started to crack I do not know. The visible effect is shown in this image that SON@OSC took on the morning of the 13th November. If you look a third of the way along the lower tail you can see a discontinuation. +Padma Yanamandra-Fisher  picked up on this event as soon as she saw the image.

Over the next few days the comet physically changes as can be seen in the following image from the morning of the 15th .

The following day, the 16th, it seems calm down a bit (through cloud).

Morning of the 19th through thin cloud again!

The next event was noticed on the morning of the 22nd. +Charles Bell  pointed this out to me. towards the end of the displayed lower tail there is a branch off - looks like half a feather on an arrow. I think that a day or two before there was another major fracture to the nucleus.

This was the last time I saw ISON . I think by this time the nucleus was fatally flawed and came apart during its near encounter with our Sun.

It is important to recognise that the images of ISON represent only part of the history of the comet. They are, of course, an important resource, especially if and when other images can be added to the time line. I still have a number of images to process and perhaps some of those will add to the story.

Other data now needs to be brought together and analysed. A lot, but not all, of this data has either been captured by amateurs or is in the public domain. A number of amateurs have already started modelling this data, some of which at first glance supports my idea. Until I fully understand this data (and other data), myself I will not present it and only then with permission.

I will be looking to see what the professionals come up with. One thing about of astronomy is that there is always something new to learn.


After a cloudy night, this morning I managed to finds some holes in the clouds and brought the cameras into focus and at dawn take some flats.

Late afternoon we struggled up the observatory hill with the framework for the new roll off observatory to house the new telescope.

This evening is cloudy again :( which was disappointing as Search Light Observatory Network had received a request to record a stellar occultation which would been taking place now. Alas the observatory hill is covered with a damp cloud.

Friday, 20 December 2013

20131220 - All change in the Observatory

As I mentioned in the previous Blog it is time for exoplanets again.

What is an exoplanet (or extrasolar planet)? It is a planet that is in an orbit around a star other than our own Sun :)

I received a few days ago, along with the other Searchlight Observatory Network Observatories, the agreed list of targets and time table from Professor +Svetlana Berdyugina at Kiepenheuer-Institut für Sonnenphysik .

Svetlana has been observing exoplanets for a number of years. It was Svetlana and her team that discovered, a number of years ago, that a planet (HD 189733b) in orbit around HD 189733 is blue. This was later confirmed this year by Hubble observations.

There are a number of different ways to discover and monitor exoplanets. The current project involves known exoplanets using a technique called Exoplanet Transits. This only works with systems that are near to edge on to us. The observation process involves measuring the change in brightness of the host star when an explanet passes in front of it. The techniques involved are similar to those used for variable star observing. I will write, in the near future, a number of Blogs covering the various methods of discovering and monitoring exoplanets :).

Ideally I should have changed the telescope configuration and started some test runs a few days ago, but after a few months of overall good observing nights the weather changed. We have had clouds, we have icy rain and lots of interuptions with the power.

Yesterday's driving rain stopped me from opening the observatory so with the alarm set early I went up to the observatory to check it out. Apart from a few small wet spots and the need to reset the power everything was OK. It was still fairly cloudy but with holes so I managed to see some stars for the first time in days. It was not suitable for imaging properly but decided to take some images of Comet Lovejoy before changing the configuration.

After these were taken it was time to start to change the configuration.

For the past couple of months the ST8 CCD Camera along with its filter wheel has been on the 4" F4 Pentax refractor and the ST7 CCD Camera was on the C14 F11 SCT.

I now needed to swap the cameras over and also reduce the focal length of the C14 by putting in a focal reducer and once done rebalance the telescope and check that the cable will not get tangled up, (four power cables and four data cables!).

That is the easy bit done! The sky or should I say the clouds stopped most other things being done until this evening and daybreak - providing that it is clear.  So hopefully I will be able to refocus the two telescopes and take new sets of dark, flat and bias frames.

N.B. For none astronomers I promise to do a Blog posting in the next few days explaining the reasons why I needed to change the configuration and what are the effects.

There are a number of jobs I can do during the day, some of which are already under way, including producing an observing timetable.

It is now starting to get dark. There are thick clouds on the horizon and thin cloud overhead. Providing the cloud overhead does not get much thicker I will be able to finalise the configuration, otherwise it will be the case of getting up at four in the morning to check if the cloud has gone and if it has to do the finalisation then.

As there will not be much to show image wise with exoplanets, I will be showing images of various objects that I have yet to process, or will be able to take when exoplanet observing is not taking place.

Other work in progress

I am in the middle of getting another observatory up and running. I have building a roll off structure for it and late afternoon we got it up to the observing area ready for cladding. Pictures tomorrow.

The other day

I mentioned in the previous Blog that a drop in power stopped the telescope mount from working for an hour or so. What I did not mention was that the computer and cameras did not stop.

