Arcturus

[Dazraz]

April 30, 2010

Arcturus, which is the third-brightest star in the night sky, is high in the east at nightfall and high in the west at first light tomorrow. The light from Arcturus that reaches your eye tonight has been traveling through space since 1973.

AMAZING !

[Merlin66]

Wait until you see the spectrum!!!!

Ken

[Dazraz]

Wait until you see the spectrum!!!!

Ken

When you say spectrum what do you mean ? sorry im a newbie

[GuillermoBarrancos]

It's one big grey wet mass here at the moment and gonna stay that way for coming days.

[Doc]

Ken have you got photo of the spectrum to post up, I'm sure loads of us would like to see it.

[Deneb]

Arcturus - Thats one fine Star, reminds me of the brightness of Capella.

If you've got a pic Ken, I would like to see it as well.

Nadeem.

[Merlin66]

Arcturus spectrum

The big boys do even better than me!!

As a K1 III star ( see Kalers' "Stars and their Spectra") it's pretty interesting!

Ken

[Deneb]

very interesting, i don't think i'll count how many colours I can detect with my human eye.

Nadeem.

[barkis]

Is there a device on sale now like an eyepiece, but is actually a diffraction grating that shows a stars spectrum directly to the eye.

I suppose also, it can be EP projected to a camera sensor to record the specta. I can't give a link unfortunately, as I just remember reading it, the memory triggered by this post.

Ron.

[Doc]

There's a filter you can screw to your eyepiece.

Paton Hawksley Education Ltd, star analyser

[DarkerSky]

April 30, 2010

Arcturus, which is the third-brightest star in the night sky, is high in the east at nightfall and high in the west at first light tomorrow. The light from Arcturus that reaches your eye tonight has been traveling through space since 1973.

AMAZING !

It is amazing. The reality of time travel with your eyes! I always like to think of it the other way around - what a planet orbiting somewhere else would see of our solar system and Earth.

[Merlin66]

The Star Analyser grating can be mounted in the nosepiece of a webcam/ CCD to produce an image of stellar spectra.

A great starting point in spectroscopy!!

[Deneb]

mm, looks like I might have to look into one of those, maybe a 2" version if it's available.

Nadeem.

[Merlin66]

Nadeem,

They, and the similar Rainbow Optics gratings only come in the 1.25" filter size...

A larger size wouldn't make any difference. They will provide a nice bright stellar spectrum, the length ( and brightness) varies with the distance between the grating and the CCD chip.

There's a neat spreadsheet ( TransSpec V2) which allows you to calculate the size of the spectrum, resolution etc on the Y! group files. Copy attached.

Ken

TransSpecV2.0.zip

[acey]

Are they worth using visually, or only with a CCD?

[Merlin66]

IMHO they are far better when used with a CCD/ DSLR. Don't need a driven mount.. just let the star drift across the FOV - this will widen the spectrum and make it look sexy!

Regulus! Astronomy Education: Spectroscopy

Sooo easy to make a start in spectroscopy.... and I'm always here to help!

Ken

[barkis]

There's a filter you can screw to your eyepiece.

Paton Hawksley Education Ltd, star analyser

That's probably what I have seen Mick.