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  #21  
Old 29-01-2020, 09:04 AM
N1 (Mirko)
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Interesting stuff. Could that be because for the colour to register "correctly" (for that particular observer), the image on the retina must have a certain size and not just be a point? Like when you defocus a star in the telescope to better see its colour
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  #22  
Old 29-01-2020, 09:36 AM
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There must be a bit of "spilling" of light over adjacent rods and cones... so precise focussing probably is not a big factor.. or not?
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  #23  
Old 30-01-2020, 02:07 PM
JohnF (John)
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https://www.sciencealert.com/a-look-...ously-vanished
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  #24  
Old 30-01-2020, 02:08 PM
JohnF (John)
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https://www.space.com/27844-missing-...-theories.html
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  #25  
Old 30-01-2020, 02:13 PM
JohnF (John)
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Bojan, I am just quoting what others are saying about stars that have gone missing. Do not know myself, and m not attempting to explain this. And whether these websites are genuine do not know.

https://www.iflscience.com/space/mis...tion-theories/
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  #26  
Old 30-01-2020, 03:33 PM
Saturnine (Jeff)
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Had some clear sky last night and had a long look at Betelgeuse, comparing it to Bellatrix and it certainly looked a smigden ( technical term ) fainter . Whereas 2 weeks ago Alpha Orionis was definitely slightly brighter than Bellatrix.
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  #27  
Old 30-01-2020, 05:32 PM
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John,

I had a look at all three links.

The first link is about records (catalogs, photographs), older and newer.
Two later ones are about discrepancies between theory and observation (chemical composition of stars in globular clusters can not be explained by current theories of clusters evolution).
The terms "missing" and "disappearance" of stars is applied in somewhat "plastic" manner.... Taken out of context, they could be misleading to "people from street".
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  #28  
Old 31-01-2020, 08:27 AM
N1 (Mirko)
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Quote:
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John,

I had a look at all three links.

The first link is about records (catalogs, photographs), older and newer.
Two later ones are about discrepancies between theory and observation (chemical composition of stars in globular clusters can not be explained by current theories of clusters evolution).
The terms "missing" and "disappearance" of stars is applied in somewhat "plastic" manner.... Taken out of context, they could be misleading to "people from street".
Absolutely. Deducting that stars that aren't observed have "gone missing" because a theory predicts their observation is turning science on its head.

Back on topic, I watched Orion appear in the evening twilight sky last night, and could detect Bellatrix before Betelgeuse. Watching the two in averted vision later (thereby reducing effects caused by their different colour) also gave Bellatrix a small but reproducible advantage.
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  #29  
Old 17-02-2020, 08:21 AM
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ESO Telescope Sees Surface of Dim Betelgeuse

Some cool highres pics from the ESO.here.
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  #30  
Old 24-02-2020, 02:06 PM
sutekh (M)
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The supernova watch is cancelled -- Betelgeuse is brightening again:

https://www.spaceweather.com/

--sutekh
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  #31  
Old 24-02-2020, 02:13 PM
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Quote:
Originally Posted by sutekh View Post
The supernova watch is cancelled -- Betelgeuse is brightening again:

https://www.spaceweather.com/

--sutekh
Well, yesterday night I saw Faintelgeuse still slightly fainter than Bellatrix.
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  #32  
Old 11-04-2020, 04:26 PM
N1 (Mirko)
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The star looked just about reinstated to me tonight. 92% of its usual brightness I'm told. This return to normal looks as impressive as the fainting.
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  #33  
Old 11-04-2020, 05:03 PM
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The star looked just about reinstated to me tonight. 92% of its usual brightness I'm told. This return to normal looks as impressive as the fainting.
Same here, last night... (today it's raining)
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  #34  
Old 10-05-2020, 05:12 PM
Saturnine (Jeff)
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Thought I would revive this thread for anyone who may be curious, have noticed over the previous 2 evenings that Betelgeuse has brightened considerably and is now almost as bright as Rigel, so that is a bit of a turn around from a few months ago.
Going by the plotted graphs on the AAVSO it is now back up to mag. 0.5, from the 1.6 at its faintest back in Jan / Feb.
Wouldn't have expected the star to brighten that quickly given its approximate 150 to 300 day period.
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  #35  
Old 11-05-2020, 06:45 AM
N1 (Mirko)
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Yes that was more rapid than the decline. Certainly an interesting object to watch, and no scope needed!
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  #36  
Old 11-01-2021, 06:07 PM
cannon_gray (Cannon Gray)
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Betelgeuse has reduced its brilliance to 38 percent of its normal brightness.
https://icdn.lenta.ru/images/2020/02...dcd13e3789.png
On the surface are huge convective cells, up to 60 percent of the star's diameter, creating bright and dim regions. The appearance of such a cell explains why some areas on the star's surface are bright, and most of the surface is dim.
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