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.

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