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T100 Observations of V404 Cyg during quiescence

ATel #8509; Tolga Guver (Istanbul Univ.), Ersin Gogus (Sabanci Univ.), Tugba Boztepe (Istanbul Univ.), Cagla Su Basaran (Istanbul Univ.), Emrah Kalemci (Sabanci Univ.)
on 6 Jan 2016; 12:50 UT
Credential Certification: Tolga Guver (tolgaguver@sabanciuniv.edu)

Subjects: Optical, Binary, Black Hole, Transient

Referred to by ATel #: 8515, 8531

We report the observations of V404 Cyg obtained in November 17th, 2015 (MJD : 57343.7120681) with the T100 Telescope located at the TUBITAK National Observatory, Antalya Turkey. The observations lasted for about 2.5 hours and each image was obtained with an exposure time of 180 s using R band filter. We used the aperture photometry tool APPHOT within IRAF and the R2 magnitude (16.37 mag.) of USNO B1.0 star 1238-0435179 (RA :306.019609 DEC:+33.881228) as our reference.

Within our images the R band brightness of V404 Cyg was roughly constant at 17.06 mag with a standard deviation of 0.05 mag as measured from 41 images. Note that, average of the individual formal uncertainties of our measurements is 0.03 magnitude, however systematic uncertainties arising from the selection of the reference star maybe much larger.

The epoch of our observations correspond to roughly 34 days before the onset of the latest activation of the system and show an agreement with the recently reported values by Hardy et al. (ATEL 8501).

Resulting light curve of our preliminary analysis can be reached from the following address :

We are grateful to TUBITAK National Observatory for their support in using T100 telescope with project numbers 388, 432 and 612 and technical support.