South Cheshire Astronomical Society

 
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(Page Updated: 30/07/2016 15:47 )

Solar Project

The descriptions of some of our solar project activities are held on this page in chronological order. To go straight to our latest news, on this page, click on the following link:

SCASTRO March 2015 Solar Eclipse Event

 

INTRODUCTION

The Society has a Lunt Solar Telescope and associated equipment purchased through a Science & Technology Facilities Council (STFC) grant award.

With it we have the opportunity to run astronomy outreach projects during daylight hours such as the recent, 13th July 2013, event in Nantwich town square attracting the attention of the public ranging in age from children to senior citizens.

We would welcome help from anyone who has expertise, or is willing to learn with us. We are very grateful for the help we have had from Keele Observatory solar-scope experts when we have visited them. As well as our members and Keele Observatory, we would like to link our endeavours with other groups involved in astronomy, science and technology.

Features such as sun spots and prominences can be examined through either the eyepiece or through a computer coupled digital camera.

From the technical point of view it is in the matter of processing digital captured image sequences that we find most challenging.

 

Equipment:

  • Lunt LS60THa Solar Scope with B1200 Blocking Filter
  • USB to PC connected digital camera: Imaging Source DFK 41AU02.AS Colour

Solar Observations Images

These image have been captured under control of the public domain application SharpCap.

We are experimenting with the settings and would welcome advice from anyone who has experience.

We would also welcome help in enhancing the image sequences captured with applications such as Registax.
Please Have a go with the sequences listed below.

Click on the Image Sequence Link image to down load a .zip compressed .avi file. Contact us with the the details of settings you have found to be best.

 

Solar image sequences captured 26 May 2013

These are all very short runs each of 50 frames, perhaps too few for getting much improvement with Registax.
We would wellcome advice on cameraSharpCap settings and optimal run duration.

Time Image Sequence File Links SharpCap Settings
18:05 Solar Image

[DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=-2(Auto)
Brightness=36
Hue=204
Saturation=195
Gamma=96
Gain=784(Auto)



18:07 Solar Image [DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=-2
Brightness=31
Hue=204
Saturation=92
Gamma=83
Gain=645
18:10 Solar Image [DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=-2
Brightness=31
Hue=204
Saturation=53
Gamma=83
Gain=606
18:15 Solar Image [DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=-3
Brightness=31
Hue=237
Saturation=13
Gamma=135
Gain=803
18:18 Solar Image [DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=-3
Brightness=31
Hue=181
Saturation=76
Gamma=135
Gain=748
19:19 Solar Image [DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=-1
Brightness=11
Hue=198
Saturation=103
Gamma=186
Gain=320
19:24 Solar Image [DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=0
Brightness=35
Hue=194
Saturation=135
Gamma=63
Gain=363
19:25 Solar Image [DFx 41AU02.AS]
Resolution=1280x960
Frame Rate (fps)=7.50
Duration=6.666secs
Number of Frames=50
Colour Space / Compression=YUY2
Exposure=0
Brightness=35
Hue=194
Saturation=135
Gamma=63
Gain=363

 

Solar image sequences captured 16 Aug 2013

Note each image sequence file is about 1 GB and takes from 15 to 25 minutes to download on average broadband services

Time Image Sequence File Links SharpCap Settings
16:42 Solar Image [DFx 41AU02.AS]
Frame Divisor=1
Resolution=1280x960
Frame Rate (fps)=7.50
Duration (mins) =2:13.333
Number of Frames=1000
Colour Space / Compression=YUY2
Exposure=-8
Brightness=24
Hue=198
Saturation=123
Gamma=139
Gain=365
16:45 solar image [DFx 41AU02.AS]
Frame Divisor=1
Resolution=1280x960
Frame Rate (fps)=7.50
Duration (mins) =2:13.333
Number of Frames=1000
Colour Space / Compression=YUY2
Exposure=-8
Brightness=24
Hue=198
Saturation=123
Gamma=139
Gain=365

article updated: 02/04/2015 22:58

SCASTRO Solar Eclipse 2015 UK Event

On 20th March 2015 we organised an observational event at the Brittles Eric Swan playing fields in Wistaston, Crewe for our members. We also invited the neighbouring junior school to bring children, to join us, under their staff care.

