Blue Planetary Spectra

[Terry B]

Dear All
I aimed my LISA spectrograph at the blue planetary neb in Centaurus. It is a mag8.4 and is 12arcsec across. A good target for the spectrograph.
Using a 24um slit I achieved the spectra below. I have labelled lots of the lines. There is virtually no background spectra. Just emission lines. This demonstrates why narrow band filters work so well with planetary nebs.

[lepton3]

Fascinating. This is a whole league forward from slipping an OIII filter in and noticing everything but the planetary gets dimmer.

How faint a target is practical with your rig?

-Ivan

[Terry B]

I Think the limit is my ability to put the target on the spectrograph slit. If the object is visible with a 5sec exposure on my STi guided then I can probably succeed. ?mag 13 but I'm not sure til I try.

[madbadgalaxyman]

Terry,
My goodness, look at all those spectral lines. You must have enjoyed identifying them.

That spectrograph of yours is a really serious instrument, as I have just realized. I haven't followed the progress of amateur spectroscopy over the years, but I may be able to suggest some really weird and bizarre extragalactic targets that have decently high surface brightness, as I do a lot of scanning of galaxies data and galaxies papers.

cheers,
Robert

[Terry B]

Thanks Robert
There has been lots of progress with amateur spectroscopy.
Take a look here.
http://www.astrosurf.com/aras/index.htm
My LISA spectrograph certainly gives very repeatable accurately calibrated spectra. The resolution isn't high but it can certainly be used for some research.
I've been following some of the recent novas with quite good success.
Cheers

[madbadgalaxyman]

Terry,

As far as "gettable" spectra of weird objects, without too much stress, I was thinking along the lines of exotic objects such as Blue Compact Dwarf galaxies and some phenomena near the centres of galaxies such as starburst regions and Active Galactic Nuclei. The visible-wavelengths surface brightness is high in these objects, so it ought to be possible for amateurs to get a spectrum.

I recently (last year) discovered a Voorwerp (an intergalactic
emission-line emitting cloud that is lit up by - hypothetically - AGN activity in a nearby galaxy), but this might be really hard to get a spectrum of.....it is barely visible on Digitized Sky Survey on the internet!! I found lots of other unusual things in a two month period when I was exploring GALEX far-ultraviolet imaging of galaxies (I was doing this, literally day and night, about 20 hours a day, but then the typical amateur pattern of being distracted by something else, happened)

cheers,
Robert