A cumulonimbus cloud with magnificent mammatus 26.6.2012

Observed phenomena: Mammatus clouds

Date: 26.6.2012
Time: 20:23-20:40
Observing place: Ulvila, Finland
Observing method: Photography
Technical information about photographing equipment: Camera: Canon EOS 1100D, lens: Canon EF-S 18-55mm IS

On 26th of June, I observed a really magnificent cumulonimbus cloud with some impressive mammatus! The beginning of this display was a humble one, but it developed into a really good show! The cloud was evolving quickly, and it was possible to see the mammatus to grow and change shape! You just don’t see clouds like this every day!

Picture 9. Cumulonimbus cloud with well-developed mammatus observed in 26th of June in Ulvila, Finland.
Cumulonimbus cloud with well-developed mammatus observed in 26th of June in Ulvila, Finland.
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Observing season 2011-2012 – a retrospective view

Overall view of the observing season

Summer solstice 2012 happened just a few days ago here in the Northern Hemisphere (21.6.2012). It means that the days are getting shorter and nights are getting longer again. It also means the change of observing season for me, the moment of summer solstice is the boundary between the seasons for me, and thus it’s now a good time to reflect the season that just ended.

I started my observing season in the Cygnus -summer meeting of Ursa, which was organized 21.-24.7.2011 in Jokioinen, Region of Kanta-Häme, Finland. The date of my first observing session was between 22.-23.7.2011. It was an early start for a season for me, but the season also ended early. The date of my last season was 6.-7.3.2012. I’ll explain later, why it was like this.

During the season, I was travelling a lot (for work). This made the season different from the previous ones, when I had been observing mostly in Stormälö, Parainen. During this season, my main observing place was the neighbourhood of Kaanaanmaa, in town of Sodankylä, Lappland Region, Finland. Besides that, I made lot’s of observations in temporary observing places all over northern Finland.

During the just ended season, I observed mostly variable stars. There are two main reasons for that: 1. the increase of my interest in observing them, 2. the lack of opportunities for observing in a good, dark sky site. My main observing site in Sodankylä town was rather light polluted – but it was still possible to observe variable stars there. Doing meaningful observations of deep sky objects there was nevertheless almost impossible. Nevertheless, I did also some deep sky -sketches, of which you can see example in picture 1.

Picture 1. Messier 38 observed 26.-27.2.2012 with L102/1000mm @ 40x in Kersilö, Sodankylä

Closest good dark sky site was located 15 km north of Sodankylä town close to village of Kersilö. The Kersilö observing place couldn’t be much more closer to perfection – it was really a dark place with really open horizon to every direction and easily accessible! The place was much like my observing place in the Stormälö island in the Archipelago of Turku. The place in Kersilö was also a gravel pit – only the use of the pit was different – in Kersilö the pit was a gravel quarry still in somewhat active use, whereas in Stormälö the pit is a motocross -track. Unfortunately I wasn’t able to observe there in Kersilö as much as I would have wanted to because of my work.

And then few words about why my observing season ended so early. The main reason for early end was the increase in my interest in atmospherical phenomenae like aurora borealis. In late February and early March 2012 there was aurorae in the sky of Sodankylä during many nights. During those times I made the decision to by my first SRL -camera, Canon EOS 1000D for photographing the aurorae. Then the focus of my hobby was slipped from variable stars to aurorae and other atmospheric phenomenae. Then I decided to end the observing season (of the dark sky objects) and to fully focus on observing and photographing aurorae.

Few words about observing conditions

During the season, I was mostly observing in rather poor, and cold conditions. The average SQM of the season was 19,5 and average NELM was 5,43. The best SQM that I measured was 21,45 which I recorded during one night during the change of month between September and October in Torinkylä, Sotkamo, Kainuu Region, Finland. The best NELM that I estimated was 6,9 and it happened during one really dark night without aurorae in my Kersilö site close to Sodankylä.

I produced the value of SQM with following procedure: I measured SQM three times in a row from zenith and then averaged those numbers. During one session, I might have done several measurements like this, if that was the case I just picked the best average for the value of SQM for that session. The way how I did estimate the NELM was like this: I draw all the stars that I could see in the vicinity of Ursa Minor to a paper – and then checked the magnitudes of the most faintest one that I had drawn – that gave me the value of NELM for that session.

During the season, coldness and aurorae were making observing difficult during many nights. The coldest temperature where I was observing was -23 °C, warmest was +14 °C and the average was -6,21 °C. The snow came 16.11.2011 in Sodankylä, and the observing season ended well before the melting of the snow. Aurorae were flickering in the sky during 14 nights.

It would have been possible for me to do some observations in April while I was in Lapinjärvi doing the induction period of the civil service that I’m accomplishing now – but then I just didn’t felt like observing but rather just admiring the sky with naked eye. I did also organize some public star viewings for the others who were there in the induction period with me.

