Spectroscope

[gareththegeek]

Is it possible to buy a spectroscope eyepiece or anything similar that allows you to view emission spectra for stars? If so would it only work for very large apertures? Would you only really see hydrogen frequencies?

[Iris]

Try here...

Paton Hawksley Education Ltd, star analyser

[Merlin66]

The Star Analyser ( or Rainbow Optics) grating is a great way to start! They just screw onto a standard eyepiece and will show the star's spectrum.

A small cylinderical lens is sometimes used behind the eyepiece to "widen" the spectrum - to make it easier to see, but this also spreads the light making the spectrum fainter.

A small prism mounted behind the eyepiece will also show stellar spectra, as will the Direct Vision type spectroscopes.

They show the whole spectrum from UV to IR.

The star analyser can be mounted infront of a webcam/ CCD to provide images of the spectrum. A graph ( for analysis) can be prepared using the freeware VisualSpec program.

The resolution of all these types ( as there is no slit invloved) is limited by the linear size of the star image, hence a low f ratio ( f5 etc) can give better resolution as the star images are smaller.

Hope this helps,

Ken

[gareththegeek]

Cool, thanks! I guess I need to get into imaging first to get the most out of spectroscopy but definitely something I'm interested in long term.

[riklaunim]

Star Analyser is simple and quite good. You can use it on stars, planets and even on nebulaes with good imaging equipment (you get cool effect of mirror images of the nebulae in O-III, H-Alfa etc. )

You can look at my Sirius spectrum made with Star Analyser and DMK21, VSPEC processed.

[gareththegeek]

Awesome, gonna have to brush up on my physics! Its good to know those results can be achieved with an explorer 150 (as I am seriously considering buying one), thanks.