1. Hα observations on the Be binary HR2142 (HD41335; V0696 Mon) by Ernst Pollmann VdS Spectroscopy Group Germany

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3. 2 Special charakteristics  high rotation velocity  „shell-line“ (Phases-dependent) Phases dependent shell line

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7. 6 periodic „gas-stream“ lines 7 6

8. 8 V ≈ 25 – 75 km/s V ≈ – 20 km/s ORBITAL MOTION AND MASS FLOW IN HR 2142

9. 9 Observer Secondary Shell Phase (1,5d) 0.03 – 0.04 Gas stream lines

10. 9 Observer Primary Shell Phase (5-8d) 0.7 – 0.98 Gas stream lines

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13. 0.986 0.858 0.796 0.758 0.525 0.437 0.352 0.215 0.104 0.036 Campain 09/2007-04/2008 11

14. In dependence of phase the emission is seen either as blue- or red shifted V/R variation The central absorption core is developing between phase 0.75 - 1.0 In this phase section the secondary star is between observer and the Be-star 11

15. 12 Philips Webcam for guiding 20cm SC- telescope SC-telescope C14 Self-build Slit-Grating Spectrograph

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17. …thanks for attention….