spectro-aras.com

http://spektroskopieforum.vdsastro.de/v ... =32&t=4451

The objective is to detect any differences from the previous periastron in 2009

here are my results from 2008/9
http://www.threehillsobservatory.co.uk/ ... tra_41.htm

Robin

Thank you Robin for sharing it, I realise having the same 600/mm grating setup you had that time!

Wanted to register to ask a few questions directly on the vdS forum, got stuck at anti spam question "Which optical instrument is used by us?:" and now locked out after 5-6 guesses.

Still reading around 1 hour the links doesn't reveal the very basic question what's the needed coverage (aiming the mentioned day "18 Dec 2016" sounds like a lottery) and what's the minimal required resolution. For a simple observer it's an overkill to come through all of this, with a high potential finally missing the period (early winter here is a dead season).

- Peter

Hi Peter,

The suggested resolution and SNR (R > 5000 and SNR >100) is given down the thread in the Convento group forum here
http://spektroskopieforum.vdsastro.de/v ... 451#p27965
though last time my resolution with the 600 grating was only ~3500 which was acceptable. I have a larger aperture scope and a wider CCD this time though so I will probably try the 1200 grating

The 18 Dec 2016 date for periastron is very certain (Our results from the last periastron increased the accuracy of the orbital parameters) but the effect of the colliding winds is seen for several weeks before and after that date. You can see the effect during last periastron (12th Jan 2009) here
http://www.threehillsobservatory.co.uk/ ... n_fast.gif
It is also a good idea to make tests now, well before periastron. (There should be no significant variation in line strength outside periastron, perhaps just some small variations on the top of the lines)

Winter is a time of bad weather in Europe of course but results from observers can be combined so any measurements covering November 2016 - Feb 2017 could be useful.

Cheers
Robin

Tony Moffat, the professional coordinating this campaign has asked anyone who is following WR140 through periastron to contact him
http://forum.vdsastro.de/viewtopic.php?t=4575#p28564

Cheers
Robin

Last call for spectra!

If you are contributing spectra for this pro-am campaign, Noel Richardson and Tony Moffat would like to have them by the end of January. You can send them to.

noel dot richardson at UToledo dot edu

Cheers
Robin