VII Bulgarian-Serbian Astronomical Conference . . ASTROINFORMATICS Astroinformatics for the Flare Stars in Stellar Clusters and Associations Katya Tsvetkova Institute of Mathematics and Informatics, Institute of Astronomy, Bulgarian Academy of Sciences Chepelare, Bulgaria, June 1 -4, 2010
. . Flare Star Definition Flare activity: - a very quick increase of the brightness and a decline from maximum to minimum for some minutes up to some hours; - a common characteristic in the early evolution of all red dwarf stars. Belonging: - to the population of young stellar clusters and associations. Flare-like activity: some Wolf-Rayet stars, stars of B and A spectral types, RS Cvn system, some members of Algol and W UMa systems, FK Com stars and even evolved systems, containing white dwarfs. All observed characteristics - energy, amplitudes, time-scales, frequencies, shows differences which could be due to the different origin. That is why collecting flare star data we have restricted the observed phenomena - so called flares, classical flares, flashes, microflaring, to the UV Ceti type variability as is classified in the General Catalogue of Variable Stars (GCVS, Kholopov et al. 1985). Chepelare, Bulgaria, June 1 -4, 2010
Flare Star Light Curves . . LS 6=ABC 145 14 Jan 1985 Min (pg)=16. 75 Max(pg)=15. 60 Delta m=1. 35 Chepelare, Bulgaria, June 1 -4, 2010
International Cooperative Programme for Flare Star Searches in . . Stellar Clusters and Associations Observatories: Tonantzintla, Byurakan, Asiago, Abastumani, Konkoly, Rozhen, etc. Period: 1960 – 1995. Wide-field telescopes: Schmidt or Maksutov type. Method: photographic multi-exposure plate observations by the method of stellar chains. Chepelare, Bulgaria, June 1 -4, 2010
Results . from the Flare Star Monitoring Optical Observations . in Stellar Clusters and Associations Stellar cluster or association Number of flare stars Number of Observing time registered flares (hours) Orion M 42/M 43 564 827 The Pleiades 547 1635 Taurus Dark Clouds 102 122 Cygnus NGC 7000 83 120 Praesepe 59 146 NGC 2264 42 43 Cygnus IC 1318 17 18 Coma Open Cluster 14 21 Alpha Persei Cluster 7 7 Scorpius-Ophiuchus 14 15 Others 70 1591 3250 870 1168 680 105 300 338 128 321 800 Total 1 9551 1519 3024 Chepelare, Bulgaria, June 1 -4, 2010
. Flare Stars in Stellar Clusters and Associations. Chepelare, Bulgaria, June 1 -4, 2010
. Flare Stars in Stellar Clusters and Associations. Chepelare, Bulgaria, June 1 -4, 2010
. Flare Stars in Stellar Clusters and Associations. Chepelare, Bulgaria, June 1 -4, 2010
. . Catalogues of Flare Stars 1. Machine-readable version of the Tonantzintla Pleiades Flare Stars (Haro+ 1982), Boletin Inst. Tonantzintla 3, No. 1, 3, Vizie. R Catalogue - II/131 since 1987. 2. Catalogues of the Cygnus flare stars (Tsvetkov and Tsvetkova, 1990), Proceedings of the 137 th Symposium of the IAU Flare Stars in Star Clusters Associations and the Solar Vicinity, eds. L. V. Mirzoyan, B. R. Pettersen and M. K. Tsvetkov, Kluwer Academic Publishers, p. 105. 3. Catalogue of flare stars in the Praesepe cluster (K. P. Tsvetkova, M. K. Tsvetkov and I. Jankovics, 1991). Chepelare, Bulgaria, June 1 -4, 2010
Flare Stars Database (FSDB) . . Tsvetkova et al. 1995, Tsvetkova et al. 1996 Database not only for UV Ceti type stars, but also for their registered flare-events, which are missing in the other existing astronomical catalogues and data sets like GCVS, the Set of Identifications, Measurements and Bibliography for Astronomical Data (SIMBAD), and the Database on UV Ceti Type Flare Stars and Related Objects (for 230 objects) of Gershberg et al. (1993). Chepelare, Bulgaria, June 1 -4, 2010
Structure and Content of the FSDB. . MAIN DATA FILE Flare-event identifier Equatorial coordinates (R. A. , DEC) of flare star for equinox J 2000. 0 Equatorial coordinates (R. A. , DEC) of flare star for equinox J 1950. 0 Galactic coordinates in the l(II), b(II) system Julian date of the flare-event First registered flare-event Telescope used Stellar magnitude at minimum in U or Pg/ BPOSS bands Stellar magnitudes at maximum in U- and Pg bands Amplitudes in U and Pg bands Criterion - m > 5 V magnitude, B-V and U-B indices at minimum Spectral class Aggregate membership Pointers to tables SIMBAD and NOTES File CROSS-IDENTIFICATION File IDENTIFICATION CHARTS File REFERENCES File SIMBAD File NOTES Chepelare, Bulgaria, June 1 -4, 2010
. . Flare Stars Identifier DF CNC 750218 V 426 TAU 711112 1 V 426 TAU 721206 2 Chepelare, Bulgaria, June 1 -4, 2010
