Bmpbmp1975 Posted February 20, 2020 Posted February 20, 2020 (edited) Does anyone have any current updates on Betelgeuse? i notice different articles say different things some say dimming stopped, some say still going and some say it seems to be a little brighter? https://www.forbes.com/sites/brucedorminey/2020/02/17/betelgeuse-has-finally-stopped-dimming-says-astronomer/#397113b67945 The star has been nearly steady in brightness now over the last 10 days,” said Guinan. We could be at minimum brightness now and very soon the star will slowly brighten if it follows its normal 420 to 430 period of pulsation, says Guinan. Or when the star periodically changes its brightness, he says. These periodicities are seen in observations of Betelgeuse as far back to the 1930s, says Guinan. But these most recent dips in the star’s brightness have been profound, he says. Edited February 20, 2020 by Bmpbmp1975
Ghideon Posted February 20, 2020 Posted February 20, 2020 (edited) On 2/20/2020 at 7:25 PM, Bmpbmp1975 said: Does anyone have any current updates on Betelgeuse? Expand Betelbot posts daily updates on Twitter: https://twitter.com/betelbot From today: (Thanks @Strange for link) Edited February 20, 2020 by Ghideon
Strange Posted February 20, 2020 Posted February 20, 2020 On 2/20/2020 at 7:25 PM, Bmpbmp1975 said: Does anyone have any current updates on Betelgeuse? i notice different articles say different things some say dimming stopped, some say still going and some say it seems to be a little brighter? Expand As you can see from the graph the (measured) brightness varies quite a lot over the short term. That means it can be hard to be sure whether the dimming has stopped, is continuing or has reversed. Only time will tell. Anyway, the absolute worst that can happen is that it completely fades from view (but I'm not even sure if that is possible).
Ghideon Posted February 20, 2020 Posted February 20, 2020 (edited) On 2/20/2020 at 7:37 PM, Strange said: That means it can be hard to be sure whether the dimming has stopped, is continuing or has reversed. Only time will tell. Expand Agree. For the impatient there is an animation here: https://twitter.com/betelbot/status/1230237194490720262/photo/1 It's a gaussian process regression intended to show expected future brightness from statistical data. I have not checked it's validity against other sources. Here is a still from the animation, showing 19 fem 2020: Since the measured brightness jumps as Strange says the blue field in the animation is jumping about and it can't be accurately predicted from the data at this time whether the star will brighten or continue to dim. Edited February 20, 2020 by Ghideon added last sentence. Spelling of process
Bmpbmp1975 Posted February 20, 2020 Author Posted February 20, 2020 On 2/20/2020 at 7:37 PM, Strange said: As you can see from the graph the (measured) brightness varies quite a lot over the short term. That means it can be hard to be sure whether the dimming has stopped, is continuing or has reversed. Only time will tell. Anyway, the absolute worst that can happen is that it completely fades from view (but I'm not even sure if that is possible). Expand I thought it can go supernova? also when you say brightness and Simms does that mean it’s going back and forth now?
Ghideon Posted February 20, 2020 Posted February 20, 2020 (edited) On 2/20/2020 at 8:57 PM, Bmpbmp1975 said: I thought it can go supernova? Expand It can and will go supernova if current models are correct. But it can't be precisely predicted when. From your own link: "There are too many uncertainties in the physical properties of star — such as mass, luminosity and age to make a precise guess". Quote Recent studies suggest that the star will most likely explode within the next million years, and perhaps as soon as 100,000 years from now. Expand https://www.nationalgeographic.com/science/2019/12/betelgeuse-is-acting-strange-astronomers-are-buzzing-about-supernova/ Edited February 20, 2020 by Ghideon
Strange Posted February 20, 2020 Posted February 20, 2020 On 2/20/2020 at 8:57 PM, Bmpbmp1975 said: I thought it can go supernova? Expand That is the best outcome. But it isn't likely to happen soon. On 2/20/2020 at 8:57 PM, Bmpbmp1975 said: also when you say brightness and Simms does that mean it’s going back and forth now? Expand I don't know how much the variation is due to measurement error (difficulty measuring the brightness, effects of the atmosphere, etc) and how much is due to the brightness varying a lot. I think one of the effects is convection in the outer layers of the star. This would be very variable.
