First & Second Flare

[andrew s]

After about 18 hrs (4600 images) of monitoring V833 Tau with no flares I swapped to HIP25953 M4Ve last night with out much expectation as there forecast was for cloud.

However, to my surprise it flared. I still have to process the spectra but here is the discovery plot of the intensity of the zero order with time  v two comparison stars . Each exposure is 100s through a SA200 grating. I will post the spectra once they are reduced.

Regards Andrew

Caption date wrong it was the 14th

 

Edited December 29, 2019 by andrew s
PS added

[JeremyS]

Congrats, Andrew! Really interesting result. Looking forward to hearing about the spectrum.

[robin_astro]

Fantastic !  Good to see the system up and running. A 50% increase in flux in what, a couple of minutes?  You would not want to be living on an exoplanet round that star. 

Cheers

Robin

[Gasman]

Nice one Andrew, do these flares have periods or just occur anytime?

Steve

[andrew s]

23 minutes ago, Gasman said:

Nice one Andrew, do these flares have periods or just occur anytime?

Steve

They are unpredictable.  People have looked for relationships between intensity and the time between flares etc. but none has yet been found.

Regards Andrew 

[andrew s]

Still to process the spectra ( work in progress) but here is a gif of the event. Blink and you will miss it! Regards Andrew

[Merlin66]

Well done Andrew, very impressive!

 

[andrew s]

Here are the spectra of the rise phase of the flare. The smother black spectra is the average of the 20 spectra before the flare. Each exposure was 100s with 2.8 seconds download time. The increase in intensity in the UV end is about 5 times the non flare level. Giving the filtering due to the cadence it all took place in some 200s! As Robin commented you would not want to live too close.

The fall phase is much slower and I have sill to process the spectra.

Spectra processed in BASS with a linear wavelength calibration, instrument response from a HD34203 spectra and Pickles reference and filtered to match the sharpest HD3403 spectra as they are over sampled.

.

Regards Andrew

Edited December 22, 2019 by andrew s

[robin_astro]

Qualitatively remarkably similar to the DN Tau event but perhaps rather hotter looking at difference in the spectra between quiescence and maximum 

http://www.threehillsobservatory.co.uk/astro/spectra_42a.htm

Cheers

Robin

[andrew s]

@robin_astro yes very similar, although in the M dwarf case hydrogen beta and gamma grow strongly but don't seem to grow in your DN Tau flare. It will be interesting  to see how they develop as the flate subsides.

Regards Andrew 

[robin_astro]

11 hours ago, andrew s said:

@robin_astro yes very similar, although in the M dwarf case hydrogen beta and gamma grow strongly but don't seem to grow in your DN Tau flare. 

Regards Andrew 

Very true. (In the DN Tau event the excess flux was effectively a good match to a black body curve with no obvious features.)  

Cheers

Robin

[andrew s]

A second flare. I promise not to post any more unless they are significantly different. 

Regards Andrew

Edited December 29, 2019 by andrew s

[JeremyS]

4 hours ago, andrew s said:

A second flare. I promise not to post any more unless they are significantly different. 

On the contrary Andrew - I hope you do. Your project is highly original and might well yield important insights. I for one would love to see how it progresses.

[andrew s]

Third Flare at a higher cadence ~ 15s (11s exp) binned 3x3. I was beginning to wonder if changing the exp and binning had jinked me.

This time it was QY Aur

Regards Andrew

Edited February 17, 2020 by andrew s

[JeremyS]

Nice work @andrew s

[andrew s]

Well almost a year later I have found a reasonably easy and reliable way to process my flare spectra. The attached shows the first and still the strongest flare I observed. After calibrating the images in astroimagej the spectra were extracted in ISIS. They are necessarily noisy so they were wavelet filtered in Python.

I also used Python to subtract the pre-flare star spectra leaving a good approximation to the flare light.

Here are the results as a contour plot and an animated gif.

 

Regards Andrew

Edited November 30, 2020 by andrew s

[JeremyS]

Nice work @andrew s. Presenting data in a way that is both clear and intuitive is important and you have done a great job there. I like the colourful result too; certainly makes for an eye catching avatar. I’d go as far as to say that flares suit you. 

[robin_astro]

Great !  The lack of H alpha in the flare  is interesting (to me at least, not really knowing anything about flares 😁)

Cheers

Robin

[andrew s]

30 minutes ago, robin_astro said:

Great !  The lack of H alpha in the flare  is interesting (to me at least, not really knowing anything about flares 😁)

Cheers

Robin

Thanks Robin, I am trying to research this in the literature.  It could be it's too hot?  Work to do on this.

Regards Andrew 

Edited November 30, 2020 by andrew s

[andrew s]

On 30/11/2020 at 12:35, robin_astro said:

Great !  The lack of H alpha in the flare  is interesting (to me at least, not really knowing anything about flares 😁)

Cheers

Robin

@robin_astro the H alpha is back. No astrophysical marvel just a software error. take me back to computer validation days in the Pharmaceuticals industry!

Regards Andrew