. FSDB RA Dec RA Dec Date . Identifier (1950) (2000) V 1581 CYG 750706 1953. 9+4425 1952. 3 +4417 19750706001 V 1513 CYG 710730 2005. 1+5427 2003. 9 +5418 19710730002 V 1513 CYG 710731 2005. 1+5427 2003. 9 +5418 19710731002 V 426 TAU 690918 033042+2226 V 426 TAU 711112 033042+2226 V 426 TAU 721206 033042+2226 V 594 TAU 730226 033042+2308 V 485 TAU 681019 033048+2250 19690918001 19711112002 19721206003 19730226001 19681019001 DF CNC 750218 083524 +1815 19750218007 DF CNC 750313 083524 +1815 19750313007 DF CNC 750402 083524 +1815 19750402007 DF CNC 760228 083524 +1815 19760228007 DF CNC 760325 083524 +1815 19760325007 DF CNC 760330 083524 +1815 19760330007 DF CNC 800319 083524 +1815 19800319007 Chepelare, Bulgaria, June 1 -4, 2010
. Flare Stars Database: Problems. A most serious obstacle for the FSDB is the lack in the literature for some stars of some necessary parameters of the flare-event: beginning of flare-events, duration, flare star identification charts, in the GCVS the information on stellar magnitude at minimum and maximum is not sufficient for assigning the flare event parameters. Very often, the lack of flare star identification charts is a reason for some missidentifications and errors here (Tsvetkova and Tsvetkov, 1989). Chepelare, Bulgaria, June 1 -4, 2010
. . Automated Flare Stars Search: Results When the plates are compared with a blink-comparator a selection effect due to the used 10 -minute duration of the single exposure, which is a low time resolution, appears. Thus it may preclude detection of energetic, but low amplitude flare-events on bright stars. The flare star surveys with used flare star monitoring photographic method of multi-exposure images each of 10 -minute duration usually discover the most chromospherically active stars. The less active stars could be missed. If the star is very faint it will be impossible to observe small flares. • An automated flare stars search method was applied for some southern stellar aggregates with different age (Aniol et al. 1990, Winterberg et al. 1995). • This procedure removes partially the selection effect and increases the number of discovered flares by 50 % compared to visual inspection by a Zeiss-comparator. • The number of slow flare events, flares on bright stars and on Intype variables was mainly increased. Chepelare, Bulgaria, June 1 -4, 2010
. . Digital Plate Archives According to the main observing programmes: Aims: to assemble and explore massive data sets in order to reveal a new knowledge existing in the data, but still not recognized in any individual data set. Preparation of digital plate archives - as a part of the long-time programme for search, preservation and re-usage of the world wide-field photographic astronomical plate collections. The last step before the systematic astronomical research: The organization of the plate scans in an image database and the development of a software system for object plate identifications and for searching in an image database with many data storage variants as current tasks. Chepelare, Bulgaria, June 1 -4, 2010
. Digital Plate Archives: Examples . • The Pleiades Plate Database - about 3100 plates obtained in the period 1885 – 1998 were found in the observatories in Asiago (Italy), Sonneberg (Germany), Harvard (USA), Kyiv (Ukraine), Moscow (Russia), Rozhen (Bulgaria), Konkoly (Hungary), Byurakan (Armenia), Potsdam (Germany), Edinburgh (UK), Bamberg (Germany). It gives the opportunity to obtain almost continuous photometric data set for the red dwarf stars in the cluster. The precise coordinates of the known Pleiades flare stars were determined as a necessary step to the further work of automated search for long-term brightness variations. The archive of the digitised plates in the Pleiades stellar cluster contains already about 1500 plates. The plate images are included into the developed Pleiades Plate Data Base (PPDB, Borisova et al. 2003; Tsvetkov et al. 2005). Chepelare, Bulgaria, June 1 -4, 2010
Digital Plate Archives: Examples . . • Konkoly Supernova Digital Plate Archive (Tsvetkova et al. 2008, Baltic Astronomy) - observing programmes carried out with the 60/ 90/180 cm Schmidt telescope, started at the end of 1963, with which Konkoly Observatory for about more than a 30 -year period took part in the international campaign initiated by F. Zwicky. • Konkoly Flare Star Digital Archive – of representative plates obtained with the Schmidt telescopes of Konkoly observatory during the observation campaign for search and investigations of the flare stars in stellar clusters and associations in 1970 -1990. Besides the primary aim to serve for investigations of the flare stars another result is the realization of an interlinking the electronic Information Bulletin on Variable Stars (IBVS) with the Wide-Field Plate Database (WFPDB). The plates are scanned with resolution 1200 dpi for plate visualization and to preserve the observer marks. The image is saved as TIFF file format with size 51. 