1. The solar limb during eclipses: Flash Spectrum Region and Baily beads Costantino Sigismondi ICRA-Sapienza, Roma; Université de Nice-Sophia Antipolis and IRSOL Istituto Ricerche Solari di Locarno sigismondi@icra.it post-éclipse meeting, IAP 30.9.2010

2. ICRA and solar physics www.icra.it/solar

3. Participating institutions ICRA, International Center for Relativistic Astrophysics Sapienza University of Rome # IOTA ES and US * # Osservatorio Astronomico di Roma # Basilica di Santa Maria degli Angeli, Roma * Yale Astronomy Department # Université de Nice-Fizeau Dept. # Observatoire de la Cote d'Azur (Calern site PICARD Sol) * Institute d'Astrophysique de Paris * # IRSOL * # # data and analysis * observations (CLAVIUS)

4. Classification of Solar diameter measurements

5. Measuring radius from Earth Drift-scan: solar angular speed * transit time = diameter problem: seeing Angular direct measurements – problem: seeing, optical aberration Mercury and Venus transits: planetary speed * transit time = diameter - problem: scintillation, black drop Eclipses with Bailys beads – problem: scintillation, signal to noise, filter, FSR

6. Last solar cycle XXIII: SOHO data (June 2010)

7. Calibrating eclipses for studying secular variations

9. Eclipse Problem 1: scintillation

11. Problem 2: Flash Spectrum Region

12. Flash Spectrum (1905)

13. Problem 3: lunar profile Watts (1962) σ>0.2 random Kaguya (2009) σ<<0.01 sampling each 0.5-5 Sampling 1-10 km

14. Real lunar limb vs Watts profile (Kilcic, Sigismondi, Rozelot & Guhl, So. Phys. 2009)

15. 10 km Locarno Solar Obsevratory IRSOL Istituto Ricerche Solari di Locarno

17. δR =-0.41±0.05 (Kilcic et al. 2009) on 29 march 2006, in agreement with SOHO 2003 data preliminary:δR =-0.36±0.15 on 15 Jan 2010, based on 6 beads from R.Nugent

18. LIMB DARKENING FUNCTION WITH BAILYS BEADS ANALYSIS Andrea Raponi and C. Sigismondi Sapienza University of Rome

19. Total Solar Irradiance changed in the past, so also the diameter ? Hendrick Avercamp (1585-1643), Amsterdam

20. Eclipses Beads of 15/01/2010 by R. Nugent with Kaguya profile; software Occult

21. Solar Limb and LDF seeing and inflection point

22. Bailys bead light curve depends on Valleys profile + real LDF scintillation

23. LDF and Flash Spectrum Region?

24. computing LDF from light curve and Kaguya lunar profile

25. LDF from 2 different beads x:units of 6 mas

26. Synthetic LDF from Poissonian noise

27. Notes: quartz oscillators physics Thewlis Enc. Dictionary of Physics, Pergamon Press 1962 Quartz, the preparation and use of, oscillators

28. Annular Eclipse of 22/9/2006 2 watches: SONY e CASIO

29. in French Guyana the temperature was > 8 °C than in Rome

30. Roman tradition in solar diameter

31. ….and in eclipses: In 1581 edition Clavius wrote: relinquebatur in Sole circulus quidam exilis undique totam lunam ambiens. He actually saw an annular eclipse. The Sun in 1567 was >2.5 arcsec larger than now ? Not possible for physical reasons…