The possible EXOR GM Cephei is the brightest I have seen it, currently about 12.5mv. It is in the photogenic nebula IC1396 sometimes known as the elephants trunk. GM Cep reaches 16m at minimum and is in an area of vigorous star formation. Observers should note that GL Cep nearby is not a YSO as previously thought but a 'red' presumably foreground object.
I should be able to add points to the light curve tonight -- have submitted BVRI image requests. We'll see what I get by the morning.
Brad Vietje, VBPA
I was watching PV CEP observations, several were done with "R" filters and CV (me). Compared with observations of GM CEP, many are done with filters B and V while it is also a UXOR.
Why and what is best for this kind of star?
Being a purely visual observer, from that point of view I could not offer advice! However PV and GM Cep are in rather different areas. GM Cep is - as well as being several magnitudes brighter than PV Cep - located in an area of heavy obscuration. It's also important to realise that YSOs need simultaneous observations at as wide a variety of filters as possible because they are active over a wide waverange, not just the 'long' end as is commonly supposed. So go ahead and observe with all the filters you have!