Still not happy with the sky background removal.....I've tried various programs but still seem to end up with residual "absorption features" - Na etc.
Don't honestly know the answer to this one....may be I'll have to dump the data and try again when there's less smoke/ haze around.
Bumma.
Finally got some results which I think are OK.
Minor P-Cyg still there in Hb?
The Ha emission line certainly seems to have brightened - just look at the comparison ADU count between the Hb peak and the Ha peak!!!
The clouds have now set in for at least the weekend...anyone else managing to collect data???
Last edited by Merlin66; 16-02-2014 at 10:33 AM.
Reason: correct the header on the Hb profile!
Finally got some results which I think are OK.
Minor P-Cyg still there in Hb?
The Ha emission line certainly seems to have brightened - just look at the comparison ADU count between the Hb peak and the Ha peak!!!
The clouds have now set in for at least the weekend...anyone else managing to collect data???
Cloudy here as well but unfortunatley not much rain. Only had 9mm total over the last few days.
I suggest you should normalize your spectra (set continuum to unity at a given wavelength) as that would make comparisons easier and more meaningful, and conform to 'standard practice'.
Steve Shore has just issued a note on the nova...
Too large a PDF to attach - email me for a copy.
The following is an extract for observers:
Extract from Steve Shores Notes of the 16th Feb 2014
On the other hand, V1369 Cen will remain, like V339 Del, a gift that keeps giving. At only _7 now, it’s still too bright to comfortably do with HST so the STIS pointing will be on hold while the V339 Del observation is still set for the observational window in April. At the current rate of decline and spectral change, any high resolution spectra of V1369 Cen, taken with a cadence of about once per week, will be very valuable with a special emphasis on the 4500 - 5200°A region for the N III 4636, He II 4686, Fe II transitions, 5400 - 6100°A for [O I] 5577, [N II] 5755, He I 5876, Na I 5890; possible [Ca V] and/or [Fe VII] 6086. Any spectra longward of 7000°A will be very important for the Ca II, O I, and He I lines and also to see how the Paschen lines develop. But the frequency isn’t pressing. Remember, these are legacy spectra. We have almost an embarrassment of riches here but this will remain, permanently, as a record. The more uniform the coverage, given all we’ve learned from the first campaign, the more valuable it will be for the future.
Don’t forget, this is real-time astrophysics and no event will ever repeat quite the same way. It is always a frustration, you know this yourselves, to go back through the literature with knowledge from the future and lament the lacunae of the past.
More will be coming and, always, thanks so much! .
Here is a spectrum from the 18th. Had to process two versions - one unstretched, in which you can see little detail other than the now huge Ha line, and one with a linear stretch applied that saturates Ha but allows the other lines to be seen.
Some movement in the last week. [Oi] 6300 grows, and now has a partner [OI] 6364. Na and some FeII lines fading.
Jon,
The Hi sitting over us sounds promising for tonight....
Malc,
What set-up were you using? Beamsplitter/ Al's reticule/ PHD???
As I've mentioned previously, a bit of a fiddle to set-up but has proved to be very effective...
Hope you have more success soon.
Malc,
What set-up were you using? Beamsplitter/ Al's reticule/ PHD???
As I've mentioned previously, a bit of a fiddle to set-up but has proved to be very effective...
Hope you have more success soon.
No Al's reticle yet, using a beamsplitter and the guiding from Maxim as I know it works. I can't leave the unit assembled between sessions so Al's reticle is not going to work for me at the moment.
Main problem is that the nova has faded to the point where it is not visible on my DSLR live view, which makes the whole process a lot more error prone. Seeing was fairly shocking and it was very windy too which didn't help matters. 15 minutes of getting the star centred on the zero order each time, then move the grating to position, expose ... nothing.
Need to decide whether to invest the effort into the beamsplitter guiding or just wait for the reflective slit upgrade. Whichever, I think I am going to have to focus on some brighter targets to get everything working.
Malc,
As long as the beamsplitter/ spectroscope remain together, then the "virtual slit" will always be in the same position.
You can calibrate the microhead/ wavelength on the sun during the day and pre-set the micro to the required central wavelength.
You don't need to use the zero order image all the time.
Certainly the reflective slit/ guiding is easier to use, but the beamsplitter on reasonable bright objects can work well.
Malc,
As long as the beamsplitter/ spectroscope remain together, then the "virtual slit" will always be in the same position.
You can calibrate the microhead/ wavelength on the sun during the day and pre-set the micro to the required central wavelength.
You don't need to use the zero order image all the time.
Certainly the reflective slit/ guiding is easier to use, but the beamsplitter on reasonable bright objects can work well.
Thanks Ken. Unfortunately I have to disassemble everything after each session as it won't fit in the carry case assembled.
Malc,
I don't know what your pain threshold is like....but I think maybe the time has come to dump the storage case and leave the beamsplitter in place...
Just wrap the instrument in a towel for temporary storage.....life is too short.
(The attached screen dump shows PHD locked onto the Nova and the sequence of subs being "farmed")
It was very windy last night but it was clear. I got a reasonable spectra that I will post tonight. Photometry was more of a challenge as the scope kept getting buffeted with wind gusts. I had to try to get exposures between gusts and limited exposures to 20secs.
Hi guys,
(I first erroneously posted this the nova Sgr thread)
I'm new to this V1369 Cen discussion because, until last night, this nova hadn't risen above my urban obstacles to be seen by me at a convenient time.
I've only covered a 150A range (4595-4745A) at R=8700 (SNR~100), using a Lhires III with 2400 grating on a 0.28m scope, as that is where I'm working at for two other long running pro-am projects.
Given that one seldom sees 'high' res nova spectra in this HeII area it may be of interest to researchers and it is interesting to note the triangular profile ... which tends to question statements that this is a classic FeII nova. It is impossible to say if any NeIII or HeII is hidden in this zone but it is most likely that many of the FeII 37 and 38 multiplets are present ... which leads me to suggest this may be a hybrid (FeII b) nova. I've not followed the discussions of this nova here, or on other forums, so this topic may already have been well covered. Unless there are requests for further coverage of this wavelength (unlikely) this is probably my first and last spectra of this nova .. unless I add it to my echelle target list.
Bernard,
Good to see some hi-res spectra of the nova...
Your peak at 4649 (?) doesn't seem to match the HeII wavelengths I have - 4542/ 4686 ??
The NIII at 4838 seems evident?
Now it's observable can you continue the data farming?
