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bright supernova alert NGC6217 - spectrum needed

PostPosted: Sun Jan 14, 2018 12:08 pm
by Robin Leadbeater
Patrick Wiggins reports a bright (mag 14.2) possible supernova in NGC6217
https://wis-tns.weizmann.ac.il/object/2018gj
A low resolution spectrum could confirm this.

Robin

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Sun Jan 14, 2018 4:15 pm
by Olivier GARDE
Hi Robin,

Thanks for this information but actually in south East of France, the weather is not very find....

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Sun Jan 14, 2018 8:00 pm
by etienne bertrand
Gelato classe cette SN comme une SN de type IIb avec une phase de ~6 jours

Image

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Le champ de ciel :
Image

C'est vraiment de la chance car toute la journée la météo a été nuageuse et ventée puis un peu dégagé vers 18h. L'année commence bien. Merci Robin pour l'alerte.

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Sun Jan 14, 2018 9:11 pm
by Robin Leadbeater
Thanks Etienne,

SNID predicts a type IIP but with reduced confidence (rlap =3.7 compared with 5.0 for a reliable classification ) see attached SNID best fit

Cheers
Robin

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Mon Jan 15, 2018 12:39 am
by etienne bertrand
Thanks Robin for the alerte.
It's a very lucky time for the weather.
For the type of SN it's possible that is a type IIP. I think it's interesting to take a new spectra in many days or 1 week. If the weather 'll good i take spectra of 1800s for a better SNR.

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Mon Jan 15, 2018 2:07 am
by Robin Leadbeater
Hi Etienne,

Yes early type II are difficult. The spectrum should develop stronger Balmer lines later.

Cheers
Robin

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Tue Jan 16, 2018 6:29 pm
by Robin Leadbeater
Type II classification now also confirmed
by professionals using the FLOYDS spectrograph on Faulkes telescope North
http://www.astronomerstelegram.org/?read=11172
https://wis-tns.weizmann.ac.il/object/2018gj

Congratulations to Patrick for the discovery and Etienne for the quick spectroscopic confirmation on TNS. Another “all amateur” supernova !

Robin

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Tue Jan 16, 2018 7:44 pm
by Paolo Berardi
Great job Etienne! A success on a very difficult object.
Very useful the Robin assistance.

Paolo

Re: bright supernova alert NGC6217 - spectrum needed

PostPosted: Fri Feb 09, 2018 11:29 am
by etienne bertrand
Merci pour vos messages.
En fin de nuit après des étoiles Be j'ai tenté de reprendre cette supernova. Malheureusement le ciel s'est couvert et est devenu très opaque, le signal reçu n'est pas bon. A refaire pour avoir un meilleur signal.
Image

Ha arrive à 6401.5A
Donc la vitesse de l'éjecta :
Vitesse ejecta = (((L1 - L0) / L0) x c) - V helio - V NGC6217
Vitesse ejecta = (((6401.5 - 6562.8) / 6562.8) x 299792.458) - 3.382 - 1363
Vitesse ejecta = - 8734 km/s

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