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SS Cyg in outburst!


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23 minutes ago, michael.h.f.wilkinson said:

Got it in the little 80mm APM triplet. I even spotted it with the 15x70 bins. I put it at about magnitude 8.7, just a tiny bit fainter than the magnitude 8.6 comparison star in the little triangle surrounding it on the AAVSO chart.

cool! Congratulations!

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22 minutes ago, SilverAstro said:

Thanks for the alert.

Guess what - I was imaging that region 3 nights ago and 2 nights ago but not last night grrrr! not much prospect tonight either :(

I understaand your frustration. It might not be entirely lost. It will also burst out in about 2 or 3 months anyway!

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On 01/09/2016 at 22:14, Cinco Sauces said:

It might not be entirely lost. It will also burst out in about 2 or 3 months anyway!

Yes ++

But, the GOOD news ( are you all sitting comfy this could take some time :) ) :--

--- is that last night I had a surprise, an astonishingly clear sky for a short while, milky way was outstanding, the Great Cygnus Rift a beaut !  , , what an exceedingly silly place to put a variable - almost directly overhead ! good view of 75 Cyg though ( an excellent point to hop from ), noted nearby stars with my binos (crick in neck as well) and came indoors to identify with CduC. Found SS, assigned it m8.4

The BAD news is :--

-- that I spent an age getting AAVSO chart sorted and to my horror I found there was a m8.6 there :( Should have paid more attention to Michael's post :(

Then spent another age doing -2.5log(-10^0.4*8.6 + etc Gulp !  If there were two close by of about 8.6 I should have seen something about 7.8 or 7.9 Arrrg and by then it was cloudy so could not check.

Did I blunder or has it faded already, did it fall off a cliff last night ?

 

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I do not think you were way off. SS Cyg has begun to fade indeed. I think the 9.7 estimate is a bit anomalous. I observed at 2210, GMT+1, and estimated it to be 8.8 +/- 0.2. It was just a bit fainter than the 8.6 comparison star in the chart. Changes can occur vary rapidly during the rise and fading phases, so depending on where you did your observation it might be perfectly OK.

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17 hours ago, SilverAstro said:

Then spent another age doing -2.5log(-10^0.4*8.6 + etc Gulp !  If there were two close by of about 8.6 I should have seen something about 7.8 or 7.9 Arrrg and by then it was cloudy so could not check

 

When one does visual estimations it is not necessary to calculate that way. This is for instrumental observations whre the response is linear, not like the eye. Visual is very simple and, some might say, a bit coarse and imprecise. However with a lot of practice one might calibrate onself and become quite precise. I am still learning, checking my estimates against those of others and still quote my estimates within 0.2 mag error bounds, which is my estimate of my average deviation for the colective measurements of others.

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4 hours ago, Cinco Sauces said:

When one does visual estimations it is not necessary to calculate that way. This is for instrumental observations whre the response is linear, not like the eye. Visual is very simple and, some might say, a bit coarse and imprecise.

Thanks for all your interesting thoughts CS. Yes, I agree :) and about the anomalous result as well. My only reason for mentioning it was not for its absolute value but only as an indication ( in advance of a few more days worth on the plot ) that it may nolonger be constant - that it may have started its dive into oblivion again. The imprecise nature of visuals that you mention leads peeps to make much more widely varying estimates on the move than during a constant phase.

It was all my fault for not explaining myself proper ! and for not explaining my reason for the use of the formula. It is all because of my rubbish aged eyes and my 10x50 binos :-

I wanted a way of estimating what I should see if I was seeing an  m8.6 star combined with a mag? star in my fuzzy unresolved vision. So I chose to calculate what two m8.6 stars would be.

From the internet I got a formula ( which I could not remember in full when I typed my previous post on account of my computer crashing meanwhile and it being late at night ! couldnt remember where all the minus signs went off top of head :) )

Thus :  Mcomb = -2.5log(10^(-0.4*M1) + 10^(-0.4*M2)) which, for M1=M2=8.6 gave me a combination which would be brighter than m8 and which would have made it comparable with the nearby ref of 7.5 in CdC , later I found that ref star to be 7.7 on AAVSO , so my combined 8.6+8.6 would have looked much like that 7.7 and it deffo was not, much less in fact. So I was then happy that either SSCyg was on the slide or that I had blundered, so I went to bed happy-ish :)

My obs sat neatly approx 1/2way between the CdC8.0 and a CdC8.6 being fractionally closer  to the 8.6 Hence my m8.4 Sadly AAVSO does not give magnitudes for those two CdC stars :( so my m8.4 is for my own internal curiosity and further research :D  at next apparition !