Bmpbmp1975 Posted February 20, 2020 Author Posted February 20, 2020 On 2/20/2020 at 9:21 PM, Strange said: That is the best outcome. But it isn't likely to happen soon. I don't know how much the variation is due to measurement error (difficulty measuring the brightness, effects of the atmosphere, etc) and how much is due to the brightness varying a lot. I think one of the effects is convection in the outer layers of the star. This would be very variable. Expand Not sure what you mean about best outcome?
Curious layman Posted February 20, 2020 Posted February 20, 2020 On 2/20/2020 at 9:27 PM, Bmpbmp1975 said: Not sure what you mean about best outcome? Expand You wouldn't want to see a supernova? Why not, it's too far away to harm us. Would be the most spectacular thing anybody has seen. Just breathtaking. I would love to witness it.
Bmpbmp1975 Posted February 20, 2020 Author Posted February 20, 2020 On 2/20/2020 at 9:35 PM, Curious layman said: You wouldn't want to see a supernova? Why not, it's too far away to harm us. Would be the most spectacular thing anybody has seen. Just breathtaking. I would love to witness it. Expand Sorry what I meant was if that was best outcome what was worst outcome
Strange Posted February 20, 2020 Posted February 20, 2020 On 2/20/2020 at 9:27 PM, Bmpbmp1975 said: Not sure what you mean about best outcome? Expand It would be spectacular. And we would learn a huge amount about how stars work. On 2/20/2020 at 9:48 PM, Bmpbmp1975 said: Sorry what I meant was if that was best outcome what was worst outcome Expand That nothing interesting happens.
Ghideon Posted February 20, 2020 Posted February 20, 2020 On 2/20/2020 at 10:01 PM, Strange said: That nothing interesting happens. Expand Second worst: Something interesting happens and we fail to learn anything from it.
Bmpbmp1975 Posted February 20, 2020 Author Posted February 20, 2020 (edited) I don’t know when it was constantly dimming I thought maybe but now since it brightens and Dims I think it may be following pattern now if I am judging the graphs right then the past few days or so it dims then brightens right ? Edited February 20, 2020 by Bmpbmp1975
Ghideon Posted February 20, 2020 Posted February 20, 2020 (edited) On 2/20/2020 at 10:15 PM, Bmpbmp1975 said: I don’t know when it was constantly dimming I thought maybe but now since it brightens and Dims I think it may be following pattern Expand I don't quite get that, can you clarify? Do you mean the normal period of pulsation? On 2/20/2020 at 10:15 PM, Bmpbmp1975 said: now if I am judging the graphs right then the past few days or so it dims then brightens right ? Expand There is room for error. I would wait before drawing conclusions. Note the error bars in the data. Edited February 20, 2020 by Ghideon x-post with Bmpbmp1975 edit
Strange Posted February 20, 2020 Posted February 20, 2020 On 2/20/2020 at 10:15 PM, Bmpbmp1975 said: I don’t know when it was constantly dimming I thought maybe but now since it brightens and Dims I think it may be following pattern now if I am judging the graphs right then the past few days or so it dims then brightens right ? Expand It has always varied. Form what I can see in the graph, the variation has decreased as it has got dimmer. (But it might have stayed the same as a proportion. One would need the raw data to know that.)
Ghideon Posted February 21, 2020 Posted February 21, 2020 Here is the analysis for yesterday's data from https://twitter.com/betelbot. @Bmpbmp1975 I interpret it as: According to the statistical method chosen, Gaussian Process Regression, Betelgeuse may be brightening or dimming in the coming days. The data shows that brightening is slightly more probable that further dimming (see dashed blue line). If data had more precision / less spread the light blue field would be narrower and prediction would have less room for error. The data betelbot uses is available at www.aavso.org Here is an example plot for 700 days, showing dimming and brightening over current and previous 420-430 days cycle: https://www.aavso.org/lcg/plot?auid=000-BBK-383&starname=BETELGEUSE&lastdays=700&start=&stop=2458900.834259699&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&visual=on&uband=on&bband=on&v=on
Bmpbmp1975 Posted February 21, 2020 Author Posted February 21, 2020 On 2/21/2020 at 8:21 AM, Ghideon said: Here is the analysis for yesterday's data from https://twitter.com/betelbot. @Bmpbmp1975 I interpret it as: According to the statistical method chosen, Gaussian Process Regression, Betelgeuse may be brightening or dimming in the coming days. The data shows that brightening is slightly more probable that further dimming (see dashed blue line). If data had more precision / less spread the light blue field would be narrower and prediction would have less room for error. The data betelbot uses is available at www.aavso.org Here is an example plot for 700 days, showing dimming and brightening over current and previous 420-430 days cycle: https://www.aavso.org/lcg/plot?auid=000-BBK-383&starname=BETELGEUSE&lastdays=700&start=&stop=2458900.834259699&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&visual=on&uband=on&bband=on&v=on Expand So it’s brightening again
Ghideon Posted February 21, 2020 Posted February 21, 2020 On 2/21/2020 at 7:51 PM, Bmpbmp1975 said: So it’s brightening again Expand No. 1
Bmpbmp1975 Posted February 21, 2020 Author Posted February 21, 2020 On 2/21/2020 at 7:56 PM, Ghideon said: No. Expand So still dimming?
