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RW Cep unusual dimming
Posted: Sat Dec 17, 2022 3:09 pm
by Robin Leadbeater
RW Cep is experiencing an unusually deep dimming currently (similar to the Great Dimming in Betelgeuse ?)
https://www.astronomerstelegram.org/?read=15800
Currently mag 7.5 it is bright enough for high resolutions but it is not clear what wavelengths would be specifically interesting so Echelle spectra could be useful.
I have taken some carefully relative flux calibrated R~1000 spectra seen here in the BAA database (I will also add any further spectra there)
https://britastro.org/specdb/data_graph ... &multi=yes
and there are some interesting discussions on Cloudy Nights
https://www.cloudynights.com/topic/8542 ... t-dimming/
AAVSO have also issued an alert
https://www.aavso.org/aavso-alert-notice-804
Cheers
Robin
Re: RW Cep unusual dimming
Posted: Tue Dec 20, 2022 6:57 pm
by Robin Leadbeater
H alpha is in emission
https://britastro.org/specdb/data_graph ... s_id=13128
There may be more lines in emission. An echelle spectrum could be interesting
There are several high resolution spectra in the ELODIE archive but none of these show H alpha in emission (here compared with my spectra)
- rwcep_elodie_archive_THO_2022-12-19_Halpha.png (119.79 KiB) Viewed 12706 times
- rwcep_elodie_archive_THO_2022-12-19_lowres.png (126.8 KiB) Viewed 12706 times
Cheers
Robin
Re: RW Cep unusual dimming
Posted: Wed Dec 21, 2022 11:26 am
by Joan Guarro Flo
Hi Robin and everyone,
That is the result of one RW Cep observation, unfortunately the bad weather didn't leave me any other oportunity to observe it.
I left this in BAA, but I don't know either if exist someone interested in more observatons..
Merry Christmas and Happy Good Year, Joan.
Re: RW Cep unusual dimming
Posted: Wed Dec 21, 2022 12:15 pm
by Robin Leadbeater
Thanks Joan !
Yes I am sure there are people who will be interested in this (I am in contact with the authors of the ATel and Christoph Quandt who ran a project on the YHG Rho Cas)
Cheers
Robin
Re: RW Cep unusual dimming
Posted: Wed Dec 21, 2022 12:20 pm
by Robin Leadbeater
Hi joan,
What do you think of the flux calibration of your spectrum ? Is it ok? What did you use as reference star?
The continuum shape is very different from mine and historic spectra in the EOODIE Archive.
https://britastro.org/specdb/data_graph ... 20+Spectra
Cheers
Robin
Re: RW Cep unusual dimming
Posted: Wed Dec 21, 2022 3:25 pm
by Joan Guarro Flo
Hi Robin,
As you said, the perfect spectrograph doesn't exist, and I'm afraid that an echelle isn't the best tool
for taking a good calibration flux, in my opinion, using a low resolution spectrograph takes very useful
data for it and more easily.
One can see that almost all studies using echelles, represent their data in a horizontal background.
BTW, it's possible that I'll have a good night today and I'll try to take this star again, and go to essay
V photometry with the Piera telescope. It's a pity that SMM one is damaged until the middle of January.
Cheers, Joan.