22 March 2021 at 4:20 pm #583995Terry McKnightParticipant
Yes it is the Bubble Daryl. I was using an Ha filter as there was some local light pollution and it did indeed pick up some nebulosity from the Bubble.22 March 2021 at 5:08 pm #583996
Taking a closer look at my image from 19th March I just got the Bubble nebula at the edge of the field. Image on my members page: V1405 Cas and the Bubble nebula.
Mike.23 March 2021 at 1:14 am #583997John CoffinParticipant
This is Monday night’s spectrum with bright helium emission lines.
There are P Cygni profiles in the hydrogen Balmer series and the helium lines With a velocity of about 1400 km/ sec.23 March 2021 at 2:30 am #583998At last a slightly murky break in the clouds here in The Mendips, to allow me to record the evolving spectrum of this beautiful nova. There are many neutral helium emission lines as well as the hydrogen Balmer series, all with very striking P Cygni profiles due to Doppler shift in the expansion along our line of sight. It is always a thrill to capture the spectrum of a unique object like this
Hugh23 March 2021 at 9:43 am #583999Mr Ian David SharpParticipant
Clear last night. Managed to get a few exposures early on. Average mag. over 8 x 20 second exposures was 8.133 +/- 0.030. This was with no filter.
Equipment: C9.25 @ f/. SX TRIUS 694 Pro CCD, Calibrated with Bias, Flats and Darks. Photometry processing in AstroArt 7.
Ian.23 March 2021 at 6:22 pm #584003Robin LeadbeaterParticipant
Finally got my spectrum a couple of days later. A nice full set of H Balmer and HeI P Cygni profiles
Robin23 March 2021 at 8:28 pm #584005Harri KiiskinenParticipant
My RGB-vesion, 3x5x15s with FSQ-85ED and QHY163M.
-Harri24 March 2021 at 11:45 pm #584007
This evening’s spectrum compared to Monday night’s. An increase in Balmer emission and very slight decrease in HeI emission (assuming that the magnitude is similar between the two nights)
Hugh5 April 2021 at 1:32 pm #584048
In my Alpy 600 spectroscope, the evolution of the spectrum of Nova Cas 2021 is really quite gentle over the last couple of weeks. According to Vmag data from the AAVSO databse, the visual magnitude has also changed only slightly over this time so I’ve made my comparisons in relative flux. The P Cygni profiles on the emission lines remain very strong. Apart from the forest of strong neutral Helium emission lines (HeI) and the hydrogen Balmer lines, I’m also suggesting the presence of two strong pairs of silicon emission lines and even some weaker nitrogen NII lines.
Hugh28 April 2021 at 9:05 am #584133Jeremy ShearsParticipant
News in from Kato-san at vsnet overnight that V1405 Cas might be brightening. Several observers in Japan reported vis or V=7.4 on Apr. 26. He notes “The nova before this brightening was apparently in “premaximum halt” “.
Time will tell – further observations encouraged!28 April 2021 at 9:45 am #584134Daryl DobbsParticipant
Pity it’s cloud, when I looked at it last Thursday it appeared to be mag 8.3 but trees are beginning to interfere. Interesting nova I’ll have to start submitting my observations one day28 April 2021 at 9:58 am #584135David BoydParticipant
The BAA light curve shows it has been rising steadily for the past 2 weeks.
David28 April 2021 at 7:09 pm #584139Gary PoynerParticipant
It seems the BAAVSS database has not combined the alias ‘Nova Cas 2021’ with the correct designation V1405 Cas. The latter shows visual and other photmetric data – which also shows the rise in brightness.
Gary28 April 2021 at 9:34 pm #584140
The He I lines labelled in my low res spectrum from 23rd April may actually be Fe II instead… More spectra planned when the skies clear again…28 April 2021 at 11:48 pm #584141
Confirmation of the emergence of FeII lines after 2021 Apr 3. All spectra are in the BAA database:29 April 2021 at 12:18 pm #584142Andy WilsonKeymaster
I’ve now merged V1405 Cas and Nova Cas 2021 into a single object. Either id can be used to upload data, and they will both show in the V1405 Cas light curve.
Andy (BAA Photometry Database Manager)29 April 2021 at 9:48 pm #584143
A link to the BAA database would be useful for those of us who haven’t used it. That’s what I like about ARAS, all the spectra are easily visible to anyone…plus they are stored in a database for scientific research by the specialists.
And that’s a very nice spectrum…a full sized version on your members page would be good.
Mike.30 April 2021 at 12:19 am #584144Robin LeadbeaterParticipant
The database contains over 8000 spectra currently and is accessible to anyone. It is fully searchable by object name, type of object, observer, resolution, date and as with the variable star database, storing spectra here gives long term security of the data and it will likely still be available to researchers long after we have all passed on.
There is a link to all the BAA spectroscopy resources including the database as a sticky at the top of the section of the forum dedicated to spectroscopy.
(These resources are all brought together on one page in the Equipment and Techniques section)
Robin30 April 2021 at 7:04 am #584145
Thanks for the information, that’s very useful,
Mike.30 April 2021 at 10:03 pm #584150
The link to the Spectroscopy Database is in the tool bar to the right of this forum thread, back up towards the top of the page under the ‘Observations’ heading. Once inside, click on the ‘Review Spectra’ tab and all of the search fields are right there. The spectra can be plotted on the screen or dowloaded as fits files for analysis at your leisure. It’s a fabulous resource.
I put up an animation on my Member page, from the blue-green end of the spectrum. Actually I might add another one for the yellow-red end
Nice to see your prism spectra!
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