spectro-aras.com

https://www.aanda.org/articles/aa/full_ ... 20-20.html

here is a new paper on indications that there might be a rather close ( 1000 LY ) black hole in a binary/ternary system. HR6819 (HD167128).

I had a look in ArasBeAm, there are 7 spectra registered.
http://arasbeam.free.fr/spip.php?page=b ... etoile=970

I will forward the link to ArasBeAm to the PI, perhaps it may be of use. The target is mag 5.33 so within reach of southern amateurs (RA 18 17 07 dec -56 01 24 ). And add it to my list of observations to make when I get everything working (have just bought a proper mono camera to go onto my L200 littrow).

Hi Hamish
This could be an interesting star to follow. I have taken spectra of it before at Ha, but Ha is not much good to measure the RV fo this star . He I 6678 is easy to image and seems to give good measurements.
This is another link to the paper.

https://www.eso.org/public/archives/rel ... o2007a.pdf

I have been working with Ed Budding on a system with some similarities to this, V Puppis. Accurately measuring RV from the massively broadened lines is quite ticklish - if you can get to about 5 km/s precision you're doing well. Terry's suggestion of the 6678 line is the one we were using for our measurements.

It looks like based on 3 further papers that HR6819 is probably not a tertiary system with a black hole after all but a binary system with the emission an accretion disk from a companion rather than a classical Be star
https://arxiv.org/abs/2007.05797
https://arxiv.org/abs/2006.11974
https://arxiv.org/abs/2006.10770

(Terry Bohlsen and Paul Luckas get an acknowledgement for their spectra in BeSS in the last one)

Cheers
Robin