V404 Cyg

[Peter Somogyi]

Hi,

Has anybody tried V404 Cyg at LoRes? (curious if I should test 150/mm today...)
Yesterday (initially between clouds) taken around H-alpha but unfortunately haven't met with any jump up in brightness (10 minute exposures).

Finally, only the sum got to be meaningful (15 x 10 min), quite noisy + tellurics present (helioc. corrected):

v404cyg_n15x600s.png (24.53 KiB) Viewed 2846 times

Confirmation would be appreciated.

Anyway, I've been surprised that I was able to guide at 1 sec with Lodestar X2 having still the old LHires guide optics at 1 sec (but switched to nearby star for being lossy, also clouds were going over). Possibly thanks to the infra brightness.

Peter

[Paolo Berardi]

Hi Peter and all,

yesterday I tried to observe V404 Cyg but haze and clouds were often in the sky. I took several 480s frames but I've used only three appeared to be better (they are not time consecutive).

I'm not having much luck because its brightness wasn't great, When I started, mag V was about 15.8. Later there was a little brightening (the increase was appreciable also in the guider view).

Integrated intensity of three profiles:



In addition to a strong H-alpha emission line, I see only neutral helium lines (He I 5876 and He I 6678) and faint H-beta. Some intensities are beyond 7000A.

The single profile times are marked (red spot) on the related AAVSO light curve:



The guider view with the target out of the slit. Target coordinates come from an astrometric calibration of guider frame by Astroart 5 (the relatively wider field of view includes many stars).



I hope to observe it again in better conditions (sky and brightness, but I fear that the target is fading...).

Paolo