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U Gem in outburst
Posted: Sat Feb 21, 2015 11:52 pm
by Francois Teyssier
The cataclysmic U Gem has been detected in outburst
It could be still on the rising
Max mag ~ 9
François
Re: U Gem in outburst
Posted: Sun Feb 22, 2015 1:31 am
by Francois Teyssier
Tonight spectrum
Broad absorptions for H beta and H gamma
- _ugem_20150221_986_fteyssier.png (18.68 KiB) Viewed 9511 times
François Teyssier
Re: U Gem in outburst
Posted: Sun Feb 22, 2015 11:56 am
by Paolo Berardi
François, congratulations for your great spectra (I also see the recent Nova Cyg 2014 observation)! During last U Gem outburst, Vmag remained brighter than 10 for about ten days. Unlike in the previous case, this ouburst occurred in a favourable moment to follow the decline phase.
Ciao!
Paolo
Re: U Gem in outburst
Posted: Mon Feb 23, 2015 9:03 pm
by Francois Teyssier
Thank you Paolo
U Gem is now at its maximum luminosity
The spectrum looks flat at a first on raw images, but ...
clearly the double peak of the disk in rotation
- _ugem_20150223_764_fteyssier.png (18.39 KiB) Viewed 9463 times
and a crop on Ha
- _ugem_20150223_764_ha.png (12.73 KiB) Viewed 9463 times
with v.sin i ~ 1000 km/s
The disk turns fast !
François
Re: U Gem in outburst
Posted: Wed Feb 25, 2015 6:50 pm
by Francois Teyssier
Spectre du 24-02
Begening of the decline
- _ugem_20150224_759_fteyssier.png (17.51 KiB) Viewed 9408 times
Note the complexe shape of Balmer lines
The V/R ration of H alpha has changed, in comparison to the previous spectrum (rotation of the disk)
A series of several hours should show the V/R evolution ... (for the next outburst)
Cloudy weather tonight, unfortunatly ...
François
Re: U Gem in outburst
Posted: Thu Feb 26, 2015 8:21 pm
by Joan Guarro Flo
Hi:
Is the U Gem in the 20150225.
J.Guarro.
Re: U Gem in outburst
Posted: Thu Mar 05, 2015 5:26 pm
by Francois Teyssier
During the decline
Noisy, but interesting shape pf H alpha and H beta
- _ugem_20150304_776_fteyssier.png (20.74 KiB) Viewed 9259 times
François Teyssier
Re: U Gem in outburst
Posted: Thu Mar 05, 2015 8:38 pm
by Francois Teyssier
Tonight spectrum
- _ugem_20150305_774_fteyssier.png (21.92 KiB) Viewed 9250 times
François
Re: U Gem in outburst
Posted: Fri Mar 06, 2015 9:19 pm
by Francois Teyssier
Nive emission from the disk
See also He I (5876 and 6678)
- _ugem_20150306_781_fteyssier.png (22.5 KiB) Viewed 9222 times
François
Re: U Gem in outburst
Posted: Mon Mar 09, 2015 9:33 pm
by Peter Somogyi
Nearly started before Francois's last spectra, a 5 hours exposure (with some technical breaks):
Animated gif of every 2 x 20 minute exposures - except last that was 3 x 20 min:
- _ugem_20150306_793_981_psomogyi.gif (80.31 KiB) Viewed 9194 times
Ref. star was: 79-Gem, taken only 4 times (using averages in between).
Interesting to see the continuum temporary rise while Balmer remains almost there, showing other features.