Nova Del 20/08/13

[Gasman]

Hi folks

Some nice emission lines from Nova Del, Hbeta seems to be increasing

Steve

[michael.h.f.wilkinson]

Very interesting. I have no spectroscope, but I wonder if the nova will "blink" (apparently increase in brightness with respect to other stars) when using a UHC filter. I use that effect to pick up near stellar planetaries. The effect is probably small, but if the weather allows, I will try that later.

[nytecam]

Don't think that will work. Unlike the PN that only emits at descrete wavelengths - the nova has a 'continuum' covering all wavelengths just like a regular star but in a nova's case has superimposed narrow emission lines as indicated. This effect needs a spectroscope :-/

[Gasman]

Would it be fair to say it is fading slightly overall despite the individual lines increasing in brightness judging by the last few days? I haven`t compared its brightness to other stars.

Steve

[michael.h.f.wilkinson]

The central star in some stellar PNs contributes a lot of continuum as well, and yet the is still a weak effect. It may be way too small of course in this case. Given my filter-switch diagonal, it is a matter of operating a single slider to try it.

[Gasman]

It would be interesting to try that Michael, might dig out my UHC too!

[michael.h.f.wilkinson]

I just looked at the nova through a UHC filter (and without). Without the filter it seemed fainter than a nearby mag 6.4 comparison star, with the filter, it was distinctly brighter.

Quite pleased with that

[Gasman]

Nice one Michael, interesting to see the UHC makes a difference. Been clouded out here for a few days

Regards

Steve

[chiltonstar]

With so much of the visible light now as H Alpha, it would be interesting for someone with an H Alpha filter to see if that brightens it relative to the surrounding stars?

Chris

[michael.h.f.wilkinson]

It should work. UHC transmits H-beta, H-alpha should show a more pronounced effect, but is beyond the spectral range of the rods in the retina.

[chiltonstar]

It should work. UHC transmits H-beta, H-alpha should show a more pronounced effect, but is beyond the spectral range of the rods in the retina.

Even though the rods give the low level vision and the cones the colour, surely most people should still be able to see H Alpha surely on a point source - at 656.3 nm it is within the visible range (390 - 700 nm).

Chris

[nytecam]

Even though the rods give the low level vision and the cones the colour, surely most people should still be able to see H Alpha surely on a point source - at 656.3 nm it is within the visible range (390 - 700 nm). Chris

Is this not wishful thinking? One can clearly see Ha in solarscope under high intensity BUT at night on a faint star with a shift of the eye's sensitivity....

[michael.h.f.wilkinson]

It heavily depends on the brightness of the source, and the size of the scope. If the source looks red or yellow, the cones are still active

[chiltonstar]

It heavily depends on the brightness of the source, and the size of the scope. If the source looks red or yellow, the cones are still active

Yes - the nova certainly looks reddish orange to me ie colour vision is still working - and I can certainly see coloured doubles of the same mag....Chris