Observing season 2016-2017

So, observing season 2016-2017 is now finally over! During the season, I was mostly working on my visual deep sky observing/sketching program. Besides this, I was also doing some visual variable star observing during Autumn 2016, but I had to give that up because of too much workload and other things that were demanding my time and energy. Since that, my variable star observing program has been on hold.

But I was able to do quite many visual deep sky observations! When I’m observing, I’m using a cardboard form made by deep sky section of Finnish Ursa astronomical association for sketching and recording the observation. During the season, I completed 86 of cardboard forms like these, though not all of them were unique deep sky object observations. One of these was a comet observation and 2 were unplanned duplicate observations. So I was able to complete 83 cardboard forms with at least one new object! The number of new objects observed for this season is larger than that, but I haven’t been counting objects, but instead of that the number of completed cardboard forms. Each cardboard form counts as one ‘observation’, which may consist of several objects in the field, typically 1 to 4. So when counting like this, the number of new, unique deep sky observations for me last season was 83.

OLYMPUS DIGITAL CAMERA
My pile of completed deep sky observation cardboard forms from season 2016-2017

Here you can see some statistics:

  • Number of new, unique observations: 83
  • Number of observing sessions: 25
  • Number of observations per observing session on average: 3,32
  • Total observing time: 59h 00min 00s
  • Best NELM recorder: 6.6
  • Best SQM meter reading recorder: 21.36

Number of observing sessions in my observing sites:

  1. Ulvila observatory, 11 sessions
  2. Stormälö, Parainen, 6 sessions
  3. Leistilänjärvi, Nakkila, 4 sessions
  4. Friitala, Ulvila, 1 session
  5. Koski, Kullaa, 1 session
  6. Saarijärvi, Lavia, 1 session
  7. Tähtikallio observatory, 1 session

Number of sessions with my instruments:

  1. 10” Newton, 15 ½ sessions
  2. 11” Catadioptric in Ulvila observatory, 9 sessions
  3. 36” Folded-Newton (Astrofox) in Tähtikallio observatory, ½ sessions

half sessions: ½ because during one session I used half of the time 10” Newton and other half of the time 36” Folded-Newton of Tähtikallio observatory

So, that was the statistics for this season. Next season will be beginning in the later half of August 2017. Then I will carry on observing my visual deep sky program, especially Herschel 400 list. I hope, that I could also finish Caldwell- and Hidden treasures -lists, at least to the extent it is possible from Finnish latitudes.

Thank you for staying with me during this season, see you again in August 2017!

 

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My variable star observations from season 2015-2016 – a qualitative mini-review

During season 2015-2016, I was observing variable stars visually with 10×50 binoculars. When observing, I was using a tripod mount. I was mostly doing observations under sub-urban, light polluted skies in Ulvila and Turku, Finland. In both places, typical NELM is about 5,5 and SQM about 20,7 at best. During the season, I made 265 visual observations in total.

The stars that I mostly observed were as follows:

  • EU Del
  • U Del
  • R Aql
  • W Cyg
  • g Her
  • X Her
  • mu Cep
  • rho Cas
  • ST Uma
  • Y Cvn
  • UU Aur
  • W Ori

Besides these, I made also some isolated observations of few other stars. Below I’m going to present you my light curves of these 12 stars that I observed the most during this season. These light curves are produced by the Light Curve Generator of AAVSO, and my observations can be seen as blue crosses plotted against the other visual and V observations of these stars from the AAVSO database. Also the 10 day average curves for visual and V observations is presented. The observations are presented on function of Julian date.

