Betelgeuse dim #Betelgeuse

Waldemar Falcone

Rod, I meant just a way to know the shape of the curve to use in your comparison. But, as you say there are other problems, like focusing.

I took some pics last night but, to the camera, the brightness difference is greater. The camera always shows more contrast then the eye...

Whoever, Betelgeuse looks incredibly red! I wonder if the dimming has made it more colourful?

De: ROD LEVENE <rodlev@...>
Enviado: sábado, 18 de janeiro de 2020 19:10:54
Para: Waldemar Falcone <W.Falcone@...>
Assunto: Re: [AstroLeeds] Betelgeuse measurement
Hi Vad.
Ta. for the suggestion. I'll have a good think about it. The star is so close to Bellatrix' brightness at the moment, that I think that's sufficient. I'd have to hand- make the apperture stops because You need high magnification to get a reasonable thickness of image and that requires a telescope. Also, I dare say that my focusing won't be perfect each time and neither would air quality be each night, which could spoil the thickness / magnitude relation. Comparing with Bellatrix is safer.

On Friday, 17 January 2020, 15:55:56 GMT, Waldemar Falcone <w.falcone@...> wrote:

Bravo Rod,

May I suggest a calibration method? To let the star trail in front of a photogaphic lens, then repeat the experiment for 1 stop  darker, 2, 3, etc
Each stop is 1/2 of the light i.e. 0.753 magnitudes. Then you'll have a graph of thickness vs magnitude. It doesn't get round the colour problem.