del Cep is monotonically bright ?

Mon, 01/06/2020 - 16:41


I started the del Cep ( ) photometry of my digital photo library from summer 2019. The images are taken on an all-sky camera with an angle of about 140 degrees based on the Canon 350D. During the photometry process I saw that the del Cep brightness was not weaker than 4.2 TG. That's when I decided to look at the AAVSO data and was very surprised! The limits of the star's brightness are now 3.3-4.2 V, while the VSX has limits of 3.49-4.36. The total star brightness is now 0.17 V!  

All the best, Ivan

File Upload
American Association of Variable Star Observers (AAVSO)
Variable + companion

Hi Ivan,

You are giving too much weight to some visual observations, the V range in the plot agrees with the combined (variable plus companion) V= 3.42 - 4.19 given in the VSX remark. The range in the table is for the variable star alone but it looks like people are measuring both stars together.


Dear Sebastian!

Visual observations as very subjective, for this star I do not take into account! I only take instrumental observations into account as having documentary value.  From AAVSO data from 1976 to 2019 it follows that in the "V" band the average brightness of the star changes (monotonically brightens), and there is some change in the limits of the brightness fluctuations themselves at almost constant amplitude. This is a very interesting fact.

All the best, Ivan