1. Pinpointing a stellar X-ray flare using XMM-Newton and VLT/UVES Uwe Wolter Hamburger Sternwarte May 2008 J.U. Ness J. Robrade J.H.M.M. Schmitt

2. The observations: Synchronizing orbits, night-time visibility, instrument schedules, … 2006 October 152006 October 14 Speedy Mic‘s rotation VLT visibility XMM orbit 1254 XMM observations  50 ks XMM-Newton data + 142 VLT/UVES spectra

3. Kürster 1994 v sin i = 132 ± 2 km/s ( Wolter et al. 2005 ) P = 0.380 ± 0.004 d ( Cutispoto et al. 1997 ) The target: Speedy Mic (BO Mic) A single K-dwarf - ultrafast and highly active A giant flare (E > 10 36 erg) DSS, d ≈ 0.0002“

4. A „moderate“ flare in X-rays and optical  Total flare energy in soft X-rays: ~ 10 34 erg ≈ 4.5 hours Wolter et al. 2008 EPIC-pn Rotation Phase Ca K Equivalent width HαHα

5. Chromospheric emission Rotational Modulation Wolter & Schmitt 2005 Ca II K λ 3933 Ǻ

6. Evolution of Ca II K Line Profiles Rotation Phase Wavelength „unsharp masked“ 1.7 Å @ 4000 Å Rotation Phase Wavelength 9.4 h A C B C A B 2006 flare

7. Flare heating and cooling Wolter, Robrade et al. 2008; Reale et al.2004  Loop half length 240,000 km ≈ 0.4 R * 0.5 · log EM [cm -3 ] log T [K]

8. A flare in a context <<<<<<<<<<< Wolter et al. 2008 ESO PR 53-2007 Phase 3.9 Phase 4.2 Phase 4.6

9. X-ray flare sites can be localized by simultaneous optical / UV Doppler imaging Summary Wolter, Robrade, Schmitt & Ness 2008, A&A 478, L12 ESO Press Release 53/07 „Speedy Mic‘s Photograph“ Flare sites are not necessarily conspicuous otherwise „ … on returning within 60 seconds was mortified to find that it was already much … enfeebled.“ (R. Carringon 1859, MNRAS XX)

10. Appendix

11. Outlook: Chromospheric heating events He I 5875, Ca II 3933 and XMM-pn at 300 s resolution Rotation Phase

12. A „solar-like“ spectrum Na D 2 5889.97 Ǻ Na D 1 5895.94 Ǻ H β 4861.34 Ǻ H α 6562.81 Ǻ Ca II K 3933.68 Ǻ Ca II H 3968.49 Ǻ Arcturus (α Boo, K1 III, T eff ≈ 5200 K ) (NOAO)

13. e.g. Deutsch 1958, Vogt & Penrod 1983, Wolter 2004 The Doppler imaging principle: Line profiles → spatial information

14. Speedy Mic vs. Sun Ultrafast rotation and high activity Valenti 2001, Sterzig & Schmitt 1997, Cardini et al. 2007, Balihunas et al. 1995 Sun Speedy Mic

15. Lost and found

16. „Ultrafast rotators“

18. BO „Speedy“ Mic in 2002 (HD 197890)

19. Aug 2 „6400 Å“

20. Aug 7 „6400 Å“

21. Photometry 2002 (SAAO)

22. The Prominences …

23. Evolution of H α (Aug 2) line profiles

24. H α (Aug 2) Ca II K (Aug 2)

25. H α (Aug 2) „A densely packed prominence system beyond co-rotation“ H α (July 19) Dunstone et al. 2006 (adapted) r = 3.5 ± 0.6 R * r ≈ 5 ± 1.5 R * R k = 1.95 ± 0.07 R *

26. Collier Cameron & Robinson 1989 Donati et al. 2000 RXJ 1508.6±4423 („post T Tauri“) H α emission AB Dor H α absorption transients Stellar prominences

27. The Plage(s) …

28. φ = 112° θ = 130° Localizing one stellar plage Ca II K (Aug 2)

29. „Localizing one (?) stellar plage“ φ = 112° θ = 130° φ = 72° θ = 99° (Aug 7) Ca II K (Aug 2)

30. The Flare …

31. APOD April 2006 „Astronomers love stars …“ „… and we have a fine one right near us.“ (Zirrin 1988) DOT HαHα

32. H α pre-flareH α flare (21:06 UT) Johns-Krull et al. 1997 The 1993 March 6 solar flare

33. „Unfortunately, the observer was eating lunch when the flare began.“ GOES „soft X-ray“ 20:23

34. (near max.) Solar flare H α profiles

35. Another solar flare (H α – 0.5 Å) Zirrin 1988 (BBSO) „after peak“ higher density „raining down“