V919 Sgr in outburst

Francois Teyssier
Posts: 1520
Joined: Fri Sep 23, 2011 1:01 pm
Location: Rouen
Contact:

V919 Sgr in outburst

Post by Francois Teyssier »

https://www.astronomerstelegram.org/?read=15528

AAVSO light curve :
v919sgr.png
v919sgr.png (12.14 KiB) Viewed 3463 times
Last edited by Francois Teyssier on Wed Aug 03, 2022 5:10 pm, edited 1 time in total.
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: V919 Sgr in outburst

Post by Joan Guarro Flo »

Hello,

Last night I observed V919 Sgr, in bad transparency conditions and unfortunately the
clouds interrupted me on the middle observation, because my intention was to take 6 integrations in total.

But I think the result is reasonably good, so I'm going to try it again tonight.

Regards, Joan Guarro.
Attachments
V919 SGR_1.png
V919 SGR_1.png (14 KiB) Viewed 3531 times
V919 SGR_2.png
V919 SGR_2.png (23.34 KiB) Viewed 3531 times
V919 SGR_3.png
V919 SGR_3.png (11.68 KiB) Viewed 3531 times
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: V919 Sgr in outburst

Post by Joan Guarro Flo »

Hello, 

That is V919 Sgr yesterday night, the observation was taken through a SC16 telescope,a NOU_T echelle and an ASI2600MM, with a 5 integrations of 1200.

I'm really glad with the NOU_T,  ( the Tim Lester echelle design ),  and its equipment results.

The most curious is the chromospheric H&K activity and the quantity of absorption lines in the blue.

Cheers, Joan.
Attachments
V919 SGR_4.png
V919 SGR_4.png (13.06 KiB) Viewed 3486 times
V919 SGR_5.png
V919 SGR_5.png (33.56 KiB) Viewed 3486 times
V919 SGR_6.png
V919 SGR_6.png (16.49 KiB) Viewed 3486 times
Francois Teyssier
Posts: 1520
Joined: Fri Sep 23, 2011 1:01 pm
Location: Rouen
Contact:

Re: V919 Sgr in outburst

Post by Francois Teyssier »

A great spectrum at Mag V ~ 10.6!

The outburst is produced by an increase of the luminosity of the hot component (envelope of the white dwarf and/or accretion disk). The mechanism is not well known.
At this state, it appears as a A-F giant/super-giant (to be precised by a detailed study of the absorption lines) which overwhelm the continuum of the cool component and its TiO bands.

See also the last spectra of BX Mon last spring.


All the best,
François
2SPOT
Posts: 110
Joined: Wed Jul 07, 2021 8:40 am
Contact:

Re: V919 Sgr in outburst

Post by 2SPOT »

Spectrum taken the 2sd august in Chile

Image

Automatic observation and process with our ARP pipeline (no human intervention).
2SPOT : Southern Spectroscopic Project Observatory Team
Website : http://www.2spot.org - Observatory Site : Deep Sky Chile https://www.deepskychile.com/fr/
Suport our action : https://www.helloasso.com/associations/ ... mulaires/2
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: V919 Sgr in outburst

Post by Joan Guarro Flo »

Hello,

Another good result with the NOU_T echelle equipment, this is V919 Sgr yesterday night.

Cheers, Joan Guarro.
Attachments
V919 SGR_7.png
V919 SGR_7.png (13.5 KiB) Viewed 3412 times
V919 SGR_8.png
V919 SGR_8.png (33.98 KiB) Viewed 3412 times
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: V919 Sgr in outburst

Post by Joan Guarro Flo »

Hello,

Another NOU_T echelle observation.

V919 Sgr seems to keep its graphic without significant variations.

Cheers, Joan Guarro.
Attachments
V919 SGR_9.png
V919 SGR_9.png (15.98 KiB) Viewed 3377 times
V919 SGR_10.png
V919 SGR_10.png (19.79 KiB) Viewed 3377 times
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: V919 Sgr in outburst

Post by Joan Guarro Flo »

Hello,

You can see here that V919 Sgr is runningo its course, this is a graphic from yesterday night of NOU_T echelle equipment from Piera.

Cheers, Joan Guarro.
Attachments
V919 SGR_11.png
V919 SGR_11.png (18.03 KiB) Viewed 3283 times
V919 SGR_12.png
V919 SGR_12.png (13.86 KiB) Viewed 3283 times
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: V919 Sgr in outburst

Post by Joan Guarro Flo »

Hello,

This is the ninth very nice V919 Sgr spectrum through a NOU_T echelle.

The aim now is to complement all these R=9000 longer range spectra with fine photometry. This is the challenge that modern astrophysics demands.

Cheers, Joan Guarro.
Attachments
V919 Sgr 210220811.png
V919 Sgr 210220811.png (20.03 KiB) Viewed 3175 times
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: V919 Sgr in outburst

Post by Joan Guarro Flo »

Hello,


You can see in this 11th observation of V919 Sgr, with the NOU_T echelles from Piera and Santa Maria M. Observatories, that the star keeps its shape
with only some variations in the hidrogen.

Cheers, Joan Guarro.
Attachments
V919sge20220814.png
V919sge20220814.png (17.59 KiB) Viewed 3082 times
Post Reply