AAVSO: American Association of Variable Star Observers

Using Bespoke 18-inch Newtonian and R = 3000 Spectrometer for High-Precision Observations (Abstract)

Volume 49 number 1 (2021)

John Menke
22500 Old Hundred Road, Barnesville, MD 20838; John@menkescientific.com

Abstract

(Abstract only) It is quite possible to make high-precision spectroscopic measurements using rather modest (home-built) equipment. This paper describes a multi-year research effort on AZ Cas, a binary eclipsing variable with a 9-year period that has giant red and blue components. The next eclipse is in 2022 when previous observations show that we can expect substantial stellar interactions between the components. There are limited data on the system, including substantial uncertainty of the doppler shifts involved. Preliminary results give hope that doppler shifts can be measured to better than 0.1 Å (about 10 km/s) even with a spectrometer resolution of about 2 Å.