- This topic has 30 replies, 9 voices, and was last updated 2 years, 9 months ago by
.
-
Posts
-
Just had a quick look at the object through the objective prism and as Robin has shown above there are strong H alpha and beta emission lines.
The spectrum has changed significantly in the past few days. Except for a relatively weak narrow H alpha emission, all the other lines previously in emission are now either missing or in net absorption.
Cheers
Robin
The H alpha emission line has weakened further and is now showing a P Cygni profile (velocity ~600km/s). The rest of the spectrum now resembles that of a G/K star photosphere but with some additional absorption lines, particularly in the red at ~7106/7766 A (The other features in that area are Tellurics)
Cheers
Robin
Significantly fainter in the spectrograph guider tonight and the spectrum has changed completely once again with a host of strong broad emission lines appearing.
Robin
Last night, 3rd August, I measured Nova Vul 2021 at V=10.97, B-V=1.14, almost a magnitude fainter than 48 hrs before and slightly redder. As Robin said, there has been a big change in the spectrum over recent days.
The following LISA spectrum (R~1062) was calibrated in absolute flux using this V magnitude and response corrected with the B9III MILES star HD192907 recorded at the same airmass as the mid-time of the nova spectrum. H-alpha has a strong P-Cyg absorption dip at -320 km/s which now falls within the much broader ~3000 km/s FWZI of the line. FeII multiplets 42, 49 and 74 are prominent with just-resolved P-Cyg dips. There are also emission features at ~5526A, ~5662A and ~7117A, all with P-Cyg dips, which I have not been able to identify in the WIlliams list of nova emission lines. Suggestions?
David
Again excellent agreement with mine ~2 hrs later (using a different MILES reference star HD192640) though the the blueward absorption in the H alpha line is not resolved in the R 500 ALPY spectrum
Robin
The nova is still about mag 11.
Here is a picture taken tonight about midnight here (UT + 2) 14″ sct + Canon 77d 10 sek.
Got a series of seven 60 s images from iTEL 18 in Spain last night 2459431.46 . Airmass of about 1.016.
All seven are around 11.47 V mag using Vphot and AAVSO comp stars.
This is a bit of a fade over the last 2 days.
Stewart
This Nova (V606 Vul) is brightening once again. Looking at the VSS database, it can be seen that the Nova has been slowly rising from mid December (Mag 18.9V on Dec 6), through January where Nick James was able to follow it to mag 14.76CG by Jan 31. I’ve just measured an image taken by SLOOH this morning (Feb 23) at mag 14.6C.
If you can get to the field at this time of year, please report your observations to the VSS.
Gary
- You must be logged in to reply to this topic.