Rob_K
07-01-2014, 11:19 PM
Just for a change of pace! Tonight I was tinkering with my telescope to make sure it was right for a public viewing night I'm assisting with on Thursday. I thought I might screw the Star Analyser grating into an eyepiece to see what I could see (if anything) of V1369 Cen (Nova Centauri 2013).
First thing I noticed in checking some bright stars is that the telescope (& eyepiece combination) wasn't really the right tool for the job. 4.5" f8 reflector at 43x was giving just too small an image scale with the spear of the spectra only a few arcminutes in apparent length. Bigger aperture at considerably more magnification would be much better.
Still waiting for the nova to clear trees, I punted on Eta Carinae. It was bright enough to throw a reasonable spear and I was pleased to see that the H-alpha emission gave a tiny little red dot at the red end! But there wasn't much else I could discern.
I had the telescope on the nova as it finally cleared the trees and spent a bit of time looking at it. The spear of the spectrum appeared to be less 'stable' than Eta Car, don't know if it was the poor seeing or not but it seemed to shift around, one second the red end strong and next second the blue. Very hard to hold for more than a moment. Nonetheless I was able to make out the H-alpha emission as a pinprick of red on the end of the spear and in a few moments of clarity I could see the bright cyan of the H-beta emission. Pretty pleased under the circumstances but probably not something I'll do regularly in the future!
Cheers -
First thing I noticed in checking some bright stars is that the telescope (& eyepiece combination) wasn't really the right tool for the job. 4.5" f8 reflector at 43x was giving just too small an image scale with the spear of the spectra only a few arcminutes in apparent length. Bigger aperture at considerably more magnification would be much better.
Still waiting for the nova to clear trees, I punted on Eta Carinae. It was bright enough to throw a reasonable spear and I was pleased to see that the H-alpha emission gave a tiny little red dot at the red end! But there wasn't much else I could discern.
I had the telescope on the nova as it finally cleared the trees and spent a bit of time looking at it. The spear of the spectrum appeared to be less 'stable' than Eta Car, don't know if it was the poor seeing or not but it seemed to shift around, one second the red end strong and next second the blue. Very hard to hold for more than a moment. Nonetheless I was able to make out the H-alpha emission as a pinprick of red on the end of the spear and in a few moments of clarity I could see the bright cyan of the H-beta emission. Pretty pleased under the circumstances but probably not something I'll do regularly in the future!
Cheers -