V1687 Cyg

[Robin Leadbeater]

Hi Fran,

We will be looking for quite small changes superimposed on the top of the lines and the star will be at quite low elevation around periastron from here so getting even relative flux calibration with high enough accuracy to measure the changes is potentially tricky. This was also the case last periastron. Fortunately the problem can be avoided by rectifying the spectra to remove the continuum shape using the same pseudo-continuum points that Marchenko used (see my post above). The changes during periastron were then extracted by subtracting the mean spectrum outside periastron. I remember there were some discussions about whether an instrument response correction using a reference star was even necessary since the spectrum was going to be rectified, but I did it for my results any way.

Here is the link to the paper produced last periastron which describes the data reduction and the measurements made on the spectra
http://cdsads.u-strasbg.fr/cgi-bin/nph- ... 8....2F&db

The PIs Tony Moffat and Noel Richardson monitor the Convento group list and would probably respond to any questions on the campaign there but note many on that list are pro astronomers who expect the "signal/noise" on the list to be kept high.

Cheers
Robin

[Robin Leadbeater]

I have attached the fits file of the spectrum Marchenko shows in fig 5 of his 2003 paper which he kindly set to me before last periastron. Except for some small scale variations on the top of the lines due to clumps in the wind, the current outside periatron spectrum should be very similar to this so it is a good test for the quality of our spectra before periastron.

Cheers
Robin

[Francisco Campos]

Hi,

sorry for my delay to reply. Thank you for your help, Robin. I am waiting for a gratting of 1200 l/mm for the DADOS and I hope to achieve resolutions of 5.000 or better. When I start to play with the upgraded spectrograph I will learn to process the spectra following your recommendations.

Greetings
Fran

[Tim Lester]

Here is my first try. High in the sky right now so relatively easy to get good S/N. R = 7300 for this spectrum.

Tim

[Joan Guarro Flo]

Hello to all,

These are the first results test of the echelle Mussol.

Friendly, Joan.

[Elio Ricciardiello]

hi,
we took the WR140 on 5 oct 2016 and 16 nov 2016 and noted wide emissions in CIII and CIV. Hbeta decrease and CIII e CIV increases in th two dates!
Celestron C11, 10Micron GM2000HPs, Dados 200l/mm, Atik 383L+
Elio Ricciardiello
Sezione di Spettroscopia
Unione Astrofili Napoletani
Osservatorio Astronomico di Capodimonte
via Moiariello 16
Napoli