It appears that V1369 Cen (Nova Cen 2013) is getting brighter again. I watched the nearby stars fade with this mornings twilight. It is at apparent Mag 4.3 with no obvious colour through binoculars.
I logged a report in the visual thread. Nova Cen 2013 just keeps on giving.
Great to hear you're back on the job Terry, even if it's going to be intermittent!
I've been getting an odd low-res spectrum and have attached one from last night (3 Jan 2014). No graph, I realise now that it's pushing jpeg data into places it shouldn't go! I notice a few lines that seem to be firming up but am having difficulty identifying some of them. Calibration isn't perfect but I think there's a Ca I line at 612nm and possibly an Fe VII line at 572nm. There's a line at around 628nm and even with calibration issues I can't see how it would be O I at 630nm. There's also a line at around 530nm and Fe I emissions at 527/533nm seem way too far off. Advice, opinions welcome.
Nice work. I expect the 530 Nm line is the FeII 5317 A line. The strength of FeII continues unabated - this is the phase Steve Shore calls "the iron curtain" phase, which hasn't lifted yet. Look at the strength of FeII 4924, for instance. Although in your spectrum this is closer to 490 Nm.
The line you have at 612Nm line could well be FeII at 6148. In fact, it's hard to see what else it could be. But there's a pattern here - these lines are showing up on your spectrum about 2 Nm blue of where they should be. That's pretty consistent with the sorts of velocities we've been seeing in the red and blue shift - up to 1500 km/s, which is 3 Nm at the wavelength of Ha. Calibration is a bit tricky - if you look at your Hb, it runs from about 482 at the blue end of the absorption line to 488 at the red end of the emission. Again, I suspect this is a bit blue of where it should be; I suspect it would be worth recalibrating. Maybe use the NaI at 5892 as a reference, and set that point towards the blue end of the emission line.
I had a lovely clear evening and took a number of spectra of Be stars. Went to bed at 11pm and got up at 3am to find a thick peasoup fog. Not a star to be seen so nothing from me last night unfortunately.
Bumma!
I know what it's like....very frustrating.
I did get the usual Hb/Na/Ha spectra last night, but still working on them.
Hopefully I'll upload the backlog later today.
Bumma!
I know what it's like....very frustrating.
I did get the usual Hb/Na/Ha spectra last night, but still working on them.
Hopefully I'll upload the backlog later today.
Looking forward to them!
Having another look at Rob's spectrum, it seems that we may be seeing the emergence of [OI] at 6300 and 5577. This is expected at this stage. This nova seems strong in OI, from what I'm reading this being a feature belonging to the wind coming of the secondary red giant energised by the initial nova outburst. But I don't understand the relationship between OI and the forbidden [OI] - the next thing on my reading list
Finally got some time to process my efforts from 2 nights ago (3rd Jan), my first spectrum of 2014
H_beta has really dropped in relative intensity, on a par with the FeII lines. Anyone else seeing this?
I have a spectrum from the 4th to process too, might not get to upload that until tomorrow.
Brightness is on the up again(!), AAVSO visual estimates coming in around 4.5, up from around 5.0 3 days ago. There seems to be a pattern emerging in the oscilations of slow rise, fast decline.
Interesting. Hb definitely less intense compared to the nearby FeII and Ha, as Malc found. Also FeII at 5018 less intense than FeII at 5169 - it was a different story a week ago.
I'm wondering if what we're actually seeing here is an artefact of the SA100 resolution. There seems to be complex structures of emission and absorption now visible, as the outer layers of the ejecta become optically thin. I wonder if the SA100 is just capturing a lessened emission when in reality what's there is a strong emission and a strong absorption just next door?
I took a spectra this morning about 2:30 so at an airmass of 1.9
With a quick check at the time, the Ha is much stronger and there seems to be a widening of all of the lines especially towards the blue. I will have to check my calibration but the telluric lines were identical with my last spectra so it should be real.
I will process it properly tonight when I'm home from work.
Sorry for the delay.
The attached spectra cover the various regions from 31st Dec/4th and 5th Jan
I also show a comparison of the changes around the Hb and Fe lines.
Comments welcome.
Great Ken
Here is last nights data compared with 28/12/13.
I have 2 versions. The first is flux calibrated.
The magnitude last night was V= 4.88 compared to 4.27 on 28th so it has dropped somewhat.
The overall flux has reduced including the output at Ha and Hb.
When I graph the spectra as "relative intensity" there has been a increase in the intensity of all the emission lines compared to the continuum.
Great stuff Ken, Terry, Jon & Malc! Here's mine from last night, just to add a bit of colour LOL!
Terry, I gather you are a bit pushed for time but there hasn't been much B-V-R photometry done on the nova. Have you been getting any data in conjunction with your spectra?
Great stuff Ken, Terry, Jon & Malc! Here's mine from last night, just to add a bit of colour LOL!
Terry, I gather you are a bit pushed for time but there hasn't been much B-V-R photometry done on the nova. Have you been getting any data in conjunction with your spectra?
Cheers -
Rob
I have taken simultaneous photometry on the 2 nights I have taken spectra. The data for B and V have been uploaded to AAVSO. I took R and I data last night as well but I don't have comp data in those bands. Hopefully it will appear in the future.
Terry
