Observation by Kevin Gurney: Chromospheric activity in Xi Boo

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Kevin Gurney


Kevin Gurney


2020 Apr 21 - 17:35


2020 May 19 - 17:50



  • Celestron C11
  • Shelyak Lhires III
  • Mesu 200 mount
  • Atik 460Ex

10 subs, 300s each



Target name

Xi Boo


Chromospheric activity in Xi Boo

About this image

My interest was piqued by a web page describing observations of the H and K Ca lines using a Lhires spectroscope (Christian Buil

http://www.astrosurf.com/buil/chromospheric_activity/ )

The observation of emission peaks in the wider absorption profiles of these lines is evidence (apparently) of so-called 'chromospheric activity'.

I tried some of the suggetsed targets including that shown here (Xi boo, HD 131156). The peaks are clear I think.

This was tricky to calibrate as I relied on weak lines due to traces of argon in the usual 'neon' lamp. You should really use the argon/neon lamp but I wasn't about to strip down my Lhires.... I fould two calibration lines that were suitable with a longer-than-usual calibration exposure (45s).

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