Spectra of Alphecca and Arcturus (Johannes D. Clausen)

Spectra of Alphecca and Arcturus

Two stellar spectra from yesterday captured through my C8-Lowspec setup in the 300 lines/mm grating / 30 µm slit configuration.

A combination of continuous bad weather and a busy work/family life has kept me largely away from astronomy for the last year, so this was my first spectroscopy session in almost 8 months. Feeling a bit rusty I decided to start with a couple of bright, easy targets, just to get back on the spectroscopy horse.

Arcturus and Alphecca are the brightest stars in Boötis and Coronae Borealis, respectively. Arcturus is an orange-red giant located some 37 light years away. Alphecca is a binary system at 75 light years distance, consisting of a white main sequence (or according to the Simbad database, subgiant) star of class A0V (or A1IV) and a G5V-class yellow dwarf companion. The A-class component is ~100-fold brighter than the companion star and, hence, dominates the spectrum.

The spectra are shown corrected for instrument response with some of the prominent absorption lines labeled.

Spectroscopy

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