This week we show the light curve of one of the objects from our latest paper “A survey for variable young stars with small telescopes: IV -Rotation Periods of YSOs in IC 5070”, which got accepted for publication in MNRAS this week. The object is called 2MASS J20505630+4419262 and known as a variable star. Not much is known of the source, other than the distance of 476pc. This places the star slightly in the foreground to the main IC5070 cluster.
In our paper we find that the star has a period of 1.8893d. The amplitudes of the variations are larger, the shorter the wavelength of the photometry. They range from about 0.6mag in the U-Band to 0.1mag in the I-Band. Thus, the periodicity has been missed (or a different period estimated) in previous papers.
In a next paper we will identify the stars in our sample where the periodic variability can be attributed to spots on the surface. We will then determine the properties of these spots, i.e. their size and temperature. The shape of the phase folded data in the plot, shows a flat minimum for about 1/3rd of the period and a symmetric ‘hump’ of increased brightness. This, together with the different amplitudes could indicate a warm/hot spot on the surface of this star. We will see what the detailed calculations in the next paper say. Stay tuned …