Plan for variable star observing for season 2016-2017

In my previous post, I made a personal, semi-scientific, qualitative mini-review on my variable star observations during season 2015-2016. In this post, I’m going to present my variable star observing plan for season 2016-2017.

During observing season 2016-2017, Im going to continue observing variable stars visually with 10×50 binoculars. Based on my conclusions I presented in my previous post, I’m going to make some adjustments to my observing program. During season 2016-2017, my observing program is going to be as follows:

  • EU Del
  • U Del
  • W Cyg
  • X Her
  • ST Uma
  • UU Aur
  • W Ori
  • Y Tau
  • X Cnc
  • RS Cnc

When I was choosing the stars to my observing program, I was considering following criterions:

  1. The star has already long history of observations, and that’s why it is worthwhile to try to extend the already long history of visual observations of the star. Such stars are included in LPV program of AAVSO, and especially in LPV Legacy program. I was selecting my stars from these programs, having emphasis on LPV Legacy stars.
  2. The star is included also in the Binocular -program of AAVSO, meaning that according to AAVSO, it makes sense to observe the star with binoculars
  3. The star is ranking high in the Binocular program of BAA.VSS, meaning that according to BAA.VSS, it is a reasonably good idea to carry on observing the star
  4. The star has suitable brightness range for 10×50 binoculars, and that the star can be observed with these binos throughout the entire cycle of the star
  5. The comp stars are reasonably close to the variable itself, so that it can be easily observed with 10×50 binos
  6. I decided to limit my program to only 10 stars, which I fully commit to observe through to whole season

All the stars happen to be semiregulars of type SRB. Some of the stars are known to be intensively red stars, which can be a challenge for observing. But based of my experience of observing a red star (for example UU Aur) during season 2015-2016, I have a reason to believe, that I can perform observing these red stars well enough.

So, after having a small hiatus from vsriable star observing from early February 2016 to June 2016, variable stars are back in my observing program! The hiatus happened because of my life situation was intensively busy, and in the spring of 2016  I was emphasizing visual deep sky observing. But from now on, I’ll be committing to observing these 10 stars and I’m going to have this small variable star observing program as my top priority! I’m going to also observe deep sky objects visually whenever I have time and energy, but these variable stars are going to be my priority number one!



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