12 MB and as JPEG file (compressed to 2000 x 2000 pixels) with size 1. 65 MB. After the cleaning the observer marks the plate is scanned with high resolution (2400 dpi) and saved as FITS file with size 409 MB. • Carte du Ciel Plate Digital Archives – Uccle (Tsvetkova et al. 2007), Potsdam (Tsvetkova et al. 2009, Astronomische Nachrichten). Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Digital Plate Archives. . Now having at disposal an observing material from the monitoring flare star observations in the Rozhen Observatory, done with the 50/70/172 cm Schmidt telescope in the period 1979 – 1994, we are going to apply an automated flare stars search method on the basis of scanned flare stars monitoring plates of the Rozhen Observatory. Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Observations: Telescope. 50/70/172 cm Schmidt . Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Observations: Telescope . 50/70/172 cm Schmidt . Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Observations: Telescope. . 50/70/172 cm Schmidt Main Characteristics WFPDB Tel. Orig. Aperture Focal Scale Tel. Field Years of Plate Instr. Ident. Name (m) Length (m) "/mm Type Size (deg) Operation Number ROZ 050 Schmidt 0. 50/0. 70 1. 72 120 Sch 4. 5 1979 -1994 7348 Chepelare, Bulgaria, June 1 -4, 2010
Plate Library in Rozhen Observatory. . Chepelare, Bulgaria, June 1 -4, 2010
. Rozhen Flare Stars Observations: Number of Plates. Stellar clusters and associations: the Pleiades, Gamma Cygni region, M 42/43 in Orion, Praesepe, Alpha Per, Tauri Dark Clouds, the open cluster NGC 2264, the emission nebula NGC 7000. Number of Plates: totally 1564 plates. Chepelare, Bulgaria, June 1 -4, 2010
. Rozhen Flare Stars Observations: Number of Plates. Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Observations: Telescope WFPDB ROZ 050 Catalogue. . Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Observations: . Emulsions and Plate Size . Used emulsions: ORWO, Kodak Plate Size: 13 x 13 cm; 16 x 16 cm Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Digital Plate Archive: Scanners. . Sofia Sky Archive Data Center: PDS 1010 plus microdensitometer with possibility for high precision; Flatbed Scanner: EPSON EXPRESSION 1640 XL Flatbed Scanner: EPSON PERFECTION V 700 PHOTO Rozhen Observatory: Flatbed Scanner: EPSON EXPRESSION 10000 XL Chepelare, Bulgaria, June 1 -4, 2010
Sofia Sky Archive Data Center: FB Scanner . . EPSON EXPRESSION 1640 XL Scanning platform: 310 x 437 mm; Resolution: 1600 x 3200 dpi, Duration: 5 min 16 x 16 cm plate; Plate Storage: FITS with volume 120 MB. Chepelare, Bulgaria, June 1 -4, 2010
. Rozhen Observatory: FB Scanner . EPSON EXPRESSION 10000 XL Scanning platform: 310 x 437 mm Resolution: 1600 x 3200 dpi Duration: 5 min 16 x 16 cm Plate Storage: FITS 2 m RCC plates 30 x 30 cm Previews: Adobe Photoshop 600 dpi, 24 bit colour TIFF; JPEG Scans: Scanfits 1600 dpi, 16 bit grayscale FITS (612 MB) Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Digital Plate Archive: Scanning. . Main parameters of the available flatbed scanners Scanner Dmax Color depth Grayscale depth Resolution (dpi) 1640 XL 3. 6 42/42 14/14 1600 10000 XL 3. 8 42/42 16/16 2400 x 4800 The used software for scanning is the standard one for making preview images - Adobe Photoshop, and the programme Scanfits for the real scans in FITS format. Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Digital Plate Archive: Scanning. . Preview images: aim: easier web accessibility and to store the information from the observer’s marks on the plate a system for quick plate visualization Parameters: 1200 dpi in TIFF format and compressed 1000 x 1000 pxl JPEG format; color depth: 8 -bit 24 bit Color Real scans: Scanning Parameters: 2400 dpi, FITS format, density range (0 – 255) and Gamma = 1. 00; color depth - 16 -bit Grayscale. Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Digital Plate Archive: Scanned plates. . ROZ 050 000291 Gamma Cyg region Chepelare, Bulgaria, June 1 -4, 2010
Rozhen Flare Stars Digital Plate Archive : Scanned plates. . ROZ 050 000383 M 42/43 region Chepelare, Bulgaria, June 1 -4, 2010
. . Acknowledgements This work is supported by the Bulgarian National Science Fund (grant BG NSF DO-02 -275). Chepelare, Bulgaria, June 1 -4, 2010
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