Spectroscope fun

[jonathan]

As it was the last day of the holiday season I decided to clear away a few things, at the bottom of the pile on my desk was a plan for a spectroscope which I had downloaded from http://www.iucaa.ernet.in/~scipop(don't think it's there anymore but I still have the PDF), printed out but not got around to mounting on card and putting together, so it was now or never.

Here are the results, it took me about 30 minutes to construct, a fun little project.  I then proceeded to run around the house looking at all the different light sources I could find like a kid with a new toy on Christmas Day!

The photo of the spectrum doesn't really do it justice, some energy saver light bulbs had definite strong lines whereas others had a more even distribution across the spectrum.

I would like to get more into this sort of thing but I suppose the application for astronomy may be a bit out of my reach on a back yard refractor budget.

[Alien 13]

Thats brilliant must make one.

Alan

[Oddsocks]

As it was the last day of the holiday season I decided to clear away a few things, at the bottom of the pile on my desk was a plan for a spectroscope which I had downloaded from http://www.iucaa.ernet.in/~scipop(don't think it's there anymore but I still have the PDF), printed out but not got around to mounting on card and putting together, so it was now or never.

Here are the results, it took me about 30 minutes to construct, a fun little project.  I then proceeded to run around the house looking at all the different light sources I could find like a kid with a new toy on Christmas Day!

The photo of the spectrum doesn't really do it justice, some energy saver light bulbs had definite strong lines whereas others had a more even distribution across the spectrum.

I would like to get more into this sort of thing but I suppose the application for astronomy may be a bit out of my reach on a back yard refractor budget.

Jonathan,

Not too expensive at all to get started using your backyard refractor!

You need a star grating filter for the telescope and a web cam or CCD camera, even a DSLR can be used.

The filter will cost between £90 and £120 depending on the type of camera you use and the focal length of the telescope.

Paton Hawsksley Education Ltd produce the SA100 and SA200 filters and these can be found at 365 Astronomy under the description "Star Analyser 100 and Star Analyser 200"

http://www.365astronomy.com/Spectroscopy-c-174/

The software to calibrate and measure a stellar spectrum can cost as little as nothing if you use the excellent and free BASS project Windows software available here:

https://uk.groups.yahoo.com/neo/groups/astrobodger/info

Follow the links under trending topics for the latest beta release, there is a link here but it may not be active for long: 

https://dl.dropboxusercontent.com/u/87095951/Spectro/BASS%20Project/0.0.1.0/0.0.1.9/1.9.0%20beta/BASS%20Project%20Release%20Notes%201.9.0.pdf

If you want to buy software then RSPEC is probably the easiest to master and costs around $100 for a full license and is free to try for a few weeks:

http://www.rspec-astro.com

I bought a Star Analyser 100 filter about four years ago and use it with a ASI USB planetary camera, 100mm refractor and RSPEC software.

With the local light pollution now getting so bad that normal imaging is all but impossible except for a few nights a year it is great to be able on the poor nights to grab a few spectra where light pollution is easily calibrated out and is not important aesthetically to the end result, plus the results obtained actually have some scientific value.

For all of 2015 I only managed three full astro images but took over a hundred spectra so actually felt I had achieved something by the end of the year!

William.

[Gazabone]

I made one of these a few months ago and they do work very well indeed.

[DaveS]

I bought a Star Analyser 100 filter about four years ago and use it with a ASI USB planetary camera, 100mm refractor and RSPEC software.

With the local light pollution now getting so bad that normal imaging is all but impossible except for a few nights a year it is great to be able on the poor nights to grab a few spectra where light pollution is easily calibrated out and is not important aesthetically to the end result, plus the results obtained actually have some scientific value.

For all of 2015 I only managed three full astro images but took over a hundred spectra so actually felt I had achieved something by the end of the year!

William.

This is a bit worrying. Whereabouts in Dorset are you ? Roughly.  I image from suburban London (NELM 4.35 / Bortle 7.5 on a good night) and have no trouble with narrow band, even with a bit of moonlight. If yours is worse than this it is indeed dire. One reason for my querry is that I hope to retire to Dorset and would be concerned if the LP is getting worse.