The following image was taken at ten o'clock at night with just moonlight. It will give you an idea of the power of the telescope (4" refractor) and a time controlled CCD camera :) The distance to the buildings is about three miles.

Monday, 16 December 2013

20131216 - ISON - Search and Rescue appears to have failed.

For the past few weeks, very much like when a yacht has been reporting missing, search and rescue have been out looking for this comet in distress.

At the beginning dozens, if not hundreds, of telescopes and binoculars swept the area of sky where the deathly remains of ISON hopefully could be found - but only if the remains were either large or dense enough to be seen.

There were a number of potential sightings by very experienced observers, though these potential sightings were always accompanied with health warnings. There was even a "sighting" report being circulated where someone had misunderstood the date format of a report which was of an earlier observation of the comet.

Everyone of these sightings needed to be followed up .... just in case someone has actually found the wreckage. Like most, I prefer for observers to post potential sightings, than for them to be sat on because of a concern of being wrong. There is always the danger though that they will get picked up by the media and misinterpreted - as is often the case, but we should never allow that to stop us making reports.

One of the good things about amateur observations are that they are distributed as soon as possible. Amateurs know that by putting out these possible sightings they may be able to be confirmed by someone in another Time Zone, before the object(s) have completely left, or are in the vicinity of that field of view.

Soon I expect the obituaries will start to be published telling us as much as possible about the life and death of ISON with the coroners verdict of Lost at Sea - sorry Lost in Space. As with all celebrities, much more will be written and published as more facts are discovered about ISON's life.

We only got to know her in her final years of life and know little of her childhood spent somewhere in the little know Oort cloud.  Someday in the distant future a little of what remains may arrive back at her original home.


I suspect that on posting this, within a day or two there will be more reports of seeing it, but as in real life there will be less suitable resources available to check.

From now on my time will be split, with Exoplanet Transits taking priority, but there will still be plenty of time for comets and other objects :) . This means that future Blogs will cover more subjects, including progress on a new SON observatory.

Wednesday, 11 December 2013

20131211 - A catch up on comet images

As I mentioned in the last post, the reaon for lack of entries it is not that nothing has been happening, but the reverse!

A comment to the previous post exclaimed surprise at the time that processing the images take.

Let us go through a simple outline processing the comet images that I now follow. I will cover an observing run another time.

OK then, I have finished and observing run and closed down the observatory. What next?

On the computer there may be as many as 500+ images from the observing run all held in a directory named after the evening before's date in reverse order. Today is the 11th December 2013, so the observing run that could have started yesterday evening and finished at daybreak today so the directory would be named 20131210.

I then create a number of subdirectories named after the objects I have imaged. Where I have imaged the same object in two different ways then I create two subdirectories. Into these subdirectories I copy the various groups of files. There could be up to a hundred or more image files in each subdirectory.

The images in each of the subdirectories need to be reduced (or calibrated). Data reduction This is to take out inconsistencies. If you want to read more about it here is a link that explains the basics. The reduced files are put into a subdirectory - we do not overwrite the original files as we need to keep these.

After this has been done what happens next depends on what type of observations have taken place on different classifications of objects.

I will now describe what I do for single framed images of comets. My starting point is a folder of reduced images of a comet. There maybe 100 images and at a quick glance you would think that they are all the same, but there are not. A comet is moving against the background of stars. If we looked at each of the images carefully you would note the comet, especially as it gets nearer to the Sun will be in a slightly different position against the stars.

We are interested in the comet - not the stars. Let us say that each of the images is a 10 seconds exposure. We have a hundred and we need to overlay each of the images so that the comet overlays itself and not the stars. A number of programmes can do this, but I have not found one better than Astrometrica . Not only can it stack the comets - called Stack and Track the programme can many other things including astrometery and photometry (where is it and how bright is it).

This exercise leaves me with a single combined image that I can save and its brightness (magnitude).

I can now load this image into another programme and prepare it for submission.

At the moment some of the images are shown here, sent to the British Astronomical Association, shown in a few Facebook groups including Comet Watch and CIOC_ISON and also shortly to the University College London.

We do not delete any of the observations because you do not know when they may be of use. A good example is the UCL where I will be going back in time to find images that meet their needs.  

Here then is a gallery of some of the images taken since the last images until the 7th December:

SON@OSC (Searchlight Observatory Network at the Observatorio Sierra Contraviesa, Granada, Spain)
Observers Tony Angel and Caisey Harlingten
4" F4 Refractor ST8 Clear bin 1x1
FOV 115.5 x 77.7 arcmin
North at top

C/2013 R1 - Lovejoy - 2nd December

C/2013 R1 - Lovejoy - 2nd December
5th December

C/2013 R1 Lovejoy - 5th December

C/2012 R1 Lovejoy - 5th December
6th December

C/2012 R1 Lovejoy - 6th December

C/2012 R1 Lovejoy - 6th December
7th December

C/2012 R1 Lovejoy - 7th December

C/2012 R1 Lovejoy - 7th December

C/2012 X1 Linear - 7th December

C/2012 X1 Linear - 7th December

C/2013 V3 Nevski - 7th December

C/2013 V3 Nevski - 7th December

Monday, 9 December 2013

20131208 - A little something to be going on with

It is not the case that I have had nothing to write about, quite the reverse. I have been observing away :) with a couple of skipped observing periods. Every observing session is generating a good eight hours of processing etc to be fed to the CIOC_ISON group - which has now extended into other comets, +Neil Norman's Comet Watch group and also to be prepared for Geraint Jone's project at UCL. I do promise to post many of the images here of a number of comets - both large and small - in the next day or two.