For us in South Cheshire the eclipse started at 8:26 am, reached maximum at 9:32am and finished at 10:41am

Starting at about 8am our members helped set up our equipment and brought some of their own improvisations. The eclipse started at about 8:30 but there was thin cloud and this made it very difficult to align our Lunt solarscope. However, from the start we were able to view through our Light Tec wooden camera obscura solarscope and through improvised equipment such as binoculars adapted to project on to a screen. The children arrived a few minutes before the eclipse maxima. The sky had cleared and we had just managed to align the Lunt. The children selected had been taking part in a school organised 5th year 'Earth & Space' project. They came equipped with solar glasses, small cubical pin hole viewers, made from flat pack kits, and other improvised safe viewers. They were enthusiastic and amazed when they progressed through our equipment to end up looking through the lunt through which not only the eclipse could be seen but, as an unexpected surprise for them, the solar prominences. We in turn were amazed by the ingenuity of the children and there teachers in constructing cheap and safe effective viewing apparatus. The children were very well behaved and hardly needed the expert steering of the staff.

Frustratingly we could not get the computer linked digital camera attachment to the Lunt working. Fortunately one of our members, Carol Davenport, succeeded in taking a photograph by placing her small pocket camera to the eye piece. It turned out well. Below is a cropped unadjusted picture, taken at 09:44am, followed by the same shot with brightness and contrast adjusted so that the turbulent surface of the sun can be seen. In both images the eclipse (at about 12 minutes after maximum) and solar prominences can be seen.

Solar Eclipse 2015Solar Eclipse 2015 adjusted

The red tint is caused by the filter built in to the Lunt (a bit like rose tinted glasses only much stronger and built in). The filter provides strong preference for passing through red light corresponding the hydrogen-alpha emission line. The prominences emit light strongly at this wave length and so they can be seen without being swamped by the light from the rest of the sun which emits light strongly at other parts of the spectrum.

Before the eclipse we learned that one of our members, Carole our committee secretary, would be traveling with her daughter to Iceland on the 20th of March to view the Northern Lights. We advised her to take special glasses in case the plane crossed the path of totality at the right time. On the evening of the 20th we had an email, addressed to SCASTRO Enquiries, from anther passenger on the plane thanking Carole for the loan of glasses. Via Facebook Carole's daughter posted: "The very kind pilot did two loops in Icelandic airspace so that we had two chances to see the eclipse lovely and very clearly from the sky! Thanks easyjet!! ". A link was provided to news and a fantastic photograph by an easyjet flight crew member - here is the link: No, THIS is the best solar eclipse photo | Metro News. In the photo the eclipse at totality can be seen, with stars in the background and the shadow falling on the earth far below. The photograph must have been taken from the flight deck.

On return Carole reported that it was very difficult to view the high in the sky eclipse through the small port windows. People had to practically lie on the floor to get the angle right. She did not mange to see it at totality but did see it at an intermediate stage.

Back to Carol Davenport, she was away for a week or so after, and on her return gave us more photographs she had taken at the event. They were taken impromptu, thru the various apparatus available on the day, with her pocket Panasonic camera.

Here is an array, in time order, of photographs of the sun as the eclipse progresses.

array of eclipse photos

They were cropped from the originals and transformed to compensate for scale, optical rotation, optical mirroring, and perspective. Variations in colouring are due to variations in light filtering and ambient conditions. Variations in quality and pixelation are attributable, depending on apparatus, to variations in: instrument magnification, sensitivity, cloud cover, ambient lighting, camera coupling and camera settings.

Colour code key to apparatus used:

  • Orange: Light Tec wooden camera obscura solarscope;
  • Shades of Green: Projection by binoculars onto sheet of paper.
    • Dark Green: Viewing through the sheet
    • Light Green: Viewing above the sheet
  • Red: Lunt Solarscope
  • No Colour: Taken through filtered solar glasses (the majority)

The maximum looks to have taken place sometime between the pictures labelled 09:29 and 09:32.

Gallery of a selection of Carol's photographs:

juniors for eclipse

Children and staff gathering (time: 09:22)
growing dim / strange light (Eclipse Max minus 10 mins)

Bin pic

Looking obliquely through a sheet of paper at the eclipse projected through binoculars above. (Time: 09:26)

camera obscura

Eclipse image cast in Light Tec camera obscura box (Time: 09:10)

throough dark glasses

Eclipse photographed through special darkened glasses. (Time: 09:32)

Eclipse through Lunt solarscope

Eclipse photographed through the eye piece of the Lunt solarscope. (Time: 09:44)
There are two processed high resolution images taken from this source at the head of this article.

More photoes taken on the scene by Bill Clutton:-

Solar Eclipse Collage - B Clutton of SCASTRO


KEEP WATCH ON THIS SPACE AS MORE NEWS AND PICTURES ROLE IN. SCASTRO MEMBERS AND FRIENDS PLEASE SEND US YOUR PICTURES & NEWS.