Those who want to start on Spectroscopy of the stars, planets and more celestial bodies, the above software is the way to go! I am doing everything with this software and they also provide the grating you would be needing. This works with any kind of telescope and even with your simple DSLRs!
This is the comparison of the spectra of the two last planets of our solar system, Neptune and Uranus. Uranus is still very low in the eastern horizon these days but i tried it anyway, almost at the end of the night sky.
Look at these two lines on the graph. Blue represents Neptune and the green is of Uranus. They match so closely, indicating that the chemical composition of these atmospheres are so closely related.
Wondering around in The Sky X, i saw this very deep red colored star and thought of taking its spectra. It is relatively a bright star and to keep the ADU counts in control, 10 seconds of exposure seemed fine. I got 150 images in total, hence a 25 minutes of total exposure.
This (HIP 105562) is an M7 class star, a very cold star, relative to the stellar temperatures. The estimated age of M class stars (main sequence lifetime on H-R Diagram) is actually much more than the lifetime of the Universe, which means this Universe in all its age of around 14 billion years has yet to see a death of a single M star! Any star that is born as an M type will live trillions of years!!
Since they are very cold so they are not bright in the night sky. You cannot see most M type stars with your eyes only, from any of the best night sky locations on earth. Our Sun has most of its neighbors of M class stars, about 75% of all the closest stars. Proxima Centauri, our nearest star to our sun is infact an M star and it will live some 4 trillion years.. talk about lifetime!
Such low temperature in these stars allow to create molecules in their atmospheres. I could easily locate Titanium Mono Oxide (TiO) absorption bands all over the spectrum of this star. Calcium (Ca) is there at 4227 angstrom. Famous Sodium Doublet (D1 and D2) are at 5896 5889 angstroms. Present Calcium form a bond with Hydrogen and makes Calcium monohydride (CaH) at 6750 angstrom.
Here is the calibrated and Normalized Spectrum from Rspec:
This is the spectrum of the furthest planet of our solar system. Neptune, these days, is for an early riser or for those (like me) who don't sleep at night. But when i saw the spectrum of Neptune, it was beautiful and so filled up with absorption bands.
Rspec does wonderful things; among them is that it fills the graph with corresponding colors of the wavelengths of light. Looks so great!
This graph has been calibrated by my instrument flux response and you can see Neptune is emitting its most of it light in the blue hue; red is very low here. Makes sense, since Neptune looks exactly like this in the telescopes.
The X axis shows the wavelengths in Angstroms and the Y axis is the intensity of each wavelength. I tried to find the absorption details for this spectrum but it seems there is not that much in visible spectrum on the web. The following image identifies the lines of mostly Methane and some Hydrogen.
Okay so this is the first compilation of the spectrum of 'all' types of stars from the observatory! Earlier i listed here some of the details about the hardware and software i am using to do the stellar spectroscopy.
Data reduction and stacking was done with Maxim DL software and spectroscopic calibration was performed in Rspec software and from here, i have received these above spectra of stars.
There is a lot to say about the stellar classification; i will however very briefly explain a few things here:
1. O type stars are the hottest stars and the temperature decreases towards M class where the temperature is the coolest.
2. Hotter stars emit more light towards bluer region of the spectrum and the cooler stars towards the redder.
3. The dark lines are due to the electron in atoms present in the atmosphere of the star, absorbing photons being generated by the star itself.
4. A type star has the strongest Hydrogen Absorption lines.
5. These absorption lines increase as the temperature gets colder so new atoms and even molecules can form in the atmosphere of the stars.
6. Our sun is a G class star and emits most of its light at the green wavelength.
So enjoy the colors in the picture and the variations in them. You can think why and how of science of spectroscopy but these colors are.. just so beautiful :)
This just happened a few minutes ago.. I was capturing the spectra of a star and the airplane just crossed the field and the lights got through the grating :) Cool Image!
I have always wanted to do spectroscopy of the stars here at my observatory. There have been a lot of photometry (multi band as well) that i have done in the past years. Though i will be doing it again but for now, its finding more about the stars with Spectroscopy.
I will write much more about the equipment that i am using for my setup here and how did i managed to adjust it appropriately; for now it is enough to say that i am using my Celestron C14 telescope and SBIG ST9XE CCD camera with Star Analyser grating.
I am capturing the images through SkyX Pro software. This is the software that controls my whole observatory. Losmandy Titan mount, CCD camera and all its accessories. The controls are so intuitive and once you know how to use it, you are almost on autopilot using it.
I use Maxim DL for data reduction. This has been THE software i have used for years, for data reduction and some analysis. I finally used Rspec software for analyzing the spectrum of Vega. Tom Field who wrote the software and is a big big help in promoting spectroscopy in amateur community around the globe, has been a good friend of mine and so very kindly gave me this software free of charge. Thanks a million my friend!
Vega is already a very bright star and my telescope's 14 inch mirror makes it very hard to not saturate the pixels. These days it is very hazy here.. clouds, high winds and what not. My exposure was 10th of a second for every sub i got! Yes it is super short exposure but i was also fighting the wind.I captured hundreds of images and selected the least effected by the winds.
Here is the image of the star Vega and its spectrum:
Already i could see the absorption lines in the spectrum! What a view :) Vega is of Spectral class A and in this class Hydrogen Absorption lines are easily seen. Those who know, balmer series is right in front of you!
I did the calibration of this spectrum in Rsec and did a non-linear calibration to get more precise measurements of the absorption lines in the spectrum. Here is the snapshot of the calibration process.
After the calibration process the hydrogen lines fell at the right place. Here i have identified them with the wavelength. See, how cool is that! So i announce to the world: Vega has hydrogen folks!! Go ahead and re-write your textbooks.. :) ok.. alright.. i am being over excited here.
This is just a start.. I have collected a lot of data with my spectroscopy setup and will be analyzing it all and posting it very soon.
