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All observing logs tagged with Sundog

2007-02-01


Location: Billingborough (South Lincolnshire, UK)
From: 2007-02-01 14:00 UT
To: 2007-02-01 15:00 UT
Equipment: Solarscope
Canon EOS 400D
Temperature: 11.6C ...
Dew Point: 8.8C ...
Humidity: 83% ...
Wind Speed: Calm ...
Pressure: 1025.6hPa ...
Notes:

Mostly clear and still day but with some cirrus cloud about. I was about to take the Solarscope out to do a quick sunspot count when I noticed that a faint circumzenithal arc was visible.

Circumzenithal Arc and Sundog

From: 2007-02-01 14:00 UT
To: 2007-02-01 14:30 UT

The circumzenithal arc was rather faint, nowhere near as good or as obvious as the last one I saw. However, I went indoors and got my Canon EOS 400D and tried to take some images. The following image is the best of that bunch. The arc is hard to see, it's in the bottom half of the picture.

Circumzenithal Arc

I then noticed that there was a sundog to the right of the Sun. This was quite bright and had some colour to it.

Sundog to right of Sun

I watched the sundog for a short while as it started to fade. I also noticed that the arc had faded to the point that it was almost impossible to see.

Sun

From: 2007-02-01 14:35 UT
To: 2007-02-01 14:40 UT

Now that the display of the circumzenithal arc and sundog had faded I got the solarscope out and did a sunspot count.

Active area 940 was still visible. It still had 1 large spot (that now had an obvious penumbra) but I could also now count 6 small faint spots in a chain close to it.

New active area 941 was visible with 1 dark spot.

Circumzenithal Arc and Sundog Again

From: 2007-02-01 14:43 UT
To: 2007-02-01 15:00 UT

The circumzenithal arc was visible again, still faint, but noticeable. I had a go at taking some more photographs. Again, it's rather hard to see in the image:

Circumzenithal Arc

The following image is the previous one, heavily processed in an attempt to better bring out the arc:

Circumzenithal Arc

I then noticed that a sundog had formed to the left of the Sun. This one was also bright and had a fair bit of colour to it too:

Sundog to the left of Sun

I watched for a short while longer as the arc and the sundog came and went as the clouds moved and then finally returned to my office at around 15:00 UT.


2006-09-09


Location: Billingborough (South Lincolnshire, UK)
From: 2006-09-09 14:20 UT
To: 2006-09-09 14:25 UT
Equipment: Solarscope
Temperature: 21.6C ...
Dew Point: 10.7C ...
Humidity: 50% ...
Wind Speed: 5.2mph ...
Wind Dir: South East ...
Pressure: 1022.2hPa ...
Notes:

Pretty clear day, although a fair bit of thin cirrus cloud about. Took the Solarscope out to do a quick sunspot count.

Sun

From: 2006-09-09 14:20 UT
To: 2006-09-09 14:25 UT

Active areas 907 and 909 were both still visible with two small, faint spots each.

Active area 908 (the return of active area 904) was also still visible and appeared to look much the same as yesterday with a large umbra and a smaller umbra both sharing a common penumbra.

Location: Billingborough (South Lincolnshire, UK)
From: 2006-09-09 16:25 UT
To: 2006-09-09 16:50 UT
Equipment: Naked Eye
Temperature: 20.9C ...
Dew Point: 13.3C ...
Humidity: 51% ...
Wind Speed: Calm ...
Pressure: 1018.2hPa ...
Notes:

Late on into the afternoon I noticed that a circumzenithal arc and a pair of sundogs had formed.

Circumzenithal Arc and Sundogs

From: 2006-09-09 16:25 UT
To: 2006-09-09 16:50 UT

While sat in the garden and admiring some cirrus cloud that was going over I noticed that a circumzenithal arc and a pair of sundogs had formed. I grabbed my small digital camera and took some images.

The circumzenithal arc:

Circumzenithal Arc

The circumzenithal arc, close up, and heavily processed in an attempt to bring the colours out more:

Circumzenithal Arc

The sundog to the left of the Sun:

Sundog

The sundog to the right of the Sun:

Sundog

I watched the display for almost half an hour, it was constantly changing as the cloud moved on.


2006-04-22


Location: Institute of Astronomy, Cambridge (Cambridgeshire, UK)
From: 2006-04-22 14:00 UT (approx)
To: 2006-04-22 14:30 UT (approx)
Equipment: Naked Eye
Notes:

The following observation was made while sat on the grass out the back of the Hoyle Building at the Institute of Astronomy, while attending Astroblast. Reasonably sunny day with lots of thin, high-level cloud about.

Partial halo around the Sun

From: 2006-04-22 14:00 UT (approx)
To: 2006-04-22 14:30 UT (approx)

Sometime between 14:00 UT and 14:30 UT (I failed to make an exact note of the time) I noticed a "rainbow" effect in the sky. Thinking back I'm not sure I can make a good estimate as to its altitude but I would have said that it was reasonable close to the zenith. It appeared to be a small arc of what could have been a halo around the Sun.

I suspect it was a partial 22 halo although there is the chance it might have been a partial 46 halo. Given that I was busy with other things at the same time I didn't really think to figure out its angular distance from the Sun.

Over a noticeable period of time it appeared to "rotate" around the Sun slightly which would suggest that the clouds responsible for the effect were slowly drifting and that the effect was rather localised.

The colours were faint but obvious and I found that I could see them better with my sunglasses than with my normal glasses.

I took the following two images of the display with the camera in my mobile phone:

Image of partial Sun halo

Image of partial Sun halo

Location: Stamford (South Lincolnshire, UK)
From: 2006-04-22 16:15 UT
To: 2006-04-22 16:45 UT
Equipment: Naked Eye
Notes:

On the way back from Astroblast I stopped off in Stamford for something to eat and, from the park in the middle of town, managed to catch an even more impressive display in the atmosphere.

Display of atmospheric phenomena

From: 2006-04-22 16:15 UT
To: 2006-04-22 16:45 UT

While sat having a bite to eat in the park in Stamford I noticed that there was an even more impressive atmospheric display. At the time I made some short notes and a quick sketch of what I saw; the following is a version of the rough sketch that I made:

Atmospheric display visible from Stamford

The sketch is rough and isn't supposed to show anything to any sensible scale, the angular distances are probably quite off too. The intent was to record the shapes and general locations of what I saw.

Checking with the Atmospheric Optics website it appears that I saw was, starting at the top: a circumzenithal arc with a parry arc below it. To the left and right of the Sun was a pair of sundogs. Both sundogs displayed a tail pointing away from the Sun and the sundog to the left was far brighter than the one to the right. Also, the one to the left had a very obvious vertical arc running through it.

Using the camera in my mobile phone I attempted to image each of the things I saw but all that came out were the following images of the sundogs:

Sundog from Stamford

Sundog from Stamford

Sundog from Stamford

Sundog from Stamford

Unfortunately the images don't really do justice to what I saw, the sundogs were much more obvious than they are in the above images and were also more colourful.


Page last modified: 2013-04-09 09:19:19 UT
Dave Pearson <davep@davep.org>
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