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
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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.