You are right about visual estimates and in my case I would not try to do better than m0.5 or even m1, in isolation ! and the single AVSSO ref of 7.7 is only good enough for me to say the combo was much more faint - not how decimally fainter, I'll leave that to the AAVSO boys !

Phew,,,,, anyway, it kept me out of mischief, thanks :)

 

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6 hours ago, SilverAstro said:

Another Grand Thought for the SGLcollective : if CdC xhip (Hipparchos?) and AAVSO cannot agree betwix 7.5 and 7.7 for a const. ref. star, then there is not a lot of point to us trying to do 0.1 on a variable :laughing4::angel8: !

This is a good point. I believe that the reliability of a given record hinges on the number of contributions made by independent observers. Although very experienced and keen visual observers might probably be capable of high accuracy estimations, I guess that the large majority are not that accurate. I would thus trust a long and large (in terms of number of obs) record like SS Cyg, Chi Cyg, or Mira, just because the vast number of observations contributed by a large number of independent observations increases the likelihood of the average. On the other hand, stars with very few observers and sparse observations are possibly very unreliable (e.g. S Sge, a star I have been using to learn how to estimate).

I am also aware that Stellarium (Hipparcos?) and AAVSO often report different magnitudes. I still prefer the AAVSO ones because in case I decide to submit my observations to the database, these can immediately be correlated to the same stars. If the magnitude value is revised or, worse, the comp star is shown to be variable itself, then there might possibly be a way to revise the reported values or correct someway.

Cheers!

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7 hours ago, SilverAstro said:

Another Grand Thought for the SGLcollective : if CdC xhip (Hipparchos?) and AAVSO cannot agree betwix 7.5 and 7.7 for a const. ref. star, then there is not a lot of point to us trying to do 0.1 on a variable :laughing4::angel8: !

They may be reporting different magnitudes (visual, bolometric, or photometric in different bands). These may differ depending on the colour of the star.

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13 minutes ago, Cinco Sauces said:

This is how SS Cyg has behaved during outburst until now. For me it seems clear that it is starting to fade back to its normal 12 mag state, a path also worth observing!

screenshot.png

It may just have started the descent, but is still quite bright. Should the skies clear, I might have another go. I am pleased to see my observation falls quite neatly in the cluster late on 09/01. I apparently haven't lost my touch. I used to do a lot of variable star observing as a teenager, and could often spot subtle differences in stellar brightness. Clearly I can still do it despite lack of recent practice.

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39 minutes ago, Cinco Sauces said:

This is how SS Cyg has behaved during outburst until now. For me it seems clear that it is starting to fade back to its normal 12 mag state, a path also worth observing!

screenshot.png

Fascinating stuff, better than TV  ! Clearly an anomalous obs by "MOD" and not the explanation for my dilemma, since my obs sits * right in the cluster just before 09/03 00:00 (midnight!)

So, latest theories  - (1) my eye was seeing either one or the other at any one moment, not summing/integrating both and my brain was ignoring the 8.6 star or (1b) falsely judging it to also be 8.4

or (2) the 8.6 star was not seen at all, only SS Cyg at 8.4  ?

* more by good luck than good judgement  :)

With any luck the next apparition will have it at a more comfortable altitude for binos :D and in a long spell of clear air, ha !

 

 

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  • 2 weeks later...

The saga continues. I wrote a few days back that SS Cyg was starting to fade, while @michael.h.f.wilkinson wisely pointed out that it was still bright. True words.

Now we are in the 14th day of the outburst, and our friend is still up and bright, gladly shining mostly brighter than mag 9 like the most normal thing in the world :happy11:

It seems that it had some local low 3 or 4 days after reaching the maximum, but it has stayed up during roughly two weeks. Cool! Isn't it?

 

screenshot.png

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  • 9 months later...

I am taking the liberty of using this older thread with the same topic to alert those of you who enjoy nighttime darkness at this time of the year that SS Cyg is right now in outburst!

 

 

screenshot.png

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  • 7 months later...
  • 9 months later...

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