fast galactic nova TCP J17562787-1714548

Alerts and Monitoring of Novae
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Hamish Barker
Posts: 226
Joined: Thu Jun 20, 2019 12:11 am

fast galactic nova TCP J17562787-1714548

Post by Hamish Barker »

I was alerted yesterday regarding Nova canditate TCP J17562787-1714548 by Andrew Pearce, co-discoverer.
Coordinates are just RA and DEC of the above numbers (i.e. J2000 RA 17h56m27.78s Dec -17 14 54.8s
http://cbat.eps.harvard.edu/unconf/foll ... 14548.html

It has also been observed today by the Swift-XRT X ray space telescope. The investigators posted
"It is somewhat unusual for a nova to show shock-powered X-rays visible to Swift/XRT less than two days after eruption. This may suggest that the transient is a very fast nova and/or a nova embedded in the wind of an evolved donor star."
https://www.astronomerstelegram.org/?read=15910

And now an atel has been posted by Kenta Taguchi, with a spectrum taken using a fiber fed IFU spectrograph on the 3.8m Seimei telescope (darn! scooped!)
https://www.astronomerstelegram.org/?read=15911

I took a spectrum this morning also. H alpha is massively broadened. Elias Aydi went so far as to describe it as "wild".

Dr Steve Shore was kind enough to have a look and has made the following comments:
" the spectrum shows a reddened continuum and strong emission with a heavily broadened base in hydrogen Balmer lines and in He I lines at 447.1 (weak), 501.6, 667.8, and
706.5 nm, all consistent in width with H-alpha. No profiles show P-Cyg absorption.
The H-alpha HWZI is 5500 km/s. The Balmer ratio Hbeta/Halpha ratio seems to be consistent with the Lyman lines still being optically thick but the lack of absorption suggests a low ejecta mass. The H-alpha line shows emission peaks at -2060, 1740, and 4200 km/s, the red wing is blended with He I 667.8 nm, typical of a complex, possibly axisymmetric ejetion. The spectral features and radial velocity are consistent with the object being a very rapidly evolving nova after visual maximum, possibly a recurrent or an ONe system. Spectroscopic monitoring is needed for this."

hd163336_20230220_664_Hamish Barker.png
velocity-halpha-hd163336_20230220_664_Hamish Barker.png
velocity-halpha-hd163336_20230220_664_Hamish Barker.png (16.82 KiB) Viewed 1993 times
More observations would be a good thing from all ARAS members. Francois sent me a message that he will be setting up a directory on the ARAS database for submissions soon - hopefully he will post the link here on the forum or otherwise it should appear here https://aras-database.github.io/database/novae.html

At declination -17, it is accessible to northern hemisphere observers also. But it IS in the predawn sky, so, to plagarising Benjamin Franklin: "Early to bed, early to rise, get a spectrum, but also tired eyes."
Hamish Barker
Posts: 226
Joined: Thu Jun 20, 2019 12:11 am

Re: fast galactic nova TCP J17562787-1714548

Post by Hamish Barker »

Another spectrum this morning, poorer signal to noise as I had some scattered clouds and some autoguiding problems.
tcpj17562787-1714548_20230221_684_Hamish Barker.png
velocity-tcpj17562787-1714548_20230221_684_Hamish Barker.png
velocity-tcpj17562787-1714548_20230221_684_Hamish Barker.png (24.04 KiB) Viewed 1918 times
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