V718 Persei / V718 Per
Light curve and phase diagram of the long period (1716 days ref AAVSO VSX and Grinin et al 2008, or 1400 days ref GCVS and Cohen et al 2003 [accessed 2023 May 3]) variable star V718 Persei / V718 Per. This star is within the star forming region IC 348 and might be pre-main sequence.
Note, this star is catalogued as an eclipsing binary of indeterminate type (type 'E', GCVS, AAVSO VSX), although an analysis of the system suggests otherwise (Grinin op cit). (Accessed 2022 May 21)
Note, this star is catalogued as an eclipsing binary of indeterminate type (type 'E', GCVS, AAVSO VSX), although an analysis of the system suggests otherwise (Grinin op cit). (Accessed 2022 May 21)
This light curve was obtained from photometry of 115 images taken with the Open University COAST telescope between 2017 July 9 and 2023 March 14 using a V filter. Phase diagrams using each of the above periods, plus the 'best fit' period to my own results, follow.
The 'best fit' period to my own observations, as suggested by Peranso, is 1609 days and is shown below.
Not surprisingly, this does not favour either of the other two suggested periods, as I have not yet covered even one complete cycle.
That said, the scatter is so large that any period determined from so few observations would be expected to be only approximate. Some of the scatter in the above diagrams is due to the exposures of the COAST system are limited to a maximum of 3 minutes which is too short for an object of this magnitude. Also, the IC 348 nebulosity increases the luminosity of the sky background around the star and the comparisons.
Possibly not an eclipsing binary system, it has been suggested that the variations are due to a single star being periodically eclipsed by an edge on circumstellar disc of material with an irregular distribution of material (Grinin op cit).
A few more years' observations might help to support one of the two suggested periods!
That said, the scatter is so large that any period determined from so few observations would be expected to be only approximate. Some of the scatter in the above diagrams is due to the exposures of the COAST system are limited to a maximum of 3 minutes which is too short for an object of this magnitude. Also, the IC 348 nebulosity increases the luminosity of the sky background around the star and the comparisons.
Possibly not an eclipsing binary system, it has been suggested that the variations are due to a single star being periodically eclipsed by an edge on circumstellar disc of material with an irregular distribution of material (Grinin op cit).
A few more years' observations might help to support one of the two suggested periods!
[This page updated 2023 May 3]