Special Notice #419: V1687 Cyg spectroscopy and sequence and Subscription reminder

August 9, 2016

V1687 Cyg spectroscopy and sequence

Further to AAVSO Alert Notice 546, spectroscopy of V1687 Cyg (WR 140, HD 193793) is encouraged. A group of amateur spectroscopists in Germany will be taking spectra in accordance with the parameters given by the astronomers, namely a resolving power >~5000, S/N~100, ideally concentrating on the wavelength region 5500-6000A. A background document sent to these spectroscopists may be found here. Dr. Richardson and colleagues would welcome your participation - if you are interested in contributing spectroscopy as outlined above and in the document, please contact Thomas Eversberg <thomas.everbserg at dlr.de>.

Also, the sequence for V1687 Cyg is in place, but because the star is so bright, small-scale charts will not show any comparison stars. Choose an 'A', 'AB', or 'B' scale chart (900, 450, or 180 arcmin field of view, respectively) for useful comparison stars. A 'C' scale chart (120 arcmin) will show sufficient (although faint) stars for CCD/PEP/DSLR work.

Coordinates (2000.0):  R.A. 20 20 27.98   Dec. +43 51 16.3

Charts: Charts with a comparison star sequence for V1687 Cyg may be created using the AAVSO Variable Star Plotter (VSP).

Please submit observations to the AAVSO International Database using the name V1687 CYG.

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This Special Notice was compiled by Elizabeth O. Waagen.


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