Ghideon Posted February 21, 2020 Posted February 21, 2020 (edited) On 2/21/2020 at 8:34 PM, Bmpbmp1975 said: So still dimming? Expand No. The data available at this time does not tell which it is: dimming, brightening or staying the same. Please read the interpretation above. Edited February 21, 2020 by Ghideon 1
Strange Posted February 21, 2020 Posted February 21, 2020 On 2/21/2020 at 7:56 PM, Ghideon said: No. Expand On 2/21/2020 at 8:56 PM, Ghideon said: No. Expand Or, to put it another way: we don't know. One of the most important (and hardest) lessons to learn in science is that "we don't know" is a valid answer. And often it is the only, or the best, answer we have. All other answers have a level of uncertainty associated with them, so we rarely (if ever) know things for sure.
Bmpbmp1975 Posted February 21, 2020 Author Posted February 21, 2020 (edited) On 2/21/2020 at 8:58 PM, Strange said: Or, to put it another way: we don't know. One of the most important (and hardest) lessons to learn in science is that "we don't know" is a valid answer. And often it is the only, or the best, answer we have. All other answers have a level of uncertainty associated with them, so we rarely (if ever) know things for sure. Expand So that also means all the scoentific information about anything is just a guess, betelguese, black holes, our sun and vacuum decay? Edited February 21, 2020 by Bmpbmp1975
Ghideon Posted February 21, 2020 Posted February 21, 2020 On 2/21/2020 at 8:58 PM, Strange said: Or, to put it another way: we don't know. Expand Good point. I could have elaborated slightly. In this case I would say we don't know yet. It would be surprising if there were no better prediction available in a few weeks or months. On 2/21/2020 at 9:05 PM, Bmpbmp1975 said: So that also means all the information about anything is just a guess, including vacuum decay? Expand No. That is not correct. It's a guess until more data is available. Wy are you in a hurry to draw conclusions?
Strange Posted February 21, 2020 Posted February 21, 2020 On 2/21/2020 at 8:21 AM, Ghideon said: Here is the analysis for yesterday's data from https://twitter.com/betelbot. @Bmpbmp1975 I interpret it as: According to the statistical method chosen, Gaussian Process Regression, Betelgeuse may be brightening or dimming in the coming days. The data shows that brightening is slightly more probable that further dimming (see dashed blue line). If data had more precision / less spread the light blue field would be narrower and prediction would have less room for error. Expand That is a good summary of the methods being used and the results. I would caution that trying to predict future behaviour based (purely) on past behaviour is fraught with all sorts of risks. If we don't fully understand the mechanisms and causes, then it may not be much better than trying to predict the weather based on what it was like yesterday. On 2/21/2020 at 9:05 PM, Bmpbmp1975 said: So that also means all the scoentific information about anything is just a guess, betelguese, black holes, our sun and vacuum decay? Expand No. There is a big difference between a guess and data (even if we know the data is not 100% accurate).
Bmpbmp1975 Posted February 21, 2020 Author Posted February 21, 2020 (edited) On 2/21/2020 at 9:07 PM, Strange said: That is a good summary of the methods being used and the results. I would caution that trying to predict future behaviour based (purely) on past behaviour is fraught with all sorts of risks. If we don't fully understand the mechanisms and causes, then it may not be much better than trying to predict the weather based on what it was like yesterday. No. There is a big difference between a guess and data (even if we know the data is not 100% accurate). Expand What do mean about data and guessing since science is more guessing that being sure? Edited February 21, 2020 by Bmpbmp1975
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