DIY Spectrography on a Budget

Every star's spectrum carries a different pattern of spectral lines — information which can be decoded to study its temperature, surface pressure, and even the atoms it's made of. Using spectra, we don't have to take a long spaceflight to study the stars — in fact, we don't even need to leave our backyards! While spectrography has been in use for hundreds of years, it's long been viewed as difficult and expensive, far out of the reach of amateurs. Nothing could be further from the truth! With recent advancements in technology, it's become possible for an amateur to record high-quality spectra using a dobsonian telescope — no tracking required! If you can take a photo of Jupiter, you can record stellar spectra. During my presentation, I will demonstrate how a backyard astronomer can use the “drift scanning method” to record scientifically useful spectra using nothing but a camera, diffraction grating, and an untracked telescope. I will also discuss simple ways to optimize your resolution, so that you can record spectra that rival those taken with dedicated slit spectrographs costing upwards of $1k. Lastly, I will show off some examples of spectra that I've recorded from my backyard right here in NW Houston. No prior knowledge is necessary, but attendees will likely find it beneficial to know ahead of time what the terms “spectrum”, “absorption”, and “emission” mean, and how to operate a simple telescope. Recommended reading: http://spiff.rit.edu/classes/phys301/... Lauren Herrington is an HAS member with a passion for education and outreach. As a young teenager she fell in love with spectroscopy after reading A Grand and Bold Thing. Too young to have access to any of the standard equipment, she believed that recording spectra of her very own was a distant, expensive, and exclusive dream — until she discovered a method for recording spectra with her 8" Dobsonian right here in Houston! When she's not working to perfect her drift scanning method, Lauren creates and shares educational materials to help other wannabe-spectrographers, available free of charge on her website tiedyeastronomer.com. Lauren is an AAVSO Ambassador, and works for the AAVSO as Webinar Coordinator.