EU Del_2015-2016

U Del_2015-2016

R Aql_2015-2016

W Cyg_2015-2016

g Her_2015-2016

X Her_2015-2016

Mu Cep_2015-2016

Rho Cas_2015-2016

ST Uma_2015-2016

Y CVn_2015-2016

UU Aur_2015-2016

W Ori_2015-2016

Some remarks

  1. In most cases, my observations are well in concert with the other visual (and V) observations, and also the brightness trend is consistent with other observations
  2. Some clear errors can be seen here and there though, but the frequence of errors seem to be rather small
  3. When compared with the other observations, my observations tend to lie in most cases in the brighter part of the light curve, especially if the star is bright. Based on this, it seems that I’m a”bright observer”.
  4. Some stars appeared to be difficult for me to observe, especially rho Cas was like this. There is large scatter in my observations from estimation to estimation, although the brightness of the star barely changed during my observation season, altought I started to observe the decrease of brightness of rho Cas correctly in the very end of my observing season
  5. In some cases, I failed to observe that the brightness of the star had actually changed, for example in the case of mu Cep. In the later part of my observing season, I kept on recording similar estimations of mu Cep, altough it had already started to brighten. I only noted that it had got brighter after having a two weeks long break from observing in the very end of my observing season.
  6. Observing the brighter stars like mu Cep, rho Cas and g Her with 10×50 binoculars was challenging because of two reasons: a) the stars were too bright when observed with this kind of instrument, b) because the distance between comp stars and the variable was too long
  7. My practical fainter limit of working is ~7,5 magnitudes. It is difficult to observe stars that are brighter than 4,5 magnitudes.

Conclusions and actions for next observing season

  1. I’m doing pretty well as a visual variable star observer. My observations aren’t  that bad
  2. For the next season, I’m going to drop some too bright stars off my observing program
  3. I’m going to focus only on those stars, that can be observed throughout their entire cycle with 10×50 binos
  4. I’m going to focus on stars, that vary between ~4 to 8 magnitudes
  5. I’m going to focus on stars, which have their comp stars at reasonable distances from the variable

Light curves from observing season 2013-2014

Here are some of the best lightcurves that I was able to obtain during last observing season, 2013-2014. I was observing mostly some brighter Mira stars but also representatives of few other variable types. All observations have been made visually either with 4” refractor or 10” Newton -type reflector. Observations have been mostly made in Turku, Finland, but also in some other locations.

R Cas
R Cas

R Cas is a Mira -star in Cassiopeia. During last season I observed the brightness of the star to reach it’s maximum, little bit less than 6 magnitudes, and then decline back to minimum, about 11 magnitudes.

T Cas 2013-2014
T Cas

T Cas is another Mira -star in Cassiopeia. It has a characteristic double-humped maximum, but I wasn’t able to observe it during this season. Instead, I observed the star getting fainter during Autumn and the reaching it’s minimum in spring 2014.

T Cep
T Cep

T Cep is a Mira -star in Cepheus. It was very fun and rewarding to follow the ascent of it’s brightness, which peaked in 6 magnitudes in late April 2014.

Omi Cet
Omi Cet

Omi Cet, a.k.a Mira, is the prototype of it’s class, the Mira stars. Omi Cet is a bright naked eye -object at it’s maximum, but it have to be observed by means of  a telescope in it’s minimum. I observed this star during the course of it’s descent towards minimum. It reached it’s minimum light around Christmas 2013.

R Cyg
R Cyg

R Cyg is a Mira -star in constellation of Cygnus. I observed this star around it’s maximum from late July to early November 2013. The maximum waa around August-September 2013. This time the maximum was little bir less than 6 magnitudes.

SS Cyg
SS Cyg

SS Cyg is a dwarf nova -type cataclysmic variable, and it is among the brightest of it’s class. When in outburst, the star reaches magnitude 8, and then descents back to minimum light, about 12 magnitudes. During the season 2013-2014, I was able to catch this star in outburst twice.

V339 Del
V339 Del

V339 Del aka Nova Del 2013 was the first nova that I have ever observed in my life! And what a spectacukar nova it was! It was among the 20 brightnest novas ever observed! The nova appeared in the sky around mid August 2013. It reached it’s peak brightness around 16th of August, then it was as bright as 4,8 magnitudes, and it was also visible with naked eye in a dark place! During the course of Autumn 2013, the star was gradually getting fainter, and it also platooed during September 2013. During the platoo-phase, it’s brightness was descending only very slightly. This object was one of the highlights of the season!

R Leo
R Leo

R Leo is a bright Mira -star in Leo. During the season 2013-2014 I observed this star to ascent from it’s minimum to maximum, and then back to minimum. It peaked around December 2013, then it was as bright as 5 magnitudes.

R Tri
R Tri

R Tri is a Mira -star in Triangulum. I was able to witness a maximum of this star, about 6 magnitudes in December 2013.

Z Uma
Z Uma

Z Uma is a semiregular variable in Ursa Major. It has a pleasently large amplitude for it’s type, which makes it easy to observe. I observed the star to reach it’s maximum in January 2014 and the descent back to minimum.

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.