Page 1 of 1

Sn 2018 gjx

Posted: Thu Sep 20, 2018 10:44 pm
by Olivier GARDE
During our mission at Calern Observatory, we have take the spectrum of Sn 2018 gjx with a one meter telescope and a LISA spectrograph with 50 µm slit.

Here's the result with 2 hours exposures (6x1200s)

Image

The auto guiding sensor during acquisitions

Image

And a comparison with a spectrum taken 4 days ago with NTT telescope (not by us...)

Image

Re: Sn 2018 gjx

Posted: Thu Sep 20, 2018 11:05 pm
by Christian Buil
Très joli boulot de l'équipe !

et la classe ce télescope... j'arrive ;-)

Elle tourne autour de quelle magnitude cette SN au moment de la prise de vue ?

Christian

Re: Sn 2018 gjx

Posted: Fri Sep 21, 2018 1:43 am
by Olivier GARDE
Christian,

Au moment ou l'on a fait le spectre, la magnitude de la Sn devait être dans les 16.
A voir sur :
https://wis-tns.weizmann.ac.il/object/2018gjx

Re: Sn 2018 gjx

Posted: Fri Sep 21, 2018 1:04 pm
by Robin Leadbeater
Hi Olivier,

It is interesting that the He II line has disappeared

Are you planning to go any fainter? It could be a good chance to set a new amateur magnitude record for officially classifying a supernova if you can get ~20 SNR in a spectrum filtered to ~40A. (My current limit with the ALPY 200 /C11 is mag 17.5)

Cheers
Robin

Re: Sn 2018 gjx

Posted: Fri Sep 21, 2018 1:22 pm
by Robin Leadbeater
at2018gro would be a good one to try for
https://wis-tns.weizmann.ac.il/object/2018gro
It was discovered yesterday in ngc7228 at mag 18.6 by an amateur team led by Dick Post and is probably brightening. It is too faint for me but f you can get it I could try classifying it and could submit it on your behalf if you don't have a TNS account.

Cheers
Robin

Re: Sn 2018 gjx

Posted: Fri Sep 21, 2018 5:54 pm
by etienne bertrand
Bravo pour ce résultat !

Re: Sn 2018 gjx

Posted: Fri Sep 21, 2018 7:37 pm
by Christian Buil
Un clin d'oeil, car difficile de lutter avec un télescope de 1 m sous le ciel de la Cote d'Azur, cette SN faite la nuit dernière avec le RC de 25 cm et UVEX2 (partie bleu du spectre). Malheureusement, passage de cirrus et puis jolie pollution de la ville (comparer l'aspect de l'image de la SN avec les caméras de guidage du Toulouse et Calern... il y a un monde !) :

Image

A part peut-être vers 4680 A et 4080 A on ne voit pas grand chose avec un tel rapport signal sur bruit (RSB = 4,5), à part l'allure générale du continuum qui indique que l'on a à faire à une type II.

Christian

Re: Sn 2018 gjx

Posted: Fri Sep 21, 2018 8:07 pm
by Olivier GARDE
Robin Leadbeater wrote: Are you planning to go any fainter? It could be a good chance to set a new amateur magnitude record for officially classifying a supernova if you can get ~20 SNR in a spectrum filtered to ~40A. (My current limit with the ALPY 200 /C11 is mag 17.5)

Cheers
Robin
Hi Robin,

Yes we are planning to go any fainter, but actually, the weather is not find, so we are waiting for a good sky...

Re: Sn 2018 gjx

Posted: Sun Sep 23, 2018 12:54 pm
by Robin Leadbeater
Robin Leadbeater wrote:at2018gro would be a good one to try for
https://wis-tns.weizmann.ac.il/object/2018gro
It was discovered yesterday in ngc7228 at mag 18.6 by an amateur team led by Dick Post and is probably brightening. It is too faint for me but f you can get it I could try classifying it and could submit it on your behalf if you don't have a TNS account.

Cheers
Robin
now classified as a subluminous type 1a 91bg-like

Robin