Last Friday a Comet ISON Followup Meeting took place in the USA. The group I belong to CIOC_ISON was represented by +Padma Yanamandra-Fisher  and Elizabeth Warner who each gave a good talk about the work the group had been doing and especially about the good cooperation between the amateurs and professionals.

This was part of the NASA Comet ISON Observing Campaign.

I was lucky to be mentioned a few times during Padma's talk and one of my images shown. It was very good - Padma's talk I mean and I felt quite chuffed with my involvement through the Searchlight Observatory Network Observatory.

The talk was streamed and recorded so it is possible to visit the site and select the video. Elizabeth and Padma were first on in the second part - Comet ISON Follow-up 2 of 2 the whole set of videos are available here . Geraint Jones of UCL also gave one of the talks. I will be submitting a number of our images for his Comet Tail Project.

Tuesday, 3 December 2013

2nd December morning - Comet C/2013 R1 Lovejoy and C/2013 V3 Nevski and a little on ISON

After nearly a week of cloudy skies I had a good observing run yesterday morning :)

I first went to Comet Lovejoy. I was using the wide field 4" F4 Refractor along with an ST8 CCD Camera. This comet is getting better, brighter and clearer each time I observe it. It was discovered by Terry Lovejoy in Australia, this is his 2nd Christmas Comet and I will say more about him in another post. He is most certainly an astronomer's astronomer. It is visible to the naked eye and well worth looking for.

I had decided that I wanted to image the whole of the comet, which because of its length meant that I would have to take a series of images, starting with its head and working along the tail.

I took them between UT 2013-12-02 5:00:34.063   and  2013-12-02T05:14:50.329 . Each image has an FOV of FOV 116.5 x 77.7 arcmins - north is on the left! You really need to click on the image to see it better!

I took seven images.each 1 minute exposure - no binning - and overlaid them.

Using simple trig the comet as displayed is a touch over 5 degrees in length. It was not until I processed the images that I realised that I had not captured the full length of the tale. I was not able to do a retake this morning, so fingers crossed for tomorrow, but it will need this evening's winds to drop. :( If it is clear then I will do x2 binning but keep the exposure time to 1 minute. That will bring out the furthest parts of the tail. As this will produce smaller images it will make it easier to create the overall image. The comet is moving against the back drop of stars, so I have to move onto taking the next image directly after the previous one, (partially guessing I am moving the right way :) ). so that there is no perceptible change.

As well as the above image I took a series of shorter exposures of the comet head. These exposures are between half a second and ten seconds. I also took a colour image as well. These are still to be processed. I used a series of the shorter images with Astrometrica by Herbert Raab to get a N Magnitude of 8.8

The next comet I images was C/2013 V3 Nevski. It is quite recently discovered - 6th November - by Vitali Nevsky using an 8" F1,5 reflecting telescope. Vitali is no stranger to discovering comets. He, along with Artyom Novichonok, discovered Comet C/2012 S1 ISON.  When discovered it was magnitude 15.1. Fellow CIOC_ISON member +Charles Bell  imaged it on the 14th November and its N Magnitude was 15.6. There had been reports that it had brightened to about magnitude 10 however when I imaged it yesterday morning the N  magnitude was 14.7.

Here is my image taken UT 2013-12-02 5:58:27.454 - FOV 116.5 x 77.7 arcmins - north is at the top. The comet is to the right of centre. It is still quite small, though a short tail has been observed.

I then took a few of Comet Linear and I will put these on next time. After Linear I did try for a couple of others, but my processing has not yet brought them out. They were a bit fainter.

To complete the observing run I finally I went to the the Eastern Horizon to see if I could capture the poor remains of C/2012 S1 ISON, but it was too bright - the sky that is, not ISON. If the weather is OK I will trying tomorrow morning.  Is there anything to see? We just do not know yet.

Before I finish for the night I must mention a particular hang out that you may wish to look at. It is the Comet Festival South Bend Today I watched yesterdays and today's editions. They have good astronomers on there and today's edition - hosted by +Chuck Bueter had +Pamela Gay , +Karl Battams and CIOC_ISON's +Padma Yanamandra-Fisher  (heck I hope I have the links right - if I have not - sorry!). Yesterday's edition was great as well, especially as it had my favourite astronomer, +Alex Filippenko, on.