Statements from professional astronomers

Tony Moffat (Université de Montréal) October 30, 2007

Two weeks ago I was in Madrid (well ESA/Vilspa actually) for a 3-day meeting with 6 others on WR140 - just WR140! Everyone could give a talk for 3 hours - great stuff. With lots of interaction and no such thing as dumb questions. But no time to stop off in Germany this trip.

During our discussions of all aspects of WR140 from radio through IR, optical, UV, X and gamma, one aspect which really came up often was getting the right orbit, based on both sets of lines (WR and O). For that we'll need good time coverage and good quality optical spectra. So the role of your amateyr friends could be quite crucial and we support their efforts. Ideally, we need steady coverage in time (once a month now), then by October 2008, increased to once every couple of nights and every night in Dec/Jan. Yellow spectra are good, but also blue would be useful, to get more O-absorption lines for a good orbit of the O star. S/N should be at least 150/pixel and no worse than ~1 A/pixel, if possible (to get good precision in RVs).

We should also get broadband (UBV best) photometry, around and after periastron passage, to look again for dust-caused dips, from which one can compare with dust models to constrain dust-grain size. Any chance of that, too?


Tony Moffat (Université de Montréal)
Wow, that's great! The only problem might be the (German!!) weather in Nov-Feb, with periastron occurring in early January. If you don't get rapid spectral coverage (every few days) continuously over that whole period of ~4 months, then it won't deliver much. However, we will also motivate a bunch of professional observatories to get into the fray. BTW, it will be good to test this winter how many spectra spread over Nov-Feb you guys can get this year, to give an idea for next year.


Olivier Chesneau (Observatoire de la Côte d'Azur)
Thanks for reminding me the WR140 event. WR140 has been for a long time too north for us, but with the development of the US CHARA interferometric array, we could have an opportunity to observe this event.