More general thoughts about the season

During the just ended season I made observations constantly during the season without having the midwinter break that I used to have often during recent seasons. It meant that the amount of observing sessions grew remarkably – during this season I had 38 observing sessions in total! Usually the number has been arond 15-20. The number of observing time was 68h and 36 m. During the season, I counted as session all nights when I did at least an observation of observing conditions. The minimum requirement for an observation of observing conditions was SQM and NELM measurement. Also the fact that it was possible for me to observe in the yard of my apartment in Sodankylä positively affectd the number of observations and observing sessions during the season.

During the season that just has ended – I also took my first astrophotos, I took thise photos while I was observing aurorae. Example of these photos you can see in picture 2. I took these astrophotos with my recently bought Canon EOS 1000D and with Canon EF-S 18-55mm lens. I’m still going to observe mostly visually, but I think that I’m still going to take also some astrophotos also in the future now when I have a decent camera for that!

Picture 2. Moon photographed 6.3.2012 with Canon EOS 1000D and Canon EF-S 18-55mm lens.

Lunar pollen corona 8./9.6.2012

Observed phenomena: Pollen corona
Light source: Moon
Origin: Pine pollen

Date: 8./9.6.2012
Time: 01:20-01:50
Observing place: Ikaalinen, Finland
Observing method: Photography
Technical information about photographing equipment: Camera: Canon EOS 1000D, lens: Canon EF-S 18-55mm, L80/400mm

I was driving back to Seitseminen, and I decided to have a break in Ikaalinen. Meanwhile, I gazed the sky for noctilucent clouds, but I couldn’t see anything. Instead, I was able to observe a rather rare lunar pollen corona! The pollen species that caused this pollen corona, was propably pine pollen. Pollen coronas are common phenomena in high latitudes during summer, but lunar pollen corona is a rather rare phenomena.

Moon pillar 7./8.6.2012

Observed phenomena: Halo phenomena
Light source: Moon
Origin: High clouds (cirrostratus)
Observed halo forms:

  • Moon pillar

Date: 7./8.6.2012
Time: 01:00-02:10
Observing place: Turku, Finland
Observing method: Photography
Technical information about photographing equipment: Camera: Canon EOS 1000D, lens: Canon EF-S 18-55mm

While observing noctilucent clouds, I observed also a Moon pillar. Sun/Moon pillar is almost an everyday -halo form, but you don’t see Moon pillars so often in summertime, at least not here in high latitudes!

Picture x. Moon pillar observed between 7th and 8th of June in Turku, Finland.
Moon pillar observed between 7th and 8th of June in Turku, Finland.

7./8.6.2012 First noctilucent clouds of the season!

Observed phenomena: Noctilucent clouds
Observed NLC forms:

  • I (Veil)
  • IIb (Bands with sharply defined edged)
  • IIIa (Short, straight and narrow streaks)
  • IVb (Simple curve(s) with angular radius of 3 – 5 degrees)

Brightness of the NLCs: 2 (clearly detected, but having low brightness)
Colour of the NLCs: pale blue
Areal extent of the NLCs: 1/4 of the sky

Date: 7./8.6.2012
Time: 01:00-02:10
Observing place: Turku, Finland
Observing method: Photography
Technical information about photographing equipment: Canon EOS 1000D

The first NLC’s of the season! This display was a small-scale one, and the NLC’s were rather faint, although clearly visible. While observing NLC’s, I observed also a Moon pillar.

A halo meets a pollen corona 7.6.2012

Observed phenomena: Halo phenomena, pollen corona
Light source: Sun
Origin: High clouds (cirrostratus), pollen of birch
Observed halo forms:

  • Sun pillar

Date: 7.6.2012
Time: 20:35
Observing place: Turku, Finland
Observing method: Photography
Technical information about photographing equipment: Camera: Canon EOS 1000D, lens: Canon EF-S 18-55mm

On 7th of June 2012, a pollen corona (caused by pollen of birch) and a halo (sun pillar) coincidentally appeared together in the evening in the sky of Turku, Finland. Both of these phenomenae are very common, but you don’t see them together every day!

Picture 2: Sun pillar and pollen corona were visible together in the sky of Turku in the evening of 7th of June 2012.
Sun pillar and pollen corona were visible together in the sky of Turku in the evening of 7th of June 2012.

Transit of Venus 6.6.2012

Observed phenomena: Transit of Venus
Type of observation: Negative
Date and time: 6.6.2012, 04:00-07:50
Observing place: Parainen, Finland
Observing conditions: Cloudy sky

The historical transit of Venus was happening behind clouds!!! Yes, the horrible truth is, that in my observing site, the sky was completely cloudy during the transit. I tried to observe the event in Stormälö, which is an island within the municipality of Parainen, in the Archipelago of Turku, Finland.

There were some holes here and there in the cloud cover, but that wasn’t simply enough that it would have been possible to see anything, so I have to make a negative observation from this one. I have to admit, that I’m disappointed, I was so prepared, and everything was so well planned and everything should have been perfect…but then Mother Nature had some different plans..well, I guess life goes on after this and there will be plenty of celestial phenomenae and events to be seen! Hopefully having better luck next time (althogh it won’t be on observing transit of Venus, but something else..)