GAIA transient GAIA21dxg / TNS AT2021wui

Hamish Barker
Posts: 226
Joined: Thu Jun 20, 2019 12:11 am

Re: GAIA transient GAIA21dxg / TNS AT2021wui

Post by Hamish Barker »

I normalised all to continuum and made a stacked plot around Hbeta. I can't see a trend there, whereas there may be one at Halpha.
at2021wui(normcont)_stacked_Hbeta.png
at2021wui(normcont)_stacked_Hbeta.png (83.54 KiB) Viewed 6868 times
at2021wui(normcont)_stacked_Halpha.png
at2021wui(normcont)_stacked_Halpha.png (85.91 KiB) Viewed 6868 times
Terry Bohlsen
Posts: 191
Joined: Thu Sep 29, 2011 7:40 am

Re: GAIA transient GAIA21dxg / TNS AT2021wui

Post by Terry Bohlsen »

I took another spectra of this star. The Ha seems to be dancing around a bit. Maybe just being double peaked and oscillating. Should this star be added to BeSS or somewhere else to keep the spectra we have taken in a central place?
Cheers
Terry
at2021wui(normcont)_20210923_463_TBohlsen.png
at2021wui(normcont)_20210923_463_TBohlsenHa.png
at2021wui(normcont)_20210923_463_TBohlsenHa.png (51.44 KiB) Viewed 6846 times
Terry Bohlsen
Armidale NSW
Australia
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
Contact:

Re: GAIA transient GAIA21dxg / TNS AT2021wui

Post by Robin Leadbeater »

Terry Bohlsen wrote:Should this star be added to BeSS or somewhere else to keep the spectra we have taken in a central place?
BeSS wont include it unless it is confirmed as a classic Be or Herbig AeBe star but you could upload them to the BAA database though for safe keeping
https://britastro.org/specdb/

Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Hamish Barker
Posts: 226
Joined: Thu Jun 20, 2019 12:11 am

Re: GAIA transient GAIA21dxg / TNS AT2021wui

Post by Hamish Barker »

stacked plot of Ha region with all the spectra taken to date by Terry, Peter and myself.

the two sharp peaks of red and blue shifted Ha are about 23 days apart. It will be interesting to see if the sharp peak reapears with blue shift, perhaps 23 days after its peak red shift, around 13 october.

I don't know what the absorbtion is around 5780. I see a dip in B start spectra there, but haven't look up what it is likely to be (or if it could be atmospheric oxygen?).
at2021wui_20210825_to-20210924_Halpha-drift.png
at2021wui_20210825_to-20210924_Halpha-drift.png (71.67 KiB) Viewed 6791 times
at2021wui_20210825_046_5780absorbtion.png
Terry Bohlsen
Posts: 191
Joined: Thu Sep 29, 2011 7:40 am

Re: GAIA transient GAIA21dxg / TNS AT2021wui

Post by Terry Bohlsen »

This star has continued to become brighter but is very low in the west now.
I took a spectrum last night when it was only about 14deg above the horizon. As a result the continuum is not properly corrected as I don't have a suitable comparison star at that low altitude. Despite this it seems that the star is no longer in Ha emission. It won't really be possible to take any more spectra of it until the next season.
Terry
at2021wui_20211116_398_TBohlsen.png
Terry Bohlsen
Armidale NSW
Australia
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