Here's my SA100 spectrum of an hour ago. Stack of 12x40s with a 10"SCT f/6.3 and Atik 383L+. Also a comparison with 12 December.
The FeII lines are stronger than my last spectrum on 12 Dec. Apart from the huge growth in Ha, if anything the new feature is an emission line that could be OI at 7773. There could be OI around 6300-6360 but at this resolution it's hard to unpick them from the FeII(74) lines.
Pete,
Out of interest....what was the issue with your LISA?
3 issues - all duly fixed. It arrived back from Shelyak today so I can test it tonight.
The calibration unit has a spring loading which flips a mirror across to cover the guide optics when taking flats and neons. The spring wasn't properly set in place and so the screen would not retract properly. I had to take the LISA off the scope to push it out of the way by hand.
The other 2 related to the guide unit. I found that guide images were of poor quality and stars showed signs of aberration off-axis.
Turns out there were 2 problems. The first was the slit mirror was misaligned. The second was the guide optics were out of kilter meaning that only stars at one corner of the guide image were able to be focused. So when stars were set for imaging, I couldn't tell whether they were on or to the side of the slit.
I was able to play with the mirror but the guide optics meant that I couldn't correct the image.
Looking at the test shots that Shelyak sent back, I should see a remarkable difference. Francois has been very attentive and helpful.
Looking forward to some clear weather to test this tonight
What time is best for observing this nova? Please tell me its a sensible hour
Pete
Nope. :-)
You could catch it visually with binoculars now or a telescope in the dawn twilight around 4.45. But if you want to image it in any way you'll need to get cracking by about 3.30 I'm afraid.
What time is best for observing this nova? Please tell me its a sensible hour
Pete, depending on your horizon it could be any time. It doesn't clear my roof until about 1am and by 4:30am the sky is getting too bright for a good view.
If you have a recent version of Stellarium enable the "Bright Novae" plugin, restart, wait a few seconds for it to update the data, hit F3, type "Nova Cen and hit Enter.
Last night's low-res spectrum attached (16.58 Dec 2013 UT), SA100 grating with Canon 650D & 200mm lens on Vixen Polarie, 18 x 13 sec, ISO 6400, F/5.6. Nova at 9-deg altitude, bright moonlight, imaged from White Cliffs, NSW, Australia (30.8-deg S). The black area on the left of the bar was an overlapping 'spectrum' of a tree in moonlight!
Here are four spectra from 6 December (initial maximum) to 16 December showing the evolution of the lines to I think the level of resolution achievable with my SA100 and system.
Apart from the obvious Balmer emission lines (and hint of P Cygni visible in the 6/12 Ha line profile), and the clear evolution of the FeII lines, there is what I think is NaI at 5889. Also strong growth of an emission line around 7773 - is it the OI triplet?
Here are four spectra from 6 December (initial maximum) to 16 December showing the evolution of the lines to I think the level of resolution achievable with my SA100 and system.
Apart from the obvious Balmer emission lines (and hint of P Cygni visible in the 6/12 Ha line profile), and the clear evolution of the FeII lines, there is what I think is NaI at 5889. Also strong growth of an emission line around 7773 - is it the OI triplet?
Cheers
Jonathan
Looking great Jonathan!
Do you think you will submit them to the ARAS database? Mine are looking awful lonely there, and represent a very low bar to exceed I'm clouded out again tonight.
I wonder if that feature at ~7770A might be second order contamination, or do you have something in place to cut that?
Do you think you will submit them to the ARAS database? Mine are looking awful lonely there, and represent a very low bar to exceed I'm clouded out again tonight.
I wonder if that feature at ~7770A might be second order contamination, or do you have something in place to cut that?
Cheers Malc. Yes, I think I'll send them to ARAS once I fathom the format. I also need to get registered there - my messages to Francois seem not to be getting through.
Ah yes, second-order contamination. Good point. I've only just got a mono CCD quite recently, and was doing spectra with a DSLR. So everything up beyond 7000 A is new territory for me. I've already made a clanger with the telluric absorption at 7600 that Ken kindly put me right about.
John has now included a section on the preparation of the necessary BeSS fits header and gives guidelines which include checking the final format. Worth looking at.
If you need help just let me know.
Quick and dirty spectrum from this morning. I'll stack and polish later, :-) this is just one 3s sub. The reason it's only 3s is cause as you can see the Ha line is going nuts. So I'm starting to take two set of images: one where everything is in linear range, and another set where I let the Ha line saturate so as to get more detail with the other lines. I hope this is a reasonable thing to do :-)
John has now included a section on the preparation of the necessary BeSS fits header and gives guidelines which include checking the final format. Worth looking at.
If you need help just let me know.
thanks Ken. Jeez, you're not having much luck with the clouds down south, are you?
Whoooooooooooo!!!!!!!:eyepo p:
What a difference a day makes!
Looks like there are few (!) options available - super saturate the Ha in longer exposures or many, many short exposures and add them.
Fantastic stuff - well done Jon!
I'm clouded out again tonight.
:eyepo p:
