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at2018blk/ATLAS18olb

Posted: Tue May 15, 2018 10:17 am
by Robin Leadbeater
ATLAS18olb (AT2018blk)
https://wis-tns.weizmann.ac.il/object/2018blk
is a mag 20 blue star in Lyra which has brightened to mag 13.1 Attached is an R~530 ALPY 600 spectrum from last night showing a blue continuum and weak broad H Balmer lines.

Cheers
Robin
at2018blk_20180514_954_Leadbeater.png
at2018blk_20180514_954_Leadbeater.png (33.98 KiB) Viewed 7767 times

Re: at2018blk/ATLAS18olb

Posted: Tue May 15, 2018 2:58 pm
by Benjamin Mauclaire
Hello Robin,

It's nice how quick you can react on alerts.
This may give possibilities to insert more and more amateur contributions in object type confirmation.

Why have ou set y label to "Relative intensity"?
Binning operation in spectral processing outputs a "Relative flux" as it computes a light power ("intensity") over the binning surface.

Benji

Re: at2018blk/ATLAS18olb

Posted: Tue May 15, 2018 4:32 pm
by Robin Leadbeater
Thanks Benji,

This one appeared on TNS which I monitor for supernovae to classify using the ALPY 200. It does not really get dark enough at this time of year here for faint supernovae but this was bright enough for the standard ALPY.

I agree Relative Flux would a more accurate description, though in this case, as the bin size is constant over the spectrum, I think they are the same.
The "Relative Intensity" label is the default in the PlotSpectra software. I just checked though and an alternative label can be entered manually so if I remember, I will change it to Relative Flux in future

Cheers
Robin

Re: at2018blk/ATLAS18olb

Posted: Thu May 17, 2018 9:14 pm
by Robin Leadbeater
A follow up spectrum taken last night. It has faded slightly to ~13.4 measured from the guider image and the spectrum shows no signifcant change.

Robin