Leisure Battery Powerbank

Hi Folks

Here’s my latest creation. I wanted a heavy duty power tank but I’ve always struggle to find a suitable box. Most plastic boxes have the handle on the lid, so all of the weight of the box is held on what are usually quite flimsy plastic catches. Anyway, after some searching I found this box on eBay for £19.99. The handle is attached to the main body and is made of substantial aluminium tube:-


I’ve fitted an inverter, a double mains socket with 2 x 5V 2.4A USB outlets, and 3 x 12V outlets. I picked up a second hand battery for £20.

The box is pretty sturdy and I’m going to put a plywood board on the lid. It is then strong enough to stand/ sit on


Plain polarised images of thin microscopic sections of a meteor and meteor impactite Zeiss IM35 microscope 29/6/2017

Microscopes do not just have to be used for biological specimens. Today, I used my Zeiss IM35 microscope to look at thin sections of a meteor and meteor impactite – the latter is the rock around the site of a meteor impact.

Polarized light waves are light waves in which the vibrations occur in a single plane. The process of transforming unpolarised light into polarized light is known as polarization. There are a variety of methods of polarizing light (www.physicsclassroom.com/class/light/Lesson-1/Polarization)

The meteor views should chondrules – these are areas of crystal formation believed to be created early in the solar system formation and can be seen as round inclusions within the meteorite structure with internal crystalisation (square structures).

The impactite shows rock crystals (square shapes) in a more diffuse matrix – the latter is composed of glasses – molten rock (now solidified of course) as the result of the energy realised by the impact. The crystals within the glasses represent areas of the rock that did not melt, perhaps due to a different chemical structure with a higher melting point.

I then tried hand-holding a single linear polariser under the condenser (the lens that focuses light from the illuminator on to the slide) and twisting it to see what effect this created. Different crystals (formed from different chemicals) bend light differently and this changes the coloured pattern seen with the polariser and hence this technique can be used to identify what the chemical components of the rock are – but don’t ask me what my images show! I don’t know! Polarising microscopes in professional labs use crossed polarisation which involves a linear polarising filter bother before and after the specimen – I am still thinking of a way to add the second polariser to my set up.

All following images were taken using Zeiss IM35 microscope, 20W LED www.retrodiode.com illuminator (I needed the extra light especially when using the polarising filter), hand-held 55mm linear polarising filter under condenser, 3.2mm and 10mm objectives, Bresser MikrOkular camera.

In future posts, I hope to be able to image these specimens in crossed polarised light.


Microscopy Chondrule rich unclassified NWA meteorite (from North African Sahara desert in 2016) 29/06/2017

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-3.2x-objective-single-linear-polariser-290617II.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-3.2x-objective-single-linear-polariser-290617I.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-single-linear-polariser-290617I.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-plain-light-290617-details-of-chondrule-structure.bmp (below – this is the same field of view as the following pictures with a polarising filter):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-rotating-singe-linear-polariser-290617-position-I.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-rotating-singe-linear-polariser-290617-position-II.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-rotating-singe-linear-polariser-290617-position-III.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-rotating-singe-linear-polariser-290617-position-V.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-rotating-singe-linear-polariser-290617-position-VI.bmp (below):

Chondrule-rich-unclassified-NWA-meteorite-Sahara-Desert-2016-10x-objective-rotating-singe-linear-polariser-290617-position-VIII.bmp (below):

Photos of microscopic images of thin sections of impactite

Gardnos-Impactite-3.2x-objective-single-linear-polariser-290617I.bmp (below):

Gardnos-Impactite-3.2x-objective-single-linear-polariser-290617II.bmp (below):

Gardnos-Impactite-3.2x-objective-single-linear-polariser-290617III.bmp (below):

Gardnos-Impactite-3.2x-objective-single-linear-polariser-290617IV.bmp (below):

Gardnos-Impactite-3.2x-objective-single-linear-polariser-290617VI.bmp (below):

Gardnos-Impactite-3.2x-objective-white-LED-light-290617I.bmp (below):

Gardnos-Impactite-3.2x-objective-white-LED-light-290617II-showing-glass.bmp (below – glass is black amorphous material between crystals):

Ritland-impactite-3.2x-objective-white-LED-white-290617I.bmp (below):

Ritland-impactite-3.2x-objective-white-LED-white-290617II.bmp (below):

A Challenge to the Quarkers out there – – –

To quote Holmes: “When you have eliminated the impossible, whatever remains, however improbable, must be the truth”

I have been musing over my recent post concerning the apparent lack of fine detail on my solar images (https://roslistonastronomy.uk/h-alpha-question-puzzle). While they are comparable with other LS35 images I have seen, and with GONG images, they do lack the fine detail you sometimes see in other published images. I am not 100% convinced it isn’t a stacking artifact, but setting this aside what else could it be?

Daytime observing suffers from atmospheric turbulence big-time, and you need a fast shutter speed to reduce this. I wonder if I simply have not got the sensitivity to employ an appropriately fast speed.

Simple optics would inform me that a Quark with an 80mm scope has the potential of being at least 2 stops faster than my LS35, everything else being equal.

So, the challenge to the Quarkers – I know that there are at least 3 of you out there, and one of them at least (mentioning no names, Andy), has a Mikrokular, the same as I use:

Can you get finer detail than I get using a fast shutter speed? Simple stacking is likely not to help, as the images you stack will be slightly displaced due to the turbulence, thus blurring the final stack.



Eagle nebula yet again again

I was thumbing through my copy of the amateur astronomer’s bible – “Burnham’s Celestial Handbook” – and came across this image of the Eagle Nebula. Coincidentally, it is almost exactly the same field of view as the image I posted a couple of weeks ago. As such it makes an interesting comparison with the 8″ SCT / PD camera version. It was done, of course, in the pre-hubble, pre-digital age. It is however, done with the 200″ Palomar telescope!

I don’t think the 200″ will fit onto my window-sill!

Skywatcher Startravel 102 refractor plus AZ3 mount for sale

HI folks

I recently acquired this scope as I know a couple of RAG members were looking for one.  It’s a 4” widefield scope that’s very versatile for everyday use and is a great ‘light bucket’. I bought one for myself just a couple of weeks ago for use as a solar scope and a widefield astrophotography scope. It’s very light and manageable and will also take 2” eyepieces which makes the view amazing

In summary, It’s a 102mm doublet refractor with a short focal length of F4.9 and the whole lot including tripod only weighs just over 3kg

It’s in virtually new condition with barely a mark on it. There’s a very minor paint scuff on the dew shield as if someone has leant it against a wall. I’ll clean that off though. The objective lens is as new

The scope owes me £90 and that’s what I’ll let it go to a genuine RAG member for their own use. If there are no takers, I’ll be putting it on eBay for over £100. I’ll put a better eyepiece or two with it

Here’s a good review of this mode that backs up my own experience of itl:-



I’ll bring it along to the meeting on Friday


Ed Mann

07802 350187


Thats a bit better! (Prominence 26/06/17)

The hoped-for half-decent prominence display arrived – if a day later than expected!

It looked good on GONG yesterday, but we were clouded out, Some of it was still there this morning, albeit through high-altitude cloud.

So here are 4 images and an animation over a period of about half an hour from the window-sill. Since the disc won’t change much in that time, I used the same disc image in all 4 – the one imaged at 08:03 UT. The animation repeats 10 times.