1. Binary star research using „microtelescopes“ Miloslav Zejda, Zdeněk Mikulášek, Jiří Liška Masaryk University Brno, Czech Republic Petr Svoboda private observatory, Brno, Czech Republic KOLOS 2011, Kolonica, December 1, 2011

3. first telescopes – diameter only several cm! Galileo & Castelli: discoveries of binaries or multiple systems: Mizar (1616), 1 Orionis – Trapez (1617)  Scorpii …

4. Variable stars observations (in modern history since 1596) Means: naked eye – limits – 6-7 mag, telescope + eye – 1844 Argelander telescope + photography – 1881 Draper – 14.7 mag telescope + photoelectric photometer 1892 Monck, 1907 Stebinns 1946 Kron, early 50‘s Johnson & Morgan UBV telescope + CCD – 1979 – Kitt Peak NO

5. Silicon age spread of objective measurements among many observatories and amateur astronomers increasing number of photometric measurements observing of fainter and fainter objects HOWEVER  stars brighter than 6 mag are too bright => lack of observations of bright stars!

6. Do we need observations of bright stars? yes, indeed! Why? variability of bright stars is usually known for a long time => unique possibility to study long-term variations usage of different methods except photometry

7. objections? surveys – ASAS… - monochromatic, unsatisfactory time resolution space missions – Hipparcos – good, but old, time resolution Kepler, COROT – excellent jobs, but … GAIA – bright limit 6 mag nano-satellite – BRITE project

8. solution? return to Galileo‘s size telescopes => usage of micro/nanotelescopes „windows astronomy“ „balcony astronomy“ break down the prejudices suitable for amateurs and small observatories Advantages: cheap acquisition cheap and efficient practise excellent opportunity to obtain unique long sets of observations possibility for students and travellers

9. suggestions? to equip the observers with a kit (CCD, photometric filters, nanotelescope) tell them what and how they should observe (targets, filters, time resolutions…) establish a network of observers – see for an example http://var.astro.cz

10. Examples of usage nanotelescopes

11. Minima timings of eclipsing binaries J. Liška: RF 0.04m + CCD ATIK 16Ic P. Svoboda; 0.035m refractor CCD SBIG ST7 filter I TW Dra NO Pup  Phe  I = 0.15 mag

12. SAAO 0,5m + single-channel PEP MJUO 0,6m + single-channel PEP L. C. Watson, J. D. Pritchard, J. B. Hearnshaw,P P. M. Kilmartin and A. C. Gilmore: MNRAS 325, 143–150 (2001) J. Liška: 0.04m refractor + CCD G2-0402 Light curves

13. P. Svoboda; 0.035m refractor, CCD SBIG ST7

14. amplitude  V≈ 0.02 mag P. Svoboda; 0.035m refractor, CCD SBIG ST7 HD 1438 (And)

15. It is worth to do it!

16. Thank you for your attention! In the presentation we used observations and materials from: VSES archive NYX archive personal archives of authors MNRAS 325, 143–150 (2001) NASA ADS servise webpages: http://ccd.mii.czhttp://ccd.mii.cz http://var.astro.cz http://www.astronomie2009.cz http://en.wikipedia.org and others Your notes are welcome! zejda@physics.muni.cz