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Re: Request for spectrum asassn 20mg dec 48 south

Posted: Sun Oct 18, 2020 9:56 am
by Hamish Barker
Good one Terry. Indeed, juggling family priorities of making dinner, bedtime story for my son, and then getting scope aligned (invariably I bump the scope slipping a clutch, or pull too hard on the cover when unwrapping it, so have to reaquire alignment stars), I find it a bit of a race to get enough exposure of this object before it gets too low.

But good that you got some data, and it's similarly undramatic (the dropoffs at each end of mine are I think contaminating stars in the background sky pixel stripes. I found it quite hard to find any areas free of either zero order or first order contamination.

Cloudy here for a few days, but I will persist when it clears. Never know if something may pop up in the spectrum!

Re: Request for spectrum asassn 20mg dec 48 south

Posted: Mon Oct 19, 2020 7:38 pm
by Hamish Barker
Krzysztof (director of ASAS-SN project) sent me a message that "Michigan State group says they see emission lines, but I did not see the spectrum."

Will be interesting to see if emission lines develop as they report, or what the object turns out to (probably) be.

Re: Request for spectrum asassn 20mg dec 48 south

Posted: Wed Oct 21, 2020 6:28 am
by Peter Velez
Here is my spectrum from last week in all its ugliness.

I've added a synthetic F5V spectrum for comparison. Looks a reasonable match to me.

Pete

Re: Request for spectrum asassn 20mg dec 48 south

Posted: Thu Oct 22, 2020 8:40 am
by Hamish Barker
Great one peter. Not ugly! I think it is interesting that the F-G type spectral trend seems consistent with what I posted. Is that a little emission at H-alpha? Given the noise, H beta and gamma could well also be hidden in there.

Does anyone have any further thoughts on its likely identification?


I am very interested to overlay your spectrum along with Terry's and mine, in order to compare and try to . I can send you the fits file of my spectrum or you could send me yours to hamish dot barker at gmail dot com.


Terry if you are reading, could you please send yours also or we can send them to you for overlaying to compare?

Cheers,
Hamish

Re: Request for spectrum asassn 20mg dec 48 south

Posted: Sat Oct 24, 2020 10:46 pm
by Terry Bohlsen
Hamish.
I sent you an email about the fit file.
Cheers
Terry

Re: Request for spectrum asassn 20mg dec 48 south

Posted: Mon Oct 26, 2020 11:10 pm
by Hamish Barker
light_curve_a043ee84-556b-4e0e-9207-78b16a61763e.png
Brightness is declining. Raining here today so no chance of an observation.

Latest asas-sn light curve included above. If it is a nova then I guess emission lines should get more obvious.

Re: Request for spectrum asassn 20mg dec 48 south

Posted: Wed Oct 28, 2020 3:32 am
by Hamish Barker
Someone finally put a 2m telescope onto the job and posted classification of CV on23 October.

https://wis-tns.weizmann.ac.il/object/2020tyr

Will be interesting if we can still get observations as it dims to see if emission lines get more prominent.

Re: Request for spectrum asassn 20mg dec 48 south

Posted: Fri Oct 30, 2020 1:27 am
by Hamish Barker
I combined Terry and Peter's spectra (note observations were different by a day) to reduce the noise a bit and overlaid the ESO spectrum from 23 October and my crappy SA100 .

I prepared an overall, and zooms on Halpha, beta, gamma and (maybe) sodium D regions.

anyone with CV expertise? Are they normally hotter than the apparent continuum slope seems to indicate in Terry and Peter's observations of around 6000K?

Cheers,
Hamish