[saac]

Jonathan that's a cool diy spectrometer you've got there.  I've used similar made from DVDs in the classroom and like you I found they do give pretty good results on different energy saving lamps - well defined spectral lines.  If you want to take things further for non astronomical use then you may be interested in Public Lab.  They are a USA based outreach program with the aim of encouraging public participation in science, particularly on local environment issues.  They have a number of diy spectral kits but they also provide a spectral analysis tool called Spectral Workbench.  I've attached links below.

Jim 

http://store.publiclab.org/

https://publiclab.org/wiki/spectral-workbench

[Stub Mandrel]

The quality and ingenuity of educational materials in India is incredible, all done on a shoestring and all focused on being practical and working.

These 'toys' linked to on that site are legendary: http://www.iucaa.ernet.in/~scipop/Teachers/toys.html

[Merlin66]

http://www.samirkharusi.net/spectrograph.html

Another easy built spectrograph using a transmission grating.

Spectroscopy can be fun, challenging and very satisfying.

[StuartJPP]

Here's the link to the PDF...

http://www.iucaa.ernet.in/~scipop/Obsetion/spectro/iucaa_mvs_spectroscope.pdf

[Oddsocks]

This is a bit worrying. Whereabouts in Dorset are you ? Roughly.  I image from suburban London (NELM 4.35 / Bortle 7.5 on a good night) and have no trouble with narrow band, even with a bit of moonlight. If yours is worse than this it is indeed dire. One reason for my querry is that I hope to retire to Dorset and would be concerned if the LP is getting worse.

I am on the Eastern side of Christchurch, been here twenty years, the last ten years or so has seen the sky glow from Bournemouth and Poole gradually spread along the coast to join up with that from Southampton in the East.

Narrow band used to be easy here but my nearest commercial source of LP switched to broadband LED floodlights, switched on most nights until one or two AM, sometimes left on continually twenty four hours even though the premises are closed. Narrow band filters are totally ineffective against broadband LED sources and because they are cheap to run and now inexpensive to buy many more businesses are installing them and leaving them on all night.

Unfortunately, while not wishing to get into politics most of the southern counties coastal towns and cities are run by a political party that puts financial interests before environmental ones, even at the local level there seems to real attempt to improve the environment, even where the costs are low or neutral, but suggest opening another twenty four hour flood lit drive through and your planning application will be waved through despite any local objection to the environmental impact.

From my garden you can see not see the milky way at all and only the brightest stars are visible. My eyesight is pretty poor these days but even on a moonless night I can easily read a newspaper in the garden and we have no street lights in my village!

My NELM reading is 3.889 on an iPhone 5s using the Dark Sky App.

Poole, Bournemouth and Southampton all match or exceed London light polution levels and due to the often damp coastal mists that roll inland the orange glow from these cities spreads far and wide.

The best dark skies in Dorset are in the east of the county and inland from the coast, Axminster, Blandford, Dorchester, Crewkerne, Bridport, Beaminster, Chard and Yeovil all have typical levels of LP for large conurbations but just a few miles outside these towns the skies are really dark.

All of the popular Dorset sea-side towns are ruined now and you need to be at least ten miles from these before finding dark skies.

Such a shame really, I remember holidaying with my parents in Poole sixty years ago and being amazed by the Milky Way, living in West London we never saw it there but even from Broadstone near the centre of Poole you could see it clearly right up until the early 1970's but you won't see it from there now!

[Oddsocks]

The best dark skies in Dorset are in the east of the county and inland from the coast,

That should have said " The best dark skies in Dorset are in the West of the county and inland from the coast"

Left it too late to edit the original post......

[DaveS]

Thanks for that info Oddsocks, even though it is very depressing especially the LEDs ruining NB which I thought fairly LP proof. I have glimpsed the milky Way from my old garden in Acton, west London but that was back in the '80s. I used to go to school just up the road from Blandford and remember nights with so many stars it was difficult to pick out the constellations.

[DaveS]

Ah, thanks for the clarification, I think you were typing at the same time as me. Need-Less flagged up a spot near East Bexington as the darkest area in Dorset, so I was a little perplexed, sorted now  . I saw on Rightmove a 2 bed bungalow with land in West Bexington for £375k. Not surprisingly it went before I could make an offer.