Hello all i'm here in the uk just lookin at Betelgeuse and for some reason it looks redder tonight has anyone any idea why? thx
Right, it's far more probably that the increased redness is a function of atmospheric conditions or some terrestrial source rather than any actual change in the star. It's notoriously difficult to predict when a star will nova, and when it does, things usually happen very fast, so there's no way of knowing "oh, Betelgeuse is gonna nova in the next 48 hours, keep your eyes peeled."Betelgeuse is a red star... it always looks red because it's surface temp is quite cool.
When Betelgeuse supernova's, we will know it. It will be brighter than a full moon due to it's relatively close proximity with Earth.
Editing because I just noticed you said 'redder'. Betelgeuse will likely get more red over time, but that's not a change we'd be able to observe with the naked eye. If it's looking redder to you, I'd assume it's just atmospheric conditions where you're at or possibly light pollution in your location. Or, your mind is just playing tricks on you.
I don't think in a human life anyone can see a red giant becoming redder just a bit. You saw it redder that night probably because of the atmosphere. I myself one everning saw quite a red moon and it turned out there was a road construction several miles away.Hello all i'm here in the uk just lookin at Betelgeuse and for some reason it looks redder tonight has anyone any idea why? thx
Observations by the observers of the AAVSO indicate that Betelgeuse probably reached magnitude 0.2 in 1933 and again in 1942.
At minimum brightness, as in 1927 and 1941, the magnitude may drop below 1.2. Betelgeuse is a semi-regular pulsating red super-giant. It is believed to be at least the size of the orbit of Mars and at maximum diameter may possibly equal the orbit of Jupiter. The star is one of the largest known; spectroscopic studies show that the diameter of the star may vary by about 60% during the whole cycle, a difference considerably larger than the radius of the Earth's orbit!
But you are not likely to notice a night to night difference, as it varies from a magnitude of 0.3 to 1.2 with a peak to peak cycle of 14 years or so. It is somewhat of a slacker when compared to a star like Mira, which can go from a magnitude of 10.1 to 2 in 100 days, actually going from being not visible to the naked eye to easily noticeable to the naked eye. (It then takes 200 days to dim back down to 10.1)I'm not sure if this is why you saw it as redded than usual but http://www.aavso.org/vstar/vsots/1200.shtml" [Broken]